Tunnel Boring Machines

Size: px

Start display at page:

Download "Tunnel Boring Machines"

David Walton
6 years ago
Views:

Tunnel Boring Machines IMIA WGP 60 Michael Spencer,

Heiko Wannick Munich Re Ronan Gallagher Allianz John

Steve Cross Zurich Chris Blueckert Zurich Presented

1 Tunnel Boring Machines IMIA WGP 60 Michael Spencer, Zurich London (Chairman) Alessandro Stolfa Generali Heiko Wannick Munich Re Ronan Gallagher Allianz John Forder Willis Beat Guggisberg Allianz Eric Bentz SCOR Steve Cross Zurich Chris Blueckert Zurich Presented by Michael Spencer IMIA Conference, Istanbul 29 th Sep. 2009

2 History 1825 Sir Marc Isambard Brunel Tunnelling Shield Rotherhithe Tunnel 5 floods in all 2

3 Early Soft Soil Tunnels Early Soft Soil Tunnels London Underground late 19 th Century 3

4 Hard Rock Machines Henri-Joseph Maus Mountain Slicer 1845 failed Wilson Patented Stone Cutting Machine 1853 failed James Robbins 1950 first successful machine used in Shale and worked 10 times faster than conventional methods 4

5 Soft Rock Machine 5

6 Hard Rock Machine 6

7 Hard Rock Machine 7

8 Largest Machines To Date 8

9 Trailing Equipment 9

10 Start of the Art Maximum diameters Slurry Machine M EPB 15.2 M Maximum Water Head above 4.5 bars (45m head of water) Marmaray 8 bars Hallandsas 8 bars Maximum Speeds Closed Mode 0-8cm/min 10

11 Operational Parameters Speed of the Shield Torque of the cutter head Thrust of the jacks Pumping flows in a slurry machine Viscosity of excavated soil in an EPB Quantity of soil excavated Changes in the chracteristics of the soil granularity/ viscosity colour 11

12 Loss Exposures TBM Fabrication and delivery to site TBM Assembly at site Excavation of the tunnel Disassembly and reshipment 12

13 Manufacture / Fabrication Manufacturing and delivery time up to 12 months new less for refurbished machines Main perils fire flood cat nat Transport marine, air, land is it covered in the Car policy? Land routes to some site especially hydro projects are often difficult Suppliers extensions 13

14 Assembly and Testing At site Up to 3 months, storage much longer in case of delays Lifting and lowering into position Flooding fire and theft Landslide and collapse of ground around the machines Faulty workmanship skilled technicians (preferably from the suppliers especially during testing) OFTA Onsite first Time Assembly Supplier Gurarantee for 50 or 100m 14

15 TBM Before excavation 15

16 Excavation Works Flood Fire and Explosion Tunnel Collapse Unexpected ground conditions Wrong Machine Inexperience of the operator Machinery Breakdown Breakthrough 16

17 Loss Prevention Mechanical and electrical Breakdown Hydraulic Oils Materials non toxic and flammable Contact surfaces sharp edges and hot surfaces Rupturing of pipes and hoses Safe access to the cutter head Handling of heavy loads Pumping equipment Control systems 17

18 TBM Launch and Arrival Launch normally into a diaphragm wall or secant bored pile wall Sealing Ring gasket system (lip seals) and soil/rock sealing block (jet grouting or lean concrete secant bored piles) Arrival the most critical as the whole tunnel can be flooded Flying launch steel structure and a hydraulic unit with hollow piston jacks faster and safety advantages 18

19 Launch and Arrival 19

20 TBM Affect of Third Party exposures Damage Category Severity Typical Damage 0 Negligible Hairline Cracks 1 Very Slight Fine Cracks 1mm 2 Slight Cracks to 5mm 3 Moderate Cracks 5-15mm 4 Severe Cracks 15-25mm 5 Very severe Major repairs 20

21 TBM Prediction of Settlement For TBMs zone of influence is centred along the centreline of the tunnel = depth of the invert below ground level on either side of the centreline Damage caused by rotation, angular strain, relative deflection, tilt, horizontal strain extent depends on the condition of the existing buildings and structures 21

22 Insurance recommendations Period Of Cover Check whether cover is required only on site or for storage transport and fabrication Excavation cover Check equipment is adequately protected against fire. Are there adequate safety measures in place taking into account the ground conditions? Ancillary covers: Is cover for abandonment and recovery expenses included? What is the cover for consumables? Is cover required for machinery breakdown? What is the basis of indemnity? 22

23 Losses 1987 Tooting Bec Open face boring machines compressed air Inundation requiring ground freezing to repair 1990 Great belt Link Flood to closed face machine left open for maintenance to the face 2 machines underwater Fire to one machine at the end of the drive Socatop fire aboard a service train for the TBM 23

24 Socatop 24

25 Great Belt Link 25

26 Machinery Breakdown Main losses are to Main bearing Motor Breaker Gripper and Pad 26

27 Conclusion The TBM has revolutionised the construction industry Developments in new machines may present challenges TBMs are varied and must match the conditions in which they need to work Commercial considerations may affect the risk levels an underwriter may face There is a lack of information about losses Closer cooperation between tunnelling machine suppliers contractors and the insurance industry The very nature of these machines and the conditions in which they work means these should only be underwritten by specialist underwriters 27

Experts in tunneling with Tunnel Boring Machines

www.eurohinca.com www.terratest.es Experts in tunneling with Tunnel Boring Machines info@eurohinca.com EUROHINCA Europea de Hincas Teledirigidas, S.A., EUROHINCA, was incorporated in 1996 for the execution