Geotechnical Assessment Report - Foss Shanahan · Geotechnical Assessment Report Project 223094 | File 223094 Geotech Report Rev1 Second Issue.docx 20 December 2011 | Revision 1 Aurecon

Geotechnical Assessment Report Northbrook Road Subdivision, Christchurch VB Properties 2008 Limited

Report ref: 223094 20 December 2011 Revision 1

Document prepared by: Aurecon New Zealand Limited Unit 1, 150 Cavendish Road Casebrook Christchurch 8140 New Zealand T: +64 3 366 0821 F: +64 3 379 6955 E: [email protected] W: aurecongroup.com

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Document ID: 223094 Geotech Report Rev1 Second Issue.docx

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Geotechnical Assessment Report

Project 223094 | File 223094 Geotech Report Rev1 Second Issue.docx 20 December 2011 | Revision 1 Aurecon Page i

Contents

1. Introduction 1

2. Summary 2

3. Site Conditions 4

3.1 Site Description 4

3.2 Access 4

3.3 Surface Water 4

3.4 Regional Geology 4

4. Geotechnical Investigation 5

4.1 General 5

4.2 Cone Penetrometer Tests 5

4.3 Tests Pits 5

4.4 Environment Canterbury Borehole Logs 6

4.5 Groundwater Levels 7

4.6 Site Walkover 8

4.6.1 Liquefaction Induced Ground Damage 8

4.6.2 Geomorphological Mapping 8

5. Ground Model 10

6. Engineering Consideration 11

6.1 General 11

6.2 Seismically Induced Liquefaction 11

6.3 Liquefaction Assessment 11

6.3.1 Introduction 11

6.3.2 Liquefaction Potential Assessment 11

6.3.3 Liquefaction Analysis Results 13

6.3.4 Ground Damage 14

6.3.5 Lateral Spreading 15

6.3.6 Discussion 15

6.4 Land Classification Technical Categories 15

6.5 Compliance with the Definition of ‘Good Ground’ 16

6.6 Peat 16

6.6.1 Infrastructure 16

6.6.2 Residential Foundations 16

6.6.3 Discussion and Recommendations 17

6.6.4 Proposed Earthworks 17

6.7 General Site Development Recommendations 17

6.7.1 Cut Excavations 17

6.7.2 Earthfill 18

7. Assessment Against RMA 19

8. References 20

9. Limitations 22


Project 223094 | File 223094 Geotech Report Rev1 Second Issue.docx 20 December 2011 | Revision 1 Aurecon Page ii

Appendix A

Figures

Appendix B

CPT Logs

Appendix C

Test Pit Logs

Appendix D

2007 Test Pit Logs

Appendix E

ECan Borehole Logs

Appendix F

LiquefyPro Settlements

Appendix G

LiquefyPro Results


Project 223094 | File 223094 Geotech Report Rev1 Second Issue.docx 20 December 2011 | Revision 1 Aurecon Page 1

1. Introduction VB Properties 2008 Limited is proposing to develop a residential subdivision on an area of vacant land located on Northbrook Road, Rangiora. The subdivision site comprises a total area of approximately 18.3ha. The area is predominantly zoned rural land and it is proposed to rezone the land to residential land use. The site is relatively flat and primarily used for pastoral farming. Aurecon New Zealand Ltd has been engaged to provide engineering services for the subdivision, part of which is to carry out a geotechnical investigation. The purpose of the geotechnical investigation described in this report is to identify any geotechnical issues with the subdivision, including addressing potential liquefaction risk, and any remediation options that may be required as part of the residential development. The scope of work was as follows:

• Review of published geotechnical and geological information on the site. • Undertake a site walkover of the proposed subdivision site. • Subsoil testing using machine excavated test pits across the site to provide information on the

upper soil layers and ground water levels. • Carry out CPT’s across the site to provide information on the soil at depth and data to allow

liquefaction assessment. • Based on the geotechnical investigation information, prepare a geological model for the site. • Carry out liquefaction analysis to confirm the liquefaction potential of the underlying natural

soil. • Preparation of a geotechnical report to present the above information, including a geotechnical

assessment on the suitability of the site and an assessment against the Resource Management Act Section 106.

This geotechnical assessment report presents the results of our geotechnical investigations, the geological ground model, our liquefaction analysis and recommendations for development of the site for the proposed subdivision. This work excludes the detailed design of any remediation options which would be dealt with at the detailed design stage of the subdivision development. Our limitations are attached as Section 9 of this report. This report shall be read as a whole.



2. Summary VB Properties 2008 Limited is proposing to develop a residential subdivision on an area of vacant land located on Northbrook Road, Rangiora. The subdivision site comprises a total area of approximately 20ha. The area is predominantly zoned rural land and it is proposed to rezone the land to residential land use. The site is relatively flat and primarily used for pastoral farming. Aurecon New Zealand Ltd has been engaged to provide engineering services for the subdivision, part of which is to carry out a geotechnical investigation. The purpose of the geotechnical investigation described in this report is to identify any geotechnical issues with the subdivision including addressing potential liquefaction risk and any remediation options that may be required as part of the residential development. The objective of the geotechnical investigation was to determine the nature and composition of the underlying ground conditions and identify the relevant geotechnical issues. The geotechnical assessment comprised of a site walkover followed by the excavation of test pits and the carrying out of cone penetrometer tests (CPT). A review of existing Environment Canterbury borehole records was also carried out. The CPT’s located in the northern third of the site show an alternating sequence of stiff silt and clayey silt overlaying predominately sandy gravels at depths ranging from 4.0m to 6.3m bgl. The upper 2.0m of silt and clayey silt layers are typically very stiff to hard while the underlying layers vary in stiffness from firm to stiff. In the southern and middle third of the site the ground conditions consist of interbedded stiff silt and clayey silt overlying an alternating layer of firm peat and clayey silt at a depth of 2.5m to 3.5m bgl, which in turn are underlain by very dense sandy gravel. A liquefaction assessment was undertaken for a Serviceability limit state (SLS) and Ultimate limit state (ULS) earthquake based on the NZGS Guidelines using NZS1170 The liquefaction analysis identified the following:

• Under a SLS earthquake case the total settlements are very low and it is unlikely there will be any liquefaction induced ground damage. The exception is CPT16, where potential total settlements are in the order of 15mm. This is still within the limits as outlined by the ‘Guidance on house repairs and reconstruction following the Canterbury Earthquake’, dated 20 December 2010.

• Under a ULS earthquake case the total settlements are typically less than 2mm. The

exception is CPT16, where potential total settlements are in the order of 15mm. This is still within acceptable limits under the new ‘Guidance on house repairs and reconstruction following the Canterbury Earthquake’, dated 20 December 2010. It is however noted that during the ULS design earthquake some building damage is likely at this level of shaking regardless of ground conditions and liquefaction potential. Further we note, that no ground damage was noted following the Darfield earthquake that may be considered to be more severe than the ULS design earthquake considered here.

• The calculated settlements across the site are consistent, especially for the CPT’s which extended to significant depths. This would indicate that the potential liquefaction induced settlements across the site are likely to be consistent. The exception the settlements calculated for CPT16 in the north eastern corner of the site. Based on our site investigations we infer that the difference from this localised area to that of other parts of the site is directly related to the underlying ground conditions, of silty sand to a greater depth.

For the Canterbury region the Department of Building and Housing (DBH, 2011) has recently released a new classification system for residential ‘Green Zone’ land on the flat in regard to the liquefaction



susceptibility. Based upon results of the liquefaction assessment the site can be placed in Technical Category 1. Due to the type and nature of the subsoil conditions, including the presence of organic deposits we suggest that site specific foundation design is undertaken. Pile foundations are recommended. As required under the new DBH guidelines for detailed house design, a building consent investigation will be required for each lot. It is assumed that the infrastructure can be placed within the sand and silt deposits overlying the thick peat deposits. Further assessment of infrastructure will be required at the detailed design stage. For deep and/or heavy infrastructure pile foundations as per the main site may be required. It is likely that the amount of earthworks required for the site will be minimal as the site is essentially flat. Removal of the peat layers is not recommended as it will be time consuming and costly as part of any preparatory earthworks.

Cuts are likely to encounter predominantly silty soil with the potential for sand layers. Any cuts greater than 1.5m in height or groundwater seepages encountered should be inspected by a geotechnical engineer or engineering geologist to confirm the acceptability and apply any site specific treatment, if required. Depending on the nature of the fill material the appropriate compaction standard will need to be applied. A geotechnical engineer should review the compaction standard prior to site earthworks. All areas where earthfill is to be placed should be stripped of topsoil and stockpiled. Slopes steeper than 3H:1V should be assessed by a geotechnical engineer as part of the detail design. If fill depths exceed 0.5m, we recommend a geotechnical engineer carries out an assessment to confirm the affect the fill surcharge will have on the peat. Our limitations are at the end of this report and this report shall be read as a whole.



3. Site Conditions 3.1 Site Description

The Northbrook Road subdivision is located on an area of land on Northbrook Road, refer to Figure 1 Appendix A. The site has a legal description of Lot 3 DP 39926, with an approximate area of 18.3Ha and is currently being used as pastoral farmland. The site is bounded to the north by a block of residential properties, to the south by Northbrook Road, to the west by Papawai Drive and to the east by pastoral farmland. The main features of the site are as follows (refer to Figure 2 in Appendix A):

• Overall the topography of the site is flat and split up into eight paddocks.

• There is a spring fed stream that starts 170m northeast from the Northbrook Road / Papawai Drive intersection and flows towards the southeast corner of the site.

• The first 70m of the stream bank is lined by large trees. Otherwise the stream banks are bordered by vines and small bushes.

• The stream is approximately 1m wide by 230m long and varies in depth from 0.1m to 0.5m.

• Power lines extend a short distance into the southern half of the site. 3.2 Access

The site can be accessed from Northbrook Road. 3.3 Surface Water

The only surface water feature is the one referred to in section 3.1 above. The south eastern end of the site below the stream is low lying and water tends to pond in this area after significant rain events. 3.4 Regional Geology

The geology of the site is described in the 1:250,000 scale geological map – ‘Geology of Christchurch,” published in 2008 by the Institute of Geological and Nuclear Sciences. The geological map indicates two different material types around the site, refer to Figure 3 in Appendix A. The map indicates the following geology:

• Dune deposits consisting of “brownish-grey river alluvium (Q1d)” are present underlying the site.

• River deposits consisting of “grey river alluvium, comprising gravel, sand and silt, in active flood plains (Q1a)” are located to the north and east of the site.

The GNS Active Fault System database (GNS, 2011a) indicates that the site is located approximately 43km northeast from the Greendale Fault System. Movement on the Greendale Fault System was responsible for the Magnitude 7.1 Darfield (Canterbury) Earthquake on 4 September 2010. The site is also located approximately 30km north of the epicentre of the Magnitude 6.3 Christchurch Earthquake on 22 February 2011 and 31km north of the Magnitude 6.3 aftershock on 13 June 2011 (GNS, 2011b).



4. Geotechnical Investigation 4.1 General

The objective of the geotechnical investigation was to determine the nature and composition of the ground conditions and identify the relevant geotechnical issues. The geotechnical assessment comprised the following:

• Site walkover by a Senior Engineering Geologist from Aurecon. • 16 cone penetrometer tests (CPT) undertaken by McMillan Drilling Services and supervised

by a Geotechnical Engineer from Aurecon. • 17 test pits excavations to confirm soil and groundwater conditions and supervised by a

Geotechnical Engineer from Aurecon. • A review of 18 Environment Canterbury GIS database borehole logs.

Overall an intrusive investigation density of at least two tests per hectare was achieved. This is in line with the recommendations issued by the Department of Building and Housing (DBH) Interim minimum requirements for geotechnical assessment for liquefaction and land development, dated August 2011. The CPT test and test pits were used to determine the upper soil layers. The ECan borehole logs in the vicinity of the site helped determine the soil profile at depth and showed that the gravel layer is continuous to depths greater than 15m bgl.

4.2 Cone Penetrometer Tests

16 CPT probes were sunk within the site. The CPT tests were undertaken to effective refusal (tip pressure reaching 30MPa) of the rig which generally occurred within dense layers. The depths achieved were typically between 2.95m and 8.40m bgl. The locations of the CPT tests are shown in Figure 4 in Appendix A and the logs are presented in Appendix B. The CPT’s located in the northern third of the site indicate an alternating sequence of silt and clayey silt layers overlaying predominately sandy gravels at depths ranging from 4.0m to 6.3m bgl. The upper 2.0m of silt and clayey silt layers are typically very stiff to hard, while the underlying layers vary in stiffness from firm to stiff. All the CPT’s refused after only limited penetration of the sandy gravels. In the southern and middle third of the site the ground conditions consist of interbedded silt and clayey silt layers, overlying alternating layers of peat and clayey silt at a depth of 2.5 to 3.5m bgl, which in turn are underlain by sandy gravels. The silt and clayey silt layers are typically very stiff for the first 2m, while the peat layers are typically firm. The sandy gravel layers at depth are typically dense to very dense. 4.3 Tests Pits

Test pits were carried out across the site to confirm the continuity of the soil profile, allow calibration of the CPT logs as well as permitting the measurement of groundwater levels. The test pit excavations were undertaken by a 13t digger and generally reached a depth of 3.0m to 4.5m bgl with a maximum depth of 4.8m bgl. Test pits were generally terminated at target depth or when groundwater was

Table 1 - Site investigation density for overall gr ound characterisation



encountered resulting in the collapse of the pit sides. The locations of the test pits are shown in Figure 5 in Appendix A, and the logs are presented in Appendix C. Test pits in the northern third of the site indicate very stiff silt, overlying medium dense to dense, fine to medium grained, silty sand at depths of 1.5m to 2.5m bgl. These in turn are underlain by firm to stiff clayey silt of high plasticity at depths of 2.5m to 3.5m bgl with gravels at 4.0m bgl in test pit 11 (TP11). Test pits in the southern two thirds of the site indicate generally very stiff silt to depths of 1.5m to 2.5m bgl, underlain by firm to stiff peat of varying thickness ranging from 0.3m to 2.4m. Underlying the peat layer is typically firm clayey silt of high plasticity or medium dense, silty sand. In the southern third of the site, sandy gravels were recorded below the clayey silt or silty sand layer at depths of 2.6m to 4.2m bgl. The sandy gravel layer gets progressively deeper from north to south (i.e. towards Northbrook Road). The exception to this general soil profile is test pit TP12 where alternating layers of very stiff silt, sandy silt and silty sand were logged to 3.4m bgl, which in turn were underlain by a firm peat layer with some tree matter to 4.3m bgl. Previous test pit logs taken in October of 2007 indicate similar ground conditions but with some slight discrepancies between the logs such as certain soil layer depths and the type of soil. The locations of the 2007 test pits are shown in Figure 6 in Appendix A, and the logs are presented in Appendix D. 4.4 Environment Canterbury Borehole Logs

A review of the Environment Canterbury GIS System (ECan, 2011) has been undertaken to identify borehole logs within the general vicinity of the site. A summary of the borehole logs are provided in Table 1 below. The borehole locations are shown on Figure 7 in Appendix A and the logs are presented in Appendix E.

