Application Reference Number: WWO10001 Tunnel …...Tunnel and Bridge Assessments Central Zone Grosvenor Rail Bridge Doc Ref: 9.15.23 Folder 96 September 2013 DCO-DT-000-ZZZZZ-091500

Tunnel and Bridge AssessmentsCentral ZoneGrosvenor Rail BridgeDoc Ref: 9.15.23

Folder 96 September 2013DCO-DT-000-ZZZZZ-091500

Gro

sven

or R

ail B

ridge

Thames Tideway Tunnel Thames Water Utilities Limited

Application for Development ConsentApplication Reference Number: WWO10001

307-RG-TPI-BR009-000001

Assessment Report Detailed Bridge Assessments Sub-Package 2C Grosvenor Rail Bridge

Printed 11/07/2012

Thames Tunnel

Assessment Report Grosvenor Rail Bridge

List of contents

Page number

1 Introduction ...................................................................................................... 6

1.1 Project Description .................................................................................. 6

1.2 Works at Grosvenor Rail Bridge .............................................................. 6

1.3 Scope of Assessment .............................................................................. 6

1.4 Other Third Party Interface/ Related Assessments .................................. 7

2 Structure Details .............................................................................................. 8

2.1 Description of Structure ........................................................................... 8

2.2 Structure Type ......................................................................................... 9

2.3 Substructure Type ................................................................................... 9

2.4 Foundation Type .................................................................................... 10

2.5 Span arrangements ............................................................................... 10

2.6 Articulation and bearing arrangements .................................................. 10

2.7 Parapet type .......................................................................................... 11

2.8 Details of any special or unusual features of the structure or the site .... 11

2.9 Services and Utilities ............................................................................. 11

2.10 Permanent Way ..................................................................................... 11

3 Inspection and Data Collection ..................................................................... 12

3.1 Inspection Summary .............................................................................. 12

3.2 Reference Data ..................................................................................... 12

3.3 Adequacy of Data and Assumptions ...................................................... 13

4 Geotechnical Assessment............................................................................. 14

4.1 Method of Ground Movement Calculation ............................................. 14

4.2 Ground Conditions ................................................................................. 15

4.3 Ground Movement Results .................................................................... 15

5 Structural Assessment – General ................................................................. 22

5.1 Reference Documents ........................................................................... 22

5.2 Structure Records .................................................................................. 22

5.3 Codes used in the Assessment ............................................................. 22

6 Structural Assessment – Methodology and Results ................................... 23

307-RG-TPI-BR009-000001


Printed 11/07/2012

6.1 Headline Result ..................................................................................... 23

6.2 Assessment of the Superstructure ......................................................... 23

6.3 Assessment of the Substructure ............................................................ 26

7 Utility Assessment ......................................................................................... 29

8 Permanent Way .............................................................................................. 30

8.1 Reference Documents ........................................................................... 30

8.2 Permanent Way Records ...................................................................... 30

8.3 Standards used in the Assessment ....................................................... 30

8.4 Permanent Way Assessment ................................................................ 30

9 Monitoring and Mitigation ............................................................................. 32

9.1 Route-Wide Monitoring .......................................................................... 32

9.2 Asset-Specific Monitoring and Mitigation ............................................... 32

10 Conclusions and Recommendations ........................................................... 33

11 Further Work Required .................................................................................. 34

Appendix A – Location Plan and Proposed Tunnel Alignment .......................... 35

Appendix B – Settlement Trough .......................................................................... 37

Appendix C – Reference Drawings ....................................................................... 39

Appendix D – Utility Data Sheets .......................................................................... 46

Appendix E – Assessment criteria for Permanent Way ...................................... 47

Appendix F – Certificate of Assessment and Checking (Structural) ................. 50

Appendix G – Certificate of Assessment and Checking (Geotechnical) ........... 51

List of figures

Page number

Figure 1: Plan of Grosvenor Rail Bridge Superstructure ............................................ 8

Figure 2: Bridge and track locations ........................................................................... 8

Figure 3: Grosvenor Rail Bridge .............................................................................. 16

Figure 4: Vertical settlement from river bed level at corners of Pier 2 ..................... 17

Figure 5: Vertical settlement from river bed level at corners of Pier 3 ..................... 17

Figure 6: Pier 2 Horizontal displacement perpendicular to the bridge centreline (Bed Level) ....................................................................................................... 18

Figure 7: Pier 3 Horizontal displacement perpendicular to the bridge centreline (Bed Level) ....................................................................................................... 19

Figure 8: Movement within the superstructure and piers due to the ground movements .............................................................................................. 24

Figure 9: Bending stress in the arch girders due to the ground movements ............ 24

307-RG-TPI-BR009-000001


Printed 11/07/2012

Figure 10: Movement within the superstructure and piers due to the ground movements .............................................................................................. 24

Figure 11: Pier 3 South Elevation – differential vertical settlement during tunnel construction ............................................................................................. 25

Figure 12: Simplified Model showing Bending Moment due to Ground Movement .. 28

List of tables

Table 1: Pier 2 and 3 settlement at the bridge centreline ......................................... 16

Table 2: Maximum tensile strain in the pier during the tunnel construction .............. 18

Table 3: Average maximum horizontal displacement (perpendicular to the bridge centreline) of the pier during the tunnel construction at the pier centreline ................................................................................................................. 19

Table 4: Maximum slope underneath piers 2 and 3 (see text above for explanation) 19

Table 5: Worst case (during and post construction) vertical and horizontal movement at river bed level ...................................................................................... 21

Table 6: Worst case tensile strain along and across pier ......................................... 21

Table 7: Worst case ground slope ............................................................................ 21

Table 8: Tensile strain along and across pier in post construction condition ............ 26

Table 9: Tensile strain along and across pier in transient condition ......................... 26

Table 10: Relationship between category of damage and limiting tensile strain (after Boscardin and Cording, 1989) ................................................................. 27

Table 11: Classification of visible damage to walls with particular reference to ease of repair or plaster and brickwork or masonry (after Burland et al, 1977) .... 27

List of abbreviations

CSO Combined Sewer Overflow

TT Thames Tunnel

PBA Peter Brett Associates

STW Sewage Treatment Works

EPB Earth Pressure Balance

TBM Tunnel Boring Machine

VTB Victoria to Windmill Bridge Junction

VIR Victoria to Ramsgate

307-RG-TPI-BR009-000001


Printed 11/07/2012

1 Introduction

1.1 Project Description

Thames Water is currently progressing with its planned London Thames Tideway Improvements programme. The improvement works consists of construction of two new tunnels, the Thames Tunnel and the Lee Tunnel, together with a programme of Sewage Treatment Works (STW) upgrades.

Construction of the Thames Tunnel (TT), stretching approximately 23km under the River Thames from West London to East London, is due to commence in 2014. The Tunnel will intercept the flow from the most polluting Combined Sewer Overflows (CSO) of the existing system. The planned alignment runs mainly beneath the River Thames at depths of up to 40m below the river bed in order to minimise the potential impact on third party assets.

The main Thames Tunnel is currently planned to be 7.2m internal diameter with a primary and secondary lining giving an effective 8.5m external diameter with an excavated cut diameter of 8.8m. A number of smaller additional tunnels are required to connect the existing CSOs to the main tunnel.

As part of the works, Thames Tunnel Project Team has appointed Peter Brett Associates (PBA) and their sub-consultant Arup, to undertake an assessment of the effects of tunnelling-induced ground movement on Grosvenor River Bridge.

1.2 Works at Grosvenor Rail Bridge

The main Thames Tunnel is to be constructed beneath Grosvenor Rail Bridge span three running east to west, at a depth of 34m below river bed level. The excavated diameter of the tunnel will be 8.8m, internal finished diameter 7.2m.

Refer to the drawing included in Appendix A for a location plan of the bridge and the proposed alignment of the Thames Tunnel.

1.3 Scope of Assessment

The scope is limited to assessing Grosvenor Rail Bridge for the effects of ground movements due to the proposed construction of the Thames Tunnel in accordance with the Approval-in-Principle (Form AA) document no. 307-EA-TPI-BR009-000001-AC.

The assessment has determined the differences in load and serviceability effects due to the tunnelling works and does not represent a full assessment of the capacity of the structure.

Reference should be made to the Form AA, which has been issued separately to this document, for the detailed scope of work and input parameters for the assessment.

307-RG-TPI-BR009-000001


Printed 11/07/2012

1.4 Other Third Party Interface/ Related Assessments

The utilities crossing the bridge have been assessed separately but, where possible, signed non-objection forms from each utility asset owner have been included for information, in the Appendices to this Report.

The river walls are the subject of a separate detailed assessment commissioned by Thames Tunnel.

307-RG-TPI-BR009-000001


Printed 11/07/2012

2 Structure Details

2.1 Description of Structure

Grosvenor Rail Bridge is a four span steel arch girder bridge made up of ten sets of arch girders forming ten individual bridge structures that make up the rail bridge. Each set of arch girders supports a series of spandrel posts between which span longitudinal girders and cross girders which in turn support the deck. The bridge spans the River Thames in London.

For a more detailed description of the form and condition of the structure, including photographs, reference should be made to the Inspection Report 307-RI-TPI-BR009-000001-AC which has been issued previously to Network Rail.

Figure 1: Plan of Grosvenor Rail Bridge Superstructure

Figure 2: Bridge and track locations

2.1.1 Network Rail Structure Identification

Name of Structure: Grosvenor Rail Bridge

Location: Between London Victoria and Battersea Pier Junction, SW London

ELR:

VIR & VTB1

Mileage:

0m 065ch

OS Grid Ref:

TQ 287 778

Structure No:

VIR 5 & VTB1 5

2.1.2 History

Grosvenor Rail Bridge is a railway bridge crossing the River Thames, located between Chelsea Bridge and Vauxhall Bridge and serving Victoria station.

The original bridge designed by Sir John Fowler was built in 1859 of wrought iron and carried two tracks to Victoria Station as part of the Victoria and Pimlico Railway.

Span 1 Span 2 Span 3 Span 4

Pier 1 Pier 2 Pier 3

307-RG-TPI-BR009-000001


Printed 11/07/2012

In 1865 the bridge was widened, designed by Sir Charles Fox and Son, to carry a further five tracks for the London and Chatham Railway. A two platform passenger station, Grosvenor Road Station, was also added in between these additional tracks.

The bridge was further widened in 1901 to carry two tracks of the London, Brighton and South Coast Railway.

The current bridge, built between 1963 and 1967, replaced the original that had deteriorated to a point where the weakened condition was inadequate for the loads it was anticipated to carry and the maintenance costs were too great. Designed by Freeman, Fox & Partners, the current bridge was rebuilt on the same site as the original Victoria Bridge and actually consists of ten separate bridges each carrying a single track.

