Alfred Benesch & Company...I • Jobenesch 14748 West Center Road, Suite 200 U engineers scientists . planners Omaha, NE 68144-2029 • P402-333-5792 I F 402-333-2248 i October 14,

Alfred Benesch & Company

2010-2011/52-80-3897 Glacier Creek Wetlands Restoration

2010-2011 - 2/18/2015

AB056/68 MOD DATE: 02/05/2015

I I I PRELIMINARY GEOTECHNICAL I

ENGINEERING REPORT

I Glacier Creek Stream & Wetland Bank Project

I

Omaha, Nebraska

I I I I I I I

II PREPARED FOR

Papio-Missouri River Natural Resources District 8901 South 154th Street

Omaha, NE 68138

October 14, 2010

PREPARED BY

' benesch NW engineers scentists planners

I •

Jobenesch 14748 West Center Road, Suite 200

U engineers scientists . planners Omaha, NE 68144-2029 • www.benesch.com

P402-333-5792

IF 402-333-2248

i October 14, 2010

I Amanda Grint, P.E.

I Papio-Missouri River Natural Resources District 8901 South 1541h Street Omaha, NE 68138

I REFERENCE: Preliminary Geotechnical Investigation for Glacier Creek Stream and Wetland Bank Project

• Omaha, Nebraska

I Dear Ms. Grint:

I Alfred Benesch & Company (Benesch) is pleased to submit the enclosed report that summarizes the findings of a geotecimical engineering study and provides recommendations related to the referenced project.

I If, any questions arise concerning this report or if additional information is needed about soil conditions at this site, please contact Benesch for assistance.

I Sincerel

AlP

ES PANY

r E-12440/OJ — I i aso 9

JEH\j eh

I Enclosures • 75509104.00

glacierprelim.doc Orig. & 2 pc.: Papio-Missouri River NRD

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GEOTECHNICAL ENGINEERING REPORT

I I

Glacier Creek Stream & Wetland Bank Project

1 Omaha, Nebraska

I I

Prepared I . for


1 Omaha, NE 68138

I October 14, 2010

I I

Prepared I - by

I ALFRED BENESCH & COMPANY 14748 West Center Road, Suite 200

Omaha, NE 68144

I

CONTENTS

Page

I. INTRODUCTION 1

II. SUBSURFACE EXPLORATION 2

III. LABORATORY ANALYSES 4

IV. GEOLOGY AND SITE CONDITIONS 6

V. DISCUSSION AND RECOMMENDATIONS 9

VI. CONCLUSIONS Ii

APPENDIX A. VICINITY MAP, BORING LOCATION PLAN AND SOILS MAP

APPENDIX B. BORING LOGS

APPENDIX C. CRITERIA USED FOR VISUAL CLASSIFICATION

Table C-I. Soil Classification Chart

Table C-2. Criteria for Describing Moisture Condition of Clay Soil

Table C-3. Criteria for Describing Moisture Condition of Granular Soil

Table C-4, Criteria for Describing Consistency of Clay Soil

Table C-5. Criteria for Describing Density of Coarse- Grained Soil

Table C-6. Criteria for Describing Strength of Rock

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I. INTRODUCTION

The Papio-Missouri River Natural Resources District (NRD) in conjunction with the

University of Nebraska-Omaha (UNO) plans to construct a stream and wetland bank in the

vicinity of the confluence of Glacier and Big Papillion Creeks. The proposed 78-acre site is

located on the northwest side of Omaha, Nebraska, northeast of the intersection of 1441hi and

State Streets. The project includes restoring degraded stream channels, and creating additional

stream channels and wetlands.

Alfred Benesch & Company (Benesch) has prepared this preliminary report to present: (a)

the findings of an exploration of the soils at the project site, (b) the results obtained from

laboratory tests, and (c) preliminary recommendations concerning the stream and wetland bank

project.

Field and laboratory work consisted of: (a) performing auger borings to determine the

depth, thickness and composition of each soil formation encountered to the depths of the

borings, (b) installing permanent groundwater monitoring wells, (c) performing a geologic study

to determine the origin of the deposits underlying the site, and (d) performing standard tests to

determine the engineering properties of the soil strata.

Recommendations are provided for preliminary design of stream and wetland features.

Soil properties that affect permeability/infiltration of existing flood plain soil when flooded, and

erosivity and dispersion of newly restored and created streams channels, have been provided.

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II. SUBSURFACE EXPLORATION

A program of test borings and soil sampling was performed at the project site on May 19,

2010. Seven (7) exploratory borings were advanced to depths of 10.0 to 20.0 feet below the

existing grade to establish the general subsurface conditions of the area under consideration.

The Dutch friction-cone sounding was performed with a mechanical penetrometer in

I accordance with ASTM D 3441-98, Standard Method for Deep, Quasi-Static, Cone, and

Friction Cone Penetration Tests of Soil. The mechanical penetrometer operates incrementally,

I using a set of inner rods to operate a telescoping penetrometer tip and to transmit the

I components of penetration resistance (cone bearing and friction sleeve resistance) to the surface

for measurement. The plot of the test data identifies the relative positions and thicknesses of

hard and soft layers. The borings were made either by use of a hand auger or in accordance

with ASTM D 1452-80 (Reapproved 2000), Standard Practice for Soil Investigation and

I Sampling by Auger Borings. The machine-driven borings used a continuous-flight auger

Ihaving a diameter of 6 inches to advance the holes for split-barrel and thin-walled tube

sampling. The bore holes were stable and casing was not required.

Seven (7) relatively undisturbed soil samples were recovered for visual observation and

I laboratory testing. This sampling was performed in accordance with ASTM D 1587, Standard

Method for Thin-Walled Tube Sampling of Soil, utilizing an open-tube sampler having an

I outside diameter of 3.0 inches.

I The vicinity map and the boring location plan are presented in Appendix A. The boring

logs (see Appendix B) present the data obtained in the subsurface exploration. The logs include

the surface elevations, the approximate depths and elevations of major changes in the character

I of the subsurface materials, visual descriptions of the materials in accordance with Appendix C,

groundwater depth, and the locations of undisturbed samples of soil. The locations of the

I soundings and borings were determined by GPS. Relative elevations between the boring

1 -2-

I I

locations were determined by survey. These relative elevations were cross-referenced with

I LiDAR 2.0-foot contour information, to determine the approximate actual elevations (NAVD

I 88)

of the borings. Water level readings were made in the auger borings at times and under

conditions stated on the boring logs,

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III. LABORATORY ANALYSES

The undisturbed soil samples obtained during the subsurface exploration were examined

in the laboratory by a member of Benesch's professional engineering staff to supplement the

field identification. Standard tests were performed on selected samples to determine the

I engineering properties of the subsurface materials.

The moisture contents and dry unit weights of selected undisturbed soil samples were

determined in the laboratory. These test results are presented in the boring logs opposite the

respective sample locations. The moisture contents were determined in accordance with either

ASTM D 4643-00, Standard Test Method for Determination of Water (Moisture) Content of

Soil by the Microwave Oven Method, or ASTM D 2216-98, Standard Test Method for

Determination of Water (Moisture) Content of Soil and Rock by Mass. The dry unit weights

were determined in accordance with the Displacement Method of the Corps of Engineers,

EMI 110-2-1906, Appendix II, Unit Weights, Void Ratio, Porosity, and Degree of Saturation.

These data correlate with the strength and compressibility of the soil. High moisture content

and low density usually indicate low strength and high compressibility.

The unconfined compressive strengths of several undisturbed samples were estimated in

the laboratory with a calibrated hand penetrometer. These strengths are presented on the boring

logs and are estimates only. Actual values are generally lower than the estimated values

indicated on the boring logs.

Seven (7) crumb tests were performed on remolded samples of subsurface materials at

the site. The crumb tests were performed in accordance with ASTM D 6572, Standard Test

Methods for Determining Dispersive Characteristics of Clayey Soils by the Crumb Test. The

crumb test is an indicator test used in the identification of dispersive soils. A summary of the

test results are presented in Table 1.

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TABLE I Dispersion Test Data

B-2 4.5 —5.2 26.0 1 1 1 B-3 3.9-4.4 34.8 1 1 1 B-4 4.4-5.1 26.2 1 1 1 B-5 4.3 - 5.0 20.9 1 1 1 B-6 3.4-4.2 26.0 1 1 1 B-7 5.4-6.1 38.8 1 1 1

aCmmbTest Grades: 1 - Nondispersive; 2 - Intermediate; 3 - Dispersive; 4 - Highly Dispersive

-5-

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IV. GEOLOGY AND SITE CONDITIONS

The project site lies in the Dissected Till Plains section of Nebraska, a part of the Central

Lowland province of the Interior Plains physiographic division'. The project site is located

primarily on alluvial bottomlands adjacent to Glacier and Big Papillion Creeks. Currently, the

majority of the project site consists of cultivated fields.

The subsurface materials encountered at the boring locations are briefly described below

in descending order of occurrence. Detailed descriptions are provided in the boring logs, which

are presented in Appendix C.

Soil Zone Description

Fill Lean clay; medium plasticity; wet; medium stiff to stiff; encountered at borings B-4 and B-5.

Topsoil Lean clay; medium plasticity; wet; medium stiff to stiff; encountered at all borings.

Subsoil Lean clay; medium plasticity; wet; stiff to very stiff; encountered at boring B-4.

Recent Alluvium Lean clay, organic clay, fat clay; medium to high plasticity; wet to saturated; soft to very stiff; encountered. at all borings except B-2 and B-4.

Bignell Alluvium Lean clay; medium plasticity; wet to saturated; stiff to very stiff; encountered at borings B-2 and B-5.

Peoria Alluvium Lean clay, fat clay; medium to high plasticity; saturated; medium stiff to very stiff, encountered at borings B- 1, B- 5, B-6 and B-7.

Peoria Loess Lean clay, silty clay; low to medium plasticity; wet to saturated; soft to very stiff; encountered at borings B-2, B-3 and B-4.

Glacial Till Lean to fat clay; medium to high plasticity; saturated; very stiff, encountered in boring B-2.

Physiographic Provinces of North America, Map by A. K. Lobeck, 1948; The Geographical Press; Columbia University, New York

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Groundwater was encountered at depths of 4.4 to 11.0 feet below grade (elevations of

1069.1 to 1080.0 feet). The water levels at each boring during the subsurface exploration (May

27 and 28, 2010) are shown in Table 2. Additionally, the water levels measured at the three

piezometers on June 27, 2010 is also shown in Table 2. The water table could be expected to

fluctuate several feet depending on surface drainage, rainfall, irrigation, vegetation, temperature

and other factors.

TABLE 2 Summary of Groundwater Levels

May27.&282O1O I . June172O1O

Boring Location Surface

Elevation, ft .. Groundwater Groundwater Groundwater Elevation, ft Depth, ft Elevation (Depth), ft

B-1 1080.5 1075.1 5.4 1078.2 (2.3)

B-2 1086.0 1075.0 11.0 -

B.-3 . 1076.5 1071.7 4.8 -

B-4 1080.5 1071.5 9.0 -

B-5 1090.0 1080.0 10.0 1081.3 (8.7)

B-6 1078.5 1073.7 4.8 . -

B-7 1073.5 1069.1 4.4 1071.5 (2.0)

Various soil properties are available from the Natural Resource Conservation Service

(NRCS) soil survey. A summary of the soil information available for the soil groups in the

vicinity of each boring are shown in Table 3 and map showing the extent of each soil group is

included in Appendix A.

I 1 I I I I [1 I I I I I I I I I F] -7-

I TABLE 3

Summary of NRCS Soil Survey

I Average Range of Average Soil Landform

Parent resence

Saturated Hydric of

Saturated Drainage Hydrologic Depth to Boring

No Map Unit

Material Permeability, Permeabilities, Clasi Soil Group Water

I o Soils

cm/sec cm/sec Table, in

B-I 7234 Kennebec Flood Plains Alluvium Partially 2.8E-04 l.4E-03 to 4.2E-04

Well Drained

C >80

B-2 8153 Contrary Loess Hills Colluvium None 33E-04 l.4E-03to Well

B >80

Moderately

I B-3 7050 Kennebec Flood Plains Alluvium Partially 9.2E-04 I 4E-03 to 4 2E-04

Well Drained

B 54

B-4 7234 Judson Hill Slopes Loess Partially 2.8E-04 4.2E-04 to Well

C > 80 I4E-04 Drained

I - Somewhat B-5 7812 Kenridge Flood Plains Alluvium Partially 2.3E-04

4E0° Poorly C 54

lirainea

Somewhat B-6 7812 Kenridge Flood Plains Alluvium Partially 23E-04

4.2E-04 to 1

l.4E-04 Poorly C 54

Drained

B-7 7050 Kennebee Flood Plains Alluvium Partially 9.2E-04 .4E-03 to

Moderately

1.4E-04 Well B 54

Drained

I I I I I I I I I I

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V. DISCUSSION AND RECOMMENDATIONS

As discussed in the Introduction section of this report, the Papio-Missouri River NRD

and UNO plan to restore stream channels and construct a stream and wetland bank in the

vicinity of the confluence of Glacier and Big Papillion Creeks. The following recommendations

are based upon site conditions, the engineering properties of the subsurface materials and the

requirements of the project.

II. Dispersive Soils. Dispersive soils have the potential to erode along paths of

groundwater flow creating pipes and jugs that can eventually undermine stream banks and

I berms. The laboratory crumb tests indicate the tested soils as being non-dispersive. It is

Benesch's opinion that the natural soils encountered at the project site will likely be non-

I dispersive.

I 2. Soil Erosivity. In order to estimate the approximate erosivity of the onsite soils

that will likely be encountered in the sides of the proposed stream channel, the soil properties

below would predominately prevail, based on soils encountered at borings B-6 and B-7 in the

upper 5 to 10 feet.