Table 2– Summary of ECan borehole logs

Hole Reference

Distance from Center of Site

(m)

Depth (m) bgl

Summary

M35/0403 680m East 9.1 Topsoil (to 0.3m), Soft Peaty Clay (to 4.6m), Blue Gravel (to 5mm), Brown gravel (to 6.6m), Fine Brown Gravel with Coarse Sand to depth

M35/6653 730m North 15.0

Topsoil with Gravel (to 0.4m), Brown Clay (to 2.4m), Grey Sandy Gravel (to 10m), Brown Clay bound Gravel (to 11.1m), Browny Grey Sandy Gravel (to 13.8m), Brown Clay bound gravel to depth

M35/8026 480m South 10.3 Topsoil (to 0.3m), Clay (to 4m), Brown Clayey Sand (to 5m), Clay bound Sandy Gravel (to 7.2m), Water bearing Sandy Gravel with Clay to depth

M35/8810 520m North 31.3 Topsoil (to 0.3m), Clay and Silt (to 2.3m), Alternating layers of Clay bound Gravel and Water bearing Gravels to depth

M35/9692 790m North 30.5 Topsoil (to 0.3m), Clay bound Gravels (to 10.2m), Sandy Gravels to depth



M35/11317 220m Southwest 5.5 Topsoil (to 0.4m), Brown Clay (to 2.6m), Peat (to 4.1m), Brown Sandy Gravels (to 4.3m), Water bearing Gravels to depth

M35/11318 365m Southwest 5.7 Topsoil (to 1.5m), Brown Clay (to 3.2m), Peat (to 3.8m), Brown Sandy Gravels (to 4.5m), Water bearing Sandy Gravels to depth

M35/11546 585m Southeast 7.0 Topsoil (to 0.3m), Brown Clay (to 4.2m), Brown Sandy Gravels to depth.

M35/11547 500m East 7.0 Topsoil (to 0.3m), Brown Clay (to 4.2m), Brown Sandy Gravels to depth.

M35/11548 470m East 7.0 Topsoil (to 0.3m), Brown Clay (to 4.3m), Brown Sandy Gravels to depth.

M35/11549 400m Southeast 7.2 Topsoil (to 0.3m), Brown Clay (to 4.1m), Brown Sandy Gravels to depth.

M35/11551 250m East 7.0 Topsoil (to 0.3m), Brown Clay (to 4.0m), Blue Gravels (to 4.3m), Brown Sandy Gravels to depth

M35/11558 400m South 4.0 Topsoil (to 0.15m), Light Brown Clay (to 1.45m), Grey Clay with Organics (to 1.6m), Black Organic soil (to 2.1m), Light brown Silty Gravel to depth

M35/11559 440m South 4.0 Topsoil (to 0.25m), Light Brown Clay (to 0.9m), Light Grey Clay with Organics (to 1m), Black Organic soil (to 2.1m), Grey Orange Silty Gravel to depth

M35/11683 400m South 1.4 Dark Brown Topsoil (to 0.2m), Light Brown Clay (to 1.15m), Black Organic soil/peat (to 1.3m), Light Brown Silty Gravels to depth

M35/11684 460m South 1.4 Dark Brown Topsoil (to 0.22m), Light Brown Clay (to 1.09m), Black Organic soil/peat (to 1.35m), Light Brown Silty Gravels to depth

M35/11690 320m South 2.6

Dark Brown Topsoil (to 0.05m), Light Brown Clay (to 1.15m), Black Organic soil/peat (to 1.8m), Bluish Grey Clay (to 2.1m), Light Brown Sand (to 2.5m), Light Brown Silty Gravels to depth

M35/11691 300m South 2.9

Dark Brown Topsoil (to 0.2m), Light Brown Clay (to 1.25m), Black Organic soil/peat (to 1.65m), Bluish Grey Clay with Organics (to 2.4m), Light Brown Silty Sand (to 2.8m), Light Brown Silty Gravels to depth

The borehole logs are reasonably consistent with the soil profile identified in the investigation logs, with silt, peat and clayey material forming the upper soil layers and gravel at depths ranging from 1.5m bgl in the south of the site, deepening 4.0m to 5.0m to the north of the site. 4.5 Groundwater Levels

Groundwater levels and groundwater seepages were measured in the test pits. A summary of the groundwater measurements is provided in Table 2.



Table 3– Measured groundwater levels

Test Pit

Groundwater Level (m)

Groundwater Seepage (m)

Test Pit

Groundwater Level (m)

Groundwater Seepage (m)

September 2011 Test pits TP15 4.2 2.6

TP1 3.1 1.1 TP16 3.6 1.6

TP2 2.3 Not Encountered TP17 3.0 Not Encountered

TP3 3.8 3.2 October 2007 Test pits

TP4 Not Encountered 2.0 TP1 2.4 Not Encountered


TP13 Not Encountered 2.6 TP3 3.5 Not Encountered


Note: Test pits not included where no groundwater level or seepage encountered These results appear to be in reasonable agreement with the groundwater levels identified in the ECan boreholes. We note that groundwater levels may vary depending on the time of year and climatic events. Groundwater in TP4 and TP13 was not reached as the digger was unable to excavate any further. It is assumed that the groundwater level in TP4 is not much further below the gravels as they are saturated. In TP13 the gravels were not reached and it is assumed that the gravels and groundwater are situated below the peat layer. 4.6 Site Walkover

4.6.1 Liquefaction Induced Ground Damage

Based on our site walkover the following was noted:

• Evidence of liquefaction surface ejecta (i.e. sand boils) was not apparent during the site walkover. Including residual evidence, such as degraded sand boils or distinct mounds covered in recent grass growth. Nor was there any evidence of accumulation of sand and silt within the stream.

• Other evidence of ground damage such as ground cracking or lateral spreading adjacent to the stream were not apparent on the site.

4.6.2 Geomorphological Mapping

Based on our site walkover and review of the general landscape, the site can be defined into two distinct geomorphological zones. The zones are shown in Figure 2 in Appendix A and are as follows: Zone 1 – Low Lying Area The low lying area comprises small hollows and indentions in the ground where surface water collects. This low lying area is located in the southern end of the site, from the top of the stream down towards Northbrook Road. Water collects in this area after rainfall events with the formation of pools of standing water.



Zone 2 – Pastoral Land Area The pastoral land area includes the rest of the site. The area is flat, grassed and relatively level throughout.



5. Ground Model Based on the ground investigation the following schematic ground model has been defined for the site. Northern Area Table 4 – Ground profile of the northern end of sit e.

Depth to Top of Unit

(m)

Depth to Base of Unit

(m) Soil Unit

0 0.2 to 0.4 TOPSOIL

0.2 to 0.4 1.5 to 2.1 SILT, Stiff to very stiff

1.5 to 2.1 2.1 to 3.5 Sandy SILT and Silty SAND, Stiff to very stiff and medium dense.

2.1 to 3.5 Depth

Investigation Clayey SILT, Sandy SILT, Stiff to very stiff

Middle Area Table 5 – Ground model of the middle section of sit e


(m)


(m) Soil Unit



2.0 to 2.7 2.9 to 4.6 PEAT, Soft to firm

2.9 to 4.6 3.5 to 4.6 Clayey Silt, Silty SAND and Sandy SILT, Firm to stiff

3.5 to 4.6 Depth

Investigation Sandy GRAVEL, medium dense to very dense

Southern Area Table 6 – Ground model of southern end of site


(m)


(m) Soil Unit



1.0 to 1.6 1.2 to 4.0 PEAT, Soft to firm

1.2 to 4.0 2.6 to 4.2 Clayey Silt and Sandy SILT, Firm to stiff

2.6 to 4.2 Depth

Investigation Sandy GRAVEL, Medium dense to very dense

The approximate extent of these areas is defined in Figure 2 in Appendix A. Using the CPT and test pit information we were able to construct three north-south cross sections displaying the bands of peat across the site, refer to Figures 8 to 10 in Appendix A.



6. Engineering Consideration 6.1 General

VB Properties Limited is proposing to develop a residential subdivision on an area of vacant land on Northbrook Road. The subdivision site comprises a total area of approximately 20ha. Based on the ground conditions encountered during the geotechnical investigation we consider that the following geotechnical aspects need to be considered as part of the subdivision:

• Potential for seismically induced liquefaction. • Recommendations for liquefaction mitigation measures, if required. • Recommendation for peat soils. • Compliance with the intent and definition of NZS3604. • Implications for building foundations. • Recommendations for infrastructure construction. • Assessment against Resource Management Act (RMA) Section 106 a) to c).

Each of these is discussed in the following sections. 6.2 Seismically Induced Liquefaction

Under cyclic loading during an earthquake cohesionless material (gravels, sands, silty-sands) tends to decrease in volume. This tendency to decrease in volume is much greater in loose than dense soils. When cohesionless soils are saturated and rapid loading occurs under undrained conditions, the tendency is that soil densification causes excess pore water pressures to increase. The increase in pore water pressure results in a loss of soil strength due to a decrease in effective stress and eventually liquefaction when the effective stress drops to zero. Liquefaction of loose sands can lead to large displacements of foundations, ground surface settlement, sand boils, and post earthquake stability failures.

As part of our geotechnical assessment for the site we have carried out a liquefaction analysis to determine the liquefaction potential for the site.

6.3 Liquefaction Assessment

6.3.1 Introduction

For the site development the main factors to be considered for liquefaction are:

• What layers can liquefy?

• What is the likelihood of further liquefaction in the future?

• What options are available to limit or prevent liquefaction?

Each of these is considered below. 6.3.2 Liquefaction Potential Assessment

The three primary factors that contribute to liquefaction potential are:

• Loose, uniformly graded soils.

• High groundwater table.

• Sufficiently high, earthquake induced ground acceleration and sustained shaking.

Each of these is considered below together with conclusions on the site liquefaction potential.



Soil Grading and Density

Based on our assessment of the soil conditions at the Northbrook site, the potential for liquefaction to occur is low. The reason for this is that the upper soil layers consist of very stiff silt with sandy gravels at depth. Groundwater

The depth to groundwater was measured in a number of the test pits at depths ranging from 2.1m to 4.2m bgl, with groundwater seepages measured at depths of 1.1m to 3.2m bgl. Soils are therefore potentially liquefiable from a depth of 1.1m onwards. Earthquake Intensity and Soil Resistance to Liquefa ction

The level of ground shaking is one of the key factors in determining whether liquefaction will or will not occur. A back analysis of the 4 September 2010 Darfield earthquake and 22 February 2011 Christchurch Earthquake has not been carried out as the nearest seismogram is located at the Ashley School, which is 5km to the North. Based on the potential variability of spatial and temporal variation from the earthquake centre and uncertainties and conservatisms associated with current analytical tools, it is considered that a back analysis of the recent earthquakes may not be accurate or representative. Therefore we have based the liquefaction analysis on Ultimate Limit State (ULS) and Serviceability Limit State (SLS) earthquake events derived using the NZGS method that in turn is based on NZS1170. This approach is generally accepted as a suitable method for liquefaction analysis as it ties into the building structural design criteria. We are aware that new seismic design guidelines for the Canterbury area are being developed by DBH and GNS, with the timing of their publication unknown at this stage. According to the ‘Minimum Requirements for Geotechnical Assessment of Liquefaction for Land Development – Canterbury Region’, these are likely to supersede the above guidelines for liquefaction analysis. However, in the absence of any updated guidelines and timeframes on when these will be published, it is considered appropriate to use the currently available guidelines. Therefore, based on the current guidelines available at the time of our analysis, we have used the following scenarios to assess the potential for liquefaction in a future seismic event: Serviceability Limit Stage (SLS) Earthquake

We have assessed the SLS earthquake return period based on the current NZS1170.0:2004 Loading Codes with the increased Z hazard factor of 0.3. NZS1170.0:2004 Table 3.3 indicates that SLS level ground shaking be based on a 1 in 33 year event. However, we consider this value to be too low to be applicable when assessing liquefaction because of its discreet nature of liquefaction (i.e. the site either liquefies or does not and when a site has liquefied there is very little difference in expected deformations for a ‘small’ earthquake that causes liquefaction relative to a ‘large’ earthquake that causes liquefaction), and the disproportionate effect seismically induced liquefaction has on a building. We have therefore adopted a more severe (although not unrealistic) earthquake event that has a probabilistic return period of 150 years. We have adopted the method outlined by the NZ Geotechnical Society with reference to the New Zealand Loadings Standard, to obtain the design earthquake for the liquefaction assessment. A 1 in 150 year return period earthquake in Lincoln area for a Class D site has a Peak Ground Acceleration (PGA) of 0.2g. In accordance with NZGS we have adopted a Magnitude 7.5 earthquake event. We consider this event to be well above the requirements from NZS1170 for SLS criteria, but believe it is realistic.