It was decided that the existing piers and foundations would be utilised in the new design, however they were not large enough to resist the thrust of the new superstructure. To resolve this, the foundations were widened, repaired and the different types of existing foundation were merged into one pier between each span.

The superstructure was then removed and replaced one track at a time to reduce the impact on passenger journeys.

Although the bridge has capacity for 10 tracks it would appear from the QUAIL Diagram (Appendix D) that only 9 are in use (four up / four down / one reversible).

2.2 Structure Type

2.2.1 Main Girders

The welded box arch ribs are 3‟8.5‟‟(1.1m) deep and 2‟(0.6m) wide and have diaphragms at the points of concentrated load i.e. at the location of spandrel members.

The welded box arch ribs support the steel deck which contains the ballasted track.

2.2.2 Ancillary structural members

The deck is considered to be of „battledeck‟ construction with a steel plate supported by longitudinal stringers which are themselves supported by cross beams.

There is no cross-bracing between the vertical spandrel members, or lateral bracing, because the rigidity at the junctions between the deck, the spandrel posts, and the arch ribs creates a portal frame system transversely, thus providing enough lateral stability.

2.3 Substructure Type

2.3.1 Abutments

The original abutments from the earlier Victoria Bridge were considered suitable for the new construction so were simply altered aesthetically in line with the finished piers. The original abutments consist of brickwork and limestone blocks.

307-RG-TPI-BR009-000001


Printed 11/07/2012

As with the piers, the limestone blocks were removed and the abutments were encased in reinforced concrete.

The north abutment was also widened due to the widening of the Grosvenor Road.

2.3.2 Piers

The piers are a combination of brickwork and reinforced concrete from earlier piers on the site encased in reinforced concrete to create a monolithic structure as described in the section below.

2.4 Foundation Type

The foundations consist of the piers from the earlier Victoria Bridge encased in reinforced concrete up to the cofferdam that was used to construct the existing piers.

The piers associated with the original bridge (1859) were brickwork with a limestone block exterior. To accommodate widening in 1865 further brickwork and limestone block foundations were constructed; likewise in 1901 a further section of pier this time of concrete with a granite block exterior was constructed.

The most suitable approach to constructing piers for the new bridge (1967) was to create a monolithic structure by stripping away the existing masonry and encompassing all the historic foundations with reinforced concrete. This resulted in a final pier width of 45‟(13.7m).

The existing foundations were also grouted to reduce the porosity of the older concrete.

2.5 Span arrangements

The arches have a clear span between pier faces of 164‟ (50m). Span 1 and 4 are each 181‟6‟‟ (55.3m) long & spans 2 and 3 are each 187‟4‟‟ (57.1m) long, between pier centrelines.

The bridge deck has a width of 167‟7.5‟‟ (50.1m) at parapet level and a width of 163‟7.5‟‟ (49.9m) at both arch crown and pier level.

2.6 Articulation and bearing arrangements

2.6.1 Arch Springings

The arch ribs are connected to the springing point on the reinforced concrete pier via the thick end plate on the rib and a pin bearing consisting of Meehanite cast-iron, 7‟‟ (178mm) in diameter and 2‟(0.6m) long, that is connected to the pier.

2.6.2 Movement Joints

The deck is supported across the piers and at both abutments on a series of single roller bearings positioned under the end of the crossbeams. The roller bearings allow movement or expansion of the deck along the length of the bridge.

307-RG-TPI-BR009-000001


Printed 11/07/2012

2.7 Parapet type

A footway and post-and-rail balustrade has been constructed on each side of the bridge.

2.8 Details of any special or unusual features of the structure or the site

The bridge is not listed and does not have any features of particular historical interest.

2.9 Services and Utilities

Information received indicates Cable & Wireless, BT services and other cables cross the bridge.

A total of eight steel cable ducts are located between the separate bridges and are supported by brackets off the rib arch girders. All brackets appear to have a rubber seating which allows for movement of the bridge structure or the services without inducing stresses in the cables. Neoprene pads between the lengths of duct provide the same function.

Two 3‟(0.9m) diameter steel gas pipes are located between bridges 9 & 8 and 10 & 5 (see Figure 2) and again are supported on brackets cantilevering from the adjacent arch ribs. They are understood to be seated on rubber shear and compression pads and to have expansion bellows at either end of bridge span.

Network Rail services are understood to consist of communications and electrical cables, as discussed in the Inspection Report 307-RI-TPI-BR009-000001-AC. Any induced stresses will be negligible and no further assessment is proposed.

Buried services owners, other than Network Rail, are being contacted separately to this Form AA in order to gain their non-objection to the Thames Tunnel works.

2.10 Permanent Way

The bridge currently carries nine tracks, identified as four up, four down, and one reversible, between London Victoria and Battersea Pier Junction.

No switches or crossings are present on the bridge, however there are a number of switches and crossings to the south of the bridge that sit outside the influence of the settlement trough.

The tracks are straight as identified on the Network Rail 5 Mile Line Diagram for Victoria (21st September 2006).

The line speed is restricted to 40mph for all four lines shown on the VIR route 5 Mile Diagram. No 5 Mile Diagram is available for the VTB route, line speeds are assumed to be consistent across the bridge and are therefore taken from the VIR route for all lines.

307-RG-TPI-BR009-000001


Printed 11/07/2012

3 Inspection and Data Collection

3.1 Inspection Summary

A visual inspection of the bridge was carried out from publicly accessible areas on 15th February 2012. The areas of the bridge which could be observed were generally in very good condition.

For photographs and further description of the condition of the structure, reference should be made to the Inspection Report 307-RI-TPI-BR009-000001-AC.

A condition factor of 1.0 will be used for the assessment.

3.2 Reference Data

Record drawings were provided for Grosvenor Rail Bridge by Network Rail. These have been supplemented by data contained within the previous Inspection and Feasibility Study Reports. Where dimensional data has had to be assumed, this is noted in Section 3.3.

A list of record drawings and other documents used in the Assessment is provided below:

a. „The Reconstruction of the Grosvenor Railway Bridge‟ by O.A.Keresnky and F.A.Partridge, Paper No.7003, 1967

b. Amey Structural Underwater Assessment Report, 2010

c. British Railways, Marples Ridgway Ltd. Grosvenor Bridge General Arrangement Drawing, 1968

d. British Railways, Marples Ridgway Ltd. Grosvenor Bridge Piers & Abutments, 1968

e. British Railways, Marples Ridgway Ltd. Grosvenor Bridge Shafts & Walls, 1968

f. British Railways, Marples Ridgway Ltd. Grosvenor Bridge Main Girder Steelwork, 1968

g. British Railways, Marples Ridgway Ltd. Grosvenor Bridge Main Girder Steelwork Details, 1968

h. British Railways, Marples Ridgway Ltd. Grosvenor Bridge Waterproofing & Drainage, 1968

i. Waterman Civils (2010). AutoRAIL 5 Mile Line Diagrams. Issue 38. Last updated October 2009.

j. QUAIL Diagram, Victoria and Waterloo, Quail Map Company

The line and level of the tunnel has been taken from the following alignments:

Abbey Mills Route – Provisional Horizontal Alignment for Phase 2 Consultation. CAD File Ref: 100-DO-DES-00000-017402-AL

Abbey Mills Route – Provisional Vertical Alignment for Phase 2 Consultation. CAD File Ref: 100-DO-DES-00000-017423-AI

307-RG-TPI-BR009-000001


Printed 11/07/2012

3.3 Adequacy of Data and Assumptions

In general, the data reviewed during the desk study and verified during the inspection were adequate to proceed with assessment. Where it has not been possible to obtain data, assumptions have been made in order to progress in specific areas, supported by evidence gathered during the desk study, inspection and previous experience, and are listed below:

a. Foundations depth taken from historic papers on the bridge construction and verified by scaling from available record drawings

b. The permanent way and utilities crossing the bridge are in good condition.

307-RG-TPI-BR009-000001


Printed 11/07/2012

4 Geotechnical Assessment

This section describes the methods of “Greenfield” ground movement calculation, the methods of assessing the ground movement effects on the bridge and gives the results for movements of the structure.

4.1 Method of Ground Movement Calculation

Sub-surface greenfield ground movements are calculated using empirical methods, Mair et al. (1993) and Taylor (1995), where a settlement trough perpendicular to the new tunnel can be estimated using an inverted normal probability curve (Gaussian curve). The three dimensional form of movement is calculated using the Attewell & Woodman (1982) methodology. This methodology is used by the Oasys program XDisp which has been used to carry out these calculations.

For tunnelling with EPB TBM in London Clay, Lambeth Group, Thanet Sand and Chalk and where no geological anomalies such as scour holes have been detected, a volume loss of 1% in accordance with Thames Tunnel‟s moderately conservative value has been adopted. The adopted value is conservative when compared with recorded parameters for similar tunnel projects in London. Experience from Channel Tunnel Rail Link Contract 220 (CTRL), indicates that an average volume loss of 0.5% was achieved for tunnelling with an 8.11m diameter EPB TBM in similar ground conditions, Wongsaroj et al (2006).

A trough width parameter, k of 0.5 at ground surface has been used for the assessment. The k value at any particular elevation is derived from an empirical equation in relation to depth below ground surface and distance from surface to tunnel axis level using the Mair et al. (1993) method.

The effect of the longitudinal “bow” wave settlement on the bridge piers as the TBM progresses has been assessed. Settlement with TBM progress is simulated as discrete tunnel sequence steps as it approaches and passes under the bridge, based on an estimated TBM progress of 10m/day. The direction of tunnelling will be east to west.

4.1.1 Geotechnical References

a. Attewell P B and Woodman J P (1982). Predicting the dynamics of ground settlement and its derivatives caused by tunnelling in soil. Ground Engineering, November 1982, 13 - 36.

b. Mair R. J., Taylor R. N. and Bracegirdle A. (1993). Subsurface settlement profiles above clay in tunnels. Géotechnique 43 No. 2, pp. 315-320.

c. Burland J B (1995) Assessment of risk of damage to buildings due to tunnelling and excavation, Invited Special Lecture: 1st International Conference of Earthquake Geotechnical Engineering, IS Tokyo, 1995.

d. Taylor R N (1995), Tunnelling in soft ground in the UK. In: Underground. Construction in Soft Ground. K Fujita and O Kusakabe (Eds). Balkema. pp123-126.

e. Wongsaroj J, Borghi F X, Soga K, Mair R J, Sugiyama T, Hagiwara T and Bowers K H. Effect of TBM driving parameters on ground surface

307-RG-TPI-BR009-000001


Printed 11/07/2012

movements: Channel Tunnel Rail Link Contract 220. Geotechnical aspects of underground construction in soft ground, Bakker et al (eds), 2006.