. USCS Soil Type = Lean Clay (CL)

I . Plasticity Index = 15 to 20

i. Void Ratio = 1,11

3. Permeability and Infiltration. The hydraulic conductivity (coefficient of

I permeability) for cohesive alluvium that was encountered at the project site can vary greatly

I both laterally and with depth due to interbedded seams of sands and silts that are typically

present in the alluvium. In addition, vertical joints are often present in these soils due to

I desiccation during and after deposition of the soils, which can result in higher hydraulic

conductivities. The permeability of various soil groups, as classified by the Unified Soil

1 -9-

Classification System (see Appendix C), encountered at the project site would generally

decrease in the following order: CL/ML, OL, CL, OH, CH.

Based on the type and variability of soils encountered at the boring locations, it is

Benesch's opinion that groundwater flow would likely not be significantly impeded in any

direction. A stream or pond with a flow line elevation above the groundwater table will lose

water through infiltration. As a result, the depth to the groundwater table will likely

significantly affect the duration of surface water remaining in the stream or pond, if a liner is

not constructed. The hydraulic conductivities provided in Table 3 should be used for

preliminary design. Further monitoring of the water table levels and the permeability testing of

the soils at the project site should be performed in order to more accurately determine the

approximate macro permeability of the soils near the surface.

4. Applicability of Recommendations. The recommendations presented in this

report are based in part upon Beneschls analyses of the data from the soil borings. The boring

logs and related information depict subsurface conditions only at the specific boring locations

and at the time of the subsurface exploration. Soil conditions may differ between the

exploratory borings and might change with the passage of time. The nature and extent of any

variations between the boring locations or of any changes in soil conditions (e.g., drying of soil)

might not become evident until grading operations have begun. If variations and changes in the

soil conditions then appear, it will be necessary to re-evaluate the recommendations stated in

this report.

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I VI. CONCLUSIONS

I. i This report has been prepared n accordance with generally accepted soil engineenng

I practices for exclusive use by the Papio-Missouri River NRD for specific application to the

Glacier Creek stream and wetland bank project. The recommendations of this report are not

I valid for any other purpose.

I . Benesch should be contacted if any questions arise concerning this report or if changes in

I the nature or design of the project are planned. If any such changes are made, the conclusions

and recommendations contained in this report shall not be considered valid unless the changes

are reviewed by Benesch and the conclusions of this report are modified or verified in writing.

This report shall not be reproduced, except in full, without the written approval of Alfred

I Benesch & Company.

Submitted .-Rx,.....-.

ALF *cMPANY

Jaso

I I I I APPENDIX A. VICINITY MAP, BORING LOCATION PLAN AND

SOILS MAP

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It FE Douglas County 2007 Aerial Imagery

V I C I N I T Y M A P

I 4 Glacier Creek

0 1,250 2,500 5,000 Stream & Wetland Bank Concept I LffJs Feet Douglas County, NE U T. 16N, R. liE, S. 24

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Douglas County 2007 Aerial Imagery

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+ 0 300 600 1,200

Feet

S.ILS MAP

cIacie,F cr- ee S,, t r e a ni j & WetIand B a n,k Concept

DOUgJIaS. County, NE T. 16.N, R. liE, . 24:

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PROJECT: Glacier Creek Wetlands 144th & State Streets - Omaha, NE BORING LOG

io benesch LOCATION: -96.140713, 41.348709 BORING No.: B-i

engineers scientists , planners

JOB NO.: 52-80-3897 SHEET 1 012

825 J Street RIG / METHOD: B-53 I Straight Auger DATE: 5-1 9-2010

Lincoln, NE 68508 CREW: GBW & PN 402-479-2200 * Fax: 402-479-2276 www.benesch.com WATER LEVELS X 5.8 lAD Y 5.4 on 5-27-2010

c >0 LITHOLOGY DESCRIPTION

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1080.5 0.0 0.0-

CL - LEAN CLAY; medium plasticity; very dark grayish brown; wet; medium stiff to stiff. (Topsoil)

1079.2 1.3 CL - LEAN CLAY; medium plasticity; very dark grayish brown with very dark gray; wet;

1 stiff to very stiff. (Recent Alluvium) 1078.5 2.0... 1 . 3*

OL - ORGANIC CLAY; medium plasticity; black; wet; stiff; friable. (Recent Alluvium) I 2.5 1077.7 2.8 ______ ______ - JEM OH - ORGANIC CLAY; high plasticity; very dark gray; wet; stiff; with very small shells, 83.8 1 33.75

(Recent Alluvium) 1 1,7*

1 . 5*

1076.0 4.5_ CH - FAT CLAY; high plasticity; very dark gray; saturated; stiff, (Recent Alluvium)

5.0-

1074.0 6.5_ CL - LEAN CLAY; medium plasticity; dark grayish brown slightly mottled with dark

pI yellowish red and very dark gray; saturated; medium stiff to stiff. (Recent Alluvium)

.

1072.5 8.0_ CH - FAT CLAY; high plasticity; very dark gray; saturated; medium stiff. (Recent Alluvium)

1071.5 .0, 9.. OH - ORGANIC CLAY; high plasticity; very dark gray; saturated; very stiff; with very small shells. (Recent Alluvium)

10.0-

1069.0 11.5_ - CL - LEAN CLAY; medium plasticity; very dark gray; saturated; medium stiff. (Recent

10685 120 Alluvium) CH - FAT CLAY; high plasticity; dark gray slightly mottled with white; saturated; very stiff. :1 (Peoria Alluvium) 12.5-

1066.5 14.0_ CL - LEAN CLAY; medium plasticity; dark greenish gray slightly mottled with white; saturated; stiff to very stiff. (Peoria Alluvium)

1065.5 15.01 15.0-

* Unconfined compressive strength was estimated using a calibrated hand penetrometer. Figure B - I a

I I I


Ilia benesch LOCATION: -96.140713,41.348709 BORING No.: B-i engineers . scientists . planners -

SHEET 2 of 2 JOB NO.: 52-80-3897 RIG / METHOD: B-53 / Straight Auger . DATE: 5-19-2010

825 J Street CREW: GBW & PN Lincoln, NE 68508.

WATER LEVELS 1 5.8 lAD 5.4 on 5-27-2010 402-479-2200 Fax: 402-479-2276 www.benesch.com

> LITHOLOGYDESCRIPTION >c:.

s:12. 8 Fz

15.0- CL - Same as above. (Peoria Alluvial Clay) -

•

17.5-

1060.5 20.0_ :1 200- Boring Terminated at: 20.Oft

- 22.5-

- 25.0-

- 27.5-

* Unconfined compressive strength was estimated using a calioratea rsano penetrometer. rigure t5 - I

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I PROJECT: Glacier Creek Wetlands

144th & State Streets - Omaha, NE BORING LOG

benesch LOCATION: -96.13910641.347726 BORING No.: B-2

engineers - scientists , planners

JOB NO.: 52-80-3897 SHEET 1 of 2

RIG I METHOD: 8-53 I Straight Auger DATE: 5-19-2010 825 J Street CREW: GBW & PN Lincoln, NE 68508 402-479-2200 * Fax: 402-479-2276 www.benesch.com WATER LEVELS 19.8 lAD 11.0 on 5-28-2010

Ui

Ui

I

> L LITHOLOGYDESCRIPTION I >-Zcr. - UJc,) w o OUJ 5" OLIJ

1086.0 001

CL - LEAN CLAY; medium plasticity; brown; wet; stiff. (Modern Colluvium)

1085.0 1.0. CL - LEAN CLAY; medium plasticity; black; wet; stiff; friable. (Topsoil)

1084.2 1.8 CL - LEAN CLAY; medium plasticity: very dark grayish brown; wet; stiff.(Bignell Alluvium)

2.5-

1081.5 4.5_ 4 1.9* CL - LEAN CLAY; medium plasticity; very dark brown; wet; stiff. (Bignell Alluvium)

85.7 26.01 50

1080.8 5.2 2 _____

CL - LEAN CLAY; medium plasticity; dark brown slightly mottled with light olive brown; wet; very stiff. (Bignell Alluvium)

2 . 3*

1079.5 6.5_ CL - LEAN CLAY: medium plasticity; olive brown; wet; stiff to very stiff. (Peoria)

1079.0 7.0 CL - LEAN CLAY; medium plasticity; light olive brown slightly mottled with yellowish red; wet; stiff. (Peoria) 7.5-

1073.5 12.5_ 0 /

CL - Same as above except soft to medium stiff. (Peoria)

1071.0 15.O_

-

15.0-

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* Unconfined compressive strength was estimated using a calibrated hand penetrometer. l-lgure b - Za



j benesch LOCATION: -96.139106,41.347726 BORING No.: B-2

engineers Scientists planners

JOB NO.: 52-80-3897 SHEET 2 of 2

825 J Street RIG / METHOD: B-53 I Straight Auger DATE: 5-19-2010

Lincoln, NE 68508 CREW: GBW & PN 402-479-2200 * Fax: 402-479-2276 www.benesch.com WATER LEVELS X 19.8 lAD L 11.0 on 5-28-2010

Lii

Iii

:D

LITHOLOGY DESCRIPTION a. . - uJ . 0 _, Cl) o

15.0-

p CL - Same as above. (Peoria)

1070.0 16.0... I ' CL - LEAN CLAY; medium plasticity; light yellowish brown with yellowish brown mottled I

- with yellowish red; saturated; soft to medium stiff; with silt seams and Silty sand Seams. I - (Peoria) I

1069.0 17.0_ I - CL/CH - LEAN TO FAT CLAY with Sand; medium to high plasticity; gray heavily mottled with grayish brown slightly mottled with yellowish red; saturated; very stiff. (Glacial Till) 17.5-

1066.0 20.0 20.0- Boring Terminated at: 20.Oft

- 22.5-

- 25.0-

- 27.5-

- . . 30.0-

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* Unconfined compressive strength was estimated using a calibrated hand penetrometer. Figure B - 2b


BORING LOG 144th & State Streets - Omaha, NE

ij benesch LOCATION: -96.137490, 41.344730 BORING No.: B-3 engineers scientists . planners

SHEET 1 of 1 JOB NO.: 52-80-3897 RIG! METHOD: B-53 / Straight Auger DATE: 5-19-2010

825 J Street CREW: GBW & PN Lincoln, NE 68508

WATER LEVELS Y 4.5 lAD Y 4.8 on 5-28-2010 402479-2200 * Fax: 402-479-2276 www.benesch.com

> LITHOLOGY DESCRIPTION LU

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Lii

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UJ 0 C/) o LSJ

ooS OLiJ

0.. uJ - -

CL - LEAN CLAY; medium plasticity; very dark grayish brown; wet; medium stiff to stiff. 1076.5 0.0 (Topsoil)

1075.5 1.0 CL - LEAN CLAY; medium plasticity; black s'ightly mottled with dark grayish brown; wet; medium stiff; friable. (Recent Alluvium)

1• 2.5-

•

.

0 . 7*

0 . 8* 79.6 34.83

1072.1 44 0 . 8* CL - Same as above except medium stiff to stiff; saturated. (Recent Alluvium)

0 . 5* 1071.5 5.0: 5.0-

' CL - LEAN CLAY; medium plasticity; very dark gray; saturated; soft to medium stiff. - (Recent Alluvium) -

1070.5 6.0_ - ' CL - LEAN CLAY; medium plasticity; very dark grayish brown with olive brown; saturated;

- soft. (Recent Alluvium)

1069.5 7.0_ 0 - CL - LEAN CLAY; medium plasticity; light olive brown mottled with grayish brown and yellowish red; saturated; medium stiff. (Peoria) 7.5-

1066.5 10.0_ Boring Terminated at: 10.Oft

- . 12.5-

- I -

5 -

•

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- I -

- I

15.0-

* Unconfined compressive strength was estimated using a calibrated nana penesrometer. . rsyuie D -

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I 1 1

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benesch LOCATION: -96.138054, 41 .342782 BORING No.: B-4

engineers . scientists , planners

JOB NO.: 52-80-3897 SHEET 1 of 1

RIG I METHOD: •B-53 I Straight Auger DATE: 5-19-2010 825 J Street CREW. GBW & PN Lincoln, NE 68508

WATER LEVELS Y 14.6 lAD I 9.0 on 5-28-2010 402-479-2200 * Fax: 402-479-2276 www.benesch.com

LITHOLOGY DESCRIPTION U.S

Lu

I

ii. . B 0.0-

ç'ç CL - LEAN CLAY; 0-5% fne sand; medium plasticity; very dark grayish brown; wet; 1080.5 0.0 1080.0 .0.5_ medium stiff. (Fill)

CL - LEAN CLAY; medium plasticity; olive brown with very dark grayish brown; wet; stiff.