Ultimate Limit State (ULS) Earthquake

For the site we have assessed the ULS earthquake return period based on the current NZS1170.0:2004 Loading Codes with the increased Z hazard factor of 0.3. A 500 year return period earthquake has been adopted, which is based on the recommendations of NZS1170.0:2004 Tables 3.2 (Importance Level 2 building), and Table 3.3 (50 year design working life). We have adopted the method outlined by the NZ Geotechnical Society for using the New Zealand Loadings Standard to obtain the design earthquake for the liquefaction assessment. A 1 in 500 year return period earthquake in the area for a Class D soil (Deep Soil Site) has a PGA of 0.34g, and in accordance with NZGS we have adopted a Magnitude 7.5 earthquake event. A summary of the shaking intensities is presented in Table 6.

Table 7 – Summary of ground shaking cases analysed

Earthquake PGA Magnitude Serviceability Limit State – Based on

NZS1170 0.20g 7.5

Ultimate Limit State – Based on NZS1170

0.34g 7.5

6.3.3 Liquefaction Analysis Results

The ability of the subsoils to resist the effects of ground shaking associated with the five earthquakes has been assessed from the information obtained from the CPT’s. The National Centre for Earthquake Engineering Research (NCEER) method as outlined by Youd et. al. (2001) has been used to assess liquefaction potential using Version 5 of the CivilTech Corporation LiquefyPro computer programme. The method of Robertson and Wride (1998) for the CPT boreholes (the NCEER’s recommended method), modified for fines content, was used to calculate the potential for liquefaction and the method of Tokimatsu and Seed (1987) for settlement. The total settlements due to liquefaction as calculated using the Tokimatsu and Seed (1987) method are presented below. The results show an average settlement for an SLS event of 0mm and 5mm for a ULS event (rounded to the nearest 5mm). Therefore, based on this evidence we have assessed the potential for liquefaction induced settlement as very low. The exception is CPT16 located in the north eastern corner of the site, where the potential total settlement calculated for a ULS event is 15mm.

Table 8 – Calculated liquefaction induced (total) s ettlement in (mm)

Test / CPT

SLS 1170 EQ

Settlement

(mm)

ULS 1170 EQ

Settlement

(mm)

1 0 0

2 0 0

3* 0 0

4* 0 0

5 0 0

6 0 0

7* 0 5

8 0 0

9* 0 10

10 0 0



11* 0 0

12* 0 5

13* 0 0

14* 0 0

15* 0 0

16* 0 15

Min 0 0

Ave 0 2

Max 0 15

Note: The settlements presented in Table 7 above are to the nearest 5mm and have a likely error of ± 50% *- CPT tests that extended to a reasonable depth to accurately quantify the liquefaction risk over the site.

We note that due to the dense nature of the sandy gravel at depth none of the CPT’s extended to depths in excess of 10m bgl. However, we consider that these tests provided a reasonable coverage of the site and hence provide a good indication of the liquefaction risk across the site. 6.3.4 Ground Damage

Published information (after Ishihara, 1985) can be used to assess the potential for surface expression of liquefaction and the likelihood of ground induced damage. Our assessment of liquefaction induced ground damage, such as sand boils and ground cracking, showed that there is a very low potential for surface expression of liquefaction to occur on the site. The potential for surface expression of liquefaction is shown below.

Table 9 – Liquefaction induced ground damage for design eart hquakes.

Damaging Surface Expression

Test / CPT SLS 1170 EQ ULS 1170 EQ

1 N N

2 N N

3 N N

4 N N

5 N N

6 N N

7 N N

8 N N

9 N N

10 N N

11 N N

12 N N

13 N N

14 N N

15 N N

16 N N



6.3.5 Lateral Spreading

Liquefaction induced lateral spreading or flow failures can occur when the shear stresses required to maintain static equilibrium are greater than the shear strength of the liquefied soil. Structures built on ground that experiences lateral spreading can be expected to sustain significant damage relative to the damage that would be expected from ground shaking alone. The watercourse on the site is relatively shallow (i.e. less than 1.0m deep) and the ground water levels are at depths greater than 1m. Therefore, the proposed stormwater drains and existing drains are unlikely to pose a lateral spreading risk to the development. Based on this evidence we have assessed the potential for lateral spreading as very low. 6.3.6 Discussion

• Under a SLS earthquake case, the total settlements are typically 0mm and there is unlikely to be any liquefaction induced ground damage.

• Under a ULS earthquake case the total settlements are typically less than 5mm. The exception is CPT16, where potential total settlement is in the order of 15mm. Based on the results there is a very low potential for liquefaction induced ground damage. It is, however, noted that during the ULS design earthquake some building damage is likely at this level of shaking regardless of ground conditions and liquefaction potential.

• The calculated settlements across the site are reasonable consistent, especially for the CPT’s which extended to depths ranging from 2.98m to 8.38m bgl. This would indicate that the potential liquefaction induced settlements across the site are likely to be consistent. The exception is CPT16 in the north eastern corner of the site. Based on our ground investigations we infer that this is due to the ground conditions at this location.

6.4 Land Classification Technical Categories

For the Christchurch region the DBH has recently released a new classification system for residential ‘Green Zone’ land on the flat in respect of liquefaction susceptibility. This new classification system is divided into three technical categories that reflect both the liquefaction experience to date and future performance expectations. The categories and corresponding criteria are summarised as follows:

• Technical Category 1 (TC1) – future land damage from liquefaction is unlikely, and ground settlements are expected to be within normally accepted tolerances.

• Technical Category 2 (TC2) – Minor to moderate land damage from liquefaction is possible in future large earthquakes.

• Technical Category 3 (TC3) – Moderate to significant land damage from liquefaction is possible in future large earthquakes.

The DBH has indicated the following liquefaction deformation limits for house foundations as summarised in Table 9 below:



Table 10 – Liquefaction deformation limits and hous e foundation implications

Technical Category

Liquefaction Deformation Limits Likely Implication for House Foundations (subject to individual assessment)

Vertical Lateral Spread SLS ULS SLS ULS

TC1 15mm 25mm Nil Nil Standard NZS3604 type foundations with tied slabs

TC2 50mm 100mm 50mm 100mm DBH enhanced foundation solutions

TC3 >50mm >100mm >50mm >100mm Site specific foundation solution

Based upon results of the liquefaction assessment described in Section 6.3 the potential for liquefaction is very low and as such the site can be placed within the TC1 category. However, this is relates only to liquefaction and not the presence of peat and other organic soils which may give rise to excessive total and differential settlement.

6.5 Compliance with the Definition of ‘Good Ground’

Based on the findings of this geotechnical assessment it is inferred that the site is non-compliant with the intent of the definition of ‘Good Ground’ in terms of the New Zealand Standards Timber Framed Buildings (NZS3604:2011) and Concrete Masonry Buildings Not Requiring Specific Engineering Design (NZS4229:1999), from an available soil bearing capacity aspect. Therefore, irrespective of any potential liquefaction risk at the site typical light weight timber framed or masonry houses (which would generally be designed within the guidelines of NZS3604:2011 or NZS4229:1999) would require specific foundation design. 6.6 Peat

The ground investigation identified peat layers predominately within the southern and middle areas of the site at between 1.0m and 4.6m bgl. The southern area of the site shows peat layers within the top 4.4m.The peat layers are between 0.8m and 2.4m thick. The middle area exhibited thickness of 1.0m to 2.3m of peat. Thin peat layers were identified in the northern area of the site but were typically less than 0.5m thick and present at depths ranging from 2.5m to 5.5m bgl. Given that peat does not liquefy, the main concern with the peat layer is in terms of foundations for buildings and infrastructure. 6.6.1 Infrastructure

On the assumption that the majority of the infrastructure is placed within the sand and silt deposits overlying the thick peat deposit, no special pre earthworks are required to protect the infrastructure, subject however to confirmation of the infrastructure design and loadings. It is anticipated that further assessment of infrastructure will be required at the detailed design stage. For deep and/or heavy infrastructure pile foundations as per the main site may be required. 6.6.2 Residential Foundations

Due to the residential nature of the development and the presence of thick deposits of peat, future residential development will require foundations to limit consolidation and creep settlement in the peat. Piles are therefore recommended and founded in the basal sandy gravels typically at 2.0m to 4.6m bgl. Pile foundations will transfer structural loads from the structure to deeper and stronger non-liquefiable sandy gravel layers at 2.0m to 4.6m bgl, thereby minimising any structural damage associated with the ground due to the presence of peat.



Piled foundations for a residential house typically comprise driven piles and can be either concrete (typically used if a concrete floor system is to be used), or timber (typically used if a timber floor and sub-floor system is to be used). A pile foundation system does not require any special soil preparation, but will require site specific investigation and design. We note that all pile foundations are to be designed to carry the full structural loads and stresses with no reliance on the ground below the slab. As required under the new DBH guidelines, a building consent investigation will be required for each lot. 6.6.3 Discussion and Recommendations

The DBH advised the above foundation systems for residential houses built in areas potentially susceptible to seismically induced liquefaction or settlement. Guidance and typical design details are provided in their publication ‘Guidance on house repairs and reconstruction following the Canterbury Earthquake’, dated 20 December 2010. It is typically recommended that piled foundation s are adopted for residential housing at sites where thick deposits of peat are present at shallow depths. If the pile foundation option is adopted, then the floor slab should be well reinforced to provide continuity across the building floor and foundation elements. The objective will be to provide additional capacity in the floor slab and enhance its ability to redistribute loads. All pile heads need to be adequately tied into the floor slab. As part of the detailed house foundation design, particular attention should be paid to detailing the connection joints of buried services (water and sewer pipes, power conduits, etc.) between the house foundation and the in situ ground. The design should allow sufficient movement and ductility to account for seismic shaking and movement, and to allow for the easy reinstatement if they were to be damaged during a future seismic event. It should be noted that the above discussion on the foundation options is generic only. The actual foundation option chosen and associated costs will depend upon the specific design of the proposed dwelling and the results of a site specific geotechnical and structural assessments. 6.6.4 Proposed Earthworks

It is likely that the amount of earthworks required for the site will be minimal as the site is relatively flat with a very low risk of liquefaction occurring. Although there are layers of peat present throughout the site, due to the depth of peat layers it would be both time consuming and costly to remove the peat as part of any preparatory earthworks. 6.7 General Site Development Recommendations

6.7.1 Cut Excavations

Based on the investigation results we make the following comments:

• Cuts are likely to encounter predominantly silty soil with the potential for sand layers. We anticipate that the soils will be easy to excavate with conventional earth moving equipment.

• Cuts greater than 1.5m in height should be inspected by a geotechnical engineer or

engineering geologist as work proceeds to confirm the acceptability of the actual slopes;

• Cut slopes of 3H:1V are likely to maintain global stability for static and seismic cases.

• Groundwater seepages maybe encountered in cut excavations. If significant groundwater inflows are encountered and left untreated, slumping of cuts could occur. If groundwater



seepages are encountered these should be inspected by a geotechnical engineer or engineering geologist and site specific treatment adopted, as required.

• Cut slopes will be vulnerable to erosion and therefore should be hydroseeded/planted or

otherwise protected as soon as practicable after excavation. 6.7.2 Earthfill

We make the following recommendations with regard to the fill placement: • Filling shall generally be carried out in accordance with NZS4431:1989 – Code of Practice for

Earth Fill for Residential Development, with appropriate on site quality control;

• Depending on the nature of the fill material the appropriate compaction standard will need to be applied. A geotechnical engineer should review the compaction standard prior to site earthworks.

• All areas where earthfill is to be placed should be stripped of topsoil and other organic material

and stockpiled.

• Benching to key the fills into the ground is required wherever the existing ground slope is steeper than 3H:1V.

• Fill slopes are likely to be stable at a slope of 3H:1V. If fill slopes are required to be steeper,

then the use of geogrids may be required to reinforce the fill edge. This should be assessed by a geotechnical engineer as part of the detail design.

• The fill slope could be vulnerable to erosion if concentrated stormwater flows develop. To

control runoff from the fill batters and scouring of the fill, the front face should be planted and stormwater runoff directed away from the fill face.

• The design of any fill slope will need to take into account the potential for liquefiable soils or the presence of peat at the base of the slope.

• If fill depths exceed 0.5m, we recommend a geotechnical engineer carries out an assessment to confirm the affect the fill surcharge will have on the peat.



7. Assessment Against RMA Section 106 of the Resource Management Act (RMA) states inter alia

… “a consent authority may refuse to grant a subdivision consent, or may grant a subdivision consent subject to conditions, if it considers that:

a) the land in respect of which a consent is sought, or any structure on the land, is or is likely to be subject to material damage by erosion, falling debris, subsidence, slippage, or inundation from any source; or

b) any subsequent use that is likely to be made of the land is likely to accelerate, worsen, or result in material damage to the land, other land, or structure by erosion, falling debris, subsidence, slippage, or inundation from any source; or

c) sufficient provision has not been made for legal and physical access to each allotment to be created by the subdivision.”