4.2 Ground Conditions

Review of borehole logs at the bridge/tunnel interface has been undertaken in order to confirm the stratigraphy as indicated on Thames Tunnel drawings and to establish ground movement assessment parameters.

The purpose of the review has been to conclude whether features such as scour hollows or other geological anomalies are present as this would impact on ground parameters and volume loss. Scour hollows (or holes) are enclosed depressions in the rockhead surface. Nearly all scour hollows in London are eroded into the London Clay, but some cut through the Lambeth Group and exceptionally the Chalk. The infill deposits consists mainly of sand and gravel with some clayey beds.

None of the borehole logs at Grosvenor Rail Bridge indicate geological anomalies. Therefore, the volume loss and k value as identified in Section 4.1 have been used for the ground movement assessment.

4.3 Ground Movement Results

4.3.1 Vertical and Horizontal Ground Movements

On completion of tunnel construction, the main effects of ground movement will be vertical settlement and horizontal ground movement towards the tunnel.

The calculated ground movement values along the centre line of the bridge on completion of the tunnel works are presented in Table 1 below. In addition, the settlement trough is shown in Appendix B. For orientation, reference should be made to the bridge plan in Figure 3.

Calculated ground movements vary with foundation depth. For the Grosvenor Rail Bridge the foundation level was estimated from the reference drawings provided by Network Rail (Section 3.2). Considering the difference in ground movements between Bed Level and Foundation Level, it can be seen that there is only a small difference in the magnitudes of the ground movements. Conservatively, the values at bed level will be adopted for assessment as this gives worst case ground movement values.

All ground movement values, where not quoted differently, are taken along the bridge centreline and calculated as an average of values at the four corners of each pier. These average values along the centreline will be used within the assessment as the pier is considered to respond consistently to the ground movements, rather than to move exactly with the ground movements at the individual corners which would give differential movement within the pier body.

307-RG-TPI-BR009-000001


Printed 11/07/2012

Figure 3: Grosvenor Rail Bridge

Bed Level Foundation Level

Pier 2 Pier 3 Pier 2 Pier 3

Vertical Settlement (mm) 3.22 3.84 2.52 3.12

Horizontal movement parallel to bridge (mm)

1.81 -2.02 1.57 -1.83

Horizontal movement perpendicular to bridge (mm)

-0.05 0.05 -0.04 0.05

Table 1: Pier 2 and 3 settlement at the bridge centreline

The maximum vertical settlement, on completion of tunnel construction, occurring directly above the centreline of the tunnel at bed level, is 15.9mm. Due to the length of the span, the maximum vertical settlements occurring at the bridge piers are 3.8mm and 3.2mm at the bed level.

Piers 2 and 3 move towards each other, both experiencing a horizontal movement of approximately 2mm. Horizontal movement perpendicular to the bridge centre line is negligible.

4.3.2 Ground Movement in the Transient Condition

The movements tabulated above are for the situation on completion of the tunnel works. The transition condition, as the tunnel is constructed is known as the „bow wave‟ and will cause a temporary differential vertical settlement across the width of the bridge. As the tunnel alignment runs approximately on a straight line and perpendicular to the two bridge piers which are positioned roughly equidistant from the tunnel crossing, the effect of the bow wave will reach both piers at approximately the same time with the tunnel construction progressing from east to west. Refer to Figures 4 and 5 below. Therefore the temporary differential between two

307-RG-TPI-BR009-000001


Printed 11/07/2012

piers will be constant and equal to that at the tunnel completion of 0.6mm. Refer to Table 1 above.

Tunnelling will cause ground curvature along the line of the piers and differential settlement between the four corners of the pier.

Figure 4: Vertical settlement from river bed level at corners of Pier 2

Figure 5: Vertical settlement from river bed level at corners of Pier 3

The transient case will cause temporary differential settlement between single pier corners (along the pier). The average temporary differential settlement has been taken conservatively as 3.22mm at Pier 2 and 3.84mm at Pier 3.

The maximum tensile strains in the piers using movement at river bed level in the transient case are presented in table 2 below.

0

1

2

3

4

5

6

7

10950 11000 11050 11100 11150 11200 11250 11300 11350 11400 11450

Ver

tica

l S

ettl

emen

t, m

m

Thames Tunnel Chainage

River Bed Level|Pier_2_NW River Bed Level|Pier_2_NE

River Bed Level|Pier_2_SW River Bed Level|Pier_2_SE

0

1

2

3

4

5

6

7

8

10950 11050 11150 11250 11350 11450

Ver

tica

l S

ettl

emen

t, m

m


River Bed Level|Pier_3_NW River Bed Level|Pier_3_NE

River Bed Level|Pier_3_SW River Bed Level|Pier_3_SE

307-RG-TPI-BR009-000001


Printed 11/07/2012

Along the pier (east to west)

[%]

Pier 2 – transient 0.003

Pier 3 – transient 0.005

Table 2: Maximum tensile strain in the pier during the tunnel construction

The horizontal displacement perpendicular to the bridge centre line is negligible in post-construction condition. However the transient condition will cause the piers to move horizontally towards the approaching tunnel and then return to their original location as the tunnel passes below the bridge. This can be observed in Figures 6 and 7 below.

Figure 6: Pier 2 Horizontal displacement perpendicular to the bridge centreline (Bed Level)

-0.2

-0.1

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

10950 11000 11050 11100 11150 11200 11250 11300 11350 11400 11450

Ho

rizo

nta

l D

isp

lace

men

t, m

m

Thames Tunnel Chainage (meters east of Blackfriars Bridge Foreshore Shaft)

River Bed Level|Pier_2_NW River Bed Level|Pier_2_NE River Bed Level|Pier_2_SW River Bed Level|Pier_2_SE

307-RG-TPI-BR009-000001


Printed 11/07/2012

Figure 7: Pier 3 Horizontal displacement perpendicular to the bridge centreline (Bed Level)

Bed Level

Pier 2 Pier 3

Horizontal movement perpendicular to bridge (mm)

0.42 0.52

Table 3: Average maximum horizontal displacement (perpendicular to the bridge centreline) of the pier during the tunnel construction at the pier centreline

4.3.3 Slope of pier due to differential ground movement

The maximum slope at the bridge piers, perpendicular and parallel to the bridge axis, has also been assessed and is presented below in Table 4. The construction stage is the slope perpendicular to the bridge, due to longitudinal displacement, and the post-construction stage is the slope perpendicular to the line of the abutments, due to the transverse displacement.

Slope (1:)

Pier 2 Pier 3

Construction

(Perpendicular to bridge)

Foundation level

20994 17604

Post-construction

(Parallel to bridge)

Foundation level

3004 2779

Table 4: Maximum slope underneath piers 2 and 3 (see text above for explanation)

-0.1

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

10950 11000 11050 11100 11150 11200 11250 11300 11350 11400 11450

Ho

rizo

nta

l D

isp

lace

men

t, m

m


River Bed Level|Pier_3_NW River Bed Level|Pier_3_NE River Bed Level|Pier_3_SW River Bed Level|Pier_3_SE

307-RG-TPI-BR009-000001


Printed 11/07/2012

4.3.4 Total vertical and horizontal movement at river bed level post-construction

Plan

Horizontal movements parallel to the bridge are at their greatest on completion of the tunnel construction.

Horizontal movements perpendicular to the bridge are negligible on completion of the tunnel construction.

Movements only take place at two piers. Ground movements at the other piers and abutments are zero.

Elevation

Vertical movements are greatest post-construction. The figure below shows the vertical ground movements post-construction.

4.3.5 Summary of additional horizontal movements induced during construction

The transient condition will cause small temporary differential settlement along the line of the pier (Pier 2 = 3.22mm; Pier 3 = 3.84mm). The effects of this were assessed considering the tensile strains due to ground movement.

This transient differential settlement will also cause a twisting effect in the bridge superstructure as the pier tilts to follow the ground slope. The maximum ground slope (along the length of the pier) in the transient condition calculated for Pier 2 is 1: 20994 and for Pier 3 is 1: 17604.

The transient condition will also cause very small temporary pier displacement in a direction perpendicular to the centreline of the bridge and towards the approaching TBM. The maximum value of this temporary displacement has been calculated as 0.52mm at Pier 3 and 0.42mm at Pier 2.

N S

N S

E

W

0.05mm

0.05mm

2.02mm

1.81mm

3.22mm

3.84mm

307-RG-TPI-BR009-000001


Printed 11/07/2012

4.3.6 Summary of worst case effects

Vertical Movement

Horizontal Movement

(parallel to bridge centre line)

Horizontal Movement (perpendicular to bridge centre

line)

[mm] [mm] [mm]

At the bridge centre line

Pier 3 3.22 1.81 0.42

Pier 4 3.84 -2.02 0.52

Table 5: Worst case (during and post construction) vertical and horizontal movement at river bed level


[%]

Pier 2 0.003

Pier 3 0.005

Table 6: Worst case tensile strain along and across pier


[1:]

Pier 3 20993.8

Pier 4 17604.2

Table 7: Worst case ground slope

307-RG-TPI-BR009-000001


Printed 11/07/2012

5 Structural Assessment – General

An assessment has been undertaken for the bridge to determine the effects of the tunnelling-induced ground movement on the structure. At Grosvenor Rail Bridge, the main effects are vertical settlement and horizontal ground movements towards the tunnel.

The structural assessment uses historical records, in addition to the information gained from the inspection, to assess any impact that may arise due to the induced ground movements.

The assessment has determined the differences in load and serviceability effects due to the tunnelling works and does not represent a full assessment of the capacity of the structure. In addition the assessment considered whether monitoring or mitigation works will be required to accommodate the effects of the ground movement.

5.1 Reference Documents

The assessment has been carried out in accordance with the Approval-in-Principle (Form AA), document no. 307-EA-TPI-BR009-000001-AC.

5.2 Structure Records

For a list of the historical records that have been used in the assessment of Grosvenor Rail Bridge refer to Section 3.2 of this report.

5.3 Codes used in the Assessment

5.3.1 List of Network Rail Standards

a. NR/GN/CIV/025, „The Structural Assessment of Underbridges‟, Network Rail, Issue 3, June 2006

b. NR/SP/CIV/035 (formerly RT/CE/S/035), „Assessment of Structures‟, Network Rail, Issue 2, February 2004

c. NR/L2/TRK/001/C01 „Inspection and Maintenance of the Permanent Way – Geometry and Gauge Clearance‟, Network Rail, Issue 4, December 2009.

d. NR/BS/LI/045 (Issue 3) „Monitoring track over or adjacent to Civil Engineering works: procedure and intervention levels‟.

307-RG-TPI-BR009-000001


Printed 11/07/2012

6 Structural Assessment – Methodology and Results

6.1 Headline Result

Ground movements have negligible effect on the substructure and superstructure of the Grosvenor Rail Bridge. Ground movements do not adversely affect the permanent way.