- (Fill) 1079.3 1.2

2 CL - LEAN CLAY; medium plasticity; black; wet; stiff; friable. (Topsoil) -

2.5-

1077.7 2.8 CL - LEAN CLAY; medium plasticity; dark grayish brown slightly mottled with dark gray - 1 . 7* and yellowish red; wet; stiff to very stiff. (Subsoil)

1076.8 3.7 2.1 CL - LEAN CLAY; medium plasticity; olive brown mottled with yellowish red slightly - mottled with black; wet; stiff. (Peoria) 4

89.8 26.15

1074.0 6.5. CL - Same as above except medium stiff. (Peoria)

ii

1070.0 10.5_ CL - LEAN CLAY; 0-5% fine gravel; 5-15% fine to coarse sand; medium plasticity; olive

- brown slightly mottled with black and light gray; wet to saturated; soft. (Peoria)

1069.0 11.5_. CL - LEAN CLAY; medium plasticity; light olive brown slightly mottled with yellowish red; - saturated; soft. (Peoria)

10680 12.5 - CUML - SILTY CLAY; low to medium plasticity; light olive brown slightly mottled with . - - yellowish red; saturated; soft. (Peoria)

1065.5 15.0_ ______

150- - rinr, Trrr,inated t. flft

i

I I I I 1 I I I

I I I I I

* Unconfined compressive strength was estimated using a calibratea flano penetrometer. 1-Igure b - 4

Uncontined compressive strength was estimated using a calibrated hand penetrometer. Figure B - 5a

I I

11 I I I 1 I I I I I I I

I


jj benesch LOCATION: -96.13387,41.34095 BORING No.: B-5

engineers , scientists , planners

JOB NO.: 52-80-3897 SHEET 1 of 2

825 J Street RIG / METHOD: B-53 I Straight Auger DATE: 5-19-2010

Lincoln, NE 68508 CREW. GBW & PN 402-479-2200 * Fax: 402-479-2276 www.benesch.com WATER LEVELS 9.8 lAD X 10.0 on 5-27-2010

LITHOLOGY DESCRIPTION

Ui

I

ui . .

1090.0 0.0 0.0-

CL - LEAN CLAY; medium plasticity; very dark grayish brown with brown; wet; stiff. (Fill)

1088.3 1.7 CL - LEAN CLAY; medium plasticity; black; wet; medium stiff to stiff; friable. (Topsoil) - -• 2.5-

1086.5 3.5_ A CL .. LEAN CLAY; medium plasticity; very dark grayish brown; moist to wet; very stiff; moderately porous. (Recent Alluvium)

1085.5 -

4,5... 5*

.. CL - LEAN CLAY; medium plasticity; very dark grayish brown; wet; very stiff. (Recent 5 79.1 20.91

- Alluvium) 4 . 0* 5.0-

4 . 2* 1084.0 6,0.. .

CL - LEAN CLAY; medium plasticity; very dark grayish brown mottled with dark yellowish - red; wet; stiff. (Bignell Alluvium)

- 0 .

1081.0 9.0 - CL - LEAN CLAY; medium plasticity; dark gray mottled with dark yellowish red; saturated;

- stiff. (Bignell Alluvium)

10.0-

1077.5 12.5_ 125- CL - LEAN CLAY; medium plasticity; brown mottled with dark yellowish red; saturated;

-, stiff. (Bignell Alluvium)

1076.5 13.5_ 42 CL - LEAN CLAY; medium plasticity; very dark gray; saturated; stiff. (Peoria Alluvium)

1075.0 150.. 15.0-


BORING LOG 144th & State Streets - Omaha, NE

benesch LOCATION: -96.13387, 41.34095 BORING No.: B-5 engineers Scientists planners

JOB NO.: 52-80-3897 SHEET 2 of 2

RIG / METHOD: B-53 I Straight Auger DATE: 5-19-2010 825 J Street CREW: GBW & PN Lincoln, NE 68508 rWATER LEVELS I 9.8 lAD JL 10.0 on 5-27-2010. 402-479-2200 * Fax: 402-479-2276 www.benesch.com

>3 LITHOLOGYDESCRIPTION

uj

2.

. 8

15.0- CL - LEAN CLAY; medium plasticity; dark greenish gray; saturated; medium stiff. (Peoria

- Alluvium)

-

1070.0 20.0_ 20.0- Boring Terminated at: 15.Oft

- . 22.5-

- 25.0-

. -

- 27.5-

30.0-

* Unconfined compressive strength was estimated using a calibratea hand penetrorneter. -igure b -

I

I I I I

I I

F I

ii I I I I I


io benesch LOCATION: -96.137273,41.339713 BORINGNo.: B-6

engineers. scientists. planners

JOB NO.: 52-80-3897 SHEET 1 of 1

RIG / METHOD: B-53'/ Straight Auger DATE: 5-19-2010 825 J Street CREW: GBW & PN Lincoln, NE 68508 402-479-2200 Fax: 402-479-2276

w.benesch.com WATER LEVELS Y 4.6 lAD Y 4.8 on 5-28-2010

uJ r w D

>0 LITHOLOGYDESCRIPTION z , .. WQ)

0i. UJ.2i cs_ 0 o ..j (0 o-

ujC' 0O

0 uJ5

1078.5 00 •

0.0 CL - LEAN CLAY; medium plasticity; very dark grayish brown; wet; stiff; friable. (Topsoil)

1076.5 20 ON m ORGANIC CLAY; high plasticity; very dark gray with black; wet; stiff. (Recent

- Alluvium) 25- 1 . 3*

6 1075.2 3.3 17* CL - LEAN CLAY; medium plasticity; very dark grayish brown mottled with very dark gray;

26.01

wet; stiff. (Recent Alluvium) 95.3

4 1 . 4*

1074.0 4.5i CL - LEAN CLAY; medium plasticity; dark grayish brown slightly mottled with yellowish

1073.5 5.0= red; saturated; stiff. (Recent Alluvium) 5.0- CL - LEAN CLAY; medium plasticity; very dark grayish brown mottled with dark yellowish

:0

red; saturated; medium stiff. (Recent Alluvium)

1072.0 6.5_ CL - LEAN CLAY; medium plasticity; dark gray; saturated; medium stiff. (Peoria Alluvium)

. 1068.5 10. 10.0- Boring Terminated at: 1 0.Oft

- 12.5-

p -

-

-

15.0-

* Unconfined compressive strength was estimated using a calioratea nana penetrorneter. 1-Igure b - o

I •1 I 1 I I I I I I I I I I I I

I I I

Li PROJECT: Glacier Creek Wetlands


4 benesch LOCATION: -96.135299,41.339648 BORING No.: B-7

engineers scientists planners

JOB NO.: 52-80-3897 SHEET I of 2

RIG I METHOD: B-53 / Straight Auger DATE: 5-19-2010 825 J Street CREW. GBW & PN Lincoln, NE 68508 402-479-2200 * Fax: 402-479-2276 www.benesch.com WATER LEVELS X 4.4 lAD YL 4.4 on 5-27-2010

LITHOLOGYDESCRIPTION u.j

. 8

1073.5 0.0 0.0

CL - LEAN CLAY; medium plasticity; black; wet; stiff. (Topsoil)

1071.5 2.0 - CL LEAN CLAY; medium plasticity; very dark grayish brown with dark gray; wet; stiff to

- very stiff. (Recent Alluvium) 2.5-

1070.5 3.0_ CL - LEAN CLAY; medium plasticity; dark grayish brown; wet; stiff. (Recent Alluvium)

1068.5 5.0_ . 07* 50- CL - LEAN CLAY; medium plasticity; very dark gray heavily mottled with black; saturated; .

1068.0 5.5_ //// medium stiff; very porous. (Recent Alluvium) 0 . 3*

CL - Same as above except soft. (Recent Alluvium) 80.3 38.78

-

7 0.3 k

0.3 k

1066.0 7.5 75 .. CL - LEAN CLAY; medium plasticity; dark gray; saturated; stiff to very stiff. (Peoria

I Alluvium)

1063.5 10.0_ 4 10.0- CL - LEAN CLAY; medium plasticity; dark gray slightly mottled with white; saturated; stiff

-

1• to very stiff; with small lime concretions. (Peoria Alluvium)

-Ø

12.5-

1060.5 130 CH - FAT CLAY; high plasticity; very dark gray with dark gray slightly mottled with white; saturated; very stiff. (Peoria Alluvium)

1059.5 14.0 / CL - LEAN CLAY; medium plasticity; dark gray slightly mottled with white; saturated; stiff;

- with small lime concretions. (Peoria Alluvium)

1058.5 150_ -

I I 1 I I I I I 1 I I I I I I I I

* Unconfined compressive strength was estimated using a calibrated hand penetrorneter. Figure B - 7a

I I I I I I I I I I I I I 1 I I I I I

PROJECT: Glacier Creek Wetlands BORING LOG 144th & State Streets - Omaha, NE

ja benesch LOCATION: -96.135299, 41.339648 BORING No.: B-7 sis

JOB NO.: 52-80-3897 . SHEET 2 of 2

RIG / METHOD: B-53 I Straight Auger DATE: 5-19-2010 825 J Street CREW: GBW & PN Lincoln, NE 68508

WATER LEVELS 1 4.4 lAD 4.4 on 5-27-2010 402-479-2200 * Fax: 402-479-2276 www.benesch.com

LITHOLOGY DESCRIPTION

- E

LU 0::

i

j: . .

15.0- CL - Same as above. (Peoria Alluvium) -

1056.0 17.5. A . 17.5- CL/CH - LEAN TO FAT CLAY; medium to high plasticity; very dark gray; saturated; very

- stiff. (Peoria Alluvium)

1055.0 18.5_ /ñ CL - LEAN CLAY; medium plasticity; dark gray; saturated; soft to medium stiff. (Peoria Alluvium)

1053.5 20.0_ 20.0- Bonng Terminated at: 20.Oft

- 22.5-

- . 25.0-

- 27.5-

- .

-Igure b - o 0

* Unconfined compressive strength was estimated using a calibrated hand penetrorneter.

Li fl

I I LI APPENDIX C.

CRITERIA USED FOR VISUAL SOIL CLASSIFICATION

I I I I I I I I LI I I [I I I

S S 0

Z Co

o

CZ

g. Al

>-- Co 0-0 0•CO S S- u

- 0 - - Al V . 0.

'a - 0

a)

'<

=00

C

• 0. '0 .0

-

A

04-

I- i1> W

0

_ U) 2

0.0 5 ) 0 5 5

& -0

<0 (3 0

U- L 0

0 0 > .- a) > 01 0) 01 0)

C) Ca 0) C 2 ol o > o C) >. C) >. . 0 IE .S2 ElE

b 0 IL Cd) 0 C') 010 U W 010

IL

a) C

'4, CD

213

u A w T1 -j - - ' C

C) VI 0

(.) C 0 O 0 Cl)

VI 0A Ca Ca 0 Al Ca Ca 0

>0 Ca >0 0 VI ..

... VI .- ) 0

0 C - 0 0

0 C

• 0 C . 0 .0

Ca a) Ca a) C Ca 0 ==

0. N- 0 C 0 0 0 0 Al V a) a) Al V a) C a) C . .1 C0 0.

2 o 0 0

C L1

C U-

:3 0 C) U U IL IL JJ

- IL 0.

0 .0. 0

0 0 (1) 0 0 C)

a) C C C

ca 0) 4F C'J LL -

0 a) I- > LO

2 C 0 U)

C cu 0 >

(3 E 2 (3 4

• 2 Ca c a) > Ctø a) C 2 Ca

0 - S o 2 CtO 0 2 0 E .0 C)j Qj W . 0 . 0 C Ca

C) Ca 13

0)

0) a) o C 0 Ct E E .0

Ca z • 0 Ct 0. C 2

2 a) C cu 0 0 0 _.z . E -

0 C ö5 - Ca2 2")

0 .0 E 0

0 IL

E ° o == >•• 0) - '0 0 Cd) Ct 13 Ct 0

C/) >C 0) C 0. CVQQ

C) C C C) 0

z Co C 0 4- .2 a

a)

Ct Mo . (0

-

DO) C0 a)U) CO.- = 0 4-00) '0

o 4-0 0 ., C_I . a) 00')) LCD 0 U.

U-'OZ I

I I

I

El

I

I

I

I

I

I

I

I

I

I

I

I

U

I

I


TABLE C-2 CRITERIA FOR DESCRIBING MOISTURE CONDITION OF CLAY SOIL

Dry Absence of moisture, dusty, dry to the touch.

Moist Damp, slightly wet, moisture content below plastic limit.

Wet Moisture content above the plastic limit.

Saturated - Very wet. Usually soil is below water table.

TABLE C-3 CRITERIA:FOR:DESRiBING:MOISTURECONDiTIONOF:GRMULARS0IL

Dry Absence of moisture, dry to the touch.

Moist Damp but no visible free water.

Wet Visible free water.

Saturated Usually soil is below water table.

TABLE C-4 CRITERIA FOR DESCRIBING CONSISTENCY OF CLAY SOIL

Penetration Resistance, N Density .. ., H. ..H:.:: i1 , ..... : B!Ô .w é1.2iñ.;..H.

Very Soft Less Than 2

Soft . 2-4

Medium 4-8

Stiff 8-15

Very Stiff .15-30

Hard - Greater Than 30

I I I I I I I I I I I I I

• 1 I I I I I

TABLE C-5

TABLE C-6 CRITERIAFOR DESCRIBiNG STRENGTH OF ROCK

:Description. . . .• . . . ..Criteria . . . .

Very soft . Permits denting by moderate pressure of the fingers.

Soft Resists denting by the fingers, but can be abraded and pierced to a shallow depth by a pencil point.

Moderately soft Resists a pencil point, but can be scratched and cut with a knife blade.

Moderately hard Resistant to abrasion or cutting by a knife blade, but can be easily dented or broken by light blows of a hammer.

Hard Can be deformed or broken by repeated moderate hammer blows.

Very hard Can be broken only by heavy, and in some rocks, repeated hammer blows.

