hk notabletunnel cat

Catalogue of Notable

Tunnel Failures -

Case Histories

(up to April 2015)

Prepared by Mainland East Division Geotechnical Engineering Office

Civil Engineering and Development Department

This catalogue of notable tunnel failures is primarily

based on published information. Both local and international

cases involving collapse or excessive deformation of the

ground are included. For contractual and other reasons, there

are relatively few cases reported in technical publications, and

those reported are usually of such scale or seriousness that

they have received public attention. Even for the cases reported,

usually only limited information is available. Apart from the

cases included, readers can find other information on tunnel

failure in the list of Bibliography given at the end of this

catalogue.

This catalogue is a live document that will be updated

from time to time as further information becomes available.

Readers are always welcome to provide us with additional

information about cases in this catalogue for future update.

The main purpose of the catalogue is to disseminate

information and promote awareness on tunnel failures which

could pose a danger to life and property. The possible causes

of the failures, the geotechnical problems and the lessons learnt,

where these are known, are outlined in the catalogue. Readers

should refer to the source reference documents quoted for

details. Clients and works agents are advised to implement

effective geotechnical risk management measures in the

planning, investigation, design and construction of their tunnel

projects.

The first edition of the catalogue was issued in February

2007 and was put together by Mr W Lee, supervised by Mr K J

Roberts. The second edition issued in March 2009 was prepared

by Ms L Y Pau, supervised by Mr L P Ho. The third edition issued

in October 2012 was prepared by Ms L Y Pau, supervised by Mr K

S Chau. This fourth edition was prepared by Ms K L Wong and Mr

H H Chan, supervised by Mr K S Chau. GEO staff, members of the

Hong Kong Institution of Engineers Geotechnical Division

Working Group on Cavern and Tunnel Engineering and other

individuals have contributed to this catalogue. All contributions

are gratefully acknowledged. Special thanks are given to Mr Guy

Lance for his valuable advice and guidance given to revising the

systematic structure of this catalogue, sourcing figures and

references from tunnel publications as well as editing reported

cases.

If any information in this catalogue is found to be

inaccurate or out-of-date, please contact the Chief Geotechnical

Engineer/Mainland East of the Geotechnical Engineering Office,

Civil Engineering and Development Department, 101 Princess

Margaret Road, Ho Man Tin, Kowloon, Hong Kong.

N F Chan

Chief Geotechnical Engineer/Mainland East

Geotechnical Engineering Office


April 2015


The Government of the Hong Kong Special Administrative Region

1. Green Park, London, UK, 1964

2. Victoria Line Underground, London, UK, 1965

3. Southend-on-sea Sewage Tunnel, UK, 1966

4. Rrvikskaret Road Tunnel on Highway 19, Norway, 18 March

1970

5. Orange-fish Tunnel, South Africa, 1970

6. Penmanshiel Tunnel, Scotland, UK, March 1979

7. Munich Underground, Germany, 1980

8. Holmestrand Road Tunnel, Norway, 16 Dec. 1981

9. Gibei Railway Tunnel, Romania, 1985

10. Moda Collector Tunnel, Istanbul Sewerage Scheme, Turkey, 1989



11. Seoul Metro Line 5 - Phase 2, Korea, 17 Nov. 1991

12. Seoul Metro Line 5 - Phase 2, Korea, 27 Nov. 1991

13. Seoul Metro Line 5 - Phase 2, Korea, 11 Feb. 1992

14. Seoul Metro Line 5 - Phase 2, Korea, 7 Jan. 1993

15. Seoul Metro Line 5 - Phase 2, Korea, 1 Feb. 1993

16. Munich Underground, Germany, 27 Sept. 1994

17. Heathrow Express, UK, 21 Oct. 1994

18. Los Angeles Metro, USA, 22 June 1995

19. Motorway Tunnels, Austria, 1993 - 1995

20. Docklands Light Rail, UK, 23 Feb. 1998



21. Athens Metro, Greece, 1991-1998

22. L rdal Road Tunnel on European Highway E 16, Norway, 15

June 1999

23. Sewage Tunnel, Hull, UK, 1999

24. Taegu Metro, South Korea, 1 Jan. 2000

25. Wastewater Tunnel, Portsmouth, UK, May 2000

26. Dulles Airport, Washington, USA, Nov. 2000

27. Istanbul Metro, Turkey, Sept. 2001

28. Channel Tunnel Rail Link, UK, Feb. 2003

29. Mtor Metro Tunnel, France, 14 Feb. 2003

30. Oslofjord Subsea Tunnel, Norway, 28 Dec. 2003



31. Shanghai Metro, China, 2003

32. Nikkure-yama Tunnel, Japan, 2003

33. Guangzhou Metro Line 3, China, 1 April 2004

34. Singapore MRT, 20 April 2004

35. Kaoshiung Rapid Transit, Taiwan, 29 May 2004

36. Oslo Metro Tunnel, Norway, 17 June 2004

37. Kaoshiung Rapid Transit, Taiwan, 10 Aug. 2004

38. Hsuehshan Tunnel, Taiwan, 1991-2004

39. Barcelona Metro, Spain, 27 Jan. 2005

40. Lausanne M2 Metro, Switzerland, 22 Feb. 2005



41. Lane Cove Tunnel, Australia, 2 Nov. 2005

42. Kaoshiung Rapid Transit, Taiwan, 4 Dec. 2005

43. Nedre Romerike Water Treatment Plant Crude Water and Potable

Water Tunnels, Norway, 2005

44. Interstate 90 Connector Tunnel, Boston, Massachusetts, USA, July

2006

45. Hanekleiv Road Tunnel, Norway, 25 Dec. 2006

46. Stormwater Management and Road Tunnel (SMART), Malaysia,

2003 2006

47. Sao Paulo Metro Station, Brazil, 15 Jan. 2007

48. Guangzhou Metro Line 5, China, 17 Jan. 2008

49. Langstaff Road Trunk Sewer, Canada, 2 May 2008

50. Circle Line 4 Tunnel, Singapore, 23 May 2008



51. M6 Motorway, Hungary, 24 Jul. 2008

52. Hangzhou Metro Tunnel, China, 15 Nov. 2008

53. Cologne North-South Metro Tram Line, Germany, 3 March 2009

54. Brightwater Tunnel, USA, 8 March 2009

55. Seattles Beacon Hill Light Rail, USA, July 2009

56. Glendoe Headrace Tunnel, Scotland, UK, Aug. 2009

57. Cairo Metro Tunnel, Egypt, 3 Sept. 2009

58. Headrace tunnel of Gilgel Gibe II Hydro Project, Ethiopia, Oct. 2006

and Jan. 2010

59. Blanka Tunnel, Czech Republic, 20 May 2008, 12 Oct. 2008 and 6

July 2010

60. Shenzhen Express Rail Link, 27 March 2011, 4 May 2011 and 10

May 2011



61. Mizushima Refinery Subsea Tunnel, Japan, 14 Feb. 2012

62. Hengqin Tunnel, Macau, 19 July 2012

63. Sasago Tunnel, Japan, 2 Dec. 2012

64. Ottawas Light Rail Transit Project, Canada, 20 Feb. 2014

65. Rios Metro Line 4, Brazil, 11 May 2014



1. MTR Modified Initial System, Prince Edward Station, Nathan

Road, Hong Kong,12 Sept. 1977

2. MTR Island Line, 22 Hennessy Road, Hong Kong, 1 Jan. 1983

3. MTR Island Line, Shing On Street, Shau Kei Wan, Hong Kong,

23 July 1983

4. MTR Island Line, 140-168 Shau Kei Wan Road, Hong Kong, 16

Dec. 1983

5. Kowloon Southern Link Contract KDB 200, Canton Road, Hong

Kong, 21 Oct. 2006

6. Kowloon Southern Link Contract KDB 200, Salisbury Road,

Hong Kong, 3 June 2007

Case No 1. Green Park, London, UK, 1964 Europe

United Kingdom

1964

Project Title Green Park to Victoria Tunnel, UK

Source of Information Clay, R.B. & Takacs, A.P. (1997). Anticipating the unexpected

Flood, fire overbreak, inrush, collapse. Proceedings of the

International Conference on Tunnelling Under Difficult Ground

and Rock Mass Conditions, Basel, Switzerland, pp 223-242.