6.2 Assessment of the Superstructure

6.2.1 Assessment of ground movements in the bridge longitudinal section

The arched main girders are pinned at the piers and act in compression.

Grosvenor Bridge was modelled as a four span GSA model using an encastre support at bed level, this being a conservative assumption based on there being ground restraint at the pier base. Ground movements were applied to the supports either side of the tunnel.

Initially the pin bearings were modelled as normal beam elements in order to investigate whether there is sufficient stress induced to overcome the friction in the bearing.

The ground movements induce a moment in the beam element at the end of the arch girders resulting in a force that acts against the friction between the bearing and the girder.

The force due to ground movements is much greater than the available friction, demonstrating that the pin bearings do indeed act as pinned connections between the arched main girders and the piers.

A second stage of the modelling looked at the effect of introducing pins into the model at the location of the pinned bearings, given the above findings. This resulted in an increased bending stress in the arch girders due to the ground movements.

Figures 8 and 9 show the movement and the related bending stress in the arch girders. It is considered that this additional stress (maximum 3N/mm2) would be easily accommodated within the capacity of the girders.

Due to the encastre nature of the base of the pier assumed for this model, strains occur within the pier.

These are also considered to be well within the tensile capacity of the concrete and are discussed further in Section 6.3.

A further model introduced an additional pin at foundation level because in reality it is considered that the pier will respond to the ground movements in a manner that is somewhere between the encastre and pinned base models. This model confirmed that no stresses would be induced within either the superstructure or the pier and the structure would accommodate the movements shown in Figure 10.

The conservative model, assuming ground restraint at the pier base with a pinned connection at the end of the arch girder, gives small and acceptable stresses (maximum 3N/mm2). In reality it is likely that the stresses will be much smaller than this due to the actual behaviour of the pier.

307-RG-TPI-BR009-000001


Printed 11/07/2012

Figure 8: Movement within the superstructure and piers due to the ground movements

Figure 9: Bending stress in the arch girders due to the ground movements

Figure 10: Movement within the superstructure and piers due to the ground movements

307-RG-TPI-BR009-000001


Printed 11/07/2012

6.2.2 Assessment of ground movements in the bridge plan

The temporary horizontal movement perpendicular to the bridge centre line will have a peak value of 0.52mm at Pier 3 at bed level towards the approaching tunnel. Due to the ground slope perpendicular to the centre line of the bridge the horizontal movement at the superstructure level will be larger than at bed level.

Span 3 of the bridge will suffer little differential horizontal movement as both Pier 2 and Pier 3 move by approximately the same distance. Span 2 and Span 4 will be subject to an average maximum horizontal differential movement of 1.2mm and 1.5mm respectively at the bridge deck level. This translates to a maximum rotation of 3.0 x 10-5 Radians.

This rotation is considered to be negligible as the machine tolerance during fabrication of the bearings will not have been accurate to 3.0 x 10-5 Radians or 0.013mm across the bearing width of 500mm; thus this movement will be readily accommodated in the roller bearings at the piers and in the pin bearings at the end of the arch girders.

6.2.3 Assessment of ground movements in the bridge cross section

Temporary differential vertical settlement during tunnel construction will have a peak value of 3.84mm along Pier 3 as shown in Figure 11 below. It will result in equivalent superstructure movement at the arch springing level. The settlement profile is approximately a straight line as can be seen from Figure 3.

Figure 11: Pier 3 South Elevation – differential vertical settlement during tunnel construction

As a result of this differential settlement there will be a small twist in the steel superstructure across the bridge width. This again will not affect Span 3 as the differential is negligible. However Spans 2 and 4 will experience a greater twist due to the differential between Piers 1 and 2 and between Pier 3 and the South Abutment.

By inspection the twist induced in Span 4 will be greatest; the twist has been assessed using a simplified model of the superstructure.

Direction of tunnelling 0.0mm 3.84mm

307-RG-TPI-BR009-000001


Printed 11/07/2012

Sections were derived based on information from „The reconstruction of the Grosvenor Railway Bridge‟ by O.A.Keresnky and F.A.Partridge, Paper No.7003, 1967 and Figure 5.

A simple GSA model was created of a single span to model the torsional effects. Stresses induced were very small, less than 0.03N/mm2, so the twisting effect is considered negligible.

In reality it is likely that the movement will be taken up within the pier with the effects unlikely to reach the superstructure meaning that stresses due to this movement are equally unlikely to occur.

6.3 Assessment of the Substructure

6.3.1 Methodology

The two piers have been modelled in a similar manner to masonry building structures, with ground strains and curvature being used to calculate a Risk of Damage Category in accordance with Burland (1995). The assessment has been carried out using the latest version of the software package XDisp by Oasys, to determine the potential for vertical cracks to develop due to ground strains.

6.3.2 Tensile Strain in the Substructure

For the calculation of the tensile strain, the following material properties and section dimensions have been assumed:

a. Poissons Ratio: 0.3

b. Ratio of Young‟s Modulus to Shear Modulus (E/G): 2.6

The analysis assumes conservatively, that the structure bends to follow the ground profile at foundation level and that the ground strains transfer directly into the structure. On this basis the maximum tensile strains in the piers in the post-construction condition are presented in Table 8 below.

Along the pier

(east to west)

[%]

Pier 3 0.00011

Pier 4 0.00035

Table 8: Tensile strain along and across pier in post construction condition

The maximum tensile strains in the piers using movement in the transient case are presented in Table 9 below.

Along the pier

(west to east)

[%]

Pier 3 0.002

Pier 4 0.003

Table 9: Tensile strain along and across pier in transient condition

307-RG-TPI-BR009-000001


Printed 11/07/2012

6.3.3 Results

The tensile strains are related to the damage categories defined by Burland (1977) and Boscardin and Cording (1989). Looking at Table 12 below, it can be seen that the tensile strains at all abutments and piers are within Category 0 – Negligible degree of severity of damage. Table 13 describes the typical damage seen and shows that Category 0 damage exhibits no more than hairline cracks; even hairline cracks are not expected however as the strain values expected are considerably lower than the 0.05% top limit of Category 0.

The piers have also been assessed for bending strain induced by the horizontal ground movements, assuming the pier to be encastre at foundation level and restrained by the deck. Figure 12 shows the bending moment induced in the piers due to ground movement.

Due to the relative flexibility of the deck compared to the pier the strains in the piers are very small. The entire pier moves horizontally by 2mm, rather than bending as the resistance offered by the deck is very small. The force, and consequent strain, experienced by the pier was found to be negligible.

Category of damage Normal degree of severity Limiting tensile strain (%)

0 Negligible 0-0.05

1 Very slight 0.05-0.075

2 Slight 0.075-0.15

3 Moderate 0.15-0.3

4 to 5 Severe to very severe >0.3

Table 10: Relationship between category of damage and limiting tensile strain (after Boscardin and Cording, 1989)

Category of damage

Normal degree of severity

Description of typical damage

0 Negligible Hairline cracks less than about 0.1mm wide

1 Very slight Fine cracks that are easily treated during normal decoration

2 Slight Cracks easily filled. Redecoration probably required. Recurrent cracks can be masked by suitable linings. Some re-pointing may be required to ensure weather-tightness.

3 Moderate The cracks require some opening up and can be patched by a mason. Re-pointing of external brickwork to be replaced.

4 Severe Extensive repair work involving breaking-out and replacing sections of walls.

5 Very severe This requires a major repair job involving partial or complete rebuilding.

Table 11: Classification of visible damage to walls with particular reference to ease of repair or plaster and brickwork or masonry (after Burland et al, 1977)

307-RG-TPI-BR009-000001


Printed 11/07/2012

Figure 12: Simplified Model showing Bending Moment due to Ground Movement

307-RG-TPI-BR009-000001


Printed 11/07/2012

7 Utility Assessment

The results of the utility assessment are not presented within this Report.

A Data Sheet has been prepared for each utility reporting on utility details, settlement data, and results of the assessment. Appendix D contains the Data Sheets for all of the utilities on the bridge:

- 307-RG-TPI-BR009-000002 - Grosvenor Rail Bridge; BT; Utility Data Sheet

- 307-RG-TPI-BR009-000003 - Grosvenor Rail Bridge; Cable and Wireless; Utility Data Sheet

- 307-RG-TPI-BR009-000004 - Grosvenor Rail Bridge; Global Crossing UK; Utility Data Sheet

- 307-RG-TPI-BR009-000005 - Grosvenor Rail Bridge; National Grid Gas; Utility Data Sheet

The aim of the data sheets is to ensure the project has written consent from each utility company / asset owner that they do not object to the Thames Tunnel project. They also provide a record for further work on the project.

It is expected that written consent will not have been received for each utility prior to submission of this report.

307-RG-TPI-BR009-000001


Printed 11/07/2012

8 Permanent Way

The permanent way assessment has considered the effects of ground movements compared to Network Rail Standard limits for movement of the permanent way.

8.1 Reference Documents

The assessment has been carried out in accordance with the Approval-in-Principle, document no. 307-EA-TPI-BR009-000001-AC which will have been agreed by Network Rail previously.

8.2 Permanent Way Records

The following records for the permanent way have been used in this assessment:

a. Waterman Civils (2010). AutoRAIL 5 Mile Line Diagrams. Issue 38. Last updated October 2010.

8.3 Standards used in the Assessment

8.3.1 Network Rail Standards

a. NR/L2/TRK/001/C01 „Inspection and Maintenance of the Permanent Way – Geometry and Gauge Clearance‟, Network Rail, Issue 4, December 2009.

b. NR/BS/LI/045 (Issue 3) „Monitoring track over or adjacent to Civil Engineering works: procedure and intervention levels‟.

8.4 Permanent Way Assessment

8.4.1 Methodology

The track has been assessed for the calculated ground movements assuming that the track follows the shape of the settled structure. The 3m twist, change in top level, line, gauge, and cant have been calculated and compared to the limits given in the Network Rail Standards listed above.

The 5 Mile Line Diagram indicates that the tracks are straight and that there are no switches and crossings on the bridge. The line speed is 40 mph in both directions. The permanent way is assumed to be in good condition and geometrically correct.

For ease of reference, the tables used for assessment, from the Network Rail Standards, have been copied into Appendix E.

8.4.2 Results

By inspection, the track gauge will not be affected as the track is ballasted and any transverse strain across the bridge piers (calculated as negligible) will not be transferred to the track above.

The 3m twist induced in the permanent way can be calculated from the difference in the slope of the ground between piers. By inspection, for the 3m twist, the transient condition will be worst.