No erosion was observed on the site. However the silty soils that directly underlie parts of the site are inferred to be potentially susceptible to erosion when the site is left without vegetation cover. We infer that the site is not susceptible to falling debris or slippage due to the topographical location. It is noted that issues surround stormwater discharge are being dealt with in the detailed civil engineering design. Therefore any potential “inundation” susceptibility due to stormwater has already been addressed. Due to the presence of peaty and organic soils at depth we infer that the site is possibly susceptible to subsidence. However, if the appropriate peaty soil mitigation measures, as outlined in this report, are undertaken then the risk of subsidence is significantly addressed. Therefore, with appropriate mitigation measures where required, the site in our opinion will generally be free of “erosion”, “falling debris”, “subsidence”, “slippage”, or “inundation”. The proposed subdivision development therefore generally complies with the intent of Section 106 (a). Due to the site being partially underlain by fine grained soils, there exists the potential for erosion and drilling of the sandy and silty soils if vegetation cover is removed for prolonged periods of time from both stormwater runoff if it is not discharged in a controlled manner, and from the wind. This susceptibility to erosion of the sandy and silty soils can be minimised with appropriate industry standard design measures undertaken during construction. Revegetation should be carried out as soon as practicable post bulk earthworks. The site has been identified as being partially susceptible to consolidation or settlement and hence has the potential for “subsidence. Provided that appropriate consolidation mitigation measures are implemented, as recommended in this report, subsequent use of the land following development is unlikely to accelerate, worsen, or result in material damage to the land, other land, or structures. In our opinion therefore, the development will comply with the intent of Section 106 (b). Section 106 (c) is not directly relevant to a geotechnical appraisal and therefore has not been considered in detail in this report, although it is noted that the site is accessible from Northbrook Road. Thus in our opinion, under Section 106 of the RMA, there are no geotechnical reasons preventing the development, provided the appropriate engineering measures as recommended in this report are carried out.



8. References Brown and Weeber, (compliers), 1992. Geology of the Christchurch urban area. Institute of Geological and Nuclear Sciences, 1:25,000 geological map 1. 1 sheet + 104p. Lower Hutt, New Zealand.

Department of Building and Housing, 2011. Compliance Document for New Zealand Building Code, Clause B1, Structures.

Department of Building and Housing, 2011. Interim Minimum Requirements for Geotechnical Assessment of Liquefaction for Land Development – Canterbury Region

Department of Building and Housing, 2011. ‘Guidance on house repairs and reconstruction following the Canterbury Earthquake’, dated 20 December 2010 – Canterbury Region

Geonet, 2011. ftp://ftp.geonet.org.nz/strong/processed/Proc

Gerstenberger, M.; Cubrinovski, M; McVerry, G.; Stirling, M.; Rhoades, D.;Bradley, B.; Langridge, R.; Webb, T.; Peng, B.; Pettinga, J.; Berryman, K.; Brackley, H. 2011. Probabilistic assessment of liquefaction potential for Christchurch in the next 50 years, GNS Science Report 2011/15 30 p.

GNS, 1999. Probabilistic Seismic Hazard Assessment and Earthquake Scenarios for the Canterbury Region, and Historic Earthquakes in Christchurch. Geological and Nuclear Sciences, Lower Hutt, Wellington.

GNS, 2011a. http://maps.gns.cri.nz/website/af/viewer.htm

GNS, 2011b. http://www.gns.cri.nz/Home/News-and-Events/Media-Releases/earthquake-part-of-aftershock-sequence

Ishihara, 1985. Stability of natural deposits during earthquakes. Proceedings, 11th International Conference on soil Mechanics and Foundation engineering, Vol 1, 321-376.

Ishihara and Yoshimine, 1992. Evaluation of settlements in sand deposits following liquefaction during earthquakes. Soils and Foundations, Vol. 32, No. 1, pp. 173-188.

Kramer, 1996. Geotechnical Earthquake Engineering. Prentice Hall, Upper Saddle River, NJ, USA.

Martin, G. and Lew, M., 1999. Recommended Procedure for Implemention of DMG Special Publication 117 – Guidelines for Analyzing and Mitigating Liquefaction in California. Southern California Earthquake Center, University of Southern California. Ca, USA.

NZS1170.0:2002. Australia/New Zealand Standard, Structural Design Actions, Part 0: General Principals. Standards New Zealand, Wellington, New Zealand.

NZS1170.5:2002. Australia/New Zealand Standard, Structural Design Actions, Part 5: Earthquake Actions – New Zealand. Standards New Zealand, Wellington, New Zealand.

NZGS, 2005. Guidelines for the Classification and Field Description of Soils and Rocks in Engineering. NZ Geotechnical Society Inc, Wellington, New Zealand.

NZGS, 2010. Geotechnical earthquake engineering practice, Module 1 – Guideline for the identification, assessment and mitigation of liquefaction hazards. NZ Geotechnical Society Inc, Wellington, New Zealand.

Robertson and Wride, 1998. Evaluating cyclic liquefaction potential using the cone penetration test. Canadian Geotechnical Journal, Vol. 35, pp. 442 – 459.



Sewell, R. J.; Weaver, S. D.; Reay, M. B. (1992) ‘Geology of the Banks Peninsular - Scale 1:100,000’. Institute of Geology & Nuclear Sciences Geological Map 3, Institute of Geological and Nuclear Sciences Ltd, Lower Hutt, New Zealand.

Structural Engineering Society (SESOC), 2011. Christchurch Seismic Design Load Levels Interim Advice.

Tonkin & Taylor, 2010 Darfield Earthquake 4 September 2010 Geotechnical Land Damage Assessment and Reinstatement Report; Stage 1 Report, for the Earthquake Commission.



9. Limitations We have prepared this report in accordance with the brief as provided. The contents of the report are for the sole use of the Client and the Waimakariri District Council for the purpose of subdivision consent only, and no responsibility or liability will be accepted to any other third party. Data or opinions contained within the report may not be used in other contexts or for any other purposes without our prior review and agreement.

The recommendations in this report are based on data collected at specific locations and by using suitable investigation techniques with limited site coverage. Only a finite amount of information has been collected to meet the specific financial and technical requirements of the Client’s brief and this report does not purport to completely describe all the site characteristics and properties. The nature and continuity of the ground and groundwater between test locations has been inferred using experience and judgment and it must be appreciated that actual conditions could vary from the assumed model.

Subsurface conditions relevant to construction works should be assessed by contractors who can make their own interpretation of the factual data provided. They should perform any additional tests as necessary for their own purposes.

Subsurface conditions, such as groundwater levels, can change over time. This should be borne in mind, particularly if the report is used after a protracted delay.

We note that resource and building consents are required from local and regional authorities in advance to develop the proposed subdivision. The application of all consents is the responsibility of the client; however Aurecon can assist if required.

This report is not to be reproduced either wholly or in part without our prior written permission.

Appendix A Figures

Aurecon New Zealand Limited

Unit 1, 150 Cavendish Road

Casebrook

PO Box 1061

Christchurch - New Zealand

Client

Project

By

Figure 1

Date Job Number

A4

Paper Size

Revision

Note: Not to scale; boundaries and locations are approximate only

1

Telephone: +64 3 366 0821

Facsimile: +64 3 379 6955

Email: [email protected]

Website: www.aurecongroup.com

VB Properties 2008 Limited

MHD 23 November2011 223094

Northbrook Subdivision

Site Location

N

Site Location

Northbrook Road

Rangiora



Casebrook

PO Box 1061


Client

Project

By

Figure 2

Date Job Number

A4

Paper Size

Revision


1

Telephone: +64 3 366 0821

Facsimile: +64 3 379 6955






Site Location and Geomorphological Features

N

Stream

Low Lying area – Zone 1

Power lines



Casebrook

PO Box 1061


Client

Project

By

Figure 3

Date Job Number

A4

Paper Size

Revision


1

Telephone: +64 3 366 0821

Facsimile: +64 3 379 6955






Geological Map of Canterbury Region

N

Site Location



Casebrook

PO Box 1061


Client

Project

By

Figure 4

Date Job Number

A4

Paper Size

Revision


1

Telephone: +64 3 366 0821

Facsimile: +64 3 379 6955






CPT Locations

16

15

3

7

8

9

10

11

13

12

14

1

2

4

5

6



Casebrook

PO Box 1061


Client

Project

By

Figure 5

Date Job Number

A4

Paper Size

Revision


1

Telephone: +64 3 366 0821

Facsimile: +64 3 379 6955






Test Pit Locations in 2011

N

TP1

TP9TP8

TP7TP6

TP5

TP4 TP3

TP2

TP16

TP17

TP15TP14

TP13TP12

TP11

TP10



Casebrook

PO Box 1061


Client

Project

By

Figure 6

Date Job Number

A4

Paper Size

Revision


1

Telephone: +64 3 366 0821

Facsimile: +64 3 379 6955






Test Pit Locations in 2006

N

TP2

TP1

TP3

TP8

TP7

TP6

TP4

TP5



Casebrook

PO Box 1061


Client

Project

By

Figure 7

Date Job Number

A4

Paper Size

Revision


1

Telephone: +64 3 366 0821

Facsimile: +64 3 379 6955






Environment Canterbury GIS Borehole Locations

N

M35/11683

M35/11559

M35/8026

M35/11684

Site Location

PEAT

PEAT

PEAT

PEAT

PEAT

??

SANDY GRAVEL

SANDY GRAVEL

TOPSOIL TOPSOIL TOPSOIL TOPSOIL TOPSOIL TOPSOILTOPSOIL

CLIENT

NORTHBROOK ROADRANGIORA

DATE

TITLE

REVISION DETAILSDATEREV APPROVED

CHECKED

APPROVED

PROJECTDRAWN DESIGNED

223094PROJECT No.

SCALE SIZE

DRAWING No. REV

A3GEOLOGICAL CROSS SECTIONSTP 2,3,4,5,6,7,8,9 Figure 8 A

AS SHOWN

NOT FOR CONSTRUCTIONT Stocker M Derkson

J Murison

M DohertyA 8-12-2011 ISSUED M Doherty

00/0

0/00


TOPSOIL TOPSOIL TOPSOIL TOPSOIL TOPSOIL TOPSOIL

SANDY GRAVEL SANDY GRAVEL ???

??

PEAT

PEAT

PEAT

PEAT

PEAT

CLIENT

NORTHBROOK ROADRANGIORA

DATE

TITLE

REVISION DETAILSDATEREV APPROVED

CHECKED

APPROVED

PROJECTDRAWN DESIGNED

223094PROJECT No.

SCALE SIZE

DRAWING No. REV

A3GEOLOGICAL CROSS SECTIONSTP 10,11,12,13,14,15,16 Figure 9 A

AS SHOWN

NOT FOR CONSTRUCTIONT Stocker M Derkson

J Murison

M DohertyA 8-12-2011 ISSUED M Doherty

00/0

0/00

PEAT

PEAT

PEAT

PEAT

PEAT

SILTSILT

SILT

SILT

SILT

SANDY GRAVEL

SANDY GRAVEL

SANDY GRAVELSANDY GRAVEL

Appendix B CPT Logs

CPT ANALYSIS NOTES

Soil Type Interpretation using chart of Robertson & Campanella (1983). This is a simple but well proven interpretation using cone tip resistance (qC) and friction ratio (fR) only. No normalisation for overburden stress is applied. Cone tip resistance measured with the piezocone is corrected with measured pore pressure (uC).

sand (and gravel)

silt-sand

silt

clay-silt

clay

peat

Liquefaction Screening The purpose of the screening is to highlight susceptible soils, that is sand and silt-sand in a relatively loose condition. This is not a full liquefaction risk assessment which requires knowledge of the particular earthquake risk at a site and additional analysis. The screening is based on the chart of Shibata and Teparaksa (1988).

high susceptibility

medium susceptibility

low susceptibility

High susceptibility is here defined as requiring a shear stress ratio of 0.2 to cause liquefaction with D50 for sands assumed to be 0.25 mm and for silty sands to be 0.05 mm.

Medium susceptibility is here defined as requiring a shear stress ratio of 0.4 to cause liquefaction with D50 for sands assumed to be 0.25 mm and for silty sands to be 0.05 mm.

Low susceptibility is all other cases.

Relative Density (DR) Based on the method of Baldi et. al. (1986) from data on normally consolidated sand.