Alfred Benesch & Company

2010-2011/52-80-3897 Glacier Creek Wetlands Restoration

20 10-2011 - 2/18/2015

AB056/69 MOD DATE: 02/05/2015

Fln. t

FINAL GEOTECHNICAL ENGINEERING REPORT

Glacier Creek Stream & Wetland Bank Project Omaha, Nebraska

PREPARED FOR


Omaha, NE 68138

November 1, 2010

PREPARED BY

benesch MW engineers scientists planners


• benesch engineers Scientists planners

Alfred Beriesch & Company 14748W. Center Road, Suite 200

Omaha, NE 68144-2029 www.benesch.com

P 402-333-5792 F 402-333-2248

November 1, 2010

Ms. Amanda Grint, P.E. Papio-Missouri River Natural Resources District 8901 South 154th Street Omaha, NE 68138

REFERENCE: Final Geotechni Cal Investigation for Glacier Creek Stream and Wetland Bank Project

Omaha, Nebraska

Dear Ms. Grint:

Alfred Benesch & Company (Benesch) is pleased to submit the enclosed report that summarizes the findings of a geotechnical engineering study and provides recommendations related to the referenced project.

If any questions arise concerning this report or if additional information is needed about soil conditions at this site, please contact Benesch for assistance.

ANY

Enclosure 75509104.00 glacier_flnal.doc Orig. & 2 pc.: Papio-Missouri River NRD

.1 I I I I 1 I I I I I I I I I I I I I

I I I I I I I

I I I I I I I I I I I

GEOTECHNICAL ENGINEERING REPORT

Glacier Creek Stream & Wetland Bank Project Omaha, Nebraska

Prepared for


Omaha, NE 68138

November 1, 2010

Prepared by

ALFRED BENESCH & COMPANY 14748 West Center Road, Suite 200

Omaha, NE 68144

CONTENTS

Page

INTRODUCTION I

SUBSURFACE EXPLORATION 2

GEOLOGY AND SITE CONDITIONS 3

DISCUSSION AND RECOMMENDATIONS 5

CONCLUSIONS 9

APPENDIX A. VICINITY MAP, BORING LOCATION PLANS AND WATER TABLE PROFILES


APPENDIX C. CRITERIA USED FOR VISUAL CLASSIFICATION

Table C-i. Soil Classification Chart

Table C-2. Criteria for Describing Moisture Condition of Clay Soil

Table C-3. Criteria for Describing Moisture Condition of Granular Soil

Table C-4. Criteria for Describing Consistency of Clay Soil

Table C-5. Criteria for Describing Density of Coarse- Grained Soil

Table C-6. Criteria for Describing Strength of Rock

I I I I I I I

.1 I I I I I I I I I I I

Ii I

I. INTRODUCTION

The Papio-Missouri River Natural Resources District (NRD) in conjunction with the

I University of Nebraska-Omaha (UNO) plans to construct a stream and wetland bank in the

vicinity of the confluence of Glacier and Big Papillion Creeks. The proposed 78-acre site is

I located on the northwest side of Omaha, Nebraska, northeast of the intersection of 1441h and

I State Streets. The project includes restoring degraded stream channels, and creating additional

stream channels and wetlands.

Alfred Benesch & Company (Benesch) has prepared this final report to present: (a) the

I findings of a second exploration of the subsurface conditions at the project site and (b) final

recommendations concerning the stream and wetland bank project.

Field consisted of: (a) performing auger borings to determine the groundwater levels and

depth, thickness and composition of each soil formation encountered to the depths of the

borings and (b) performing infiltration tests to approximate potential seepage rates in the

I proposed stream channels.

I Recommendations are provided for design and construction of stream and wetland

features. Groundwater depths and infiltration rates have also been provided.

I I

II] I

I 1

II I

II. SUBSURFACE EXPLORATION

A program of test borings and soil sampling was performed at the project site on October

22 through 26, 2010. Eleven (11) exploratory borings were advanced to depths of 11.0 to 20.0

feet below the existing grade to establish the general subsurface conditions of the area under

I consideration. Previously, seven borings were performed at the project site to determine

I general groundwater depths and soil types, and are presented in Benesch's report dated October

14, 2010. The additional borings performed for this report were performed primarily to further

I delineate the water table profile perpendicular to Big Papillion Creek on the south portion of the

project site and the tributary to Big Papillion Creek on the north portion of the project site. The

I borings were made in accordance with ASTM D 1452, Standard Practice for Soil Investigation

Iand Sampling by Auger Borings. The machine-driven borings used a continuous-flight auger

having a diameter of 6 inches. The bore holes were stable and casing was not required.

The vicinity map and the boring location plans are presented in Appendix A. The boring

logs (see Appendix B) present the data obtained in the subsurface exploration. The logs include

the surface elevations, the approximate depths and elevations of major changes in the character

of the subsurface materials, visual descriptions of the materials in accordance with Appendix C,

groundwater depth, and the locations of undisturbed samples of soil. The locations of the

I borings were determined by GPS. Relative elevations between the boring locations were

I determined by survey. These relative elevations were cross-referenced with LiDAR 2.0-foot

contour information, to determine the approximate actual elevations (NAVD 88) of the borings.

I Water level readings were made in the auger borings at times and under conditions stated on the

boring logs.

I I I 1

I I

HI. GEOLOGY AND SITE CONDITIONS

The project site lies in the Dissected Till Plains section of Nebraska, a part of the Central

I Lowland province of the Interior Plains physiographic division. The project site is located

primarily on alluvial bottomlands adjacent to Glacier and Big Papillion Creeks. Currently, the

I majority of the project site consists of cultivated fields.

1 The subsurface materials encountered at the boring locations generally consisted of lean

clay alluvium and fat clay alluvium on the southern and northern portions of the project site,

I respectively, to the depths of the borings.

I The water levels at each boring during the second subsurface exploration (October 26,

2010) are shown in Table 1. Cross sections showing the water table profile with respect to

I existing and proposed grades, as well as the boring location plans, are shown in Appendix A for

both the northern and southern project areas.

TABLE I

I Summary of Groundwater Levels

Boring Location Surface Elevation, ft Groundwater Groundwater Depth,

I Elevation, ft ft

SB-l00 1073.6 1056.6 17.0

I SB-102

SB-101 1073.5

1072.1

1059.0

1060.8

14.5

11.3

SB - 102A 1073.4 1066.1 7.3

I SB - 103 1074.7 1067.9 6.8

SB-104 1076.8 1070.4 6.4

. SB-105 1088.6 1078.6 10.0 I NB- 300 1079.7 1066.6 13.1

NB-301 1080.0 1066.6 13.4

I NB - 302 1079.5 1072.6 6.9

NB-303 1081.7 1075.1 6.7

Physiographic Provinces of North America, Map by A. K. Lobeck, 1948; The Geographical Press; Columbia

I University, New York .

I --

I I

The infiltration rates were measured at various locations along the proposed new stream

I channel alignments at the proposed flow line elevation. The results of the infiltration rate

I testing are shown in Table 2 and the locations of the tests are shown in Appendix A.

TABLE 2 Infiltration Rate Test Results

Test Location Infiltration Rate, in /day*

I SP-200 . 2.00

SP-201 0.25

I . SP-202 12000

SP-203 1.00

I SP-204 0.35

SP-205 1.10

I NP-400 0.90

NP-401 1.10

I NP-402 . 2.30 *Based on a hydrostatic head of 3.0 feet.

I I I LI I I I I 1• -4-

I I

IV. DISCUSSION AND RECOMMENDATIONS

As discussed in the Introduction section of this report, the Papio-Missouri River NRD

• and UNO plan to restore stream channels and construct a stream and wetland bank in the

vicInity of the confluence of Glacier and Big Papillion Creeks. The following recommendations

are based upon site conditions, the engineering properties of the subsurface materials, and the

requirements of the project.

II. Stream Channel Infiltration. As discussed in Benesch's previous geotechnical

report dated October 14, 2010, the hydraulic conductivity (coefficient of permeability) for

I cohesive alluvium can vary greatly both laterally and with depth due to interbedded seams of

sands and silts that are typically present in the alluvium. As indicated by the infiltration rate

tests, a sand/silt seam (likely present at SP-202) can increase the infiltration rate significantly.

For this reason, Benesch recommends that any sand or silt seams encountered during grading of

I the new stream channels be over-excavated and replaced or capped with at least 2.0 feet of

Icohesive, controlled earth fill conforming to the moisture content and compaction

recommendations presented in Table 3. Controlled earth fill is defined as earth fill that is

I designed, compacted and tested in accordance with generally accepted good practice and placed

Iwith observation by the Geotechnical Engineer.

2. Groundwater Levels. At the south site, the ground water was generally

I encountered at a depth of approximately 6.5 feet during the second exploration (October 26,

I

2010). It should be noted that no precipitation had been recorded in the area since September

25, 2010, such that the water table levels are likely on the low side of normal. During the

I previous exploration (May27 and 28, 2010), the average groundwater depth was approximately

4.5 feet. This exploration was performed before the majority of the spring rains. Readings at

the piezometer installed in this area after the spring rains on June 17, 2010, indicated a

groundwater depth of 2.0 feet. The water table was observed to start dropping significantly

I . I -5

I I

towards the flow line of Big Papillion Creek at about 250 to 300 feet from the centerline of the

creek.

1 At the north site, the groundwater was generally encountered at depths of 7.0 and 13.0

feet on the south and north sides of the tributary to Big Papillion Creek, respectively. The water

table is above the tributary flow liie on the south side and below the flow line on the north side.

I

The lower water table levels on the north side of the tributary are likely due to drawdown from

Big .Papillion Creek. On the south side of the tributary, the groundwater depth was

I approximately 5.5 feet before the spring rains and 2.5 feet after the rains. The zone of influence

for groundwater drawdown by Big Papillion Creek is also approximately 250 to 300 feet from

the creek centerline.

I 3. OSHA Excavation Requirements. Excavations that will be occupied by

personnel should be made in accordance with the Occupational Safety and Health

I Administration (OSHA) Constnction Standards-29 CFR Part 1926, Subpart P-Excavations as

I published in the Federal Register, Vol. 54, 209, Tuesday, October 31, 1989, Rules and

Regulations. The cohesive materials that Benesch anticipates will be exposed during

excavating operations are classified as Type B soils (maximum allowable slope of 1 .0[H]

I .0[V]). OSHA states that a soil should be reclasified if the properties, factors, or conditions

I affecting the soiPs classification change in any way. Sheet piling and/or shoring will be

necessary if the sides of the excavations cannot be sloped to meet OSHA regulations.

4. Grading Recommendations. In areas to receive fill, all vegetation and the

I upper 0.5 feet of existing soils should be removed from the area to be filled. In areas that are

1 required to retain water, all sandy/silty soils encountered during grading operations should be

removed and replaced or capped with at least 2.0 feet of cohesive controlled earth fill

I conforming to the moisture content and compaction recommendations presented in Table 3.

The proposed cut depths for this project will likely extend into soft to medium:stiff saturated

I 1 -6-

I I

lean clays. These soils might become disturbed by repeated passes of construction equipment

during excavating operations if groundwater conditions at the time of grading are the same as at

the time of the subsurface exploration. If possible, excavation operations should take place

during a dry period, such as July or August. To prev.ent excessive disturbance, the final one to

two feet of materials in the proposed cuts might need to be removed with track-type equipment

and possibly a backhoe instead of rubber-tire equipment. The Geotechnical Engineer should

observe the areas to be graded to verif' that all unsuitable soils have been removed and

replaced. In areas to be filled, upon approval of the site by the Geotecimical Engineer, any

exposed ground surface that has not been previously reworked should be scarified to a

minimum depth of 6 inches and reworked to conform to the moisture content and compaction

recommendations presented in Table 3. Areas to be filled should then be raised to the desired

elevation with controlled earth fill.

Types of Soils to be used as Fill and Backfill. Controlled earth fill placed

at the project site should be constructed of inorganic CL 2 or CH 3 materials. The Peoria and

cohesive alluvium soils encountered at the project site are considered suitable for use as fill. It

should be noted, however,, that some of the subsurface materials are high in moisture content

and might require manipulation (drying) to achieve the moisture content necessary for proper

compaction. Proposed fill and backfill materials should be subject to approval by the

Geotechnical Engineer. Representative samples of the proposed fill and backfill materials

should be submitted to the Geotechnical Engineer at least three days prior to placement so the

necessary laboratory tests can be performed.

Placement of Fill and Backfill. The suggested basis for controlling the

placement of fill and backfill on the site, excluding free-draining granular materials, are the

"optimum moisture content" and "maximum dry density" as determined by ASTM D 698,

2 Lean clay, lean clay with sand and sandy lean clay. Fat clay, fat clay with sand and sandy fat clay..

I

I I I I I I I I I I I 1

I -7-

I I

Procedure A, Standard Test Methods for Laboratory Compaction Characteristics of Soil Using

I Standard Effort (12,409 ft-lbflft 3) (600 kN-m/m3). The recommended acceptable values of

moisture content and degree of compaction are given in Table 3.

TABLE 3

I Compaction Recommendations of Controlled Earth Fill and Backfill

Minimum Soil

I Location Moisture Minimum

Om ntejdC

Within strearnchannels and Leand Fat 1 Optimum 95%

In areas that will not be required to Lean and Fat 2% Below 92% retain water. Clays Optimum

IPercent of Maximum Dry Density (ASTM D 698, Procedure A)

7. Applicability of Recommendations. The recommendations presented in this

report are based in part upon Benesch's analyses of the data from the soil borings and

infiltration tests. The boring logs and related information depict subsurface conditions only at

the specific boring and test locations and at the time of the subsurface exploration. Soil

I

conditions may differ between the exploratory borings and tes.t locations and might change with

the passage of time. The nature and extent of any variations between the boring and test

I locations or of any changes in soil conditions (e.g., drying of soil) might not become evident

until grading operations have begun. If variations and changes in the soil conditions then

I appear, it will be necessary to re-evaluate the recommendations stated in this report.