Keywords (for searching) Green Park, London, UK, London Clay

Figures

Clay & Takacs (1997)

Background Segmental lined tunnel (Green Park to Victoria) driven through

London Clay with low soil cover

Nature and Type of Failure Construction failure

Inflow of sand and gravel, burying most of the shield

Ground and Groundwater Conditions London Clay overlain by water-bearing sands and gravels

Construction Methods and Support Using drum-digger shield

Possible Cause of Failure The crown of the shield penetrated through the London Clay

layer into sand and gravel

Consequence Little physical damage to the shield

Programme delayed

Emergency and Remedial Measures A shaft was sunk from the surface to enable the material to be

staunched and treated.

The loose material was dug out by hand

Lessons Learnt Unpublished

Case No 2. Victoria Line Underground, UK, 1965 Europe

United Kingdom

1965

Project Title Victoria Line Underground Railway





Keywords (for searching) Victoria Line, London, UK, London Clay

Figures


Background Tunnel (300m long and 3.7m internal diameter) driven through

London Clay under a disused railway marshalling yard


Inflow of sand and gravel

Ground and Groundwater Conditions London Clay underlain by sands and gravels

Construction Methods and Support Using hand-shield and lined with cast-iron

Possible Cause of Failure The shield was ineffective in supporting the overlying ground

Consequence No significant damage

Programme delayed for about 6 months

Emergency and Remedial Measures Lengthy grouting operation for stabilizing the ground in the

vicinity


Case No 3. Southend-on-Sea Sewage Tunnel, UK, 1966 Europe

United Kingdom

1966

Project Title Southend-on-Sea Sewage Tunnel, UK





Keywords (for searching) Southend-on-Sea, London, UK, London Clay

Figures


Background Tunnel 40m long with diameter of 1.35m driven mostly by hand


Water inflow into the tunnel

Ground and Groundwater Conditions London Clay overlain by sands and gravels

Construction Methods and Support Driven mostly by hand and lined with PCC segments

Possible Cause of Failure The tunnel intersected the bottom of an abandoned 600mm

diameter well

Consequence No loss of life or injury

Emergency and Remedial Measures The tunnel drive was continued in a timbered box heading and

two plates were fabricated for closed off the bottom of the well. Grouting was also applied


Case No 4. Rrvikskaret Road Tunnel on Highway 19, Norway, 18 March 1970

Europe

Norway

18 March 1970

Project Title Rrvikskaret Road Tunnel on Highway 19

Source of Information Karlsrud Kjell (2010). Technical Note : Experience with tunnel

failures in Norwegian tunnels. The Government of the Hong

Kong Civil Engineering and Development Department.

(Unpublished).

Keywords (for searching) Rrvikskaret, Norway, cave in

Figures

Karlsrud (2010)

Background The road tunnel was 726m long and 8m wide


Tunnel face collapsed and a 100m high cave-in shaft from the tunnel up to the ground surface was created

The top of the shaft on the ground surface had a dimension of about 25m x 50m

Although soft material was hauled out from the tunnel during the spring in 1971, cave-in continued from the shaft until autumn

1972

The cave-in zone extended 30m along the tunnel and the total volume of material hauled out from the tunnel was about

75,000m3

Ground and Groundwater Conditions Crystalline gneisses of granitic and syenitic composition

The tunnel was excavated into a large zone of swelling clay. The rock at the failure was completely altered to swelling clay

Construction Methods and Support Constructed by the drill-and-blast method and mainly supported

by rock bolts, steel straps and mesh

Possible Cause of Failure Preliminary investigation carried out without any drilling

Probe drilling was not performed during tunnelling

No stabilization measures to support a large swelling clay section before blasting

Consequence Programme delayed for more than 3 years

Double the cost of the tunnel compared to the estimated cost

Emergency and Remedial Measures Installation of corrugated steel vault, steel tubes and 500mm thick

concrete lining was not successful

The cave-in ceased after filling of about 3,000m3 concrete into the

shaft to form a plug from the tunnel up to 10m above the crown

and another 4,000m3 of sand and stone from the top of the shaft

above the concrete plug

Lessons Learnt The importance of the adequate ground investigation to identify if

weak ground is present and to provide measures to support the

weak ground before tunnel excavation

Case No 5. Orange-fish Tunnel, South America, 1970 South Africa

1970

Project Title Orange-fish Tunnel, South Africa





Keywords (for searching) Orange-fish, South Africa, fire

Figures N/A

Background Circular tunnel designed to carry irrigation water from the

Orange River (80km long and 5.3m in diameter, 1,200m above

sea level)


First failure Heavy water inflow (of about 55,000 litres/min into the tunnel at 14 bars)

Second failure Fire (Methane gas ignited by a blast, but no explosion occurred as the gas did not reach the explosive

concentration)

Ground and Groundwater Conditions Sandstones, siltstones and mudstones, generally horizontally

bedded with occasional dolerite dykes

Construction Methods and Support Tunnelling using the rail-mounted drill and blast method and lined

with 225mm of insitu concrete

1.5m long tensioned resin-grouted bolts at 1.5m spacing with occasional shotcrete

Possible Cause of Failure First failure The tunnel passed through a shallow anticline and

intersected a fissure, about 75mm wide, almost perpendicularly

Second failure Methane gas from a methane bearing fissure entered the tunnel during excavation

Consequence

First failure Entire 1.6km tunnel section flooded within 24 hours

Second failure The fire burnt for about 6 months

Emergency and Remedial Measures

First failure Grouting was carried out from the surface and the tunnel was pumped dry. Blob-grouting method with a ring of very thick grout of unhydrated bentonite to seal the fissures a short distance away from the tunnel was developed for the subsequent excavation

Second failure A wall was built across the tunnel, the void beyond, including the methane-bearing fissure, was grouted up with cement


Case No 6. Penmanshiel Tunnel, Scotland, UK, March 1979 Europe

Scotland, UK

March 1979

Project Title Enlargement of the Penmanshiel Tunnel

Source of Information McNaughton, I.K.A. (1983). Report on the collapse of Penmanshiel

Tunnel that occurred on 17th March 1979 in the Scottish Region, British Railways, Department of Transport, 7 p. .

Keywords (for searching) Europe, Scotland, 1979, Penmanshiel Tunnel, British Railways,

construction failure, fall of rock, anticlinal structure, over-stressed rock

Figures Penmanshiel Tunnel, near Grantshouse in Scotland

Source from http://en.wikipedia.org/wiki/Penmanshiel_Tunnel

Background The double rail track Penmanshiel tunnel of 7.72m span and

4.7m height was driven in 1845/1846

In 1979 the roof of the tunnel collapsed during tunnel enlargement works when the tunnel invert was being reconstructed to increase the headroom

Nature and Type of Failure

Ground failure during reconstruction

Fall of rock over a length of some 20m

Ground and Groundwater Conditions Sedimentary rock of steeply inclined and complex stratification

with an average cover of 25 to 30m

Dry conditions

Construction Methods and Support Rock bench system with an arch lined with 4 or 5 rings of bricks

Possible Cause of Failure The existence of complex anticlinal structure over the line of the

tunnel, which could not have been deduced from rock exposed in the tunnel but was later exposed in the open cut excavation after the diversion of the tunnel alignment

The degeneration of the rock within the anticlinal structure built up heavy loading on the arch ring and side walls

Additional excavation in the tunnel increased the stresses in the already overstressed rock in the side walls

Consequence Broken rock pouring into the tunnel with a complete blockage

13 workers escaped but 2 workers were killed

Emergency and Remedial Measures Immediate support provided to the adjacent portion of the tunnel

by a number of steel arches

Long term abandonment of 1,000m of the tunnel and the diversion of the line to a new alignment in open cut with the ends of the old tunnel filled in

Lessons learnt The consequences of adjusting the profile of a working tunnel

without stress analysis and appropriate support

The importance of understanding the geological conditions of the site and the need for analysis

Case No 7. Munich Underground, Germany, 1980 Europe

Gemany

1980

Project Title Munich Underground, Germany

Source of Information Construction Today (1994b). Unstable ground triggers Munich

tunnel collapse. Construction Today, October Issue, p 5.