Undrained Shear Strength (SU)

Derived from the bearing capacity equation using SU = (qC –σVO)/15.

rwise

McMDS

PIEZOCONE PENETROMETER TEST (CPTU) INTERPRETIVE REPORT

qc (MPa) Type Liq Dr (%) Su (KPa)

Job No:

CPT No:

Project:

Location:

Date:

Operator:

Remark:

9552

CPT001

Aurecon

Northbrook Subdivision, Rangiora

28/10/2011

J. Kendrick

Effective Refusal

0 10 20 30 40 50

0510

0

2

4

6

8

10

Friction Ratio (%)

0 20 40 60 80 0 40 80 120 160 200

tchater

MSDS LOGO



Job No:

CPT No:

Project:

Location:

Date:

Operator:

Remark:

9552

CPT002

Aurecon


28/10/2011

J. Kendrick

Effective Refusal

0 10 20 30 40 50

0510

0

2

4

6

8

10

Friction Ratio (%)

0 20 40 60 80 0 40 80 120 160 200

tchater

MSDS LOGO



Job No:

CPT No:

Project:

Location:

Date:

Operator:

Remark:

9552

CPT003

Aurecon


28/10/2011

J. Kendrick

Effective Refusal

0 10 20 30 40 50

0510

0

2

4

6

8

10

Friction Ratio (%)

0 20 40 60 80 0 40 80 120 160 200

tchater

MSDS LOGO



Job No:

CPT No:

Project:

Location:

Date:

Operator:

Remark:

9552

CPT004

Aurecon


28/10/2011

J. Kendrick

Effective Refusal

0 10 20 30 40 50

0510

0

2

4

6

8

10

Friction Ratio (%)

0 20 40 60 80 0 40 80 120 160 200

tchater

MSDS LOGO



Job No:

CPT No:

Project:

Location:

Date:

Operator:

Remark:

9552

CPT005

Aurecon


28/10/2011

J. Kendrick

Effective Refusal

0 10 20 30 40 50

0510

0

2

4

6

8

10

Friction Ratio (%)

0 20 40 60 80 0 40 80 120 160 200

tchater

MSDS LOGO



Job No:

CPT No:

Project:

Location:

Date:

Operator:

Remark:

9552

CPT006

Aurecon


28/10/2011

J. Kendrick

Effective Refusal

0 10 20 30 40 50

0510

0

2

4

6

8

10

Friction Ratio (%)

0 20 40 60 80 0 40 80 120 160 200

tchater

MSDS LOGO



Job No:

CPT No:

Project:

Location:

Date:

Operator:

Remark:

9552

CPT007

Aurecon


28/10/2011

J. Kendrick

Effective Refusal

0 10 20 30 40 50

0510

0

2

4

6

8

10

Friction Ratio (%)

0 20 40 60 80 0 40 80 120 160 200

tchater

MSDS LOGO



Job No:

CPT No:

Project:

Location:

Date:

Operator:

Remark:

9552

CPT008

Aurecon


28/10/2011

J. Kendrick

Effective Refusal

0 10 20 30 40 50

0510

0

2

4

6

8

10

Friction Ratio (%)

0 20 40 60 80 0 40 80 120 160 200

tchater

MSDS LOGO



Job No:

CPT No:

Project:

Location:

Date:

Operator:

Remark:

9552

CPT009

Aurecon


28/10/2011

J. Kendrick

Effective Refusal

0 10 20 30 40 50

0510

0

2

4

6

8

10

Friction Ratio (%)

0 20 40 60 80 0 40 80 120 160 200

tchater

MSDS LOGO



Job No:

CPT No:

Project:

Location:

Date:

Operator:

Remark:

9552

CPT010

Aurecon


28/10/2011

J. Kendrick

Effective Refusal

0 10 20 30 40 50

0510

0

2

4

6

8

10

Friction Ratio (%)

0 20 40 60 80 0 40 80 120 160 200

tchater

MSDS LOGO



Job No:

CPT No:

Project:

Location:

Date:

Operator:

Remark:

9552

CPT011

Aurecon


28/10/2011

J. Kendrick

Effective Refusal

0 10 20 30 40 50

0510

0

2

4

6

8

10

Friction Ratio (%)

0 20 40 60 80 0 40 80 120 160 200

tchater

MSDS LOGO



Job No:

CPT No:

Project:

Location:

Date:

Operator:

Remark:

9552

CPT012

Aurecon


28/10/2011

J. Kendrick

Effective Refusal

0 10 20 30 40 50

0510

0

2

4

6

8

10

Friction Ratio (%)

0 20 40 60 80 0 40 80 120 160 200

tchater

MSDS LOGO



Job No:

CPT No:

Project:

Location:

Date:

Operator:

Remark:

9552

CPT013

Aurecon


28/10/2011

J. Kendrick

Effective Refusal

0 10 20 30 40 50

0510

0

2

4

6

8

10

Friction Ratio (%)

0 20 40 60 80 0 40 80 120 160 200

tchater

MSDS LOGO



Job No:

CPT No:

Project:

Location:

Date:

Operator:

Remark:

9552

CPT014

Aurecon


28/10/2011

J. Kendrick

Effective Refusal

0 10 20 30 40 50

0510

0

2

4

6

8

10

Friction Ratio (%)

0 20 40 60 80 0 40 80 120 160 200

tchater

MSDS LOGO



Job No:

CPT No:

Project:

Location:

Date:

Operator:

Remark:

9552

CPT015

Aurecon


28/10/2011

J. Kendrick

Effective Refusal

0 10 20 30 40 50

0510

0

2

4

6

8

10

Friction Ratio (%)

0 20 40 60 80 0 40 80 120 160 200

tchater

MSDS LOGO



Job No:

CPT No:

Project:

Location:

Date:

Operator:

Remark:

9552

CPT016

Aurecon


28/10/2011

J. Kendrick

Effective Refusal

0 10 20 30 40 50

0510

0

2

4

6

8

10

Friction Ratio (%)

0 20 40 60 80 0 40 80 120 160 200

tchater

MSDS LOGO

CIVIL CONSTRUCTION OVERVIEW 5 x Piling Rigs (20 to 80 tonne); 4 x Tieback/Micro-Piling Rigs (0.5 to 20 tonne); Sheet Piling & Injection Grouting; Dewatering; 26 x Drilling Rigs Company wide.

A NEW ZEALAND FIRST METHOD – INTRODUCED TO THE MARKET BY MCMILLAN’S: Provisionally Patented Vibration Free Stone Column Method:

Can be used next to sensitive buildings; No mess (dry); Cost effective (minimal setup times); Further savings possible for building construction – i.e.

ground beams, deep rafts, pile starters, boxing to piles; No corrosion issues, all natural materials; Reliance on individual piles, and the risk of differential

settlement is reduced.

Fully Instrumented Continuous Flight Auger / Displacement Auger Piling:

Cost effective; Sizes 350mm to 900mm and 19m depth; Fast (150m of 600mm diameter reinforced concrete pile can

be installed per day); Lateral load capacity of RC piles exceed some other piling

methods; Quiet & vibration free; Fully reinforced concrete piles, with no corrosion issues.

McMILLAN’S ALSO OFFER THE FOLLOWING SERVICES: Screw Piles; Conventional Bored Concrete Piles; Mini & Micro Piles; Retaining Walls; Sheet Piling; Anchors & Tiebacks.

Please contact us to find out more information or visit our website www.drilling.co.nz


Project 223094 | File 223094 Geotech Report Rev1 Second Issue.docx 20 December 2011 | Revision 1 Aurecon Page i

Appendix C Test Pit Logs

0.30

1.00

1.20

3.00

3.10

TOPSOIL Silty with some rootlets; Dark brown. Loose. Dry. Low plasticity.Friable.

SILT; Light yellow grey with orange brown mottling. Stiff. Moist. Low plasticity.Friable.

PEAT with some tree branches and minor silt; Dark brown. Firm. Saturated.Low plasticity. Organic. Fibrous.

Clayey SILT; Light blue grey. Stiff. Saturated. High plasticity.

Sandy GRAVEL; Light brown yellow. Medium dense. Saturated. Gravel fine tocoarse grained and sub rounded. Sand coarse grained.

End of Test Pit at 3.1m (GW reached)

Last

Genera

ted:

8/1

2/2

011 3

:59:1

6 p

.m.

Sheet 1 of 1

Logged by: MHDInput by: MHDChecked by: JSMVerified by: JK

Remarks:

Groundwater encountered @ 1.1mGroundwater encountered @ 3.1m

Sa

mp

le

Wa

ter

Le

ve

l (m

)

Ele

va

tio

n (

m)

-1

-2

-3

-4

De

pth

(m

)

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

Gra

ph

ic L

og

Soil Description

Telephone: +64 3 366 0821

Facsimile: +64 3 379 6955 Sheet 1 of 1


CO-ORDINATES NZTMEasting: 1568145 mNorthing: 5204745 mGround Level: 0 m

Data

base F

ile:

223094_T

ES

TP

IT_LO

GS

.GP

J,

Lib

rary

: C

OP

Y O

F C

HC

H L

IBR

AR

Y F

EB

2011.G

LB

, D

ata

tem

pla

te:

CH

CH

DA

TA

TE

MP

LA

TE

NO

V 2

010.G

DT

, Last

Genera

ted:

8/1

2/2

011.

Date Started: 30/09/2011Date Completed: 30/09/2011

Client: VB Properties 2008 LimitedProject Name: Northbrook Subdivision - RangioraLocation: See Location PlanProject Reference: 223094 - Northbrook Subdivision

TP01

TEST PIT INFORMATIONExcavator Type: 13 Tonne ExcavatorTest Pit Dimensions:Contractor: BG Contractors

Aurecon (New Zealand) Limited

Unit 1, 150 Cavendish Rd

PO BOX 1061

Christchurch 8140

New Zealand

www.aurecongroup.com


.

Shear

Vane T

ests

Pocket

Penetr

om

ete

r T

ests

0.30

1.40

2.30

2.60

3.10


SILT; Light yellow grey with orange brown mottling. Very stiff. Dry to moist.Low plasticity. Friable.

PEAT with some tree branches and minor silt; Dark brown. Firm. Saturated.Low plasticity. Organic. Fibrous.




Last

Genera

ted:

8/1

2/2

011 3

:59:1

7 p

.m.

Sheet 1 of 1


Remarks:

Groundwater encountered @ 2.3m

Sa

mp

le

Wa

ter

Le

ve

l (m

)

Ele

va

tio

n (

m)

-1

-2

-3

-4

De

pth

(m

)

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

Gra

ph

ic L

og

Soil Description

Telephone: +64 3 366 0821




Data

base F

ile:

223094_T

ES

TP

IT_LO

GS

.GP

J,

Lib

rary

: C

OP

Y O

F C

HC

H L

IBR

AR

Y F

EB

2011.G

LB

, D

ata

tem

pla

te:

CH

CH

DA

TA

TE

MP

LA

TE

NO

V 2

010.G

DT

, Last

Genera

ted:

8/1

2/2

011.



TP02




PO BOX 1061

Christchurch 8140

New Zealand



.

Shear

Vane T

ests

Pocket

Penetr

om

ete

r T

ests

0.30

1.70

3.20

3.70

3.80



PEAT with some tree branches and minor silt; Dark brown. Firm. Saturated.Organic. Low plasticity. Fibrous.

Sandy SILT; Light blue grey with brown mottling. Stiff. Saturated. Lowplasticity. Sand fine grained.



Last

Genera

ted:

8/1

2/2

011 3

:59:1

7 p

.m.

Sheet 1 of 1


Remarks:

Groundwater seepage @ 3.2mGroundwater encountered @ 3.8m

Sa

mp

le

Wa

ter

Le

ve

l (m

)

Ele

va

tio

n (

m)

-1

-2

-3

-4

De

pth

(m

)

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

Gra

ph

ic L

og

Soil Description

Telephone: +64 3 366 0821




Data

base F

ile:

223094_T

ES

TP

IT_LO

GS

.GP

J,

Lib

rary

: C

OP

Y O

F C

HC

H L

IBR

AR

Y F

EB

2011.G

LB

, D

ata

tem

pla

te:

CH

CH

DA

TA

TE

MP

LA

TE

NO

V 2

010.G

DT

, Last

Genera

ted:

8/1

2/2

011.



TP03




PO BOX 1061

Christchurch 8140

New Zealand



.

Shear

Vane T

ests

Pocket

Penetr

om

ete

r T

ests

0.30

2.00

3.00

3.50

4.00

4.10



PEAT with some tree banches and minor silt; Dark brown. Firm. Saturated.Organic. Low plasticity. Fibrous.


Silty SAND; Light blue grey with brown mottling. Stiff. Saturated. Sand finegrained.


End of Test Pit at 4.1m (Required depth reached)

Last

Genera

ted:

8/1

2/2

011 3

:59:1

8 p

.m.

Sheet 1 of 1


Remarks:

Groundwater seppage @ 2.0m

Sa

mp

le

Wa

ter

Le

ve

l (m

)

Ele

va

tio

n (

m)

-1

-2

-3

-4

De

pth

(m

)

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

Gra

ph

ic L

og

Soil Description

Telephone: +64 3 366 0821




Data

base F

ile:

223094_T

ES

TP

IT_LO

GS

.GP

J,

Lib

rary

: C

OP

Y O

F C

HC

H L

IBR

AR

Y F

EB

2011.G

LB

, D

ata

tem

pla

te:

CH

CH

DA

TA

TE

MP

LA

TE

NO

V 2

010.G

DT

, Last

Genera

ted:

8/1

2/2

011.



TP04




PO BOX 1061

Christchurch 8140

New Zealand



.

Shear

Vane T

ests

Pocket

Penetr

om

ete

r T

ests

0.30

2.20

3.10

4.60



SILT; Light grey with orange brown mottling. Very stiff. Moist. Low plasticity.Friable.

PEAT with some silt and tree matter; Light grey brown. Stiff. Wet to saturated.High plasticity.


Last

Genera

ted:

8/1

2/2

011 3

:59:1

9 p

.m.

Sheet 1 of 1


Remarks:

No groundwater encounteredTree root/branch encountered @ 3.1m

Sa

mp

le

Wa

ter

Le

ve

l (m

)

Ele

va

tio

n (

m)

-1

-2

-3

-4

De

pth

(m

)

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

Gra

ph

ic L

og

Soil Description

Telephone: +64 3 366 0821




Data

base F

ile:

223094_T

ES

TP

IT_LO

GS

.GP

J,

Lib

rary

: C

OP

Y O

F C

HC

H L

IBR

AR

Y F

EB

2011.G

LB

, D

ata

tem

pla

te:

CH

CH

DA

TA

TE

MP

LA

TE

NO

V 2

010.G

DT

, Last

Genera

ted:

8/1

2/2

011.



TP05




PO BOX 1061

Christchurch 8140

New Zealand



.

Shear

Vane T

ests

Pocket

Penetr

om

ete

r T

ests

0.30

2.70

2.90

4.50

TOPSOIL Silty with some rootlets; Dark brown. Loose. Dry. Friable. Lowplasticity.