I I I I I

I I

V. CONCLUSIONS

This report has been prepared in accordance with generally accepted soil engineering

I practices for exclusive use by the Papio-Missouri River NRD for specific application to the

Glacier Creek stream and Wetland bank project. The recommendations of this report are not

I valid for any other purpose. Grading operations might encounter both groundwater which could

Ilead to unstable subgrade conditions, and sand seams that will allow unacceptably high

infiltration rates. Recommendations have been provided to address these situations.

Benesch should be contacted if any questions arise concerning this report or if changes in

the nature or design of the project are planned. If any such changes are made, the conclusions

and recommendations contained in this report shall not be considered valid unless the changes

are reviewed by Benesch and the conclusions of this report are modified or verified in writing.

This report shall not be reproduced, except in full, without the written approval of Alfred

Benesch & Company.

ANY

/

I I I I I I

I I El I I APPENDIX A. VICINITY MAP, BORING LOCATION PLANS AND

WATER TABLE PROFILES

I I I Li [I I I LI I I I Li I I

I: q A Douglas County 2007 Aerial Imagery

w sQ,,,tioI,g

4 0 1250 2500 5,000

Feet

VICt.NiTV MAP

GIaeie.r QreI Stream: , Wetland: B:nk C.Qnpt

UogI;as CMulty,, NE 'V.. 1,6,N:, R . lIE, S. 24.

I C'J - 0 0) co r- (0 '4) C C'l 0 0 0 0

a ('4

D

'4

I __ • • ____ ..-. . ____ 2

NI11Idd9I1I D

HJ4Q MO D

I . . .

I sri H.LdG MO A313 MO

H.Ld]G MO - • : . HOM = AB MO

I -........ .

0 LLJ - 90313O

- I 1 .99 = H.LdC MO - .6L90 = A31 MO .....

• I COI8S - -

2 . .

I.'

I H1dOMD .. . ' s.. - VOLOI=Aa,3MO D ,.

_- : - : D _

I •-

:

___ ..

-

---

On ZZ

wo

___ I! .. .

1 .

-------

I - •N ••• ...

.

I - . -

WW

Mw

--

-I

- - :

- :,98L01.

.

__-_,OOI.=HJ4JOMO A1 MO

- ..

-.----

D

- / E9O - 8S

It

CD

0 0 0 Cl C) 0) N- (0 U) o 0

D 0

• • \

3I3 IlOflhiciYd 018 •

-,

- - ................w = •

- - . .

• :0

z o

,I.c1.=Hld2aMo I - -99901. =A81 MO

OO - 8N

.t'EI= H1d30MO I - ,99901. =Al2 M0 - D

— .ON

- • I... /.. .

•9LOI. = A13

I I ZOC-8N

9=HiUMD ..

-

0 I / 1

0 I --

-

. I

- .L9 = H1d30 MO VSLU=AB13MD

COE-ON .

o 0 0 0 0 0) (0 N- (0 U) Cl 0 0 0 0

w -J

=

rii

I I I I I


ri I

I

I] I I I I I I I

I I I I

I

PROJECT: Glacier Creek Wetlands BORING LOG

jj bene.sch LOCATION: 144th and State Streets BORING No.: NB-300 Omaha, NE engineers. scientists, planners

JOB NO.: 75-50-9104 SHEET lofi

825 J Street RIG / METHOD: Bobcat / Straight Auger DATE: 10-22-2010

Lincoln, NE 68508 CREW: BB & GBW 402-479-2200 * Fax: 402-479-2276 www.benesch.com WATER LEVELS Y 13.1 lAD 1 13.1 on 10-25-2010

> - LITHOLOGYDESCRIPTION 0 I-.--. CL

W.

o . . 0 -J Co c

0.0- 1079.7

001 CL - LEAN CLAY; medium plasticity; very dark gray; moist to wet; stiff. (Topsoil)

1078.9 08 p -

CH - FAT CLAY; high plasticity; very dark gray; wet; stiff. (Alluvium).

2.5-

1075.7 4.0_ CH - FAT CLAY; high plasticity; dark gray slightly mottled with light gray; wet; medium stiff to stiff. (Alluvium)

1073.5 6.2 ML - SILT; low plasticity; gray with light gray; wet; loose. (Alluvium)

1072.3 CL - LEAN CLAY; medium plasticity; gray with dark gray; wet; medium stiff. (Alluvium) 7.5-

1071.7 8 .O_ CH - FAT CLAY; high plasticity; very dark gray: wet; medium stiff to stiff. (Alluvium)

10707 9.0_ / CH - FAT CLAY; same as above except stiff to very stiff. (Alluvium)

1069.2 10.5_ - CH - FAT CLAY; high plasticity; dark gray; wet; stiff to very stiff. (Alluvium)

1067.7 12.0 - CH - FAT CLAY; same as above except saturated. (Alluvium)

2.5-

1064.7 5.0- Boring Terminated at: 15.Oft

- . 7.5-

I C. C

C C (I

0 C C

C C.

I-C. C 'I

S

C

I

•1 I

1

S


benesch LOCATION: 144th and State Streets BORING No.: NB-301 Omaha, NE engIneers scientists , planners

JOB NO.: 75-50-9104 SHEET 1 of 1 RIG / METHOD: Bobcat! Straight Auger DATE: 10-22-2010 825 J Street CREW: BB & GBW Lincoln, NE 68508

402-479-2200 * Fax: 402-479-2276 www.benesch.com WATER LEVELS £ 13.0 lAD T 13.4 on 10-26-2010

• LITHOLOGY DESCRIPTION 0 I

d z UJ 0 0—

•< UJ5

0.0- 1080.0 0.0 CL - LEAN CLAY; medium plasticity; very dark grayish brown; wet; medium stiff. (Fill) 1079.4 0.6 - 1079.1 0.9 .ML - SILT; low plasticity; light gray; wet; very loose. (Fill)

171 CL - LEAN CLAY; medium plasticity; very dark gray with dark grayish brown; wet; stiff. (Fill)

1078.3 CL/CH - LEAN TO FAT CLAY; medium to high plasticity; black; wet; medium stiff to stiff; with a trace of shells

2.5

1076.0 4.0_ CH - FAT CLAY; high plasticity; very dark gray slightly mottled with light gray; wet; medium stiff. (Alluvium)

1073.0 7.0 CL - LEAN CLAY; medium plasticity; gray; wet; medium stiff. (Alluvium)

7.5-

1072.0 81 .0

- CL - LEAN CLAY; medium plasticity: gray; wet; medium stiff; with silt and silty clay seams. (Alluvium)

1070.8 9.2 CH - FAT CLAY; high plasticity: very dark gray; wet; stiff. (Alluvium)

0.01

1068.5 11.5. CH - FAT CLAY; same as above except very stiff. (Alluvium)

2.5-

1067.0 13.0. CH - FAT CLAY; high plasticity; dark gray; saturated; very stiff. (Alluvium)

1065.0 15.0 5.0 Boring Terminated at: 15.0ft

- 7.5-

- .

I I I

11

I I I I I I

Figure B - 2

I Figure B - 3


benesch an State Streets BORING No.: NB-302 LOCATION: 4:h E

engineers. scientists , planners -

JOB NO.: 75-50-9104 SHEET 1 of 1

- RIG / METHOD: Bobcat / Straight Auger 10-22-2010 825 J Street . . - Lincoln, NE 68508 -

WATER LEVELS 9.5 lAD Y .6.9 on 10-25-2010 - 402-479-2200 * Fax: 402-479-2276 www.benesch.com

> - LITHOLOGY DESCRIPTION w -J °-

I

LU

0.0 1079.5 0.01 CL - LEAN CLAY; medium plasticity; very dark grayish brown; moist to wet; stiff. (Alluvium)

1078.3 1,2 4 - ?7' CL - LEAN CLAY; medium plasticity; black; moist; stiff. (Alluvium)

2.5-

1076.5 3.0_ - CH - FAT CLAY; high plasticity; very dark gray; wet; stiff to very stiff; with a trace of shells. (Alluvium)

- 5.0-

1073.5 6.0_ ML - SILT; low plasticity; gray; wet; loose. (Alluvium)

1072.5 7.0 / CL - LEAN CLAY; medium plasticity; dark gray; saturated; medium stiff. (Alluvium)

-/ 7.5-

1071.5 8.0 - CH - FAT CLAY; high plasticity; very dark gray; saturated; stiff. (Alluvium)

0.0-

1068.5 11.0_ CH - FAT CLAY; high plasticity; dark gray; saturated; stiff. (Alluvium)

2.5-

1064.5

i

15.0_ 50- Boring Terminated at: 15.0ft -

- 7.5-

__-- -

I I I I I

I I I 1

I I I I I i

I H 0 0

I

0 C; 0

0

H C) 0 0 C 0

I I I 1 I

I i


i. bene.sch LOCATION: 144th and State Streets BORING No.: NB-303 Omaha, NE engineers scientists. planners

JOB NO.: 75-50-9 104 SHEET 1 of I

RIG! METHOD: Bobcat I Straight Auger DATE: 10-22-2010 825 J Street CREW: BB & GBW Lincoln, NE 68508 402-479-2200 * Fax: 402-479-2276 www.benesch.com WATER LEVELS X 7.0 lAD 6.7 on 10-25-2010

LITHOLOGY DESCRIPTION 0 I

—'z uJ___

Uj a.-- 0 —J

0.0- 1081.7 00 CL - LEAN CLAY; medium plasticity;dark brown; moist; very stiff. (Alluvium)

1080.7 1 0

/ CL - LEAN CLAY; medium plasticity; black; moist to wet; stiff. (Alluvium)

2.5-

1078.2 3.5... Cl-I - FAT CLAY; high plasticity; very dark gray; wet; stiff. (Alluvium)

5.0-

1075.2 6.5 CL - LEAN CLAY; medium plasticity; dark gray with gray; saturated; medium stiff. (Alluvium)

1073.7 8.0_ CL/CH - LEAN TO FAT CLAY; medium to high plasticity; very dark gray: saturated; soft to medium stiff. (Alluvium)

10.0-

1070.7 11.0_i CH - FAT CLAY; high plasticity; very dark gray; saturated; stiff, (Alluvium)

1069.2 12.5_ . CH - FAT CLAY; high plasticity; dark grayish brown with very dark gray; saturated; stiff. (Alluvium)

. .

1066.7 15 Boring Terminated at: 15.Oft

- 17.5-

-

I I

I I I

I

I Figure B - 5


j benesch LOCATION: 144th and State Streets BORING No.: SB-100 Omaha, NE engineers. certists pianner

JOB NO.: 75-50-9104 SHEET 1 of 1

RIG I METHOD: Bobcat / Straight Auger DATE: 10-22-2010 825 J Street Uncoln, NE 68508 CREW: BB & GBW 402-479-2200 * Fax: 402479-2276 www.benesch.com rWATER LEVELS Y 19.7 lAD IL 17.0 on 10-26-2010

d LITHOLOGYDESCRIPTON ui

uJ 0 (0 a,.. -j

0.0 1073.6 0.0 CL - LEAN CLAY; medium plasticity; very dark grayish brown; wet; stiff. (Alluvium)

1072.8 08 CL - LEAN CLAY; medium plasticity; black; wet; stiff. (Alluvium)

1071.1 2.5_ 2.5- CL - LEAN CLAY; medium plasticity; very dark grayish brown; wet; medium stiff. (Alluvium)

0..-

.

. 50

10676 6.0_ /Ø /

CL - LEAN CLAY: same as above except soft. (Alluvium)

7,5-

10.0 .

12.5-

6 13 CL - LEAN CLAY; medium plasticity; bluish gray; wet; medium stiff. (Alluvium)

15.0-

1056.1 17.5_ 0 17.5- CL - LEAN CLAY; medium plasticity; bluish gray; saturated; stiff. (Alluvium)

1053.6 20.0 20.0_ nt 70 flif

F

I I I I

11 F I I I I I

I 1 I

I


benesch LOCATION: 144th and State Streets BORING No.: SB-1•01 Omaha, NE engineers. Scientists , planners

JOB NO.: 75-50-9104 SHEET 1 of 1

RIG! METHOD: Bobcat / Straight Auger DATE: 10-22-2010 825 J Street Lincoln, NE 68508 CREW: BB & GBW

WATER LEVELS T 16.2 lAD L 14.5 on 10-26-2010 402-479-2200 * Fax: 402-479-2276 www.benesch.com

0 >>

I . LITHOLOGYDESCRIPTION

Ui 1 - a- l.——

ui w C-.-

o -J cO

<We oit_

- 0.0 1073.5 0,0 CL - LEAN CLAY; 0-5% fine sand; medium plasticity; very dark grayish brown; moist to wet; very stiff. (Alluvium)

1072.5 1.0_v CL - LEAN CLAY; medium plasticity; very dark grayish brown; wet; stiff. (Alluvium)

2.5-

1070.0 3,5_ CL - LEAN CLAY; same as above except medium stiff to stiff. (Alluvium)

1067.0 6.5_

CL

- LEAN CLAY; medium plasticity; very dark grayish brown; wet; soft. (Alluvium)

7.5-

1062.5 11.0_ CL - LEAN CLAY; medium plasticity; very dark gray; wet; very soft. (Alluvium) -

1060.5 13.0_ CL - LEAN CLAY; medium plasticity; bluish gray; wet; stiff. (Alluvium) - H

1058.5 15.0 15.0- CL/CH - LEAN TO FAT CLAY; medium to high plasticity; bluish gray; saturated; stiff. (Alluvium)

1056.0 17.5_ 17.5- CL - LEAN CLAY; medium plasticity; bluish gray; saturated; medium stiff to stiff. (Alluvium)

1053.5 200 20.0 Tnrr,ir,st*,1 Ui 7fl rift

I I

I I I I I I

I I

Ii I

I l-lgure 13- U

I Figure B - 7


j. bene.sch LOCATION: 144th and State Streets BORING No.: SB-102 Omaha, NE engineers. Scientists. planners

JOB NO.: 75-50-9104 SHEET 1 of 1

825 J Street RIG! METHOD: Bobcat / Straight Auger DATE: 10-22-2010

Lincoln, NE 68508 CREW: BB & GBW 402-479-2200 Fax: 402-479-2276 www.benesch.com WATER LEVELS 13.8 lAD I 11.3 on 10-26-2010

> -. LITHOLOGY DESCRIPTION uj

0 I F—.-.. EL w< z

0 0 . . <

1072.1 00 CL - LEAN CLAY; medium plasticity; very dark grayish brown; wet; medium stiff to stiff. (Alluvium) 0.0-

2.5

1068.6 35 CL - LEAN CLAY; same as above except soft to medium stiff. (Alluvium)

5

1066.1 60_ 0 CL - LEAN CLAY; medium plasticity; very dark gray; wet; medium stiff. (Alluvium)

1065.1 - 7.0 _ CL - LEAN CLAY; medium plasticity; very dark grayish brown; wet; soft. (Alluvium)

/

1063.6 8.5 CL - LEAN CLAY; medium plasticity; very dark grayish brown; wet; soft; with silty clay seams. (Alluvium)

. I 10.0- .