Keywords (for searching) Munich, Germany, sinkhole

Figures

Construction Today (1994b)

Background New Austrian Tunnelling Method (NATM) construction of twin 6m

diameter tunnels


Huge flow of soft clay into the tunnel

Ground and Groundwater Conditions Flinty marl with 3m of cover above the tunnels, overlain by 12.5m

of soft clay

Construction Methods and Support New Austrian Tunnelling Method (NATM)

Possible Cause of Failure Local variation in geology with reduction in marl cover to 1-1.5m

and led to overstressing of the sprayed concrete temporary lining

Consequence 10m wide, 14m deep sinkhole

No injury

Emergency and Remedial Measures Void was backfilled with crushed rock and cement and pressure

grouted

Lessons Learnt The danger of tunnel excavation through thin marl cover

Case No 8. Holmestrand Road Tunnel, Norway, 16 Dec. 1981 Europe

Norway

16 December 1981

Project Title The Holmestrand Road Tunnel




(Unpublished).

Keywords (for searching) Keywords (for searching) Holmestrand, Norway, cave in

Figures

Karlsrud (2010)

Background The road tunnel was 1.78km long and 10m wide


A minor cave-in from the face and partly from the crown occurred during the process of moving the steel formwork for

cast concrete lining forward to the face

Ground and Groundwater Conditions Various rock types (basalt, volcanic dykes, soft siltstone and

quartz conglomerate)

Construction Methods and Support Constructed by the drill-and-blast method and supported by cast

concrete lining

Possible Cause of Failure A weak fault zone was encountered No spiling bolts ahead of the face to support the weak ground

Consequence More time (5 hours extended to 25 hours) required for hauling out

and concreting the foundation for the mould

Emergency and Remedial Measures About 600m3 of debris was hauled in to the face for temporary

support

Until break through, the tunnel was excavated with only 2m long bore holes combined with 6m long spiling bolts from the cast concrete

lining of the former round, and cast concrete lining close to the face

Lessons Learnt Spiling bolts ahead of the face in combination with fibre reinforced

sprayed concrete, rock bolts, and reinforced ribs of sprayed concrete

are required at the fault zones with extremely poor rock mass quality

Case No 9. Gibei Railway Tunnel, Romania, 1985 Europe

Romania

1985

Project Title Gibei Railway Tunnel, Romania





Keywords (for searching) Gibei, Romania

Figures


Background Railway tunnel 2.21km long and 9m in diameter


Compact fissured clay layer failed suddenly, allowing water inflow >600 litres/min into the tunnel

Ground and Groundwater Conditions Compacted Clay with fissures

Construction Methods and Support Shield (A hooded mechanical sheld 9.05 m in diameter, fitted

with a hydraulic bucket and a bottom-monuted conveyor belt)

Possible Cause of Failure The tunnel penetrated a lens of waterlogged fine-grained sand

just above the crown

Consequence Ingress of water at more than 10 L/s accompanied by running

sand to the tunnel covering the machine

Programme delayed for about 6 months

Emergency and Remedial Measures Unpublished


Case No 10. Moda Collector Tunnel, Istanbul Sewerage Scheme, Turkey, 1989

Europe

Turkey

1989

Project Title Moda Collector Tunnel





Keywords (for searching) Moda Collector, Istanbul, Turkey

Figures


Background The TBM broke out 8m from the shaft with anticipated 3 m of

rock cover


Fine soil flowed into the tunnel forming a hole in the road as the TBM went through the rock into the soft ground

Ground and Groundwater Conditions Various ground conditions (very fine and unstable mud & rock)

Construction Methods and Support Tunnel constructed by Tunnel Boring Machine (TBM)

Possible Cause of Failure The tunnel intersected a hidden area of soft clay

Consequence A hole formed in the road some 5m above

Broken rock jammed the shield

Emergency and Remedial Measures A shaft was sunk down to release the TBM

Lessons Learnt Probe holes should be drilled to confirm the rockhead profile

Case No 11. Seoul Metro Line 5 Phase 2, Korea, 17 Nov. 1991 Asia Korea 17 November 1991

Project Title Second Phase of Seoul Subway

Source of Information Lee, I. M. & Cho, G. C. (2008). Underground construction in

decomposed residual soils (presentation slides). The 6th

International Symposium on Geotechnical Aspects of Underground

Construction in Soft Ground (IS-Shanghai 2008), Tongji University,

Shanghai, April.

Madrid (1996). Informe sobre el NATM del Health & Safety Executive, de Inglaterra, 1996. (1996).

Source of Information Shin, J.H., Lee, I.K., Lee, Y.H. & Shin, H.S. (2006). Lessons

from serial tunnel collapses during construction of the Seoul

subway Line 5. Tunnel and Underground Space Technology,

Issue no. 21, pp 296-297.

Keywords (for searching) Seoul, Korea, cave-in

Figures

Lee & Cho (2008)

Background Construction of Seoul Metro tunnel near Majang

Tunnel at 15-30m below ground


After blasting : daylight collapse up to ground surface, involving the embankment of a river

20m x 15m and 4m deep crater at the ground surface

Water from river flowed into the tunnel

Ground and Groundwater Conditions Various weathered granite

Groundwater table at typical 3-10m below the ground surface

Construction Methods and Support by drill and blast method

Possible Cause of Failure Thin weathered rock cover

Inflow of soil and groundwater

Consequence Roads collapse and gas mains fractured

Emergency and Remedial Measures Backfilling the crater with soil followed

by cement grouting and chemical grouting

Lessons Learnt Insufficient ground investigation

Unexpected groundwater inflow

No tunnel face stability analysis

No consideration of blasting effects closed to weathered zone with shallow cover

Majang Bridge

Alluvium

Soft rock

Hard rock

Cheonggye-choeon

4. grouting(JSP)

2. sand mat

3. face shotcrete

Fill(SM)Silty sand

Decomposedgranite soil

Weatheredrock

1. backfilling

-3.5m

-24.0m

-29.5m

-3.2m

18.0m

1.4m

-26.5m

1000m3

Sink hole

-12.8m

-13.3m

-18.0m

Case No 12. Seoul Metro Line 5 Phase 2, Korea, 27 Nov. 1991 Asia Korea 27 November 1991



decomposed residual soils (presentation slides). The 6th International

Symposium on Geotechnical Aspects of Underground Construction in

Soft Ground (IS-Shanghai 2008), Tongji University, Shanghai, April.


Shin, J.H., Lee, I.K., Lee, Y.H. & Shin, H.S. (2006). Lessons from serial tunnel collapses during construction of the Seoul subway Line 5.

Tunnel and Underground Space Technology, Issue no. 21, pp 296-

297.


Figures

Lee & Cho (2008)

Background Construction of Seoul Metro tunnel near Tangsan Tunnel at 15-30m below ground


27 November 1991 10:40am : blasting

4:00pm : rock falls at the tunnel face

10:00pm : soil and groundwater inflow into the tunnel

28 November 1991 3:20am : substantial daylight collapse up to ground surface

forming a 25m diameter crater

Ground and Groundwater Conditions Various weathered granite Groundwater table at typical 3-10m below the ground surface

Construction Methods and Support by drill and blast method

Possible Cause of Failure Weathered granite at the face

and high permeability soil

Consequence Three buildings collapsed

Several water mains, gas pipes and sewerage were broken


Backfilling the crater with soil followed by cement grouting and chemical grouting

25.0

m

20.0

m

D=20.0m-1.2m

-4.8m-6.0m

-28.5m

-37.5m

-22.2m

-25.1m

-29.2m

Fill sand

Silt

Sand

Weathered

rock

Soft rock

Hard rock

: Cement mortar: Cement milk: Chemical grout

15.0m5.0m10.0m5.0m

backfilling

Lee & Cho (2008)

Case No 13. Seoul Metro Line 5 Phase 2, Korea, 11 Feb. 1992 Asia Korea 11 February 1992



decomposed residual soils (presentation slides). The 6th

International Symposium on Geotechnical Aspects of Underground

Construction in Soft Ground (IS-Shanghai 2008), Tongji University,

Shanghai, April.


Shin, J.H., Lee, I.K., Lee, Y.H. & Shin, H.S. (2006). Lessons from serial tunnel collapses during construction of the Seoul subway Line

5. Tunnel and Underground Space Technology, Issue no. 21, pp

296-297.