PEAT with some tree branches; Light grey brown. Firm. Moist. Low plasticity.Fibrous.

Clayey SILT with minor sand and tree branches; Light blue grey. Stiff. Moist.High plasticity. Sand is fine grained.


Last

Genera

ted:

8/1

2/2

011 3

:59:1

9 p

.m.

Sheet 1 of 1


Remarks:

No groundwater encounteredTree branch encountered @ 2.7mTree branch encountered @ 4.0m

Sa

mp

le

Wa

ter

Le

ve

l (m

)

Ele

va

tio

n (

m)

-1

-2

-3

-4

De

pth

(m

)

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

Gra

ph

ic L

og

Soil Description

Telephone: +64 3 366 0821




Data

base F

ile:

223094_T

ES

TP

IT_LO

GS

.GP

J,

Lib

rary

: C

OP

Y O

F C

HC

H L

IBR

AR

Y F

EB

2011.G

LB

, D

ata

tem

pla

te:

CH

CH

DA

TA

TE

MP

LA

TE

NO

V 2

010.G

DT

, Last

Genera

ted:

8/1

2/2

011.



TP06




PO BOX 1061

Christchurch 8140

New Zealand



.

Shear

Vane T

ests

Pocket

Penetr

om

ete

r T

ests

0.40

1.50

1.90

3.50

4.50



Silty SAND; Light yellow brown with orange brown mottling. Medium dense.Moist. Sand fine to medium grained.

Sandy SILT with some tree matter; Light blue grey. Very Stiff. Moist. Lowplasticity. Sand is fine grained.

Clayey SILT with minor sand; Light blue grey. Stiff. Moist to wet. Highplasticity. Sand is fine grained.


Last

Genera

ted:

8/1

2/2

011 3

:59:2

0 p

.m.

Sheet 1 of 1


Remarks:

No groundwater encounteredTree branches and roots from 2.2m - 2.6m

Sa

mp

le

Wa

ter

Le

ve

l (m

)

Ele

va

tio

n (

m)

-1

-2

-3

-4

De

pth

(m

)

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

Gra

ph

ic L

og

Soil Description

Telephone: +64 3 366 0821




Data

base F

ile:

223094_T

ES

TP

IT_LO

GS

.GP

J,

Lib

rary

: C

OP

Y O

F C

HC

H L

IBR

AR

Y F

EB

2011.G

LB

, D

ata

tem

pla

te:

CH

CH

DA

TA

TE

MP

LA

TE

NO

V 2

010.G

DT

, Last

Genera

ted:

8/1

2/2

011.



TP07




PO BOX 1061

Christchurch 8140

New Zealand



.

Shear

Vane T

ests

Pocket

Penetr

om

ete

r T

ests

0.30

2.10

2.40

2.60

4.40


SILT; Light yellow grey with orange brown mottling. Very stiff. Dry. Lowplasticity. Friable.

Sandy SILT; Light yellow brown. Stiff. Moist. Low plasticity. Sand fine tomedium grained.

Clayey SILT; Light blue grey. Stiff. Moist to wet. High plasticity.

Sandy SILT with some tree matter; Light blue grey. Very Stiff. Moist to wet.High plasticity. Sand is fine grained.


Last

Genera

ted:

8/1

2/2

011 3

:59:2

0 p

.m.

Sheet 1 of 1


Remarks:

No groundwater encountered

Sa

mp

le

Wa

ter

Le

ve

l (m

)

Ele

va

tio

n (

m)

-1

-2

-3

-4

De

pth

(m

)

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

Gra

ph

ic L

og

Soil Description

Telephone: +64 3 366 0821




Data

base F

ile:

223094_T

ES

TP

IT_LO

GS

.GP

J,

Lib

rary

: C

OP

Y O

F C

HC

H L

IBR

AR

Y F

EB

2011.G

LB

, D

ata

tem

pla

te:

CH

CH

DA

TA

TE

MP

LA

TE

NO

V 2

010.G

DT

, Last

Genera

ted:

8/1

2/2

011.



TP08




PO BOX 1061

Christchurch 8140

New Zealand



.

Shear

Vane T

ests

Pocket

Penetr

om

ete

r T

ests

0.30

2.10

3.40

4.40

TOPSOIL gravelly with some rootlets; Dark brown. Loose. Dry. Friable. Gravelmedium grained and sub rounded.



Clayey SILT; Light blue grey with orange brown mottling. Stiff. Moist to wet.High plasticity.


Last

Genera

ted:

8/1

2/2

011 3

:59:2

1 p

.m.

Sheet 1 of 1


Remarks:


Sa

mp

le

Wa

ter

Le

ve

l (m

)

Ele

va

tio

n (

m)

-1

-2

-3

-4

De

pth

(m

)

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

Gra

ph

ic L

og

Soil Description

Telephone: +64 3 366 0821




Data

base F

ile:

223094_T

ES

TP

IT_LO

GS

.GP

J,

Lib

rary

: C

OP

Y O

F C

HC

H L

IBR

AR

Y F

EB

2011.G

LB

, D

ata

tem

pla

te:

CH

CH

DA

TA

TE

MP

LA

TE

NO

V 2

010.G

DT

, Last

Genera

ted:

8/1

2/2

011.



TP09




PO BOX 1061

Christchurch 8140

New Zealand



.

Shear

Vane T

ests

Pocket

Penetr

om

ete

r T

ests

0.40

1.50

3.10

4.20

4.40




Clayey SILT; Light blue grey with orange brown mottling. Stiff. Moist. Lowplasticity.

Sandy SILT; Light blue grey. Stiff. Moist. Low plasticity. Sand fine to mediumgrained.


Last

Genera

ted:

8/1

2/2

011 3

:59:2

1 p

.m.

Sheet 1 of 1


Remarks:


Sa

mp

le

Wa

ter

Le

ve

l (m

)

Ele

va

tio

n (

m)

-1

-2

-3

-4

De

pth

(m

)

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

Gra

ph

ic L

og

Soil Description

Telephone: +64 3 366 0821




Data

base F

ile:

223094_T

ES

TP

IT_LO

GS

.GP

J,

Lib

rary

: C

OP

Y O

F C

HC

H L

IBR

AR

Y F

EB

2011.G

LB

, D

ata

tem

pla

te:

CH

CH

DA

TA

TE

MP

LA

TE

NO

V 2

010.G

DT

, Last

Genera

ted:

8/1

2/2

011.



TP10




PO BOX 1061

Christchurch 8140

New Zealand



.

Shear

Vane T

ests

Pocket

Penetr

om

ete

r T

ests

0.20

1.60

2.10

2.60

4.00

4.10




Clayey SILT; Light blue grey with orange brown mottling. Stiff. Moist. Lowplasticity.




Last

Genera

ted:

8/1

2/2

011 3

:59:2

2 p

.m.

Sheet 1 of 1


Remarks:


Sa

mp

le

Wa

ter

Le

ve

l (m

)

Ele

va

tio

n (

m)

-1

-2

-3

-4

De

pth

(m

)

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

Gra

ph

ic L

og

Soil Description

Telephone: +64 3 366 0821




Data

base F

ile:

223094_T

ES

TP

IT_LO

GS

.GP

J,

Lib

rary

: C

OP

Y O

F C

HC

H L

IBR

AR

Y F

EB

2011.G

LB

, D

ata

tem

pla

te:

CH

CH

DA

TA

TE

MP

LA

TE

NO

V 2

010.G

DT

, Last

Genera

ted:

8/1

2/2

011.



TP11




PO BOX 1061

Christchurch 8140

New Zealand



.

Shear

Vane T

ests

Pocket

Penetr

om

ete

r T

ests

0.30

1.60

1.80

2.20

3.00

3.40

4.30


SILT; Light yellow grey with orange brown mottling. Very stiff. Dry to Moist.Low plasticity. Friable.

Sandy SILT; Light yellow brown with orange brown mottling. Stiff. Moist. Lowplasticity. Sand fine to medium grained.

Silty SAND; Orange brown. Medium dense. Moist. Sand fine to coarsegrained.

SILT; Light yellow grey with orange brown mottling. Stiff. Moist. Low plasticity.Friable.


PEAT with some silt and minor tree branches; Light blue grey. Soft to firm.Wet. High plasticity.


Last

Genera

ted:

8/1

2/2

011 3

:59:2

2 p

.m.

Sheet 1 of 1


Remarks:


Sa

mp

le

Wa

ter

Le

ve

l (m

)

Ele

va

tio

n (

m)

-1

-2

-3

-4

De

pth

(m

)

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

Gra

ph

ic L

og

Soil Description

Telephone: +64 3 366 0821




Data

base F

ile:

223094_T

ES

TP

IT_LO

GS

.GP

J,

Lib

rary

: C

OP

Y O

F C

HC

H L

IBR

AR

Y F

EB

2011.G

LB

, D

ata

tem

pla

te:

CH

CH

DA

TA

TE

MP

LA

TE

NO

V 2

010.G

DT

, Last

Genera

ted:

8/1

2/2

011.



TP12




PO BOX 1061

Christchurch 8140

New Zealand



.

Shear

Vane T

ests

Pocket

Penetr

om

ete

r T

ests

0.40

2.00

2.60

4.50


SILT; Light yellow grey with orange brown mottling. Very stiff. Dry to Moist.Low plasticity. Friable.

SILT; Light blue grey with orange brown mottling. Stiff. Moist to wet. Highplasticity.

PEAT with some silt and minor tree branches; Light blue grey. Stiff. Wet. Highplasticity.


Last

Genera

ted:

8/1

2/2

011 3

:59:2

3 p

.m.

Sheet 1 of 1


Remarks:

Groundwater seepage @ 2.6m

Sa

mp

le

Wa

ter

Le

ve

l (m

)

Ele

va

tio

n (

m)

-1

-2

-3

-4

De

pth

(m

)

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

Gra

ph

ic L

og

Soil Description

Telephone: +64 3 366 0821




Data

base F

ile:

223094_T

ES

TP

IT_LO

GS

.GP

J,

Lib

rary

: C

OP

Y O

F C

HC

H L

IBR

AR

Y F

EB

2011.G

LB

, D

ata

tem

pla

te:

CH

CH

DA

TA

TE

MP

LA

TE

NO

V 2

010.G

DT

, Last

Genera

ted:

8/1

2/2

011.



TP13




PO BOX 1061

Christchurch 8140

New Zealand



.

Shear

Vane T

ests

Pocket

Penetr

om

ete

r T

ests

0.30

2.10

4.40

4.60

4.80


SILT; Light grey with orange brown mottling. Stiff. Dry. Low plasticity. Friable.

PEAT with some silt and tree branches; Dark brown. Soft to firm. Saturated.Low plasticity.

Clayey SILT; Light blue grey with orange brown mottling. Stiff. Moist to wet.High plasticity.



Last

Genera

ted:

8/1

2/2

011 3

:59:2

3 p

.m.

Sheet 1 of 1


Remarks:

Groundwater seepage @ 2.1m

Sa

mp

le

Wa

ter

Le

ve

l (m

)

Ele

va

tio

n (

m)

-1

-2

-3

-4

De

pth

(m

)

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

Gra

ph

ic L

og

Soil Description

Telephone: +64 3 366 0821




Data

base F

ile:

223094_T

ES

TP

IT_LO

GS

.GP

J,

Lib

rary

: C

OP

Y O

F C

HC

H L

IBR

AR

Y F

EB

2011.G

LB

, D

ata

tem

pla

te:

CH

CH

DA

TA

TE

MP

LA

TE

NO

V 2

010.G

DT

, Last

Genera

ted:

8/1

2/2

011.



TP14




PO BOX 1061

Christchurch 8140

New Zealand



.

Shear

Vane T

ests

Pocket

Penetr

om

ete

r T

ests

0.30

1.60

4.00

4.20

4.40



PEAT with some silt and tree branches; Dark brown. Soft to firm. Saturated.Low plasticity. Fibrous.




Last

Genera

ted:

8/1

2/2

011 3

:59:2

4 p

.m.

Sheet 1 of 1


Remarks:

Tree branches @ 1.6mGroundwater seepage @ 2.6mGroundwater encountered @ 4.2

Sa

mp

le

Wa

ter

Le

ve

l (m

)

Ele

va

tio

n (

m)

-1

-2

-3

-4

De

pth

(m

)

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

Gra

ph

ic L

og

Soil Description

Telephone: +64 3 366 0821




Data

base F

ile:

223094_T

ES

TP

IT_LO

GS

.GP

J,

Lib

rary

: C

OP

Y O

F C

HC

H L

IBR

AR

Y F

EB

2011.G

LB

, D

ata

tem

pla

te:

CH

CH

DA

TA

TE

MP

LA

TE

NO

V 2

010.G

DT

, Last

Genera

ted:

8/1

2/2

011.



TP15




PO BOX 1061

Christchurch 8140

New Zealand



.

Shear

Vane T

ests

Pocket

Penetr

om

ete

r T

ests

0.30

1.60

3.10

3.60



PEAT with some silt and tree branches. Dark brown. Soft to firm. Saturated.Low plasticity. Fibrous.

Sandy GRAVEL; Light blue grey. Dense. Saturated. Gravel fine to coarsegrained and sub rounded. Sand coarse grained.

Sandy GRAVEL; Light yellow brown. Dense. Saturated. Gravel fine to coarsegrained and sub rounded. Sand coarse grained.


Last

Genera

ted:

8/1

2/2

011 3

:59:2

4 p

.m.