10601 12.0. 0 . CL - LEAN CLAY; medium plasticity; bluish gray; saturated; stiff. (Alluvium)

12.5-

15.0-

1055.1 170_ CL - LEAN CLAY; same as above except medium stiff. (Alluvium)

17.5-

1052.1 20.0 - . Trinntd nt 7fl flif . 20.0

I

[1 []

I I I I I I I I

I Li I 1

I I

I I

I I

LI I I

I I I I


' benesch LOCATION: 144th and State Streets BORING No.: SB-102A Omaha, NE engineers scientists planners

JOB NO.: 75-50-9104 SHEET 1 of I

RIG / METHOD: Bobcat / Straight Auger DATE: 10-25-2010 825 J Street CREW: BB & GBW Lincoln, NE 68508

WATER LEVELS Y 7.3 lAD Y 7.3 on 10-26-2010 402-479-2200 * Fax: 402-479-2276 www.benesch.com

0 > > LITHOLOGYDESCRIPTION LU

Q F-.--

c < o

Lu .

0.0- 1073.4

- 0.0 ' CL - LEAN CLAY; medium plasticity; very dark grayish brown with very dark gray; moist to wet; very stiff.

(Alluvium) 1072,5 0.9_ 0 CL - LEAN CLAY; medium plasticity; very dark grayish brown; wet; stiff. (Alluvium)

H2.5-

:

1068.4 5.0 0 5.0- CL - LEAN CLAY; medium plasticity; very dark gray with dark gray; wet; soft to medium stiff. (Alluvium)

1065.4 S.0.. CL - LEAN CLAY; medium plasticity; very dark gray; saturated; soft to medium stiff. (Alluvium)

1063.4 10.0_ 0.0-

- CL - LEAN CLAY; same as above except very soft. (Alluvium)

1062.4 11.0_ CH - FAT CLAY; high plasticity; very dark gray; saturated; stiff. (Alluvium)

2.5-

1060.4 13.0_ 0 CL - LEAN CLAY; medium plasticity; bluish gray; saturated; medium stiff. (Alluvium)

5.0-

1055.9 17.5_ 7.5 -. CH - FAT CLAY; high plasticity; bluish gray; saturated; stiff. (Alluvium)

10534 20.O 0.0 Rrwir,n Trrrir*f*rl of' gn rtff - -

hgure 13 -

I t-igure Ii -


j'• benesch LOCATION: 144th and State Streets BORING No.: SB-103 Omaha, NE enySneers sientists pianners

JOB NO.: 75-50-9104 SHEET 1 of 1

RIG! METHOD: Bobcat / Straight Auger DATE: 10-22-2010 825 J Street Lincoln, NE 68508 CREW: BB & GBW

WATER LEVELS Y 9.5 lAD Y 6.6 on 10-25-2010 402-479-2200 * Fax: 402-479-2276 www.benesch.com

>> I— LITHOLOGYDESCRIPTION Lu

I—.--..

LU< . < WQ)

O-

- 0 1074.7 0.01 CUCH - LEAN TO FAT CLAY; medium to high plastici; black; wet; very stiff

1073.7 1.0 CL - LEAN CLAY; medium plasticity; dark gray with gray slightly mottled with dark yellowish red; wet; stiff

1070.2 4.5 d CL - LEAN CLAY; medium plasticity: dark gray with gray slightly mottled with dark yellowish red; wet; medium stiff

1068.7 6.0_ CH - FAT CLAY; high plasticity; very dark gray; saturated; stiff

1065.7 9.0. CL/CH -LEAN TO FAT CLAY; medium to high plasticity; dark greenish gray; saturated; medium sti ff

1063.7 11.0 •

• -. Boring Terminated at: 11 Oft

— 12.5-

-

I

. 15.0-

5 - 17.5-

I- -

-

•

I -

S -

- I I - I

-

•

I - -

I I I

I] I I I I

I] I I

. 1 I I I

I Figure B - 10


j benesch LOCATION: 144th and State Streets BORING No.: SB-104 Omaha, NE engineers. scientists. planners

JOB NO.: 75-50-9104 SHEET 1 of 1 RIG / METHOD: Bobcat / Straight Auger DATE: 10-22-2010 825 J Street

Lincoln, NE 68508 CREW: BB & GBW 402479-2200 * Fax: 402-479-2276 www.benesch.com WATER LEVELS Y 9.0 lAD Y 6.4 on 10-25-2010

LITHOLOGY DESCRIPTION 0 F-.-

Lii..... 0- ..J o u a, D.

- 0.0 1076.8 00 CL - LEAN CLAY; medium plasticity; black; wet; stiff. (Alluvium) .

1075.8 1.0

/ CL - LEAN CLAY; medium plasticity; dark gray mottled with dark yellowish red; wet; stiff. (Alluvium)

2.5-

1071.8 5.0_ 5.0- . CL - LEAN CLAY; medium plasticity; dark gray mottled with dark yellowish red; wet; soft to medium stiff. (Alluvium)

1069.8 7.0.. CL - LEAN CLAY; medium plasticity; dark gray mottled with dark yellowish red; saturated; stiff. (Alluvium)

- A 1068.8 8.0.. CH - FAT CLAY; high plasticity; very dark gray; saturated; stiff. (Alluvium)

1067.8 9.0 CL - LEAN CLAY; medium plasticity; dark greenish gray; saturated; stiff. (Alluvium)

10658 11.0 Boring Terminated at: 11 Oft

- . 12.5-

- 15.0-

- 17.5-

-

Li I I I I I

I] I I I I

F I ii I I

Ii I

I I I I I I I 1 I I I I I I I I I I I

C

C' C

C C

C 2 S C a


j• benesch LOCATION: 144th and State Streets BORING No.: SB105 Omaha, NE engineers. Scientists. planners

JOB NO.: 75-50-9104 SHEET I of 1

825 J Street RIG / METHOD: Bobcat / Straight Auger DATE: 10-22-2010

Lincoln, NE 68508 CREW: BB & GBW 402-479-2200 * Fax: 402-479-2276 www.beriesch.com WATER LEVELS 0.0 lAD Y 10.0 on 10-25-2010

LITHOLOGY DESCRIPTION LU

0

ri iZ o.... 0 ..j CO 0-..-

0.0- 1088.6 00 CL - LEAN CLAY; medium plasticity; very dark grayish brown; moist to wet; very stiff. (Subsoil)

1086.6 2.0_ 0 CL - LEAN CLAY; medium plasticity; brown; wet; very stiff. (Peoria) - 2.5-

5.0-

1083.1 5.5_ 0 CL - LEAN CLAY; medium plasticity; olive brown slightly mottled with light gray and yellowish red; wet; medium - stiff. (Peoria)

HI, 1080.1 8.5_

CL - LEAN CLAY; medium plasticity; olive brown slightly mottled withlight gray and yellowish red; wet to -

saturated, soft to medium stiff. (Peoria)

10.0

12.5-

10736 15.0- 15.0 1 Boring Terminated at: 15.Oft

- 17.5-

- .

Figure B - 11

I 1 I I II

I APPENDIXC CRITERIA USED FOR VISUAL SOIL CLASSIFICATION

I I 1 I I I I I I I I I I I

S r C

0

!

- s Z a) N -

a a

O t 0 0 C) 0 >

AI>

5_S _ - - o 0.2

C °.a

o 0 0 U

C5

-C Z0aQ

CO a V

• 0 C) - CO

CO 0

< 0

0 C • 0. 0-.•-' - a. ç CO a .2 - 0 . )50 C

( AIbCOoAIQ._0

.0

U)

Or a d a

r

0-c

!- i - - — 0 C) U> CO

') t

. - - - -

® 8 -

- a.O

O 0 C.o 0 0.

- - -? R - ? ? C.

<C U C

C'

U-- L

- 0. - ) - - -

a a '- OICO = 010 ul U > 0 01 0

-

E lE i .2

' , . - j) E 0 () 0 0- -' 05 010

- u- LU 010

CO z-o

0 0 • J -J -J r I = 0 0 (D Co 0) CC) (1) o 2 0 o 2 0 a

Oco

a) c

= I I > c ci .2• ci 0 0 = V V

L W a) U

c Ui l _

o _ - o =

() ,, 0 U) U) 5 .2

Cl) 0 Al 5

0 - . CO

0 '- CO .

CO . - -

>0 0 C

>Q 0 C

VI _ w 0

.r- CO

.- CO

VI . r 0 U) ) 0

0 U o - -

0 0 -

CO U 22 0 .0 EE C') C')

' C.) CO

C.) 0

w w CO CO

() CO

Z CO

C . = =.2

0 .2

w .2

= .

2 ) 0 0 0 u U- 0 ()

. U-

. CL.

! L 0- 0.

.-

.0 C) C - o 0

0 0 O -

0 0

CO a) 0 0)

a) a) 0 C 0 C =

2 0 CO

a) N o itN

> 5

02 Cfl 5 '

0 E 0

0 E 0

C 5 .2

o 0 .2 0 a) o ° 8 0 0-i Co .2 .2

0) .2

CO -D

CO a) ó o CO

• 2 CO 2 C') Z

0 a)

0. a CO CC

CO 2

2 80 C 0 0 —z

8 2 2

• - • 02

.0 S >.

(1) a)

c COO® COD

05 COD

a. 0 Coin C') o

(fl_i CO

0 0) C

5, d z

0 = 0

CO ..2 C CO a)

' 0 V a)

0) a) CO-- 0

CO S

• LLCi)Z 0

> -C a I

I I I

I El

I

I I I I C'

I I I


TABLE C-2 CRITERIA FOR DESCRIBING MOISTURE CONDITION OF CLAY SOIL

Description.... . . ..Criteria...: ...... . ..•.•....

Dry Absence of moisture, dusty, dry to the touch.

Moist . Damp, slightly wet, moisture content below plastic limit.

Wet Moisture content above the plastic limit.

Saturated Very wet. Usually soil is below water table.

TABLE C-3 CRITERIA FOR DESCRIBING MOISTURE CONDITION OF GRANULAR SOIL

Description . . . Criteria ......... ......... -.

Dry Absence of moisture, dry to the touch.

Moist Damp but no visible free water.


Saturated Usually soil is below water table.

TABLE C-4 CRITERIA FOR DESCRIBING. CONSISTENCY, OF CLAY SOIL, .

Penetration Resistance, N Density . .. . . BlOws per 12 in . -j ...

Very Soft Less Than 2

Soft 2-4

Medium 4-8

Stiff 8-15

Very Stiff 15-30

Hard Greater Than 30

U I I I I I I I I I I I I I I I I I I

TABLE C-5 CRITERIA FOR DESCRIBING DENSITY OF COARSE-GRAINED SOiL

Penetration Resistance, N Density , Blows per 12 in.

Loose LessThanlO

Medium 10-30

Dense 30-50

Very Dense Greater Than 50

TABLE C-6

• Description Criteria

Very soft Permits denting by moderate pressure of the fingers.

Soft Resists denting by the fingers, but can be abraded and pierced to a shallow depth by a pencil point.

Moderately soft Resists a pencil point, but can be scratched and cut with a knife blade.

Moderately hard Resistant to abrasion or cutting by a knife blade, but can be easily dented or broken by light blows of a hammer.


Very hard Can be broken only by heavy, and in some •rocks, repeated hammer blows.

120625.00 120625 Geotech Addendum (jeh-sy).docx

TO: Amanda Grint, P.E.

ADDRESS: Papio-Missouri River Natural Resources District

8901 South 154th Street

Omaha, NE 68138

FROM: Seth Youree, P.E.

SUBJECT: North 144th Street Bridge Foundations Glacier Creek Stream & Wetland Bank Project LOCATION: Between 144th Street and Big Papillion Creek, North of State Street, Omaha, NE

DATE: February 18, 2020

PROJECT OVERVIEW

This report is an addendum to the preliminary geotechnical engineering report dated October 14, 2010 (Project

No. 52-80-3897), and the final geotechnical engineering report dated November 1, 2010. This report provides

subsurface information at, and recommendations for design and construction of, a proposed bridge where North

144th Street crosses Glacier Creek. Approximately 2 feet of fill will be placed for the proposed bridge approach

embankments. The proposed bridge will be supported by spread footings, and its surface will be gravel.

