Summary of Lahmeyer International’s tunnelling work |
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Goldisthal, Germany |
Baglihar, India (located on the Chenab river in Jammu & Kashmir) |
Mohale dam, Lesotho |
Swabi SACRP, Pakistan |
Pehur high level canal in Pakistan |
•Type of tunnelling: |
•Type of tunnelling: |
•Type of tunnelling: |
•Type of tunnelling: |
•Type of tunnelling: |
Access tunnel to power house:7.3m diameter and 1300m long.Two headrace tunnels: 7m diameter and 820m long each. |
Two diversion tunnels: 10.5×10.6m, 400m and 540m long respectively. Diversion capacity of 3000m3/sec.Headrace tunnel: 2069m long with a discharge of 430m3/sec. |
Water conveyance transfer tunnel from Mohale reservoir to Katse reservoir. (32km long and 4m in diameter). |
Two tunnels. The first is the rehabilitation of an existing 4.9m diameter, 3.4km long tunnel with a discharge of 50m3/sec. This is used for irrigation, hydro power and water conveyance.The second tunnel is a new auxiliary one for irrigation water conveyance with hydro power potential. (5.3m diameter, 3.4km long and with a discharge of 60m3/sec). |
Three tunnels. a) Baja – irrigation water conveyance. b) Gandaf Rock – irrigation water conveyance with hydro power potential. Diameter of 3.4m and 2.2km long. c) Gandaf Soft – irrigation water conveyance with hydro power potential. Diameter of 3.1m and 1.8km long. All tunnels have a discharge of about 28m3/sec. |
•Methods: |
•Methods: |
•Methods: |
•Methods: |
•Methods: |
Drill and blast — NATM. Lining— Primary (shotcrete SN anchors) and secondary (concrete and steel). |
Drill and blast – NATM. Lining: first (shotcrete) and second (concrete lining, t=50cm). |
Excavation by two double shielded telescopic TBMs. One is driving from the inlet structure, the other from the outlet structure. With a precast concrete segmental lining (d=25cm). |
Repairs included dental concreting/shotcreting with concrete invert. Drill and blast – NATM and a shotcrete lining with concrete invert. |
a) Drill and blast – NATM. Shotcrete lining with concrete invert. b) Drill and blast – NATM. Primary lining: shotcrete. Secondary lining: concrete. c) Shield. Segmental concrete and steel lining. |
•Schedule: |
•Schedule: |
•Schedule: |
•Schedule: |
•Schedule: |
The whole project is scheduled for 1997-2003. Excavation works were completed in 2000 with a delay of about four months |
Diversion tunnels – 7 months. Headrace tunnel – 24 months. Access tunnel to power house – 6 months Tailrace tunnel – 4 months. the whole project was started in 1998 and is expected to finish in 2004. At the present time there is a delay of three months. |
13.5km of tunnel completed. |
Completed in 1999 |
a) Completed on time in 2000. b) Current delay of four months. c) Completed on time in 2000. |
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