Sheet 1 of 1


Remarks:

Groundwater seepage @ 1.6mGroundwater encountered @ 3.6m

Sa

mp

le

Wa

ter

Le

ve

l (m

)

Ele

va

tio

n (

m)

-1

-2

-3

-4

De

pth

(m

)

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

Gra

ph

ic L

og

Soil Description

Telephone: +64 3 366 0821




Data

base F

ile:

223094_T

ES

TP

IT_LO

GS

.GP

J,

Lib

rary

: C

OP

Y O

F C

HC

H L

IBR

AR

Y F

EB

2011.G

LB

, D

ata

tem

pla

te:

CH

CH

DA

TA

TE

MP

LA

TE

NO

V 2

010.G

DT

, Last

Genera

ted:

8/1

2/2

011.



TP16




PO BOX 1061

Christchurch 8140

New Zealand



.

Shear

Vane T

ests

Pocket

Penetr

om

ete

r T

ests

0.20

1.60

2.40

2.70

3.00



PEAT with some silt and tree branches; Dark brown. Soft to firm. Saturated.Low plasticity. Fibrous.

Sandy GRAVEL; Light blue grey. Dense. Saturated. Gravel fine to coarsegrained and sub rounded. Sand coarse grained.

Sandy GRAVEL; Light yellow brown. Dense. Saturated. Gravel fine to coarsegrained and sub rounded. Sand coarse grained.

End of Test Pit at 3m (GW reached)

Last

Genera

ted:

8/1

2/2

011 3

:59:2

5 p

.m.

Sheet 1 of 1


Remarks:


Sa

mp

le

Wa

ter

Le

ve

l (m

)

Ele

va

tio

n (

m)

-1

-2

-3

-4

De

pth

(m

)

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

Gra

ph

ic L

og

Soil Description

Telephone: +64 3 366 0821




Data

base F

ile:

223094_T

ES

TP

IT_LO

GS

.GP

J,

Lib

rary

: C

OP

Y O

F C

HC

H L

IBR

AR

Y F

EB

2011.G

LB

, D

ata

tem

pla

te:

CH

CH

DA

TA

TE

MP

LA

TE

NO

V 2

010.G

DT

, Last

Genera

ted:

8/1

2/2

011.



TP17




PO BOX 1061

Christchurch 8140

New Zealand



.

Shear

Vane T

ests

Pocket

Penetr

om

ete

r T

ests


Project 223094 | File 223094 Geotech Report Rev1 Second Issue.docx 20 December 2011 | Revision 1 Aurecon Page ii

Appendix D 2007 Test Pit Logs

Location

Logged By Weather Conditions

FI FineUndrained Shear Strength (kPa)

Measured Using a Hand Held Shear Vane1

25 50 75 100 125 150

Scala Penetrometer Test2

(Blows/ 50mm)

2 4 6 8 10 12

TOPSOIL, dark brown

Clayey SILT, ligth brown with orange mottling, stiff,

0.5 dry 3.5

Fine silty CLAY, light grey with orange mottling, firm

to stiff, dry

1 4

Fine silty CLAY, dark grey, firm to stiff, dry

1.5 4.5

PEAT with timber, black, soft, saturated

2 5

Clayey SILT with fine sand, grey, soft, moist

2.5 5.5

Fine to coarse SAND with rounded gravel, light

brown, loose, moist

END OF TEST PIT AT 2.8m

Water at the bottom of the test pit draining out of the

upper peat layer and the gravel at the bottom, rising

1 - Hand held shear vane test in accordance with BS1377:1990

2 - Scala Penetrometer Test in accordance with NZS4402:1986 for the first three meters

Test Descriptions:

High School Block, Rangiora P31346-002

Wat

er

Dep

th (

m)

Soi

l Sym

bol FACE 1

25/10/2007Project Job Number

Rangiora

SOIL DESCRIPTION:

Colour, structure, weathering, subordinate/ main / minor

COMPONENTS.

SOIL DESCRIPTION:


COMPONENTS.

Open Excavation LogTest Pit No.

Client Date

Wat

er

Dep

th (

m)

Soi

l Sym

bol FACE 1 Continued

Prenda Investments Ltd

aaaTP1

Connell Wagner Limited195 Hereford St. (PO Box 1061

Christchurch New Zealand

Telephone: +64 3 366 0821

Facsimile: +64 3 379 6955

Location




25 50 75 100 125 150


(Blows/ 50mm)

2 4 6 8 10 12

TOPSOIL, dark brown

Fine to coarse rounded GRAVEL with some sand,

light brown, dense, moist

Fine to coarse SILT with some clay, brown to grey, END OF TEST PIT AT 3.4m

0.5 firm, dry, Cu 130/20 kPa 3.5 Water at the bottom of the test pit draining out of the


1 4

Fine silty CLAY, light grey, stiff, moist

1.5 4.5

2 5

PEAT, black, soft to firm, wet to saturated

Fine silty CLAY with sand and some peat, grey

with orange mottling, soft to firm, moist,

Cu 62/10 kPa



2.5 with orange mottling, soft to firm, moist, 5.5



with orange mottling, soft to firm, moist,

PEAT, black, soft, wet

Fine to coarse sandy rounded GRAVEL, light grey

to blue, dense, moist




Client Date

Prenda Investments Ltd 25/10/2007Project Job Number

Rangiora


Wat

er

Dep

th (

m)

Soi

l Sym

bol FACE 1

Wat

er

Test Descriptions:

Dep

th (

m)

Soi

l Sym


SOIL DESCRIPTION:


COMPONENTS.

SOIL DESCRIPTION:


COMPONENTS.

aaaTP2



Telephone: +64 3 366 0821

Facsimile: +64 3 379 6955

Location




25 50 75 100 125 150


(Blows/ 50mm)

2 4 6 8 10 12

TOPSOIL, dark brown

Clayey fine to coarse SILT, brown to grey with Peat lense

orange mottling, firm to stiff, dry, Cu >140 kPa

Sandy fine to coarse rounded GRAVEL, light grey

0.5 3.5 to blue, loose


Water at the bottom of the test pit draining out of the


CLAY with fine sand, brown, soft to firm, moist

1 4

1.5 4.5

PEAT with timber, black, soft, seepage

CLAY with fine to medium silt, organic material,

grey, soft, moist

PEAT layers mixed with clay material and silt

2 5

Peat lense

2.5 5.5

Peat lense

Peat lense



Test Descriptions:


Wat

er

Dep

th (

m)

Soi

l Sym

bol FACE 1


Rangiora

SOIL DESCRIPTION:


COMPONENTS.

SOIL DESCRIPTION:


COMPONENTS.


Client Date

Wat

er

Dep

th (

m)

Soi

l Sym



aaaTP3



Telephone: +64 3 366 0821

Facsimile: +64 3 379 6955

Location




25 50 75 100 125 150


(Blows/ 50mm)

2 4 6 8 10 12

TOPSOIL, dark brown

Fine to coarse SILT, brown to grey with orange Peat lense

mottling, stiff, dry, Cu 115/25 kPa

0.5 3.5

SILT with some fine sand, brown to red, soft to firm, PEAT, black, soft, moist

moist

Fine to medium SILT with some clay, grey with

orange mottling, firm to stiff, moist

1 4

Fine to coarse rounded GRAVEL with some sand


1.5 4.5

2 5

Silty CLAY, grey, soft, moist, Cu 24/5 kPa

Organic CLAY with timber, dark grey to black, soft,

becoming firm to depth, wet to saturated

2.5 5.5

Peat lense

Peat lense




Client Date


Rangiora


Wat

er

Dep

th (

m)

Soi

l Sym

bol FACE 1

Wat

er

Test Descriptions:

Dep

th (

m)

Soi

l Sym


SOIL DESCRIPTION:


COMPONENTS.

SOIL DESCRIPTION:


COMPONENTS.

aaaTP4



Telephone: +64 3 366 0821

Facsimile: +64 3 379 6955

Location




25 50 75 100 125 150


(Blows/ 50mm)

2 4 6 8 10 12

TOPSOIL, dark brown

Peat lense

Fine to medium sandy SILT, grey to light brown

with orange mottling, firm to stiff, surface moist PEAT with organic material, black, stiff,

moist

0.5 3.5 Organic silty CLAY with peat and timber, grey to

black, soft, moist

Peat lense

SILT with some clay, light grey to blue, firm, moist

1 4

END OF TEST PIT 4.3m

Clayey fine SILT, light grey with orange mottling, Water rising rapidly

firm to stiff, moist

1.5 4.5

2 5

PEAT with timber, black, soft, wet to saturated

2.5 5.5

Organic silty-CLAY, with peat and timber, grey to

black, soft, moist

Peat lense



Test Descriptions:


Wat

er

Dep

th (

m)

Soi

l Sym

bol FACE 1


Rangiora

SOIL DESCRIPTION:


COMPONENTS.

SOIL DESCRIPTION:


COMPONENTS.


Client Date

Wat

er

Dep

th (

m)

Soi

l Sym



aaaTP5



Telephone: +64 3 366 0821

Facsimile: +64 3 379 6955

Location




25 50 75 100 125 150


(Blows/ 50mm)

2 4 6 8 10 12

TOPSOIL, dark brown

Fine sandy SILT, light brown to light grey, stiff, dry

Fine SILT with some clay and some fine sand, light

0.5 brown with orange mottling, soft to firm, moist 3.5

1 4

1.5 4.5

2 5

Clayey SILT, light grey with orange mottling, soft PEAT, black, soft, moist

to firm, moist


PEAT, dark brown, firm, moist to wet

2.5 5.5

Clayey SILT, grey, firm, moist, Cu 50/12 kPa




Client Date


Rangiora


Wat

er

Dep

th (

m)

Soi

l Sym

bol FACE 1

Wat

er

Test Descriptions:

Dep

th (

m)

Soi

l Sym


SOIL DESCRIPTION:


COMPONENTS.

SOIL DESCRIPTION:


COMPONENTS.

aaaTP6



Telephone: +64 3 366 0821

Facsimile: +64 3 379 6955

Location




25 50 75 100 125 150


(Blows/ 50mm)

2 4 6 8 10 12

TOPSOIL, dark brown

Fine sandy SILT, brown with grey and orange

mottling, firm to stiff, dry, becoming moist with depth

0.5 3.5

Fine sandy SILT, grey, firm, moist

1 4

SILT with some sand and some clay, grey, soft to

1.5 4.5 firm, moist


2 5

Fine to medium sandy SILT, grey, soft, moist

2.5 5.5

Fine to coarse SAND with some silt, grey, loose,

moist



Test Descriptions:


Wat

er

Dep

th (

m)

Soi

l Sym

bol FACE 1


Rangiora

SOIL DESCRIPTION:


COMPONENTS.

SOIL DESCRIPTION:


COMPONENTS.


Client Date

Wat

er

Dep

th (

m)

Soi

l Sym



aaaTP7



Telephone: +64 3 366 0821

Facsimile: +64 3 379 6955

Location




25 50 75 100 125 150


(Blows/ 50mm)

2 4 6 8 10 12

TOPSOIL, dark brown Fine to medium SAND with some silt, light grey,

dense

Silty fine to medium SAND, light brown to grey with

orange mottling, loose

0.5 3.5


1 4

1.5 4.5

Fine to medium SAND with silt, light brown with

grey mottling, soft, moist

2 5

2.5 5.5

Fine to medium sandy SILT, grey, soft, moist




Client Date


Rangiora


Wat

er

Dep

th (

m)

Soi

l Sym

bol FACE 1

Wat

er

Test Descriptions:

Dep

th (

m)

Soi

l Sym


SOIL DESCRIPTION:


COMPONENTS.

SOIL DESCRIPTION:


COMPONENTS.

aaaTP8



Telephone: +64 3 366 0821

Facsimile: +64 3 379 6955


Project 223094 | File 223094 Geotech Report Rev1 Second Issue.docx 20 December 2011 | Revision 1 Aurecon Page iii

Appendix E ECan Borehole Logs


Project 223094 | File 223094 Geotech Report Rev1 Second Issue.docx 20 December 2011 | Revision 1 Aurecon Page iv

Appendix F LiquefyPro Settlements

Job Northbrook Sub Division

Job No. 223094

Client VB Properties 2008 Limited

Date 21-Nov-11

LIQUEFACTION ASSESSMENT RESULTS

SLS 1170 EQ M = 7.5 PGA = 0.20g

ULS 1170 EQ M = 7.5 PGA = 0.34g

CALCULATED SETTLEMENT in mm (Tokimatsu and Seed)

1 0 0

2 0 0

3 0 0

4 0 0

5 0 0

6 0 0

7 0 5

8 0 0

9 0 10

10 0 0

11 0 0

12 0 5

13 0 0

14 0 0

15 0 0

16 0 15

Min 0 0

Ave 0 2

Max 0 15

Over 50mm Settlement



SLS 1170 EQ

Settlement (mm)

ULS 1170 EQ

Settlement (mm)Test / CPT

223094 Settlements Liquefy pro.xls

1 2.4 0.0 N

2 3.0 0.0 N

3 3.9 0.3 N

4 3.7 0.2 N

5 2.5 0.0 N

6 >5.5 0.0 N

7 4.4 0.2 N

8 >5 0.0 N

9 2.3 0.2 N

10 5.7 0.1 N

11 >6.5 0.0 N

12 3.7 0.1 N

13 >8 0.0 N

14 >5 0.0 N

15 >6.5 0.0 N

16 3.6 0.5 N

1 2.4 0.1 N

2 >3 0.0 N

3 3.9 0.3 N

4 3.7 0.2 N

5 >3.2 0.0 N

6 >5.5 0.0 N

7 4.3 0.2 N

8 >5 0.0 N

9 2.3 0.2 N

10 5.5 0.1 N

11 >6.5 0.0 N

12 3.7 0.9 N

13 4.1 0.1 N

14 >5 0.0 N

15 4.0 0.1 N

16 3.5 0.6 N

Damaging Surface

Expression

Thickness of Upper

Liquefiable Layer (m)

Crust Thickness

(m)

Damaging Surface

Expression

Crust Thickness

(m)

Thickness of Upper

Liquefiable Layer (m)Test / CPT

Test / CPT

SLS 1170 EQ

ULS 1170 EQ


1 N N

2 N N

3 N N

4 N N

5 N N

6 N N

7 N N

8 N N

9 N N

10 N N

11 N N

12 N N

13 N N

14 N N

15 N N

16 N N

Test / CPTSLS 1170 EQ Settlement (mm)ULS 1170 EQ Settlement (mm)

1 0 0

2 0 0

3 0 1

4 0 2

5 0 0

6 0 0

7 2 3

8 0 0

9 1 8

10 0 1

11 0 1

12 0 7

13 0 1

14 0 1

15 0 1

16 2 16

Min 0 0

Ave 0 3

Max 2 16

Damaging Surface Expression

ULS 1170 EQSLS 1170 EQTest / CPT



Project 223094 | File 223094 Geotech Report Rev1 Second Issue.docx 20 December 2011 | Revision 1 Aurecon Page v

Appendix G LiquefyPro Results

Liq

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Pro

C

ivilT

ech S

oft

ware

U

SA

ww

w.c

ivilt

ech.c

om

CivilTech Corporation

LIQUEFACTION ANALYSISNorthbrook Sub-division

SLS Event Plate A-1

Hole No.=CPT1 Water Depth=2.3 m Magnitude=7.5

Acceleration=0.2g

(m)0

1

2

3

4

5

Silty-CLAY

PEAT

Silty-CLAY

Silty-SAND

SAND

Shear Stress Ratio

CRR CSR fs1Shaded Zone has Liquefaction Potential

0 0.5Soil DescriptionFactor of Safety

0 51Settlement

SaturatedUnsaturat.