SUBSURFACE EXPLORATION

One (1) Dutch friction-cone sounding and one (1) exploratory boring were performed to depths of 44 feet and 75

feet, respectively, below the existing grade. The vicinity map and the boring location plan are presented in

Appendix A. The penetration diagrams for the Dutch friction-cone soundings and the boring logs are presented

in Appendix B and C, respectively. The locations of the soundings and borings were determined by tape

measurements from the existing drainage drop structure. Elevations (approximate) at the sounding and boring

locations were determined by survey with reference to the top of the drop structure. Benesch survey indicated

that the elevation of this benchmark is 1084.76 feet (NAVD88). Water level readings were made in the auger

borings at times and under conditions stated on the boring logs.

The following ASTM methods were followed:

Dutch friction-cone soundings

ASTM D 3441, Standard Method for Deep, Quasi-Static, Cone, and Friction Cone Penetration Tests of Soil

Soil borings

ASTM D 1452, Standard Practice for Soil Investigation and Sampling by Auger Borings (Mud Rotary methods

were used)

Standard penetration tests

ASTM D 1586, Standard Method for Penetration Test and Split-Barrel Sampling of Soils (CME Automatic Free-

Fall SPT Hammer, efficiency approximately 80%)

Undisturbed soil sampling (Shelby tubes)

ASTM D 1587, Standard Method for Thin-Walled Tube Sampling of Soil

Papio-Missouri River NRD | Bridge Geotech Addendum|2

LABORATORY ANALYSES

The moisture contents and dry unit weights of selected undisturbed soil samples were determined in the

laboratory. These test results are presented in the boring logs opposite the respective sample locations. The

moisture contents were determined in accordance with either ASTM D 4643, Standard Test Method for

Determination of Water (Moisture) Content of Soil by the Microwave Oven Method, or ASTM D 2216, Standard

Test Method for Determination of Water (Moisture) Content of Soil and Rock by Mass. The dry unit weights

were determined in accordance with the Displacement Method of the Corps of Engineers, EM1110-2-1906,

Appendix II, Unit Weights, Void Ratio, Porosity, and Degree of Saturation.

The unconfined compressive strengths of several undisturbed samples were estimated in the laboratory with a

calibrated hand penetrometer. These strengths are presented on the boring logs and are estimates only. Actual

values are generally lower than the estimated values indicated on the boring logs.

The compressibility of undisturbed samples of alluvium were determined in accordance with ASTM D 2435,

Standard Test Method for One-Dimensional Consolidation Properties of Soils, except that time-rate readings were

not obtained. The test reports are presented in Appendix E.

The unconfined compressive strengths of undisturbed samples of alluvium were determined in accordance with

ASTM D 2166, Standard Test Method for Unconfined Compressive Strength of Cohesive Soil. The test reports

are presented in Appendix F.

GEOLOGY AND SITE CONDITIONS

The city of Omaha lies in the Dissected Till Plains section of Nebraska, a part of the Central Lowland province

of the Interior Plains physiographic division1. The site is located in alluvial flood plains.

The subsurface materials encountered at the boring locations are briefly described below in descending order of

occurrence. Detailed descriptions are provided in the boring logs, which are presented in Appendix C.

SOIL ZONE DESCRIPTION Fill Lean clay: 0-5% fine gravel, 5-15% fine to coarse sand, wet,

stiff, encountered to a depth of 6.0 feet below grade.

Alluvium and Outwash Lean clay: 0-10% fine to medium sand, wet to saturated, very

soft to medium stiff; encountered to a depth of 53.5 feet

below grade.

Glacial Till Fat clay: 5-15% fine to coarse sand, wet, stiff to very stiff;

encountered to the depth of the boring (75.0 feet).

Groundwater was encountered at an elevation of 1073.4 feet (16.8 feet below existing grade). The water table

could be expected to fluctuate several feet depending on surface drainage, rainfall, vegetation, temperature and

other factors.

1 Physiographic Provinces of North America, Map by A. K. Lobeck, 1948; The Geographical Press; Columbia University, New York


DISCUSSION AND RECOMMENDATIONS

Four basic requirements for a satisfactory foundation of a structure are as follows:

A. The base of the foundation must be located below the depth to which the soil is subject to frost action

and seasonal volume change caused by alternate wetting and drying.

B. The foundation (including the earth beneath it) must be stable or safe from failure.

C. The foundation must not settle or deflect enough to disfigure or damage the structure.

D. The foundation structure must be properly located with respect to any future influence that could

adversely affect its performance.

The following recommendations for design and construction of the foundation for the proposed bridge are based

upon site conditions, the engineering properties of the subsurface materials, and the requirements of the proposed

structure.

Suitable Subgrade Material

The project site will be filled approximately 2 feet above existing grade. The existing fill soils may be left in the

areas to receive fill if these soils are "wet" and prove stable under a loaded dump truck or similar piece of

equipment. By Benesch’s definition, a "wet" cohesive soil contains sufficient moisture to be rolled into a 1/8-

inch-diameter thread without crumbling. A "moist" cohesive soil would crumble when being rolled to form a

1/8-inch-diameter thread.

At the time of the exploration, the existing fill soils were wet. The existing fill soils has slight volume-change

potential and may swell as its moisture content increases. Since the proposed road surface is gravel, the potential

damage due to swelling soils is minimal.

Suitable Foundation Material

The minimum depth to suitable natural foundation material for column footings is approximately 10 feet below

existing grade (elevation of 1080.2 feet).

Existing Underground Structures

Two existing 48” CMP culverts are currently located within the proposed bridge area. The CMP culverts are

planned to be removed and replaced with the proposed bridge.

Minimum Depth of Footings

The bottoms of all exterior footings should be placed at a minimum depth of 40 inches below finished grade to

provide reasonable protection against frost action and seasonal volume change.

Allowable Bearing Pressure

The allowable net bearing pressure on the natural materials located at a depth of 10 feet below existing grade

(elevation of 1080.2 feet) is 1,500 lbf/ft2. Should the footing excavation extend deeper than 12 feet below existing

grade (elevation of 1078.2 feet), the allowable bearing pressure should be reduced, Benesch should be contacted


to evaluate the allowable bearing pressure of deeper footings. The net bearing pressure is the contact pressure at

the base of the foundation in excess of the pressure at the same level due to the surrounding surcharge. The

surcharge pressure is equal to the total weight of a column of soil that extends from the lowest immediately

adjacent ground surface to the bottom of the foundation divided by the soil column's area.

Settlement

It is understood that the allowable settlement of the structure is 1.0 inches or less. Settlement of the proposed

column footings was calculated to be approximately 0.8 inches.

Preparation of the Bridge Area and Areas to receive fill

All vegetation and the upper 0.5 feet of existing soils should be removed from the areas to receive fill. Thereafter,

the exposed ground located in areas that have been "cut" to the proposed subgrade elevations and areas to be filled

should be proofrolled with a loaded dump truck or similar piece of equipment (in the presence of the Geotechnical

Engineer) to locate unstable materials. Any unstable material should be either removed and replaced with

controlled earth fill or reworked to conform to the moisture content and compaction recommendations presented

in Table 1.

The footing excavations should extend into the suitable natural foundation materials as described in the Allowable

Bearing Pressure section of this report. The Geotechnical Engineer should observe the foundation excavations to

verify that the footings will be seated in suitable natural foundation material.

OSHA Excavation Requirements

Excavations that will be occupied by personnel should be made in accordance with the Occupational Safety and

Health Administration (OSHA) Construction Standards-29 CFR Part 1926, Subpart P-Excavations as published

in the Federal Register, Vol. 54, 209, Tuesday, October 31, 1989, Rules and Regulations. The cohesive materials

that Benesch anticipates will be exposed during excavating operations are classified as Type B soils (maximum

allowable slope of 1.0[H]:1.0[V]). OSHA states that a soil should be reclassified if the properties, factors, or

conditions affecting the soil's classification change in any way. Sheet piling and/or shoring will be necessary if

the sides of the excavations cannot be sloped to meet OSHA regulations.

Stepping and Benching of Existing Slopes

The existing embankment slopes that will receive new fill should be stepped and benched in order to bond the

new fill materials with the existing soils. The base of each step should be cut as nearly horizontal as possible and

the face of each step should be cut no steeper than 0.5[H]:1.0[V]. Slopes flatter than 4.5[H]:1.0[V] need not be

stepped and benched.


Types of Soils to be Used as Fill and Backfill

Controlled earth fill should be constructed of inorganic CL2, ML3, SM4, and/or SC5 materials (all with a liquid

limit less than 50 and a plasticity index less than 30). The existing site fill and alluvial soils encountered at the

project site are considered suitable for use as fill for the subgrade. Some of the alluvial soils are high in moisture

content and would require manipulation (drying) to achieve the moisture content necessary for proper compaction.

Proposed fill and backfill materials should be subject to approval by the Geotechnical Engineer. Representative

samples of the proposed fill and backfill materials should be submitted to the Geotechnical Engineer at least three

days prior to placement so the necessary laboratory tests can be performed.

Placement of Fill and Backfill

The suggested basis for controlling the placement of fill and backfill on the site, excluding free-draining granular

materials, are the "optimum moisture content" and "maximum dry density" as determined by ASTM D 698,

Procedure A, Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort

(12,400 ft-lbf/ft3) (600 kN-m/m3). The recommended acceptable values of moisture content and degree of

compaction are given in Table 1.

TABLE 1 COMPACTION RECOMMENDATIONS FOR CONTROLLED EARTH FILL AND BACKFILL

Location Soil

Type Minimum Moisture

Content

Minimum

Compaction*

From 0.0 to 1.0 foot below subgrade

elevation.

Glacial Till Optimum 100%

Silts and Lean Clays 2% Below Optimum 100%

Silty and Clayey

Sands ** 100%

Greater than 1.0 foot below subgrade

elevation outside the building area.

Glacial Till Optimum 95%

Silts and Lean Clays 2% Below Optimum 95%

Silty and Clayey

Sands ** 95%

*Percent of Maximum Dry Density (ASTM D 698, Procedure A)

**Moisture as necessary to obtain density (near Optimum)

Clean free-draining sand used as backfill should be consolidated by means of a vibratory compactor to at least

55% "relative density", as determined in accordance with ASTM D 4253 (Standard Test Methods for Maximum

Index Density and Unit Weight of Soils Using a Vibratory Table) and D 4254 (Standard Test Methods for

Minimum Index Density and Unit Weight of Soils and Calculations of Relative Density).

2 Lean clay, lean clay with sand and sandy lean clay. 3 Silt, silt with sand and sandy silt. 4 Silty sand. 5 Clayey sand.


Grading Observation

Observation and frequent testing by the Geotechnical Engineering Firm during compaction of fill and backfill are

necessary to verify proper moisture content and degree of compaction. A professional opinion should be obtained

from the Geotechnical Engineer that the site has been properly prepared, that all footings will be seated on suitable

foundation materials, and that all fill, backfill, and subgrade materials conform to the moisture content and

compaction recommendations presented above. If these testing and observation services are not performed, the

allowable bearing pressure stated in the Allowable Bearing Pressure section of this report might be invalid. As

the Geotechnical Engineer for this project, Benesch has interpreted the results of the subsurface exploration and

laboratory tests to arrive at the recommendations presented in this report. Consequently, Benesch is in the best

position to relate actual observed conditions to those assumed for this report and to provide revised

recommendations if differences are found during grading operations and construction of the foundation for the

referenced project.

Applicability of Recommendations

The recommendations presented in this report are based in part upon Benesch’s analyses of the data from the

Dutch friction-cone sounding and soil boring. The penetration diagram, boring log, and related information depict

subsurface conditions only at the specific sounding and boring location and at the time of the subsurface

exploration. Soil conditions might change with the passage of time. The nature and extent of any variations of

any changes in soil conditions (e.g., drying of soil) might not become evident until grading operations and

construction of the foundation for the referenced project have begun. If variations and changes in the soil

conditions then appear, it will be necessary to re-evaluate the recommendations stated in this report.

APPENDIX A. VICINITY MAP AND BORING LOCATION PLAN

5 Project Location

Omaha, NE

UV64

UV133

UV64

Fort

Blondo

Military132Nd

120Th

144Th

156Th

100

Ida

168Th

144Th

100

Military Ida

Standing Bear LakeStanding Bear Lake

G lac i e r C re ek We t l a nd sGlac i e r C re ek We t l a nd s144 th S t . Nor th o f S ta te S t .144 th S t . Nor th o f S ta te S t .

Oma ha , NEOma ha , NEV i c i n i t y M a pV i c i n i t y M a p

F i g u r e BF i g u r e B0 2,500 5,0001,250Feet

/

PU

State Street

144th

Stree

t

B-101

Source: Esri, DigitalGlobe, GeoEye, Earthstar Geographics, CNES/AirbusDS, USDA, USGS, AeroGRID, IGN, and the GIS User Community

G lac i e r C re ek We t l a nd sGlac i e r C re ek We t l a nd s144 th S t . Nor th o f S ta te S t .144 th S t . Nor th o f S ta te S t .