307-RG-TPI-BR009-000001


Printed 11/07/2012

The absolute change in cant over the width of a standard track gauge, due to the slope of the piers, is 0.08 mm. Maximum 3m twist is equal to 0.004 mm. These are negligible when compared with the limits shown below, in Clause 14 of NR/LI/BS/045 (10mm for 3m twist, 15mm for cant) and NR/L2/TRK/001/C01 (12mm for 3m twist, 160mm on cant).

By inspection, all other relative movements are negligible.

The average maximum vertical absolute movement of one track is 6.5mm in Span 4 as taken from the GSA model of the structure. The average maximum absolute horizontal movement perpendicular to the bridge of 0.52mm is the greatest at Pier 3 but is exacerbated by ground slope to a maximum of 1.5mm.

The absolute movements are compared to the alert limits for „top‟ and „line‟ given in Table 5c of NR/L2/TRK/001/C01 (shown below). This shows that the absolute change in level of the track, from original position, at a permissible speed of 40 mph is 20mm before an action to correct the level of the track during planned maintenance is required. The absolute vertical movement is approximately 32.5% of this allowable change in „top‟.

The absolute change in line of the track, from original position, at a permissible speed of 40 mph is 17mm before an action to correct the line of the track during planned maintenance is required. The absolute horizontal movement is approximately 9% of this allowable change in „line‟.

The maximum deviation at mid-chord, for a chord between points on the track 20m apart, for both „top‟ and „line‟ must also be checked. The limits, before any action for maintenance is required, are 15mm for both „top‟ and „line‟ at 30 mph. By inspection, the absolute movements give deviations at any mid-chord of significantly less than the prescribed limits.

The cyclic top limit at 40mph on both rails is 38mm thus the change in cyclic top is negligible; cyclic cross-level doesn‟t apply because of the 40mph speed restriction imposed on the tracks.

Likewise combinations of cyclic top and line or cyclic top and twist are also negligible.

307-RG-TPI-BR009-000001


Printed 11/07/2012

9 Monitoring and Mitigation

9.1 Route-Wide Monitoring

A route-wide Instrumentation and Monitoring Plan will be developed by the Thames Tunnel Project Team. It will include provision for monitoring of vertical and horizontal ground movements, on sections transverse to the centreline of the tunnel, at regular centres. This would monitor the performance of the tunnelling contractor and ensure that ground movements are in line with those predicted by the analysis.

9.2 Asset-Specific Monitoring and Mitigation

The assessment has shown that the effects of tunnelling on Grosvenor Rail Bridge are minimal. Therefore no specific asset mitigation measures are proposed.

The site-wide monitoring outlined above will be adequate to ensure that ground movements are in line with those predicted by the analysis and therefore no asset-specific monitoring is proposed.

It is recommended that the permanent way be monitored in accordance NR/BS/LI/045 Monitoring of track over or adjacent to Civil Engineering works: procedure and intervention levels. The site-wide monitoring outlined above will be adequate to confirm that the ground movements are in line with those predicted by analysis.

307-RG-TPI-BR009-000001


Printed 11/07/2012

10 Conclusions and Recommendations

Greenfield settlement calculations have been undertaken for the proposed Thames Tunnel using OASYS XDisp analysis.

The results of this analysis indicate the following movements post-construction at Grosvenor Rail Bridge:

a. The maximum vertical settlement at pier 2 and pier 3 will be 3.8mm.

b. The total horizontal movement parallel to the bridge will be a maximum of 2.0mm at river bed level.

c. The total horizontal movement perpendicular to the bridge will be a maximum of 0.1mm.

The effects of the „bow wave‟ as the tunnel approaches the bridge have been compared to the effects in the post-construction condition.

The temporary vertical differential movement is greatest at pier 3 with a differential of 3.84mm.

The average maximum horizontal displacement perpendicular to the bridge centreline is 0.5mm, again at pier 3.

A structural assessment of Grosvenor Rail Bridge has been carried out to assess the impact of the anticipated ground movements on the bridge; this has been based on an inspection of the bridge, from publicly accessible areas, and historical records.

The impact of the ground movements on the superstructure results in small geometrical changes which cause small stresses within the main arch girders that are deemed to be within acceptable limits for the capacity of the girders. Ground movements in the bridge plan are very small and taken up within the bearings.

The impact of the ground movements on the abutments and piers is minimal. Strains directly due to ground movement are well within the lowest damage category as defined by Burland. Strain due to bending of the pier from horizontal movement is well within the tensile capacity of the concrete.

The effects of the ground movements on the Permanent Way have been compared with applicable guidelines published by Network Rail. The most significant effect is a reduction in rail level which is 33% of the appropriate trigger level for works to be incorporated in planned maintenance.

It is concluded that the effects of ground movements due to construction of the Thames Tunnel will not adversely affect the structure or the Permanent Way.

Based on the results of this assessment, no asset-specific monitoring is proposed. A route-wide Instrumentation and Monitoring Plan will be developed by the Thames Tunnel Project Team. It will include provision for monitoring of vertical and horizontal ground movements, on sections transverse to the centreline of the tunnel, at regular centres. This will demonstrate whether the ground movements at Grosvenor Rail Bridge are in line with those calculated in the assessment.

307-RG-TPI-BR009-000001


Printed 11/07/2012

11 Further Work Required

No further inspection of Grosvenor Rail Bridge is required.

A route-wide Instrumentation and Monitoring Plan will be developed by the Thames Tunnel Project Team in order to monitor the performance of the tunnelling contractor and ensure that ground movements are in line with those predicted by the analysis.

307-RG-TPI-BR009-000001


Printed 11/07/2012

Appendix A – Location Plan and Proposed Tunnel Alignment

The line and level of the tunnel has been taken from the following alignments:

Abbey Mills Route – Provisional Horizontal Alignment for Phase 2 Consultation. CAD File Ref: 100-DO-DES-00000-017402-AL

Abbey Mills Route – Provisional Vertical Alignment for Phase 2 Consultation. CAD File Ref: 100-DO-DES-00000-017423-AI

Figure A1: Location plan

Grosvenor Rail Bridge

307-RG-TPI-BR009-000001


Printed 11/07/2012

Figure A2: Proposed Thames Tunnel Alignment at Grosvenor Bridge

307-RG-TPI-BR009-000001


Printed 11/07/2012

Appendix B – Settlement Trough

307-RG-TPI-BR009-000001


Printed 11/07/2012

Figure B1: Grosvenor Rail Bridge settlement trough along the centre line of the structure

307-RG-TPI-BR009-000001


Printed 11/07/2012

Appendix C – Reference Drawings

307-RG-TPI-BR009-000001


Printed 11/07/2012

Figure C1: Grosvenor Rail Bridge – General Arrangement Drawing

307-RG-TPI-BR009-000001


Printed 11/07/2012

Figure C2: Grosvenor Rail Bridge – Piers & Abutments

307-RG-TPI-BR009-000001


Printed 11/07/2012

Figure C3: Grosvenor Rail Bridge – Shafts & Walls

307-RG-TPI-BR009-000001


Printed 11/07/2012

Figure C4: Grosvenor Rail Bridge – Main Girder Steelwork

307-RG-TPI-BR009-000001


Printed 11/07/2012

Figure C5: Grosvenor Rail Bridge – Main Girder Steelwork Details

307-RG-TPI-BR009-000001


Printed 11/07/2012

Figure C6: Grosvenor Rail Bridge – Waterproofing & Drainage

307-RG-TPI-BR009-000001


Printed 11/07/2012

Appendix D – Utility Data Sheets

307-RG-TPI-BR009-000001


Printed 11/07/2012

Appendix E – Assessment criteria for Permanent Way

Table 1: Assessment criteria for permanent way – Part 1 (after NR/L2/TRK/001/C01 Inspection and Maintenance of the Permanent Way – Geometry and Gauge Clearance)

307-RG-TPI-BR009-000001


Printed 11/07/2012

Table 2: Assessment criteria for permanent way – Part 2 (after NR/L2/TRK/001/C01 Inspection and Maintenance of the Permanent Way – Geometry and Gauge Clearance)

307-RG-TPI-BR009-000001


Printed 11/07/2012

Table 3: Assessment criteria for permanent way – Part 3 (after NR/BS/LI/045 Monitoring track over or adjacent to Civil Engineering works: procedure and intervention levels)

307-RG-TPI-BR009-000001


Printed 11/07/2012

Appendix F – Certificate of Assessment and Checking (Structural)

307-RG-TPI-BR009-000001


Printed 11/07/2012

Appendix G – Certificate of Assessment and Checking (Geotechnical)

307-RI-TPI-BR009-000001| AB | 30 March 2012

Network Rail


THIS REPORT INCLUDING THE DRAWINGS AND OTHER SUPPORTING DOCUMENTATION IS PROVIDED FOR THE PURPOSE OF IDENTIFYING AND AGREEING THE LIKELY EFFECTS OF THE CONSTRUCTION OF THE THAMES

TUNNEL ON THE ASSETS AND INFRASTRUCTURE OF THE PARTY IN RECEIPT OF THIS REPORT AND FOR THE PURPOSE OF SECURING APPROVAL IN PRINCIPLE TO THE DESIGN OF THE THAMES TUNNEL. THE REPORT IS

CONFIDENTIAL TO THAMES WATER AND THE INTENDED RECIPIENT AND THEIR CONSULTANTS [APPOINTED WITH THE AGREEMENT OF THAMES WATER]. THE REPORT SHALL NOT BE PROVIDED TO ANY THIRD PARTY

WITHOUT THE EXPRESS WRITTEN PERMISSION OF THAMES WATER UTILITIES LIMITED.