Figures

Lee & Cho (2008)

Background Construction of Seoul Metro tunnel near Youido



Significant inflow of groundwater

About 4.5 tonnes of soil flowed into tunnel

38m wide x 6m deep crater at the ground surface


Groundwater table at -11.8m below the ground surface

Construction Methods and Support Excavated by road header

Possible Cause of Failure Weathered granite at the tunnel

face and high permeability soil

Consequence 4-lane road collapsed

Utilities damaged



Lee & Cho (2008)

-5.6m

-7.8m

-9.9m

-13.2m

-21.7m

-25.9m-26.4m

-11.8m

Fill

Alluvium(SC)

Alluvium(SP)

Alluvium(ML)

Hard Rock

Weathered rock

Soft rock

Sewer box

MBC

Sewer Box

38.0m

3. urethan grouting

2. cement mortal grouting

1. back filling

-23.5m

-33.0m

3m

Decomposed

rock

Case No 14. Seoul Metro Line 5 Phase 2, Korea, 1 Jan. 1993 Asia Korea 7 January 1993








Tunnel and Underground Space Technology, Issue no. 21, pp 296-297.


Figures

Lee & Cho (2008)

Background Construction of Seoul Metro tunnel near Yongdungpo



Tunnel collapsed after removing spoil

Tunnel collapsed starting from the left side of the crown

900m3 of loose material flowed into the tunnel and water inflow of up to 300 litres/min recorded


Construction Methods and Support By drill and blast method

Possible Cause of Failure Weathered granite at the tunnel

face

High groundwater pressure

Consequence 2-lane road collapsed

Utilities damaged



Fill

Alluvium(ML)

Alluvium(SP)

Weathered rock

Soft rock

-1.1m

-7.1m

-16.5m

-21.5m

-4.9m

-20.14m

-28.34m

Sewer box

900m3

2. cement mortar

3. cement mortar

4. chemical grouting

1. back filling

Lee & Cho (2008)

Case No 15. Seoul Metro Line 5 Phase 2, Korea, 1 Feb. 1993 Asia Korea 1 February 1993








Tunnel and Underground Space Technology, Issue no. 21, pp 296-

297.

Keywords (for searching) Seoul, Korea, Anyangcheon, cave-in

Figures

Lee & Cho (2008)

Background Construction of Seoul Metro tunnel near Anyangcheon



Daylight collapse when weathered granite found at the tunnel face

Groundwater flowed into the tunnel

60m wide oval shaped area subsided


Construction Methods and Support excavated by road header

Possible Cause of Failure Weathered granite and alluvium

at the tunnel face

High groundwater pressure

Consequence Six heavy plants buried



8.3m

24.0m

59.3m

cement milk

grouting

59.3m

jet grouting

5.0m-21.0m

-24.0m

-29.0m

Weathered rock

Soft rock

Anyang cheon

Alluvium2. cement milk

grouting

Sewer box

-24.0m

-32.0m

3. jet grouting

1. backfilling

Decomposed granite soil

Sewer Box

Lee & Cho (2008)

Case No 16. Munich Underground, Germany, 27 Sept. 1994 Europe Germany 27 September 1994

Project Title Munichs U-Bahn U2 Underground Extension

Source of Information Boos, R., Braun, M., Hangen, P., Hoch, C., Popp, R., Reiner, H.,

Schmid, G., & Wannick, H. (2004). Underground Transportation

Systems, Chances and Risks from the Re-insurers Point of View. Munich Re Group, Germany, pp 58-62.

(31 Jan. 2007).

Construction Today (1994a). Police probe repeat Munich tunnel breach. Construction Today, October Issue, pp 4-5.

Ground Engineering (1994). London NATM controversy. Ground Engineering, November Issue, p 6.

Keywords (for searching) Munich, Germany, sinkhole

Figures

Construction Today (1994a)

Background 7m diameter tunnel supported by sprayed concrete lining

The tunnel was assumed to be beneath a clay layer overlying water-bearing gravel and groundwater would not be drawn down


Quick inflow of water and ground materials

Large subsidence crater quickly filled with groundwater

20m wide, 18.5m deep crater

Ground and Groundwater Conditions Flinty marl overlain by some 15.5m of groundwater bearing gravel

Groundwater at about 4m below ground level

Construction Methods and Support New Austrian Tunnelling Method (NATM)

Possible Cause of Failure Layer of marl separating

groundwater bearing layers was

much thinner than originally

assumed

Sand-infilled cracks in the marl layer acted as preferential

pathways for water

Consequence Bus fell into the crater

Three passengers killed

30 people injured

Construction Today (1994a)

Emergency and Remedial Measures Bored-pile wall to form a shaft

Excavation inside the shaft for rescue

Tunnel driven again using compressed air

Lessons Learnt The danger of tunnel excavation through thin marl cover

2000 report

Case No 17. Heathrow Express Tunnel, UK, 21 Oct. 1994 Europe United Kingdom 21 October 1994

Project Title Heathrow Express Tunnel

Source of Information Ground Engineering (2000). Catalogue of disaster. Ground Engineering,

August Issue, pp 10-11.

HSE (1996). Safety of New Austrian Tunnelling Method (NATM) Tunnels. Health & Safety Executive, UK, 86p.

HSE (2000). The Collapse of NATM Tunnels at Heathrow Airport. Health & Safety Executive, UK, 116p.

ICE (1998b). HSE signs up QC Carlisle for HEX prosecution. New Civil Engineer, Institution of Civil Engineers, March Issue, pp 4-5.

ICE (1999). Heathrow Express court cases kicks off. New Civil Engineer, Institution of Civil Engineers, January Issue, p 6.

1996 report

Keywords (for searching) London, United Kingdom, NATM, sinkhole

Figures

Ground Engineering (2008) ICE (1998b)

Background NATM in London Clay


10m diameter crater formed

Ground and Groundwater Conditions

London Clay

Construction Methods and Support

New Austrian Tunnelling Method (NATM) ICE (1998b)

Possible Cause of Failure A series of design and management errors combined with

poor workmanship and quality control

Consequence Differential settlement induced at adjacent buildings

Rail services to Terminal 4 were halted for one month

Remedial measures caused chaos at Heathrow Airport

Recovery cost 150M (3 times original contract sum)

Central Terminal Area

Settlement Contours

Emergency and Remedial Measures Backfilling with 13,000m3 concrete

Lessons Learnt Measures to ensure safety must be planned

Do not lose sight of critical technical issues in the pursuit of time and cost reduction

Whilst a number of factors contributed to the collapse, half of them were matters of management

However much engineers are pressured to build quickly and cheaply, the industry will be judged by its own failures

Case No 18. Los Angeles Metro, USA, 22 June 1995 North America

United States of America

22 June 1995

Project Title The Los Angeles Metro

Source of Information Civil Engineer International (1995). Tunnel lining removal

prompts LA Metro cave in. Institution of Civil Engineers, July

Issue, p10.

Keywords (for searching) Los Angeles, USA, cave in

Figures

Civil Engineer International (1995)

Background Re-mining/remedial works to realign an existing TBM tunnel

(6.7m diameter, 25m deep), which had been bored off line


25m deep sinkhole caused by collapse of south bore

Serious cracking observed in temporary lining of north bore

Ground and Groundwater Conditions Hard siltstone overlain by alluvium with groundwater level 10-

12m below surface

Construction Methods and Support TBM with segmental lining

Rock bolts to stabilise segments before removal

Possible Cause of Failure Failure occurred during removal of segmental lining in tunnel roof

and relining of tunnel to correct the horizontal alignment

Unexpected ground conditions (alluvium found much deeper)

Fractured water mains (unconfirmed)

Consequence 30m length of a four lane road (Hollywood Boulevard) affected

leading to road closure

Collapsed 250mm water main possibly contributing to failure

Broken gas pipe

Evacuation of local residents

Emergency and Remedial Measures Steel rings installed in tunnel either side of the collapse