Oma ha , NEOma ha , NEB o r i n g L o c a t i o n P l a nB o r i n g L o c a t i o n P l a n

F i g u r e AF i g u r e A0 200 400100Feet

/

APPENDIX B. DUTCH FRICTION-CONE PENETRATION DIAGRAM

PENETRATION DIAGRAM OF DUTCH FRICTION CONE PENETROMETER

Project Name: Sounding No: S-1.1 Date:

Project Location: Location: B-1 Tested By:

Project Number: Surface Elevation: 1090.2 feet Recorded By:

stiff very stiff hard

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Glaciar Creek - 144th St Bridge

144th and State, Omaha NE

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Cone Bearing (qc), kg/cm2

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APPENDIX C. BORING LOG

0.0

3.5

6.0

6.7

7.7

10.0

14.5

18.5

CL - LEAN CLAY; medium plasticity; brown with very dark brown; wet; stiff. (Fill)

CL - LEAN CLAY; 0-5% fine gravel; 5-15% fine to coarse sand; medium plasticity;brown with very dark brown; wet; stiff. (Fill)

CL - LEAN CLAY; 5-15% fine to coarse sand; medium plasticity; brown with very darkbrown; wet; stiff. (Modern Colluvium)CL - LEAN CLAY; medium plasticity; black with very dark brown; wet; medium stiff tostiff. (Modern Colluvium)

CL - LEAN CLAY; medium plasticity; grayish brown with strong brown and brown; wet;medium stiff. (Alluvium)

CL - LEAN CLAY; medium plasticity; greenish gray with gray; wet to very wet; soft.(Alluvium)

CL - LEAN CLAY; medium plasticity; very dark grayish brown mottled with yellowishred; wet to very wet; soft. (Alluvium)

CL - LEAN CLAY; 0-5% fine to medium sand; medium plasticity; bluish gray; very wetto saturated; medium stiff. (Alluvium)

28.7

31

1090.2

1086.7

1084.2

1083.5

1082.5

1080.2

1075.7

1071.7

444

(8)

233

(6)

112

(3)

111

(2)

1.8*

1.3*0.7*

1.3*

0.4*0.5*

0.5*

0.8

0.4*

78.8

91.0

BORING LOG

SHEET 1 of 4

DATE: 12-2-2019

Figure 1a

825 M Street, Suite 100Lincoln, NE 68508402-479-2200 * Fax: 402-479-2276www.benesch.com

JOB NO.:RIG / METHOD:CREW:

120625.00CME 55 / Hollow-StemSH & O'Malley

WATER LEVELS 16.8 IAD

* Unconfined compressive strength was estimated using a calibrated hand penetrometer.

LOCATION: 20' N of inlet 41.341231 N; 96.139058 W

PROJECT: Glacier Creek Wetland144th St. north of State St.; Omaha, NE

BORING No.: B-101

BO

RIN

G L

OG

BO

RIN

G L

OG

S.G

PJ

HW

S.G

DT

12/

17/

19

DE

PT

H(f

eet) LITHOLOGY DESCRIPTION

DE

PT

H (

feet

)

MO

IST

UR

E(%

)

SA

MP

LE

LOG

ELE

V(N

AV

D88

)

SP

T

qu (

tsf)

DR

YD

EN

SIT

Y(p

cf)

1

T-1

2

3

T-2

4

0.0

2.5

5.0

7.5

10.0

12.5

15.0

17.5

20.0

21.0

24.5

33.0

34.7

CL - LEAN CLAY; 5-10% fine to medium sand; medium plasticity; very dark gray; verywet to saturated; very soft to soft. (Alluvium)

CL - LEAN CLAY; 5-10% fine to medium sand; medium plasticity; very dark gray;saturated; very soft to soft. (Alluvium)



36.3

36.4

1069.2

1065.7

1057.2

1055.5

000

(0)

000

(0)

0.3*0.3*

0.40.4*0.4*

0.3*

0.3*0.4*

0.4*

85.0

83.8

BORING LOG

SHEET 2 of 4

DATE: 12-2-2019

Figure 1b








BORING No.: B-101

BO

RIN

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OG

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RIN

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DT

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19

DE

PT

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DE

PT

H (

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)

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IST

UR

E(%

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SA

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LE

LOG

ELE

V(N

AV

D88

)

SP

T

qu (

tsf)

DR

YD

EN

SIT

Y(p

cf)

T-3

5

T-4

6

20.0

22.5

25.0

27.5

30.0

32.5

35.0

37.5

40.0

43.5

48.5

53.5

58.5

60.0

CL - LEAN CLAY; medium plasticity; dark gray; wet; very soft to soft. (Alluvium)

CL - LEAN CLAY; medium plasticity; dark grayish brown with dark gray; wet; mediumstiff; contains 20% silty fines. (Glacial Outwash)

CH - FAT CLAY with Sand; 15-25% fine to medium sand; high plasticity; very darkgray; wet; medium stiff. (Glacial Till)

CH - FAT CLAY with Sand; 0-5% fine gravel; 15-25% fine to coarse sand; highplasticity; very dark gray; wet; medium stiff. (Glacial Till)

1046.7

1041.7

1036.7

1031.7

1030.2

001

(1)

022

(4)

223

(5)

224

(6)

BORING LOG

SHEET 3 of 4

DATE: 12-2-2019

Figure 1c








BORING No.: B-101

BO

RIN

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DE

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H(f


DE

PT

H (

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)

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IST

UR

E(%

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SA

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LE

LOG

ELE

V(N

AV

D88

)

SP

T

qu (

tsf)

DR

YD

EN

SIT

Y(p

cf)

7

8

9

10

40.0

42.5

45.0

47.5

50.0

52.5

55.0

57.5

60.0

68.5

73.5

75.0

CH - FAT CLAY; 5-15% fine to coarse sand; high plasticity; very dark grayish brown;wet; stiff. (Glacial Till)

CH - FAT CLAY; 5-15% fine to coarse sand; high plasticity; very dark gray slightlymottled with red and white; wet; stiff. (Glacial Till)

CH - FAT CLAY; 5-15% fine to coarse sand; high plasticity; very dark gray slightlymottled with red and white; wet; very stiff. (Glacial Till)

Boring Terminated at: 75.0ft

1021.7

1016.7

1015.2

344

(8)

366

(12)

4710

(17)

BORING LOG

SHEET 4 of 4

DATE: 12-2-2019

Figure 1d








BORING No.: B-101

BO

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V(N

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D88

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SP

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DR

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Y(p

cf)

11

12

13

60.0

62.5

65.0

67.5

70.0

72.5

75.0

77.5

80.0

APPENDIX D. CRITERIA USED FOR SOIL CLASSIFICATION .

GENERAL NOTES

CRITERIA FOR DESCRIBING CLAY SOILS

MOISTURE CONDITION

Description Criteria

Dry Absence of moisture, dusty,

dry to touch.

Moist Damp, slightly wet, moisture

content below plastic limit.

Wet Moisture content above the

plastic limit.

Saturated Very wet. Usually soil is

below the water table.

CONSISTENCY

Description Penetration Resistance, N60 (blows/ft)1

Very Soft Less than 3

Soft 3 to 4

Medium Stiff 5 to 8

Stiff 9 to 16

Very Stiff 16 to 32

Hard Greater than 32

CRITERIA FOR DESCRIBING GRANULAR SOILS

MOISTURE CONDITION


Dry Absence of moisture, dry to

the touch.

Moist Damp but no visible free

water.


Saturated Usually soil is below water

table.

DENSITY

Description Penetration Resistance, N60 (blows/ft)1

Very Loose Less than 5

Loose 5 to 10

Medium Dense 11 to 30

Dense 31 to 50

Very Dense Greater than 50

CRITERIA FOR DESCRIBING ROCK

STRENGTH/HARDNESS


Very Soft Permits denting by moderate pressure of the fingers.

Soft Resists denting by the fingers, but can be abraded and pierced to a shallow depth by a

pencil point.

Moderately Soft Resists a pencil point, but can be scratched and cut with a knife blade.

Moderately Hard Resistant to abrasion or cutting by a knife blade, but can be easily dented or broken by

light blows of a hammer.


Very Hard Can be broken only by heavy, and in some rocks, repeated hammer blows.

1Blow counts shown on the boring logs are those recorded directly in the field and have not been corrected for hammer efficiency.

The boring log blow counts must be corrected to an equivalent hammer efficiency of 60% in order to use the criteria in this table.

ROCK QUALITY DESIGNATION (RQD)

This is a general method by which the quality of the rock at a site is obtained based on the relative amount of

fracturing and alteration.

The Rock Quality Designation (RQD) is based on a modified core recovery procedure that, in turn, is based

indirectly on the number of fractures (except those due directly to drilling operations) and the amount of

softening or alteration in the rock mass as observed in the rock cores from a drill hole. Instead of counting the

fractures, an indirect measure is obtained by summing the total length of core recovered by counting only those

pieces of hard and sound core which are 4 inches or greater in length. The ratio of this modified core recovery

length to the total core run length is known as the RQD.

An example is given below from a core run of 60 inches. For this particular case, the total core recovery is 50

inches yielding a core recovery of 83 percent. On the modified basis, only 38 inches are counted the RQD is

63 percent.

CORE

RECOVERY, in MODIFIED CORE

RECOVERY, in

10 10

2 -

2 -

3 -

4 4

5 5

3 -

4 4

6 6

4 4

2 -

5 5

----- -----

50 38

% Core Recovery = 50/60 = 83%; RQD = 38/60 = 63%

A general description of the rock quality can be made for the RQD value as follows:

RQD DESCRIPTION OF ROCK

QUALITY

0 – 25 Very Poor

25 – 50 Poor

50 – 75 Fair

75 – 90 Good

90 – 100 Excellent

APPENDIX E. CONSOLIDATION TEST REPORTS

Project: Project No.:

Boring No.: Depth: Lab No.:

Type of Specimen: Date:

Remarks: Classification:

Initial Saturation: % Overburden Pressure: ton/ft2

Final Saturation: % Preconsolidation Pressure: ton/ft2

Initial Dry Density: lb/ft3

Compression Index:

Initial Water Content: % Recompression Index:

Liquid Limit: Specific Gravity:

Plastic Limit: Initial Void Ratio:

Plasticity Index: Final Void Ratio:

2.70

0.83

0.61

100.0

0.27

0.018

91.9

29.7

CONSOLIDATION TESTASTM D2435

825 M Street, Suite 100

Lincoln, NE 68508

(402) 479-2200

www.benesch.com

96.4 0.53

1.4

15.2'-15.7'B-1

Glacier Creek

3" Tube

Swell Pressure = 0.13 TSF

120625.00

44643.2

12/12/2019

CL

0.42

0.46

0.50

0.54

0.58

0.62

0.66

0.70

0.74

0.78

0.82

0.86

0.01 0.1 1 10

VO

ID R

ATI

O

Pressure, ton/ft2

2 3 5 20 320.50.030.02 0.2 0.30.05

Y:\Omaha\120600S\00120625.00\Eng_Docs\Goetech\Lab\Cons\

120625-00-Con-B01-155-LN44643.2.xlsm 12/18/20199:48 AM



Type of Specimen: Date:


Initial Saturation: % Overburden Pressure: ton/ft2

Final Saturation: % Preconsolidation Pressure: ton/ft2

Initial Dry Density: lb/ft3

Compression Index:

Initial Water Content: % Recompression Index:

Liquid Limit: Specific Gravity:

Plastic Limit: Initial Void Ratio:

Plasticity Index: Final Void Ratio:

2.70

1.00

0.61

100.0

0.40

0.027

84.1

33.2

CONSOLIDATION TESTASTM D2435


Lincoln, NE 68508

(402) 479-2200

www.benesch.com

89.3 0.97

0.97

34.0'-34.6'B-1

Glacier Creek

3" Tube

Normally Consolidated

120625.00

44645.2

12/13/2019

CL

0.46

0.50

0.54

0.58

0.62

0.66

0.70

0.74

0.78

0.82

0.86

0.90

0.94

0.98

1.02

1.06

0.01 0.1 1 10

VO

ID R

ATI

O

Pressure, ton/ft2

2 3 5 20 320.50.030.02 0.2 0.30.05

C:\Users\syouree\Desktop\

Copy of 120625-00-Con-B01-343-LN44645.2.xlsm 12/18/20199:49 AM

APPENDIX F. UNCONFINED COMPRESSION TEST REPORTS



Type of Specimen: Humidity During Trimming:


Wet Unit Wt (lb/ft3)

Dry Unit Wt (lb/ft3)

Water Content (%)

Saturation (%)

Length/Diameter SKETCH/PHOTO

Average Strain Rate (%/min)

Strain at failure

Unconfined Compressive Strength

lbs/in2

tons/ft2

GRAPH

UNCONFINED COMPRESSION TESTASTM Designation: D2166

Glacier Creek 120625.00

B-1 15.7'-16.3' 44675.0


Lincoln, NE 68508

(402) 479-2200

www.benesch.com

6.0%

11.3

0.8

3" Tube

120.7

95.5

SAMPLE INFORMATION

CL

26.4

94.2

1.87

0.03

0.0

2.0

4.0

6.0

8.0

10.0

12.0

0.0% 2.0% 4.0% 6.0% 8.0%

Stre

ss (

lbs/

in2)

Axial Strain (%)

Y:\Omaha\120600S\00120625.00\Eng_Docs\Goetech\Lab\Unc\120625-00-Unc-B01-160-LN44675.0.xlsx 12/17/2019



Type of Specimen: Humidity During Trimming:


Wet Unit Wt (lb/ft3)

Dry Unit Wt (lb/ft3)

Water Content (%)

Saturation (%)

Length/Diameter SKETCH/PHOTO

Average Strain Rate (%/min)

Strain at failure

Unconfined Compressive Strength

lbs/in2

tons/ft2

GRAPH

6.7%

5.5

0.4

3" Tube

116.4

86.9

SAMPLE INFORMATION

CL

33.9

98.4

1.79

0.058

UNCONFINED COMPRESSION TESTASTM Designation: D2166

Glacier Creek 120625.00

B-1 23.5'-24.0' 44644.2


Lincoln, NE 68508

(402) 479-2200

www.benesch.com

0.0

1.0

2.0

3.0

4.0

5.0

6.0

0.0% 2.0% 4.0% 6.0% 8.0%

Stre

ss (

lbs/

in2)

Axial Strain (%)

Y:\Omaha\120600S\00120625.00\Eng_Docs\Goetech\Lab\Unc\120625-00-Unc-B01-238-LN44644.2.xlsx 12/17/2019

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