S = 0.00 cm

0 (cm) 1

fs1=1.00

Liq

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Pro

C

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ech S

oft

ware

U

SA

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ivilt

ech.c

om


LIQUEFACTION ANALYSISNorthbroook Sub-division

SLS Event Plate A-1


Acceleration=0.2g

(m)0

1

2

3

4

5

Silty-CLAY

SANDSilty-CLAY

PEAT

Silty-CLAY

Silty-SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.00 cm

0 (cm) 1

fs1=1.00

Liq

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Pro

C

ivilT

ech S

oft

ware

U

SA

ww

w.c

ivilt

ech.c

om



SLS Event Plate A-1


Acceleration=0.2g

(m)0

1

2

3

4

5

6

7

8

9

10

Silty-CLAY

PEAT

Silty-CLAY

PEAT

Silty-CLAY

Silty-SAND

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.00 cm

0 (cm) 1

fs1=1.00

Liq

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Pro

C

ivilT

ech S

oft

ware

U

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ww

w.c

ivilt

ech.c

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SLS Event Plate A-1


Acceleration=0.2g

(m)0

1

2

3

4

5

Silty-CLAY

PEAT

Silty-CLAY

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.01 cm

0 (cm) 1

fs1=1.00

Liq

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Pro

C

ivilT

ech S

oft

ware

U

SA

ww

w.c

ivilt

ech.c

om



SLS Event Plate A-1


Acceleration=0.2g

(m)0

1

2

3

4

5

SILT

Silty-CLAY

PEAT

Silty-CLAY

SILT

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.01 cm

0 (cm) 1

fs1=1.00

Liq

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Pro

C

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oft

ware

U

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ivilt

ech.c

om



SLS Event Plate A-1


Acceleration=0.2g

(m)0

1

2

3

4

5

6

7

8

9

10

SILT

Silty-CLAY

PEAT

Silty-CLAY

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.01 cm

0 (cm) 1

fs1=1.00

Liq

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Pro

C

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oft

ware

U

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ivilt

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SLS Event Plate A-1


Acceleration=0.2g

(m)0

1

2

3

4

5

6

7

8

9

10

SILT

Silty-CLAY

PEAT

Silty-CLAY

SILT

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.15 cm

0 (cm) 1

fs1=1.00

Liq

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Pro

C

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oft

ware

U

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ivilt

ech.c

om



SLS Event Plate A-1

Hole No.=CPT8 Water Depth=4 m Magnitude=7.5

Acceleration=0.2g

(m)0

1

2

3

4

5

6

7

8

9

10

Silty-CLAY

PEATSilty-CLAY

SILT

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.00 cm

0 (cm) 1

fs1=1.00

Liq

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Pro

C

ivilT

ech S

oft

ware

U

SA

ww

w.c

ivilt

ech.c

om



SLS Event Plate A-1


Acceleration=0.2g

(m)0

1

2

3

4

5

6

7

8

9

10

Silty-CLAY

PEATSILT

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.11 cm

0 (cm) 1

fs1=1.00

Liq

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Pro

C

ivilT

ech S

oft

ware

U

SA

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w.c

ivilt

ech.c

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SLS Event Plate A-1


Acceleration=0.2g

(m)0

1

2

3

4

5

6

7

8

9

10

Silty-CLAY

PEAT

SILT

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.01 cm

0 (cm) 1

fs1=1.00

Liq

uefy

Pro

C

ivilT

ech S

oft

ware

U

SA

ww

w.c

ivilt

ech.c

om



SLS Event Plate A-1


Acceleration=0.2g

(m)0

1

2

3

4

5

6

7

8

9

10

Silty-CLAY

Silty-SAND

Silty-CLAY

Silty-SAND

Silty-CLAY

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.04 cm

0 (cm) 1

fs1=1.00

Liq

uefy

Pro

C

ivilT

ech S

oft

ware

U

SA

ww

w.c

ivilt

ech.c

om



SLS Event Plate A-1


Acceleration=0.2g

(m)0

1

2

3

4

5

6

7

8

9

10

SILT

PEATSILT

Silty-CLAY

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.04 cm

0 (cm) 1

fs1=1.00

Liq

uefy

Pro

C

ivilT

ech S

oft

ware

U

SA

ww

w.c

ivilt

ech.c

om



SLS Event Plate A-1


Acceleration=0.2g

(m)0

1

2

3

4

5

6

7

8

9

10

SILT

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.02 cm

0 (cm) 1

fs1=1.00

Liq

uefy

Pro

C

ivilT

ech S

oft

ware

U

SA

ww

w.c

ivilt

ech.c

om



SLS Event Plate A-1


Acceleration=0.2g

(m)0

1

2

3

4

5

6

7

8

9

10

SILT

Silty-SAND

Silty-CLAY

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.03 cm

0 (cm) 1

fs1=1.00

Liq

uefy

Pro

C

ivilT

ech S

oft

ware

U

SA

ww

w.c

ivilt

ech.c

om



SLS Event Plate A-1


Acceleration=0.2g

(m)0

1

2

3

4

5

6

7

8

9

10

Silty-CLAY

SILT

Silty-CLAY

SILT

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.03 cm

0 (cm) 1

fs1=1.00

Liq

uefy

Pro

C

ivilT

ech S

oft

ware

U

SA

ww

w.c

ivilt

ech.c

om



SLS Event Plate A-1


Acceleration=0.2g

(m)0

1

2

3

4

5

6

7

8

9

10

Silty-CLAY

Silty-SAND

Silty-CLAY

Silty-SAND

SILT

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.20 cm

0 (cm) 1

fs1=1.00

Liq

uefy

Pro

C

ivilT

ech S

oft

ware

U

SA

ww

w.c

ivilt

ech.c

om



ULS Event Plate A-1


Acceleration=0.34g

(m)0

1

2

3

4

5

Silty-CLAY

PEAT

Silty-CLAY

Silty-SAND

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.03 cm

0 (cm) 1

fs1=1.00

Liq

uefy

Pro

C

ivilT

ech S

oft

ware

U

SA

ww

w.c

ivilt

ech.c

om


LIQUEFACTION ANALYSISNorthbroook Sub-division

ULS Event Plate A-1


Acceleration=0.34g

(m)0

1

2

3

4

5

Silty-CLAY

SANDSilty-CLAY

PEAT

Silty-CLAY

Silty-SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.01 cm

0 (cm) 1

fs1=1.00

Liq

uefy

Pro

C

ivilT

ech S

oft

ware

U

SA

ww

w.c

ivilt

ech.c

om



ULS Event Plate A-1


Acceleration=0.34g

(m)0

1

2

3

4

5

6

7

8

9

10

Silty-CLAY

PEAT

Silty-CLAY

PEAT

Silty-CLAY

Silty-SAND

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.11 cm

0 (cm) 1

fs1=1.00

Liq

uefy

Pro

C

ivilT

ech S

oft

ware

U

SA

ww

w.c

ivilt

ech.c

om



ULS Event Plate A-1


Acceleration=0.34g

(m)0

1

2

3

4

5

Silty-CLAY

PEAT

Silty-CLAY

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.20 cm

0 (cm) 1

fs1=1.00

Liq

uefy

Pro

C

ivilT

ech S

oft

ware

U

SA

ww

w.c

ivilt

ech.c

om



ULS Event Plate A-1


Acceleration=0.34g

(m)0

1

2

3

4

5

SILT

Silty-CLAY

PEAT

Silty-CLAY

SILT

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.02 cm

0 (cm) 1

fs1=1.00

Liq

uefy

Pro

C

ivilT

ech S

oft

ware

U

SA

ww

w.c

ivilt

ech.c

om



ULS Event Plate A-1


Acceleration=0.34g

(m)0

1

2

3

4

5

6

7

8

9

10

SILT

Silty-CLAY

PEAT

Silty-CLAY

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.01 cm

0 (cm) 1

fs1=1.00

Liq

uefy

Pro

C

ivilT

ech S

oft

ware

U

SA

ww

w.c

ivilt

ech.c

om



ULS Event Plate A-1


Acceleration=0.34g

(m)0

1

2

3

4

5

6

7

8

9

10

SILT

Silty-CLAY

PEAT

Silty-CLAY

SILT

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.28 cm

0 (cm) 1

fs1=1.00

Liq

uefy

Pro

C

ivilT

ech S

oft

ware

U

SA

ww

w.c

ivilt

ech.c

om



ULS Event Plate A-1


Acceleration=0.34g

(m)0

1

2

3

4

5

6

7

8

9

10

Silty-CLAY

PEATSilty-CLAY

SILT

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.01 cm

0 (cm) 1

fs1=1.00

Liq

uefy

Pro

C

ivilT

ech S

oft

ware

U

SA

ww

w.c

ivilt

ech.c

om



ULS Event Plate A-1


Acceleration=0.34g

(m)0

1

2

3

4

5

6

7

8

9

10

Silty-CLAY

PEATSILT

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.76 cm

0 (cm) 1

fs1=1.00

Liq

uefy

Pro

C

ivilT

ech S

oft

ware

U

SA

ww

w.c

ivilt

ech.c

om



ULS Event Plate A-1


Acceleration=0.34g

(m)0

1

2

3

4

5

6

7

8

9

10

Silty-CLAY

PEAT

SILT

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.06 cm

0 (cm) 1

fs1=1.00

Liq

uefy

Pro

C

ivilT

ech S

oft

ware

U

SA

ww

w.c

ivilt

ech.c

om



ULS Event Plate A-1


Acceleration=0.34g

(m)0

1

2

3

4

5

6

7

8

9

10

Silty-CLAY

Silty-SAND

Silty-CLAY

Silty-SAND

Silty-CLAY

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.08 cm

0 (cm) 1

fs1=1.00

Liq

uefy

Pro

C

ivilT

ech S

oft

ware

U

SA

ww

w.c

ivilt

ech.c

om



ULS Event Plate A-1


Acceleration=0.34g

(m)0

1

2

3

4

5

6

7

8

9

10

SILT

PEATSILT

Silty-CLAY

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.74 cm

0 (cm) 1

fs1=1.00

Liq

uefy

Pro

C

ivilT

ech S

oft

ware

U

SA

ww

w.c

ivilt

ech.c

om



ULS Event Plate A-1


Acceleration=0.34g

(m)0

1

2

3

4

5

6

7

8

9

10

SILT

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.07 cm

0 (cm) 1

fs1=1.00

Liq

uefy

Pro

C

ivilT

ech S

oft

ware

U

SA

ww

w.c

ivilt

ech.c

om



ULS Event Plate A-1


Acceleration=0.34g

(m)0

1

2

3

4

5

6

7

8

9

10

SILT

Silty-SAND

Silty-CLAY

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.06 cm

0 (cm) 1

fs1=1.00

Liq

uefy

Pro

C

ivilT

ech S

oft

ware

U

SA

ww

w.c

ivilt

ech.c

om



ULS Event Plate A-1


Acceleration=0.34g

(m)0

1

2

3

4

5

6

7

8

9

10

Silty-CLAY

SILT

Silty-CLAY

SILT

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 0.13 cm

0 (cm) 1

fs1=1.00

Liq

uefy

Pro

C

ivilT

ech S

oft

ware

U

SA

ww

w.c

ivilt

ech.c

om



ULS Event Plate A-1


Acceleration=0.34g

(m)0

1

2

3

4

5

6

7

8

9

10

Silty-CLAY

Silty-SAND

Silty-CLAY

Silty-SAND

SILT

SAND

Shear Stress Ratio



0 51Settlement

SaturatedUnsaturat.

S = 1.62 cm

0 (cm) 10

fs1=1.00

Documents

Geotechnical Assessment Report - Foss Shanahan · Geotechnical Assessment Report Project 223094 | File 223094 Geotech Report Rev1 Second Issue.docx 20 December 2011 | Revision 1 Aurecon