3,300m3 of grout to fill void and stabilise area

Road resurfacing

Lessons Learnt Unpubished

Case No 19. Motorway Tunnels, Austria, 1993-1995 Europe

Austria

1993 - 1995

Project Title Motorway Contract





Keywords (for searching) Motorway, Austria, inrush, water inflow

Figures Extent of overbreak

1. Rock bolts

2. Second layer WM & shotcrete

3. Support core

4. Rock debris

5. Shotcrete in the overbreak

6. Water & rock flow

7. Overbreak


Background Four three-lane, twin-tube tunnels (T1-T4) with internal cross-

section of 103 m2 and 30 m apart between centrelines

constructed by the drill & blast method

T1 - 376m long; T2 - 562m; T3 2,760m and T4 1,230m


Failures at T4 in 1993

- About 131 recorded overbreak incidents with total volume of

1,461m3, maximum deformation of 120mm measured in the

tunnel

- 200m3 of loose material collapsed after a blast, resulting in

water inflow of up to 450 litres/min

Nature and Type of Failure (cont) Two failures at T3 in 1995

- The first collapse came with 650m3 of loose material flowed into

the tunnel, water inflow of up to 1,500 litres/min recorded

- The second collapse of the same size occurred days after the 6

months of recovery of the loss of the 10 m of tunnel. Radial

movement of rib of about 300mm recorded

Ground and Groundwater Conditions Sandstone and shale with zones of crushed and weathered

material

Construction Methods and Support Drill and blast, heading and benching

Shotcrete, rock bolts, forepoling, steel ribs and invert beams

Possible Cause of Failure Failures at T4 in 1993 Failure to apply the support in time

Two failures at T3 in 1995 The tunnel pierced through the water-bearing impermeable thinly bedded shale stratum, which

is located at and above the failure location

Consequence the tunnel face caved in

construction delay

Emergency and Remedial Measures Failures at T4 in 1993 For the subsequent excavation,

umbrella of forepoling with 6m long, 50mm perforated grouted

pipes was adopted. An ample central core was kept and the

excavation was carried out in small sections

Two failures at T3 in 1995 work progressed with extreme caution

Lessons Learnt Initial support should be installed in time

Case No 20. Docklands Light Rail, UK, 23 Feb. 1998 Europe

United Kingdom

23 February 1998

Project Title Docklands Light Railway Lewisham Extension

Source of Information ICE (1998a). Bulkhead location blamed for DLR blast. New

Civil Engineer, Institution of Civil Engineers, February Issue, pp

3-4.

ICE (2004) Docklands tunnel blowout down to elementary error, says judge. New Civil Engineer, Institution of Civil Engineers, January Issue, pp 8-9.

Keywords (for searching) Docklands, UK, sinkhole

Figures

ICE (2004)ICE (1998a)

Background Tunnel constructed for Docklands Light Rail (diameter 5.2m)

by slurry TBM


22m wide and 7m deep crater formed in the grounds of George Green School

ICE (1998a)

Ground and Groundwater Conditions Thames Sands and Gravels

Construction Methods and Support slurry TBM

Possible Cause of Failure Insufficient overburden above the tunnel

High compressed air pressure within tunnel causing blow out failure

Consequence Windows up to 100m away broken by the shower of mud and

stones released


Lessons Learnt To require specific assessments/calculations to demonstrate the

adequacy of factor of safety against blow out failure

Case No 21. Athens Metro, Greece, 1991-1998 Europe

Greece

1991 - 1998

Project Title The Athens Metro

Source of Information IMIA. .

IMS. .

Source of Information (cont) Kavvadas, M., Hewison, L.R., Laskaratos, P.G., Seferoglou,

C. & Michalis, I. (1996). Experiences from the construction

of the Athens Metro. Proceedings of International

Symposium on the Geotechnical Aspects of Underground

Construction in Soft Ground, City University, London, April.

Mihalis, I. & Kavvadas, M. (1999). Ground movements caused by TBM tunnelling in the Athens Metro Project.

Proceedings of International Symposium on the

Geotechnical Aspects of Underground Construction in Soft

Ground, Japan, July, pp 229-234.

Keywords (for searching) Athens, Greece, cave-in

Figures

IMS

IMIA

Background Construction of the Olympic Metro under a turnkey contract

(estimated cost about 2 billion ECUs)

Construction started in November 1991 and operation in 1998

TBM used for construction of 11.7km long, 9.5m diameter tunnels located at a depth of 15-20m (with penetration rate

ranging from 1.6m to 18m per day based on 18-hour-per-day

shift, depending on the ground conditions)

Cut and cover, supported by soldier piles, struts and prestressed anchor tiebacks for 6.3km long tunnels and

stations

NATM for other short auxiliary tunnels and oval-shaped stations where existence of buried antiquities precluded open

excavation


Roof collapses of appreciable size often occurred

Large and occasionally uncontrollable overbreaks for TBM

Ground and Groundwater Conditions Athenian schist a thick sequence of flysch-type sediments,

comprising thinly bedded clayey and calcareous sandstones,

alternating with siltstones, phyllites, meta-sedimentary shales and

occasionally, with limestones and marls

Construction Methods and Support TBM, cut-and-cover and NATM

Possible Cause of Failure Ravelling of the ground seems to be due to insufficient strength

in the intensely weathered and highly tectonised zones of Athenian schist (which is a flysch-type sediment consisting of thinly bedded clayey and calcareous sandstones with alterations and subjected to intense folding, thrusting, faulting and fracturing)

Large muck openings of the TBM cutterhead which cannot adequately control muck-flow (the cutterhead operates in the open air, i.e. under atmospheric pressure)

Consequence Major delay in TBM tunnelling

Emergency and Remedial Measures Cavities caused by the TBM overbreaks was backfilled by grout

(which sometimes reached the ground surface)


Case No 22. L rdal Road Tunnel on European Highway E16, Norway, 15 June 1999

Europe

Norway

15 June 1999

Project Title The L rdal Road Tunnel on European Highway E 16




(Unpublished).

Keywords (for searching) L rdal, Norway, cave in

Figures The L rdal Tunnel

Ch.11080

CAVE IN

DEBRIS

1200-1500m3

Karlsrud (2010)

Background Road tunnel at about 1,100m depth, 24.5 km long and 9m wide


A cave-in involving 17m length of tunnel and extending up to about 11-12m above the crown. The volume of the failed rock mass was

estimated to be 1,200-1,500m3

Ground and Groundwater Conditions Precambrian gneisses with layers of amphibolities and massive

granitic rock. Excavation through a major fault zone (rock mixed

with lot of swelling clay)

Construction Methods and Support Constructed by drill-and-blast method and supported by steel fibre

reinforced sprayed concrete and rock bolts

Possible Cause of Failure Poor communication : the driller did not inform the engineer about

abnormal drilling rate encountered

Expansion of the swelling clay under high stress to water during drilling of the rock bolts

The combination of the swelling of the clay and high stress produced a squeezing effect, which resulted in gradual weakening of the rock mass in the tunnel

Consequence The crew was evacuated in time and no one was hurt

About 10 days delay in the excavation works and cost increased for the remedial works


Reinforced ribs of sprayed concrete in addition to layers of sprayed concrete and rock bolts were installed just behind the cave-in zone

Rock material was hauled into the tunnel building up a barrier up to 2m below the crown and concrete was pumped through a steel pipe to fill the void above the debris

Debris was gradually hauled out with step wise installation of rock anchors and sprayed fibre reinforced concrete

The L rdal Tunnel

Fa

ce

be

fore

ca

ve

in

11

07

0

11

08

0

11

08

7

Debris

1200-1500 m3

Cave in

zone

Concrete

700 m3 concrete

Debris hauled out

Ch

.no

Karlsrud (2010)

Lessons Learnt The importance of good communication between the driller

and the engineer

Importance of having good understanding of the geological conditions and their influence on the stability

Swelling of clay in condition of high stress could provide a squeezing effect and result in weaking of the rock mass in a tunnel

Case No 23. Sewage Tunnel, Hull, UK, 1999 Europe

United Kingdom

1999

Project Title Hull Sewage Tunnel

Source of Information Boos, R., Braun, M., Hangen, P., Hoch, C., Popp, R., Reiner,

H., Schmid, G., & Wannick, H. (2004). Underground

Transportation Systems, Chances and Risks from the Re-

insurers Point of View. Munich Re Group, Germany, pp 58-62. (31 Jan. 2007).