Inspection Report Detailed Bridge Assessments Sub-Package 2C

307-RI-TPI-BR009-000001



Printed 29/03/2012

Thames Tunnel

Inspection Report - Grosvenor Rail Bridge

List of contents

Page number

1 Introduction ................................................................................................................... 6

1.1 Project Description ............................................................................................. 6

1.2 Works at Grosvenor Rail Bridge ...................................................................... 6

1.3 Purpose of this Document................................................................................. 6

2 Desk Study..................................................................................................................... 7

3 Site Inspection Purpose and Methodology........................................................... 7

4 Description of the Structure ..................................................................................... 8

4.1 General ................................................................................................................ 8

4.2 History ................................................................................................................ 10

4.3 Superstructure .................................................................................................. 10

4.4 Substructure ...................................................................................................... 14

4.5 Foundations....................................................................................................... 15

4.6 Finishes.............................................................................................................. 16

4.7 Services and Utilities ....................................................................................... 16

4.8 Rail Infrastructure ............................................................................................. 16

5 Access Arrangements for Inspection................................................................... 17

6 Findings of the Inspection ..................................................................................... 17

6.1 Superstructure .................................................................................................. 17

6.2 Substructure ...................................................................................................... 17

6.3 Articulation and Movement Capacity............................................................. 18

6.4 Parapets............................................................................................................. 18

6.5 Foundations....................................................................................................... 18



7 Condition Factors for Assessment ....................................................................... 19

8 Adjacent Structures .................................................................................................. 20

9 Discussion ................................................................................................................... 20

9.1 Review of Available Data ................................................................................ 20

9.2 Structural Issues ............................................................................................... 20

9.3 Finishes.............................................................................................................. 20

9.4 Heritage Issues ................................................................................................. 21

307-RI-TPI-BR009-000001



Printed 29/03/2012



10 Conclusions and Recommendations ................................................................... 22

Appendix A............................................................................................................................ 23

A.1 List of Reviewed Information .......................................................................... 23

Appendix B............................................................................................................................ 24

B.1 Photographic Records ..................................................................................... 24

Appendix C............................................................................................................................ 33

C.1 General Arrangement Drawing ...................................................................... 33

C.2 Demolition - Piers & Abutments ..................................................................... 34

C.3 Piers - Shafts & Walls ...................................................................................... 35

C.4 Main Girder Steelwork ..................................................................................... 36

C.5 Main Girder Steelwork Details........................................................................ 37

C.6 Piers – Waterproofing & Drainage ................................................................. 38

Appendix D............................................................................................................................ 39

D.1 Quail Diagram ................................................................................................... 39

D.2 Network Rail 5 Mile Diagram (VIR route only) ............................................. 40

List of figures

Page number

Figure 1: Location Plan........................................................................................................... 8

Figure 2: Proposed Thames Tunnel alignment .................................................................. 9

Figure 3: Plan of Grosvenor Rail Bridge Superstructure ................................................... 9

Figure 4: Bridge and track locations ................................................................................... 10

Figure 5: Typical Girder Longitudinal Section ................................................................... 11

Figure 6: Cross Sections through Steelwork..................................................................... 13

Figure 7: Old Bridge Pier Elevation .................................................................................... 14

Figure 8: River Pier Elevation and Cross Section ............................................................ 15

List of photographs

Page number

Photo 1: Grosvenor Rail Bridge – West Elevation (Looking East) ................................ 24

Photo 2: Grosvenor Rail Bridge – Span 1 (Looking East) .............................................. 24

Photo 3: Grosvenor Rail Bridge – Arch connection to substructure .............................. 25

Photo 4: Grosvenor Rail Bridge – Cast-iron Half-pin bearing at sprining point ........... 25

Photo 5: Grosvenor Rail Bridge – Pier 1 showing bearings ........................................... 26

307-RI-TPI-BR009-000001



Printed 29/03/2012

Photo 6: Grosvenor Rail Bridge – Pier 1............................................................................ 26

Photo 7: Grosvenor Rail Bridge – Joint in deck over Pier 1 ........................................... 27

Photo 8: Grosvenor Rail Bridge – Pier 1............................................................................ 27

Photo 9: Grosvenor Rail Bridge – Span 3 ......................................................................... 28

Photo 10: Grosvenor Rail Bridge – Underside of deck and superstructure ................. 28

Photo 11: Grosvenor Rail Bridge – View of deck drainage from North parade ........... 29

Photo 12: Grosvenor Rail Bridge – Deck and Parapet on East side............................. 29

Photo 13: Grosvenor Rail Bridge – Utilities troughs between individual bridges ........ 30

Photo 14: Grosvenor Rail Bridge – Gas pipe between bridges 5 & 6 ........................... 30

Photo 15: Grosvenor Rail Bridge – Gas Pipe entering ground at the North Parade .. 31

Photo 16: Grosvenor Rail Bridge – Typical bracket support with rubber seating........ 31

Photo 17: Grosvenor Rail Bridge – Gas Pipe entering ground under bridge VTB1 8 adjacent to the south abutment of the Grosvenor Bridge ........................... 32

List of abbreviations

CSO Combined Sewer Overflow

TT Thames Tunnel

PBA Peter Brett Associates

STW Sewage Treatment Works

PLA Port of London Authority

307-RI-TPI-BR009-000001



Printed 29/03/2012

1 Introduction

1.1 Project Description

Thames Water is currently progressing with its planned London Thames Tideway Improvements programme. The improvement works consists of

construction of two new tunnels, the Thames Tunnel and the Lee Tunnel, together with a programme of Sewage Treatment Works (STW) upgrades.

Construction of the Thames Tunnel (TT), stretching approximately 23km

under the River Thames from West London to East London, is due to commence in 2014. The Tunnel will intercept the flow from the most

polluting Combined Sewer Overflows (CSO) of the existing system. The planned alignment runs mainly beneath the River Thames at depths of up to 40m below the river bed in order to minimise the potential impact on

third party assets.

The main Thames Tunnel is currently planned to be 7.2m internal

diameter with a primary and secondary lining giving an effective 8.5m external diameter with an excavated cut diameter of 8.8m. A number of smaller additional tunnels are required to connect the existing CSOs to the

main tunnel.

As part of the works, Thames Tunnel Project Team has appointed Peter

Brett Associates (PBA), and their sub-consultant Arup, to carry out the Thames Tunnel Detailed Bridge Assessments for Sub-Package 2C bridges. Grosvenor Rail Bridge is one of the bridges being assessed within

this Sub-Package. The purpose is to demonstrate that the predicted effects from ground movements, induced by the TT works, are within

acceptable limits.

1.2 Works at Grosvenor Rail Bridge

The main Thames Tunnel is to be constructed beneath Grosvenor Rail Bridge span 3 (refer to Figure 3 for span numbers) running east to west, at

a depth of 34m below river bed level. The excavated diameter of the tunnel will be 8.8m, internal finished diameter 7.2m. A location plan of the

bridge is included in Section 4.1.

1.3 Purpose of this Document

This Inspection Report presents the findings of the desk study and visual

and element specific inspection, carried out in order to inform subsequent assessment of the bridge for the effects of ground movements due to tunnel construction. It will discuss the observations made, in both the desk

study and inspection, and state recommendations for further work, as appropriate.

307-RI-TPI-BR009-000001



Printed 29/03/2012

2 Desk Study

A desk study was carried out prior to the site inspection, with the following aims:

a. To gain an understanding of the structural behaviour of the bridge;

b. To review the available information, and determine where additional information might be required in order to carry out the assessment;

c. To prepare for, and plan, the site inspection.

A list of the documents, and other information, that were reviewed during the desk study is provided in Appendix A. Specific findings of the desk

study are reported in Section 6.

3 Site Inspection Purpose and Methodology

The site inspection was carried out with the following aims:

a. To gain an understanding of the structural behaviour of Grosvenor Rail Bridge to supplement that gained from desk study;

b. Where possible, to confirm that the data made available for this structure reflects the current situation;

c. To note any features of the structure that may be particularly affected

by settlement due to the construction of the Thames Tunnel;

d. To confirm, wherever possible, the locations of utility services within

the bridge or that may be affected by settlement of the bridge itself;

e. And to note any heritage features of the structure.

The inspection was carried out on 15th February 2012 in fair conditions.

The inspection comprised a visual inspection of all accessible elements of the bridge from public areas only. The inspection was carried out from

ground level and no intrusive works were undertaken.

The area of investigation was all regions of the bridge that were easily accessible from public areas, including the Thames Path adjacent to the

river, the North Parade, and the footpath adjacent to the A3216 on the Chelsea Road Bridge. The inspection also included observations of any

structures immediately adjacent to the bridge which could be affected by settlement of the bridge itself.

A photographic record of the inspection is given in Appendix B.

307-RI-TPI-BR009-000001



Printed 29/03/2012

4 Description of the Structure

4.1 General

Grosvenor Rail Bridge is a four span underline bridge and spans the River

Thames in London. Spans are numbered 1 to 4 from the north. The bridge lies on the Brighton Main Line and Chatham Main Line between London Victoria and Battersea Pier Junction and has capacity to carry ten tracks.

For orientation, the North end refers to the abutment on the North bank of the River Thames and the East side refers to the side of the downside

lines. The structure is located at Grid Reference TQ 287 778, a location plan is shown below. Grosvenor Rail Bridge is owned by Network Rail, and has the following references:

Name: Grosvenor River Bridge (Thames)

Structure Number: VIR 5 & VTB1 5

ELR: VIR & VTB1

Mileage: 0m 65ch

Figure 1: Location Plan


307-RI-TPI-BR009-000001



Printed 29/03/2012

Figure 2: Proposed Thames Tunnel alignment

The bridge is constructed of four spans. Span 1(Northern span) and span 4 are each 181’6’’ (55.3m) long & spans 2 and 3 are each 187’4’’ (57.1m) long. The piers are perpendicular to the spans. Refer to Figure 3 below

and the General arrangement drawing in Appendix C.1. For general views of the structure refer to Photos 1, 2 and 9.

Figure 3: Plan of Grosvenor Rail Bridge Superstructure

Span 1 Span 2 Span 3 Span 4

307-RI-TPI-BR009-000001



Printed 29/03/2012

4.2 History

Grosvenor Rail Bridge is a railway bridge crossing the River Thames, located between Chelsea Bridge and Vauxhall Bridge and serving Victoria

station.

The original bridge designed by Sir John Fowler was built in 1859 of

wrought iron and carried two tracks to Victoria Station as part of the Victoria and Pimlico Railway.

In 1865 the bridge was widened, designed by Sir Charles Fox and Son, to

carry a further five tracks for the London and Chatham Railway. A two platform passenger station, Grosvenor Road Station, was also added in

between these additional tracks.

The bridge was further widened in 1901 to carry two tracks of the London, Brighton and South Coast Railway.

The current bridge, bui lt between 1963 and 1967, replaced the original that had deteriorated to a point where the weakened condition was

inadequate for the loads it was anticipated to carry and the maintenance costs were too great. Designed by Freeman, Fox & Partners, the current bridge was rebuilt on the same site as the original Victoria Bridge and

actually consists of ten separate bridges each carrying a single track.

It was decided that the existing piers and foundations would be utilised in

the new design, however they were not large enough to resist the thrust of the new superstructure. To resolve this, the foundations were widened, repaired and the different types of existing foundation were merged into

one pier between each span.

The superstructure was then removed and replaced one track at a time to

reduce the impact on passenger journeys.

Although the bridge has capacity for 10 tracks it would appear from the QUAIL Diagram (Appendix D) that only 9 are in use (four up / four down /

one reversible).

4.3 Superstructure

The superstructure is formed of ten separate mild steel bridges each

carrying a single track. The bridges are numbered 1 to 9 from west to east as per the position of the original 9 tracks. Bridge 10 is then located between bridge numbers 5 and 6 as shown in Figure 4.

Figure 4: Bridge and track locations

Each of the ten bridges is formed of two circular two-pinned arch ribs across each river span as described in the ‘The Reconstruction of the

Grosvenor Railway Bridge’ by O.A.Keresnky and F.A.Partridge, Paper No.7003.