Keywords (for searching) Hull, UK, Sewage

Figures

Boos et al (2004)

Background Construction of a 10.5km long underground sewer


Water and sand ingress

Tunnel subsided by 1.2m causing serious subsidence at surface

Ground and Groundwater Conditions Water-bearing ground

Construction Methods and Support EPB TBM (diameter 3.85m) supported by reinforced concrete

segmental lining

Possible Cause of Failure Fluctuation of groundwater level caused by tidal effects resulting

in vertical movement of the tunnel tube causing opening of joints

Consequence Damage to buildings, roads and utility lines

TBM had to be abandoned

Emergency and Remedial Measures Ground freezing

Reconstruction of tunnel using sprayed concrete

Lessons Learnt The design of the segment connections should take account of

the fluctuations of groundwater level

Case No 24. Taegu Metro, South Korea, 1 Jan. 2000 Asia

South Korea

1 January 2000

Project Title The Taegu Metro





Keywords (for searching) Taegu, South Korea, diaphragm wall, cave in

Figures

Boos et al (2004)

Background Construction of underground Taegu Metro


Failure of diaphragm wall

Excavation pit caved in


Construction Methods and Support Cut and-cover

Possible Cause of Failure Rapid fluctuation of groundwater level caused movement of

unidentified gravel and sand strata

Additional loading on diaphragm wall was not considered in design

Consequence Bus buried and bus driver seriously injured

Three passengers killed

Neighbouring buildings suffered considerable damage

Emergency and Remedial Measures Excavation pit backfilled

Subsoil grouted and diaphragm wall strengthened


Case No 25. Wastewater Tunnel, Portsmouth, UK, May 2000 Europe

UK

May 2000

Project Title Portsmouth Sewage Transfer

Source of Information Tunnels & Tunnelling (2000). Portsmouth scheme held up.

Tunnels & Tunnelling International, July 2000. p 9.

Keywords (for searching) Sewage tunnel, Lining crack, Portsmouth

Figures N/A

Background Wastewater tunnel 4km long and 3.3m diameter constructed

with precast concrete tunnel segments by the TBM method


Cracks were found in the tunnel segments together with associated water ingress

Ground and Groundwater Conditions Mixed ground comprising Chalk, Calcareous sands, gravels

and stiff clay

Water head of 21m above the tunnel crown

Construction Methods and Support EPB TBM

Possible Cause of Failure Localised poor ground conditions not account for in the design

of the tunnel segments

Consequence Tunnel drive was halted and delayed

Emergency and Remedial Measures Temporary application of compressed air, followed by ground

freezing

Replacement of damaged rings and back grouting

Lessons learnt Understanding the ground conditions and account for them in

design

Case No 26. Dulles Airport, Washington, USA, Nov. 2000 North America

Washington, United States of America

November 2000

Project Title Expansion at Washington DCs Dulles airport

Source of Information Tunnels & Tunnelling (2000). US airport collapse claims miners

life. Tunnels & Tunnelling International, December 2000 issue, p 8.

Stehlik, E & Srb, M. NATM Tunnelling at Dulles Airport. Proceedings of the World Tunnel Congress 2007 and 33rd ITA/AITES Annual General Assembly, Prague, May 2007, pp 1609-1612.

Keywords (for searching) Dulles, Washington, NATM

Figures Project Layout

Tunnels & Tunnelling (2000)

Background Pedestrian tunnel of approximate cross-sectional area 100m2 with

shallow ground cover of 4.5m

Excavated in 4 stages using two side drifts followed by bench and invert, using road-header

NATM design with systematic spiling, steel-fibre reinforced shotcrete and lattice girder support


One of the tunnel headings caved in without the collapse extending to the surface

Ground and Groundwater Conditions Mixed face comprising clay, silt and competent siltstone

Construction Methods and Support NATM, following a sequence of a top heading comprising two

side-wall drifts, followed by bench and invert. 1m-1.6m advances in each round of excavation

Steel-fibre reinforced shotcrete and lattice girders at 1m-1.6m c/c

Possible Cause of Failure Unknown

Consequence A miner was killed

Emergency and Remedial Measures An area of 40x40x10m deep was excavated from the surface to

recover the body of the trapped worker

Lessons learnt Necessity for safe application of NATM in shallow tunnelling works

Introduction of a requirement for NATM Engineer in the second contract of the project

Case No 27. Istanbul Metro, Turkey, Sept. 2001 Europe

Turkey

September 2001

Project Title Istanbul Metro Construction

Source of Information World Tunnelling (2001). Istanbul Metro collapse investigations,

World Tunnelling, December 2001 issue, pp. 490-492.

Keywords (for searching) Istanbul, Metro, boarding house

Figures Collapsed building above tunnel Longitudinal section

World Tunnelling (2001)

Background Metro tunnel 7.9km long with 14m wide sections of 100m2

constructed by a multiple drift technique coupled with pipe umbrella roofing and benching at central drift

Nature and Type of Failure Construction Failure

Soft clay kept falling through the gaps between the pipe umbrella and liquid mud flowed from the face.

Tunnel collapsed and a 25m wide crater was created

Three 2-storey buildings and a workshop building caved in

Ground and Groundwater Conditions Soft ground with groundwater close to ground level

Construction Methods and Support Multiple drift mined Tunnel

Pipe umbrella, shotcrete lining and lattice girders as temporary support

Possible Cause of Failure Existing well 1.5-2.0m above the tunnel crown not properly

filled causing the saturated clay and well water flowing into the tunnel and subsequent collapse of the well walls and surrounding clay followed by the draining of the upper fine-grained sand layer into the tunnel and the undermining of the building structures

Consequence 5 people died


Lessons learnt The importance of the study of the construction history of

buildings that are under-tunnelled

Case No 28. Channel Tunnel Rail Link, UK, Feb. 2003 Europe

United Kingdom

February 2003

Project Title Channel Tunnel Rail Link

Source of Information ICE (2003). Ground failure linked to well collapses. New

Civil Engineer, Institution of Civil Engineers, February Issue,

pp 6-7.

Keywords (for searching) UK, Channel, Rail, sinkhole

Figures

ICE (2003)

Background Boring at a depth of 21m


10m diameter and 20m deep void formed in the ground behind a row

of houses


Thanet Sands


Tunnelling using TBM (diameter 8.2m)

ICE (2003)

Possible Cause of Failure The vibration from the TBM may have caused the nearby wells

(30m deep and 1.8m diameter) to collapse

Consequence Three uncharted wells collapsed

Emergency and Remedial Measures The voids were backfilled with grout


Case No 29. Mtor Metro Tunnel, France, 14 Feb. 2003 Europe

France

14 February 2003

Project Title The Mtor Metro Tunnel

Source of Information Dubois, P. & Rat, M. (2003). Effondrement sur le chantier

"Mtor. Conseil Gnral des Ponts et Chausses, France, 22p. (31 Jan. 2007).

Keywords (for searching) Mtor, Pairs, France, sinkhole

Figures

Dubois & Rat (2003)

Figures Location map and section

Dubois & Rat (2003)

Figures Hall plan

Dubois & Rat (2003)

Background Construction of the extension of Mtor Metro Tunnel including

the Olympics station and a maintenance hall


About 3,000m3 of sedimentary deposits collapsed underneath a school, occupying an area of 400m2 on plan


Coarse limestone and plastic clay (clays of Sparnacian)


Supported by bolts and shotcrete

Dubois & Rat (2003)

Possible Cause of Failure The coarse limestone had inferior mechanical characteristics to

the homogeneous medium assumed in the design

Unfavorable orientation of the fracture

Implementation of inadequate support due to the overreliance on calculations

Consequence No casualties

The school had to be closed for a year affecting 900 students

Emergency and Remedial Measures Filling the hall under the building by concrete


Case No 30. Oslofjord Subsea Tunnel, Norway, 28 Dec. 2003 Europe

Norway

28 December 2003

Project Title The Oslofjord Subsea Tunnel


failures in Norwegian tunnels. The Government of the Hong Kong

Civil Engineering and Development Department. (Unpublished).