307-RI-TPI-BR009-000001



Printed 29/03/2012

The welded box arch ribs support the steel deck which contains the ballasted track.

Figure 6 shows a series of cross-sections through the deck structure and

arch ribs.

According to the paper noted above, the deck acts as a lateral girder

between the piers to resist forces due to wind and nosing.

Mild steel was chosen for the superstructure due to its performance in deflection and fatigue.

The arches have a clear span between pier faces of 164’ (50m). Span 1 and 4 are each 181’6’’ (55.3m) long & spans 2 and 3 are each 187’4’’

(57.1m) long, between pier centrelines.

The bridge deck has a width of 167’7.5’’ (50.1m) at parapet level and a width of 163’7.5’’ (49.9m) at both arch crown and pier level.

For the General Arrangement drawing, refer to Appendix C.1.

4.3.1 Main Girders

The welded box arch ribs are 3’8.5’’(1.1m) deep and 2’(0.6m) wide and have diaphragms at the points of concentrated load i.e. at the location of spandrel members.

Again as per Paper No.7003, the ends of the arch ribs are finished with a 6’’(150mm) thick welded-on transverse slab machined for engagement

with a Meehanite cast-iron half-pin, 7’’(178mm) in diameter and 2’(0.6m) long, mounted on the pier.

Figure 5: Typical Girder Longitudinal Section

4.3.2 Ancillary structural members

The deck is considered to be of ‘battledeck’ construction with a steel plate

supported by longitudinal stringers which are themselves supported by cross beams.

At the piers the deck is supported by roller bearings allowing for horizontal

movement along the length of the bridge. The deck includes bearing stiffeners above the point of contact with the bearings.

307-RI-TPI-BR009-000001



Printed 29/03/2012

It is also clear that no cross-bracing between the columns, or lateral bracing, has been provided because the rigidity at the junctions between the deck and the arch ribs is designed to provide enough lateral stability

(again this was reported in Paper No.7003).

307-RI-TPI-BR009-000001



Printed 29/03/2012

Figure 6: Cross Sections through Steelwork

307-RI-TPI-BR009-000001



Printed 29/03/2012

4.4 Substructure

4.4.1 Abutments

The original abutments from the earlier Victoria Bridge were considered

suitable for the new construction so were simply altered aesthetically in line with the finished piers.

The north abutment was altered due to the widening of the Grosvenor Road resulting in a 10’(3m) wide colonnade, the columns of which support the north end of the deck.

4.4.2 Piers

The piers associated with the original bridge were brickwork with a

limestone block exterior. To accommodate the widening in 1865 further brickwork and limestone block foundations were constructed; likewise in 1901 a further section of pier this time of concrete with a granite block

exterior was constructed.

Figure 7: Old Bridge Pier Elevation

The most suitable approach to constructing piers for the new bridge was to

create a monolithic structure by stripping away the existing masonry and encompassing all the historic foundations with reinforced concrete. This

resulted in a final pier width of 45’(13.7m).

The existing foundations were also grouted to reduce the porosity of the older concrete.

As can be seen in Figure 8 and as is recorded in Paper No.7003 that has been referred to previously, the piers taper from the base but widen again at springing level to shorten the span of the arch from 175’(53.3m) to

164’(50m). This is reported to reduce the overturning moment by 16%.

Photo 5 in Appendix B shows Pier 1 and the detail discussed above. It can

also be seen that the pier supports a reinforced concrete wall which in turn supports the deck across the piers on a series of roller bearings.

307-RI-TPI-BR009-000001



Printed 29/03/2012

Figure 8: River Pier Elevation and Cross Section

4.4.3 Arch Springings

The arch ribs are connected to the springing point on the reinforced concrete pier via the thick end plate on the rib and the Meehanite cast-iron half-pin, 7’’(178mm) in diameter and 2’(0.6m) long, that is connected to the

pier. Refer to Figure 8 and Photo 4.

4.4.4 Movement Joints and Articulation

The deck is supported across the piers and at both abutments on a series of single roller bearings positioned under the end of the crossbeams. The roller bearings allow movement or expansion of the deck along the length

of the bridge.

As reported in Paper no.7003, the bearings are set 3/8’’(10mm) high in

order to prevent uplift due to live load on the penultimate bay of the deck; this necessitates holding down the deck at the end columns (each is accordingly welded to crossbeam and to rib), the remaining columns are

designed as simple round-ended props.

4.5 Foundations

The foundations consist of the previous piers as described in Section 6.2.2

encased in reinforced concrete up to the cofferdam that was used to reconstruct the piers in 1967.

The foundations can be assumed to be in good condition and performing adequately as there are no reported defects of the superstructure which would give concern regarding their condition or performance. The 2010

Amey Structural Underwater Assessment Report found that the foundations and substructure were in a fair condition overall. Small areas

of concrete spalling were noted.

307-RI-TPI-BR009-000001



Printed 29/03/2012

4.6 Finishes

There are several finishes that have been used on the different elements of the bridge superstructure and substructure that have been recorded in

Paper No.7003, previously referenced, and that are summarised below.

The concrete of the abutments and piers were covered i n a

chlorinated rubber-based coating.

The steel deck was waterproofed using bitumen and bituminous

sheeting protected by ‘brindle Ruabon reject tiles’ on the base and precast concrete slabs on the sides.

Both the arch ribs and columns are sealed to ensure they are air-

tight so that internal corrosion cannot occur.

The deck units underwent a blast-cleaning and primer process

during fabrication before being finished on site with iron-oxide paint.


Eight steel cable ducts are present between the separate bridges which

carry power, signal and telephone cables. The ducts are supported by brackets cantilevered off the rib arch girders.

All brackets appear to have a rubber seating which allows for movement of

the bridge structure or the services without inducing stresses in the cables.

Neoprene pads between the lengths of duct provide the same function.

Two 36 inch (0.9m) diameter steel gas pipes are located between bridges 9 & 8 and 10 & 5 and again are supported on brackets cantilevering off the adjacent arch ribs.

The gas pipes are seated on rubber shear-compression units and have expansion bellows located just before the pipe runs underground at both

the north and south abutments. Refer to Photos 15 to 17 in Appendix B.

The deck of the river spans is flat so drainage is provided by outlets at intervals of each individual bridge. These pipes run into a 4 inch diameter

cast-iron pipe to the pier wall from where it is discharged into the river.

The land spans are self draining into pipes positioned at the end of the

spans that carry the water down the abutment and discharge into the river.

A footway and post-and-rail balustrade has been constructed on each side of the bridge.

4.8 Rail Infrastructure

The desk study and site visit identified that the bridge currently carries nine tracks. The tracks have been identified as four up, four down, and

one reversible between London Victoria and Battersea Pier Junction.

No switches or crossings are present on the bridge; however there are a

number of switches and crossings to the south of the bridge that sit outside the influence of the settlement trough.

307-RI-TPI-BR009-000001



Printed 29/03/2012

The tracks are straight as identified on the Network Rail 5 Mile Line Diagram for Victoria (21st September 2006) (Appendix D).

The line speed is restricted to 40mph for all four lines shown on the VIR

route 5 Mile Diagram. No 5 Mile Diagram is available for the VTB route and line speeds are assumed to be the same as on the VIR route.

5 Access Arrangements for Inspection

Access to the bridge for inspection was from publicly accessible areas as noted in Section 3. The inspection was carried out from ground level and no intrusive works were undertaken.

Most elements of the superstructure could be visually inspected from these areas.

The substructure and underside of the deck (particularly in the mid river spans) was not inspected due to a lack of access to these areas.

To carry out a more detailed inspection, access would be needed to the

service walkways on the bridge, with roped access to inspect the underside of the bridge. A boat or barge on the River Thames would be

required to inspect the substructure.

6 Findings of the Inspection

6.1 Superstructure

The parts of the main girders that were accessible were generally in a

good condition. No corrosion or cracking was noted during the inspection.

The top of the arch ribs appeared to be discoloured as can be seen in Photo 10 (Appendix B), it is unclear what has caused this discolouration,

however it is possible that general dust and smog is the cause. There didn’t however appear to be any noticeable section loss.

There was a localised area of deformation within the external girder on the west side of the bridge Span 1; it is likely to have been caused by ship impact.

No other defects were noted. However, no detailed Examination or Assessment Reports have been made available and it was not possible to

inspect all areas of the bridge within the limits of the current inspection.

Within the scope of the site inspection, bearing in mind access was limited to public areas only; the inspection confirmed that the available

information broadly reflects the layout and details of the structure.

6.2 Substructure

The substructure is assumed to be in good condition and performing adequately as there are no reported, or visible, defects of the

superstructure which would give concern regarding the condition and performance of the substructure.

307-RI-TPI-BR009-000001



Printed 29/03/2012

There was water dripping from the deck at the north abutment. There appeared to be discolouration currently caused by the presence of the water but there were no obvious signs of any resulting corrosion.

Inspection of the bearings, abutments, and piers was not possible.

No Detailed Examination or Assessment Reports have been made

available and a detailed examination was not carried out.

Within the scope of the site inspection, bearing in mind access was limited to public areas only; the inspection confirmed that the available

information broadly reflects the layout and details of the structure.

6.3 Articulation and Movement Capacity

Bearings and movement joints could not be inspected or measured during

the current inspection.

It is assumed that they are generally in good condition and are performing adequately as there are no apparent defects of the superstructure which

would give concern regarding their condition or performance.

Within the scope of the site inspection, bearing in mind access was limited

to public areas only; the inspection confirmed that the available information broadly reflects the layout and details of the structure.

6.4 Parapets

The footway and post-and-rail balustrade appears to be in good condition. This could not be inspected due to access arrangements.

6.5 Foundations

Inspection of the foundations of the abutment and piers was not possible.

The foundations can be assumed to be in good condition and performing

adequately as there are no reported defects of the superstructure which would give concern regarding their condition or performance.

The 2010 Amey Structural Underwater Assessment Report found that the

foundations and substructure were in a fair condition overall. Small areas of concrete spalling were noted.


In addition to the services as described in Section 4.7 which show no noticeable defects, information received indicates Cable & Wireless, BT

services and other cables across the bridge.

Due to the inspection being limited to public areas only, it was not possible to inspect the utilities along the rail corridor and hence their condition was

not ascertained.


No information on the condition of the rail infrastructure is available and no

inspection could be undertaken due to the limitations on access to public areas only.

307-RI-TPI-BR009-000001



Printed 29/03/2012

7 Condition Factors for Assessment

Structural calculations for the main steel arch ribs and the steel superstructure, if required, would be based on section dimensions found in

the reviewed material listed in Appendix A as well as the current visual inspection.

No further inspection of the main girders is proposed.

An overall condition factor of 1.0 will be applied. This is based on the condition of members visible during the inspection; bearing in mind access

was limited to public areas only. The visible members appeared to be in a good condition.