Keywords (for searching) Oslofjord, Norway, subsea tunnel, rock fall

Figures

First failure Third failure

Karlsrud (2010)

Background The road tunnel was 7.3 km long and 11.5 m wide (3 lanes)

Three major failures and many minor failures occurred

Nature and Type of Failure In service failure

First failure occurred on 28 December 2003: about 20m3 of crushed and weathered rock involving with clay, which came

down from the crown went through the frost insulated water

shielding vault and down to the carriageway

Second failure involved about 3m3 of heavily weathered rock, which came down from the springline and fell down to the invert

Third failure involved 2-3m3 of completely weathered rock, which fell down from the crown and rested on top of the water

shielding vault

Ground and Groundwater Conditions Precambrian gneisses with lenses of amphibolites, veins of

pegmatite, and a few dykes of diabase and rhomb porphyry

Swelling clay was found at the weakness zones

Construction Methods and Support Mainly supported by steel fibre reinforceed shotcrete combined

with rock bolts

Possible Cause of Failure The humidity behind the vault constructed for frost insulated

water shielding was high and the high content of swelling clay in the weathered rock started sucking water and expanded gradually over a long period of time

Consequence Closure of the tunnel for more than 3 months for extensive repairs

and upgrading of the tunnel support

Emergency and Remedial Measures Complete removal of the vault before installing additional rock

support including fiber reinforced shotcrete, rock bolts and reinforced ribs of sprayed concrete

Lessons Learnt The importance of proper geological mapping and rock mass

classification

The need to identify swelling minerals and the potential of deterioration of strength in weathered rock

The importance of adequate support design for long-term stability in weathered rock

Case No 31. Shanghai Metro, China, 2003 Asia

China

2003

Project Title Shanghai Metro Project





Keywords (for searching) Shanghai, China, water ingress, ground subsidence

Figures

Boos et al (2004)

Background Expansion of the Shanghai Metro () Line 4 crossing

beneath the Huangpu River ()

Two parallel tunnel tubes constructed by earth pressure balance TBM


Failure occurred during construction of a cross passage

Massive ingress of water and material at the face at a depth of 35m

Several metres ground subsidence


Construction Methods and Support EPB TBM

Possible Cause of Failure Failure of ground freezing unit

Consequence High rise office buildings seriously damaged

Flood protection dyke on the river badly damaged



Case No 32. Nikkure-yama Tunnel, Japan, 2003

Asia

Japan

2003

Project Title

Nikkure-yama Tunnel of the Joshinnetsu Expressway

Source of Information Takahashi, Hiroshi (2010). Huge collapse leading to ground

surface caving in 130m earth thickness.

Keywords (for searching) Japan, mudstone, sinkhole

Figures

Takahashi (2010)

Background East work section of Nikkure-yama Tunnel


Ground collapse of an avalanche type containing cobbles, gravels and water took place at the point 900m away from the tunnel portal

A large crater was observed at the ground surface about 130m above the tunnel


Mudstone


Shortcrete and ribs

Takahashi (2010)

Possible Cause of Failure Existence of high groundwater

pressure

Decrease in cover of the mud-stone layer

Water path created by the investigation drillhole

Consequence Programme delayed for about 2

years


Filling the cave-in area by foam concrete

Grouting under the collapse area

Boring for drainage from the tunnel

Takahashi (2010)

Lessons Learnt The importance of adequate ground investigation before

tunnelling

The importance of investigations and observations during construction for adopting appropriate support measures

Case No 33. Guangzhou Metro Line 3, China, 1 April 2004 Asia China 1 April 2004

Project Title The Guangzhou Metro Line 3

Source of Information China Daily (2004). 100 homeless after metro site collapse.

(2 April

2004).

Soufun (2004). : 3 . (4 April 2004).

Longhoo (2004). 3 .

(2 April 2004).

Keywords (for searching) Guangzhou, China, diaphragm wall, building collapse

Figures

ChinaDaily (2004)

Background Construction of a 58.5km long underground metro in which

45.6km is a single-tube shield TBM


Failure of a diaphragm wall

Ground and Groundwater Conditions Unpublished

Construction Methods and Support Single-tube shield TBM

Possible Cause of Failure Rapid fluctuation of groundwater level due to the heavy rainfall

Complicated geology including a layer of swelling soil

Consequence A three-storey building collapsed and sunk into the ground

Collapse of nearby underground water mains

Emergency and Remedial Measures Backfilled with crushed rock and cement


Case No 34. Singapore MRT, 20 April 2004 Asia

Singapore

20 April 2004

Project Title Circle Line of the Singapore MTR

Source of Information Government of Singapore (2005). Report of the Committee of

Inquiry into the Incident at the MRT Circle Line Worksite That

Led to the Collapse of Nicoll Highway on 20 April 2004.

Government of Singapore, Land Transport Authority. (31 Jan. 2007).

Keywords (for searching) Singapore, MRT, Cut-and-Cover, diaphragm wall

Figures

Government of Singapore (2005)

Background An open cut tunnel excavated for Singapore MRTs new Circle

Line

Design and build

Excavated trench of 15m wide and 33m deep supported by 0.8-1.0m thick diaphragm wall which is 35-45m deep without rock

socket

Steel struts: 4-5m horizontal and 3m vertical spacing

Bottom-up construction

Jet grouted base slabs

Layer 1-1.5m thick at 28.5m below ground

Layer 2-3m thick at 33.5m below ground (Layer 2 not yet constructed when collapse occurred)


9th level of struts being installed when collapse took place

Unusual cracking and groaning noises heard early in the morning (6 hours)

Loud cracking noise heard in the afternoon, 15 minutes before collapse

Collapse plan area was 100m by 130m

Settlement up to 15m

Diaphragm walls displaced

Steel struts mangled

Ground and Groundwater Conditions Mainly marine clay with some fluvial clay

Government of Singapore (2005)

Construction Methods and Support Cut-and-Cover method

Possible Cause of Failure Under-design of the strut-waler connection in the strutting

system

Incorrect use of Finite Element Method

No proper design reviews

Disregard of different warnings, for example, excessive wall deflections and surging inclinometer readings

Poor construction quality

Ineffective instrumentation and monitoring system

Failure to implement risk management

Consequence Part of Nicoll Highway, Singapores major east-west harbour-front

road, destroyed

Four workers killed

Several others injured

15,000 people and 700 businesses affected

Three offices and retail towers at risk from further ground movement

Damage of a gas service line, resulting in an explosion and fire

A storm drain damaged

Emergency and Remedial Measures Rescue and backfilling

Structurally disconnected the Merdeka Bridge

All contracts of the Circle Line put on hold

All contracts to carry out checks and review of design and construction of temporary works

All Professional Engineers to confirm in writing the adequacy of their designs

All designs to be independently checked by the Building & Construction Authority

Lessons Learnt This is a need for robust design, risk management, design review

and independent checking, purposeful back analysis, an effective

instrumentation, monitoring and interpretation regime, an effective

system of management of uncertainties and quality during

construction, corporate competencies and safety management

The safety of temporary works is as important as that of permanent works and should be designed according to

established codes and checked by competent persons

Case No 35. Kaohsiung Rapid Transit, Taiwan, 29 May 2004

Asia

Taiwan

29 May 2004

Project Title Kaohsiung Rapid Transit

Source of Information Lee, W. F. & Ishihara, K. (2011) Forensic diagnosis of a

shield tunnel failure. Engineering Structures. Volume 32,

Issue 7, July 2010, Pages 1830-1837.

Keywords (for searching) Kaohsiung, Taiwan, diaphragm wall, building damaged,

sinkhole

Figures

Lee & Ishihara (2010)

Background Chemical Churning Piles (CCP) of

350mm diameter installed as guide walls

for the diaphragm wall construction

Soil improvement works by the use of Super Jet Grouting (SJG) method at the

reception area for break-out operations

The diaphragm wall panels were first cored through by chain saw according to

the face-shape of the shield tunnel

machine and manual power tool was

used to disassemble the reinforced

concrete residual inside the coring holes

EPB Tunnel Boring Machine 500mm away from the wall face awaiting for

break-out and invert leakage started



Sinkhole of about 10m in diameter formed at the ground surface

Ground settlement influence zone ranging from 40m to 50m in diameter with maximum settlement from 500mm to 1,500mm.

Several rings of tunnel s

Chemical Churning Pile

(CCP)

Soil Improvement Zone

Diaphragm Wall

egmental linings were damaged

CCP

Possible

Collapse Zone

Soil Improvement Zone

Leakage spot

Tunnel Boring Machine

Path of Leakage

Lee Lee & & IshiharIshihara a (2(2010)010)

Settled Area of Ground Surface

Ground and Groundwater Conditions Silty sand and sandy silt soil layers

Silt deposit sandwiched by impermeable clay layers

Construction Methods and Support Tunnelling by EPB Tunnel Boring Machine

Possible Cause of Failure Progressive development of unexpected cracks inside the soil

improvement zone resulting in groundwater leakages in the

reception area as a result of piping and/or hydraulic fracturing

Leakage paths at the interfaces between Chemical Churning Pile (CCP) and the diaphragm wall, CCP and Super Jet Grout (JSG)

materials, or inside the lower portion of the JSG body

Chloride assault and deterioration of CCP, which were installed two years before the wall breaking process, had significant effects on the

integrity and water tightness at the interfaces

Possible Cause of Failure (cont) The highly sensitive and erodible soil dispersed around the SJG

might have been disturbed due to the application of highly

pressured water jet in the grouting process

Mechanical and/or vibration disturbances occurred during the wall

breaking process leading to serious cracks and fissure

development inside the deteriorated CCP and defective SJG

blocks

Unfavourable sub-surface conditions which consisted of silty

sands and sandy silts with water contents almost reaching their

liquid limits

Consequence Adjacent buildings were damaged


Emergency and Remedial Measures Stabilizing the ground by piling-up sand bags in front of the tunnel

face to reduce leakage, backfilling the sinkhole and grouting the

tunnel crown and invert

Advancing the TBM further to reduce the gap between the D-wall

and the tunnel

Installation of steel frames to reinforce the damaged ring segments

Lee & Ishihara (2010) Lessons Learnt Unpublished

Case No 36. Oslo Metro Tunnel, Norway, 17 June 2004 Europe

Norway

17 June 2004

Project Title The Oslo Metro Tunnel




(Unpublished).

Keywords (for searching) Oslo, Norway, cave in

Figures

F:\i\21\miljo\div\2000\ah-1.ppt

T-baneringen Modell 3

Strste hovedspenning, 1 er styrt av lagdelingssprekkene og tverrsprekken. Strekkspenninger over taket til

Hasletunnelen og videre til indre lp mot Sinsen.

Karlsrud (2010)

F:\i\21\miljo\div\2000\ah-1.ppt

Planned

concrete wall

Cave in area

F:\ i\21\miljo\div\2000\ah-1.ppt

Background Metro line tunnel 1.3km long and 7m wide connecting with an old

tunnel


At the junction where the two tunnels met in an acute angle, tunnel cave-in after removal of most part of the rock pillar between the

tunnels

Ground and Groundwater Conditions Interlayered shale and nodular limestone with 1-5cm thick clay

seams along many of the bedding planes

The bedding planes were dipping 20-45 and running almost parallel to the tunnel

Construction Methods and Support Constructed by drill-and-blast method supported by rock bolts

and fibre reinforced sprayed concrete. A concrete wall/pillar was

planned to be constructed between the old tunnel and new

tunnel

Possible Cause of Failure Unfavourable direction of the bedding planes in relation to the

geometry and span of the tunnels

Over excavation of the rock pillar and the removal of the remaining rock pillar and old concrete wall before the planned concrete pillar was constructed

Consequence Programme delayed for about 3 months

Cost implication: extra cost of the remedial works

Emergency and Remedial Measures Filling up the whole opening by concrete above the fallen debris

Installation of 10m long cable anchors together with permanent support of 200mm thick lining of reinforced sprayed concrete, reinforced ribs of sprayed concrete and additional 6m long rock bolts

Lessons Learnt The importance of adequate ground investigation

The need to follow the sequence of rock support installation in accordance with the design plans during construction

Case No 37. Kaohsiung Rapid Transit, Taiwan, 10 Aug. 2004

Asia

Taiwan

10 August 2004

Project Title Kaohsiung Rapid Transit

Source of Information Taiwan Info (2004). Nouvel incident sur le chantier du mtro

de Kaohsiung. Taiwan. (31 Jan. 2007).

Keywords (for searching) Kaohsiung, Taiwan

Figures

Taiwan Info (2004)

Background Construction of the Kaohsiung Rapid Transit Blue & Orange

Lines in Kaohsiung City


First collapse on 29 May 2004 underneath a street

Second collapse in mid June 2004

Third collapse on 13 July 2004 with formation of a large sinkhole

Fourth collapse on 10 Aug 2004

Ground and Groundwater Conditions Unpublished

Construction Methods and Support Unpublished

Possible Cause of Failure Possible adverse ground and groundwater conditions

Consequence First collapse - Several buildings affected and 100 people

evacuated

Third collapse - Three residential buildings evacuated and significant disruption to water/electricity supply

Fourth collapse - No casualty, one building affected and part of the works suspended



Case No 38. Hsuehshan Tunnel, Taiwan, 1991-2004

Asia

Taiwan

1991 - 2004

Project Title

The Taipei-Ilan Expressway

Source of Information TANEEB ( 2 0 0 5 ) . Hsuehshan Tunnel. Taiwan Area

National Expressway Engineering Bureau ( ) , Taiwan. (31 Jan. 2007).

Keywords (for searching) Hsuehshan, Taiwan, groundwater inflow, tunnel collapse

Figures

Taiwan Info (2004)

TANEEB (2005)

Background Construction of 12.9km long and 11.7m diameter Hsuehshan

Tunnel in Taiwan ()

Works commenced in 1991 and completed in 2004

Comprised 2 main tunnels (East & Westbound) and a pilot tunnel

Westbound Eastbound

Pilot Tunnel

TANEEB (2005)


Eastbound - 28 collapses occurred

Westbound - TBM badly damaged due to tunnel collapse and groundwater inflow of 45,000 litres/min into the tunnel

Pilot Tunnel - 8 collapses occurred

Ground and Groundwater Conditions The major geologic elements are Eocene, Oligocene and minor

Miocene folded sedimentary rock formations

Highly fractured rock with six major faults

Construction Methods and Support Eastbound by TBM method (July 1993 to Sept. 2004)

Westbound by TBM method (July 1993 to April 2004)

Pilot tunnel by drill & blast method (July 1991 to Oct. 2003)

Possible Cause of Failure Unexpected difficult geology with fractured rock and massive

inflows of water

6 major faults found along the tunnel alignment

Consequence Eastbound - Failure in May 1993 affected 56 buildings and 73

families

Westbound - 11 men died

Pilot Tunnel - 13 stoppages



Case No 39. Barcelona Metro, Spain, 27 Jan. 2005 Europe

Spain

27 January 2005

Project Title Barcelona Line 5 Metro Extension

Source of Information European Foundations (2005). Tighter NATM rules follow

Barcelona failure. European Foundations, Spring Issue, No.

26, p 3.

Keywords (for searching) Barcelona, Spain, sinkhole

Figures

European Foundations (2005)

Background Tunnel for Barcelona Line Five Metro Extension


Part of the lining collapsed

30m wide and 32m deep crater formed

Ground and Groundwater Conditions Weathered slate and ancient and weathered metamorphic

ground with a vertical and hidden fault at the location of

collapse

Construction Methods and Support Tunnelling using NATM

Possible Cause of Failure A hidden vertical fault located 1m behind the sprayed

concrete lining

Consequence 2 five-storey buildings and a smaller one demolished

More than 50 families made homeless

Emergency and Remedial Measures The void was backfilled with grout of about 2,000m3

The tunnel section was backfilled with 18,000m3 of grout through a horizontal borehole in the debris and five points from the surface

Additional boreholes, horizontal probes and supports for future excavation


Case No 40. Lausanne M2 Metro, Switzerland, 22 Feb. 2005 Europe

Switzerland

22 February 2005

Project Title Lausanne Metro M2 project

Source of Information Tunnels & Tunnelling (2005). Lausanne Metro Tunnel collapse.

Tunnels & Tunnelling International, April Issue, p 6.

Keywords (for searching) Lausanne, Switzerland, sinkhole

Figures

Tunnels & Tunnelling (2005)

Background Tunnel (6km long, approximately 10m wide x 7m high) for

Lausanne Metro M2 Project (cost US$472M) in Switzerland


50m3 of material displaced into the tunnel at a depth of 12m, leading to a crater at the surface

Ground and Groundwater Conditions Collapse in area of soft ground (lake deposits)

Construction Methods and Support Tunnelling using an Eickhoff ET 380-L roadheader

Possible Cause of Failure Tunnel driven through a pocket in the glacial moraine, causing

sudden inflow of groundwater

Consequence People in two buildings, a supermarket and a food outlet in

commercial district evacuated when their cellars collapsed

No injuries reported

Emergency and Remedial Measures A curtain of 11 piles constructed ahead of the collapsed face with

grouting to strengthen the ground and limit further flow of material into the tunnel

The void was backfilled with 800m3 of glass-sand (recycled glass)


Case No 41. Lane Cove Tunnel, Australia, 2 Nov. 2005 Australia

2 November 2005

Project Title L

hk notabletunnel cat

Documents

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