307-RI-TPI-BR009-000001



Printed 29/03/2012

8 Adjacent Structures

Other nearby structures

Other structures that have been identified close to Grosvenor Rail Bridge

that may be affected by the tunnelling works are:

Chelsea Road Bridge;

Pedestrian bridge adjacent to Grosvenor Road crossing the Grosvenor Waterside marina inlet;

Crane and dockyard infrastructure adjacent to the disused Battersea Power Station.

From provisional settlement trough profi les it is likely that the above

structures sit outside the 1mm contour.

The Chelsea Road Bridge is being assessed as part of another Detailed

Bridge Assessment Package.

9 Discussion

9.1 Review of Available Data

Prior to the inspection, a desk study of available information was carried

out. This was based on documents listed in Appendix A. The document that contains the most information on the existing bridge is ‘The Reconstruction of the Grosvenor Railway Bridge’ by O.A.Keresnky and

F.A.Partridge, Paper No.7003. This paper is a summary of the reconstruction of Grosvenor Bridge in 1967 to its current form and includes

dimensions of main structural elements as well as details discussed in Section 6.

9.2 Structural Issues

Information gained from the inspection and ‘The Reconstruction of the Grosvenor Railway Bridge’ by O.A.Keresnky and F.A.Partridge, Paper No.7003 shows that the structural behaviour of Grosvenor Rail Bridge is a

series of arch spans between massive reinforced concrete piers.

Adequate information is available to carry out the structural assessment.

9.3 Finishes

From the site inspection it appeared that the finishes described in Section 6.4 were still working as anticipated with only two notable points of minor

deterioration.

There was water dripping from the deck at the north abutment. There appeared to be discolouration currently caused by the presence of the

water but there were no obvious signs of any resulting corrosion.

The top of the arch ribs appeared to be discoloured as can be seen in

Photo 10 (Appendix B), it is unclear what has caused this discolouration. There didn’t however appear to be any noticeable section loss.

307-RI-TPI-BR009-000001



Printed 29/03/2012

9.4 Heritage Issues

The bridge is not listed and does not have any features of particular historical interest.


The desk study and site visit identified that the bridge carries currently nine tracks, identified as four up, four down aned one reversible between

London Victoria and Battersea Pier Junction.

No switches or crossings are present on the bridge.

The tracks are straight as identified on the Network Rail 5 Mile Line Diagram for Victoria (20th July 2010) (Appendix D).

The line speed is restricted to 40mph for all four lines shown on the VIR

route 5 Mile Diagram. No 5 Mile Diagram is available for the VTB route and line speeds are assumed to be the same as on the VIR route.

The information available is adequate to proceed with assessment of the rail infrastructure.


The services crossing and in the vicinity of the bridge appeared to be as

described in Section 6.6 with no noticeable defects.

Eight steel cable ducts are present between the separate bridges and are

supported by brackets off the girders.

The gas pipes are located between bridges 9 & 8 and 10 & 5 and again are supported on brackets cantilevering off the adjacent girder.

All brackets appear to have a rubber seating which allows for movement of the bridge structure or the services without inducing stresses in the cables

or gas pipes.

Information received indicates Cable & Wireless and BT services across the bridge.

Due to the existing provision for movement within the services and utility infrastructure and the fact that the telecommunication services identified

crossing the bridge comprise solely of flexible cabling and ducts , it is anticipated that ground settlements will have negligible effect and therefore the information available is adequate to proceed with the

assessments.

307-RI-TPI-BR009-000001



Printed 29/03/2012

10 Conclusions and Recommendations

The visual and element specific inspection was carried out on 15th February 2012 and the data from the inspection was collated with that from desk studies. The following conclusions were reached:

Sufficient dimensional data and condition information has been acquired from the inspection and desk study to proceed with the

assessment of the structure for effects of settlement due to the proposed construction of the Thames Tunnel.

Assessment will be based on information provided in the reference documents and drawings listed in Appendix A.

There are no structural elements, or finishes, that would give

particular cause for concern in the event of moderate levels of settlement of the structure.

There are no heritage features of concern.

The cable troughs and two gas mains that cross the bridge are

seated on rubber pads on the bracket supports, allowing for expansion and movement. Thus it is anticipated that ground movements will have negligible effect. The information available is

adequate to proceed with the assessments.

As the telecommunication services identified crossing the bridge

comprise solely of flexible cabling and ducts, it is anticipated that ground movements will have negligible effect and therefore the

information available is adequate to proceed with the assessments.

Assessment of the permanent way can proceed with the information gained from the desk study and inspection.

Calculations are being carried out as part of the Thames Tunnel Detailed Bridge Assessments, to determine the anticipated ground movements at

Grosvenor Rail Bridge. Adequate information is available to continue with the assessment of the effects of ground movement on the structure.

307-RI-TPI-BR009-000001



Printed 29/03/2012

Appendix A

A.1 List of Reviewed Information

a. ‘The Reconstruction of the Grosvenor Railway Bridge’ by O.A.Keresnky and F.A.Partridge, Paper No.7003, 1967

b. Amey Structural Underwater Assessment Report, 2010

c. British Railways, Marples Ridgway Ltd. Grosvenor Bridge General Arrangement Drawing, 1968

d. British Railways, Marples Ridgway Ltd. Grosvenor Bridge Piers & Abutments, 1968

e. British Railways, Marples Ridgway Ltd. Grosvenor Bridge Shafts & Walls, 1968

f. British Railways, Marples Ridgway Ltd. Grosvenor Bridge Main Girder

Steelwork, 1968

g. British Railways, Marples Ridgway Ltd. Grosvenor Bridge Main Girder

Steelwork Details, 1968

h. British Railways, Marples Ridgway Ltd. Grosvenor Bridge Waterproofing & Drainage, 1968

i. Waterman Civi ls (2010). AutoRAIL 5 Mile Line Diagrams. Issue 38. Last updated October 2009.

j. QUAIL Diagram, Victoria and Waterloo, Quail Map Company

307-RI-TPI-BR009-000001



Printed 29/03/2012

Appendix B

B.1 Photographic Records

Photo 1: Grosvenor Rail Bridge – West Elevation (Looking East)

Photo 2: Grosvenor Rail Bridge – Span 1 (Looking East)

307-RI-TPI-BR009-000001



Printed 29/03/2012

Photo 3: Grosvenor Rail Bridge – Arch connection to substructure

Photo 4: Grosvenor Rail Bridge – Cast-iron Half-pin bearing at springing point

307-RI-TPI-BR009-000001



Printed 29/03/2012

Photo 5: Grosvenor Rail Bridge – Pier 1 showing bearings

Photo 6: Grosvenor Rail Bridge – Pier 1

307-RI-TPI-BR009-000001



Printed 29/03/2012

Photo 7: Grosvenor Rail Bridge – Joint in deck over Pier 1

Photo 8: Grosvenor Rail Bridge – Pier 1

307-RI-TPI-BR009-000001



Printed 29/03/2012

Photo 9: Grosvenor Rail Bridge – Span 3

Photo 10: Grosvenor Rail Bridge – Underside of deck and superstructure

307-RI-TPI-BR009-000001



Printed 29/03/2012

Photo 11: Grosvenor Rail Bridge – View of deck drainage from North parade

Photo 12: Grosvenor Rail Bridge – Deck and Parapet on East side

307-RI-TPI-BR009-000001



Printed 29/03/2012

Photo 13: Grosvenor Rail Bridge – Utilities troughs between individual bridges

Photo 14: Grosvenor Rail Bridge – Gas pipe between bridges 5 & 6

307-RI-TPI-BR009-000001



Printed 29/03/2012

Photo 15: Grosvenor Rail Bridge – Gas Pipe entering ground at the North Parade

Photo 16: Grosvenor Rail Bridge – Typical bracket support with rubber seating

Expansion bellow is visible at the

top of the northern vertical

section of pipe.

307-RI-TPI-BR009-000001



Printed 29/03/2012

Photo 17: Grosvenor Rail Bridge – Gas Pipe entering ground under bridge VTB1 8

adjacent to the south abutment of the Grosvenor Bridge

Expansion bellow is visible within

southern vertical section.

307-RI-TPI-BR009-000001



Printed 29/03/2012

Appendix C

C.1 General Arrangement Drawing

307-RI-TPI-BR009-000001



Printed 29/03/2012

C.2 Demolition - Piers & Abutments

307-RI-TPI-BR009-000001



Printed 29/03/2012

C.3 Piers - Shafts & Walls

307-RI-TPI-BR009-000001



Printed 29/03/2012

C.4 Main Girder Steelwork

307-RI-TPI-BR009-000001



Printed 29/03/2012

C.5 Main Girder Steelwork Details

307-RI-TPI-BR009-000001



Printed 29/03/2012

C.6 Piers – Waterproofing & Drainage

307-RI-TPI-BR009-000001



Printed 29/03/2012

Appendix D

D.1 Quail Diagram

307-RI-TPI-BR009-000001



Printed 29/03/2012

D.2 Network Rail 5 Mile Diagram (VIR route only)

Copyright notice Copyright © Thames Water Utilities Limited September 2013. All rights reserved. Any plans, drawings, designs and materials (materials) submitted by Thames Water Utilities Limited (Thames Water) as part of this application for Development Consent to the Planning Inspectorate are protected by copyright. You may only use this material (including making copies of it) in order to (a) inspect those plans, drawings, designs and materials at a more convenient time or place; or (b) to facilitate the exercise of a right to participate in the pre-examination or examination stages of the application which is available under the Planning Act 2008 and related regulations. Use for any other purpose is prohibited and further copies must not be made without the prior written consent of Thames Water. Thames Water Utilities LimitedClearwater Court, Vastern Road, Reading RG1 8DB The Thames Water logo and Thames Tideway Tunnel logo are © Thames Water Utilities Limited. All rights reserved.

Copyright notice Copyright © Thames Water Utilities Limited September 2013. All rights reserved. Any plans, drawings, designs and materials (materials) submitted by Thames Water Utilities Limited (Thames Water) as part of this application for Development Consent to the Planning Inspectorate are protected by copyright. You may only use this material (including making copies of it) in order to (a) inspect those plans, drawings, designs and materials at a more convenient time or place; or (b) to facilitate the exercise of a right to participate in the pre-examination or examination stages of the application which is available under the Planning Act 2008 and related regulations. Use for any other purpose is prohibited and further copies must not be made without the prior written consent of Thames Water. Thames Water Utilities LimitedClearwater Court, Vastern Road, Reading RG1 8DB The Thames Water logo and Thames Tideway Tunnel logo are © Thames Water Utilities Limited. All rights reserved.

10243-A4P-Copyright-imp-V01.pdf p1 12:03:39 September 21, 2013