Sleemanabad Carrier Tunnel
Hybrid EPB built using Onsite First Time Assembly (OFTA)
|Machine Type||Hybrid Earth Pressure Balance Machine (EPB TBM)|
|Diameter||10.0 m (32.8 ft)|
|Tunnel Type||Water Transfer|
|Tunnel Lengths||12 km (7.4 mi)|
|Contractor||M/s Patel Engineering, SEW, & Coastal Projects Limited (CPL)|
|Location||Madhya Pradesh, India|
Narmada Valley, located in Central India’s Madhya Pradesh state, is a drought-prone region for eight months out of every year. The Sleemanabad Carrier Canal is part of the Indian Government’s Bargi Diversion Project, which will source water from the Narmada River to irrigate 250,000 acres (100,000 hectares) of land.
The major trans-valley canal will stretch 194 km (120 mi) from the existing Bargi Dam on the Narmada River to arid areas. Once complete, the Bargi Diversion Project will transfer 152 cubic meters (40,000 gallons) of water per second to Katni, Satna, Panna, and Jabalpur districts, irrigating over 100,000 hectares (250,000 acres) of land.
The contractor, a joint venture of M/s Patel Engineering, SEW, and Coastal Projects Limited (CPL), signed a contract with Robbins for the supply of a 10.0 m (32.8 ft) diameter EPB, as well as the back-up system, cutting tools, spares and continuous conveyor system. CPL also opted for Onsite First Time Assembly (OFTA) of the machine at the jobsite, in order to expedite the project schedule.
Hybrid Machine Design For Mixed Ground Conditions
The Robbins hybrid machine is a fully functional hard rock Single Shield and soft ground EPB TBM, designed for long sections of 180 MPa (26,000 psi) UCS jointed rock and marble, interspersed with clay and gravel. In sections of soft ground, the machine runs as a standard, pressurized EPB with an abrasion-resistant, shaft-type screw conveyor. When short sections of rock or mixed ground are encountered, the machine can be run in non-pressurized EPB mode. In longer sections of rock, the TBM can be converted to a hard rock Single Shield setup by switching out the screw conveyor with a belt conveyor.
The hybrid EPB was completed using Onsite First Time Assembly (OFTA) in Madhya Pradesh, India on March 14, 2011. A commissioning ceremony celebrated the launch of the TBM at the 12 km (7.5 mi) long Sleemanabad Carrier Canal.
The launch ceremony also marked the first time OFTA has been used on a hybrid EPB. The Robbins-developed method allowed the TBM to be initially assembled on location, rather than in a manufacturing facility. Critical subsystems, such as the electrical and hydraulic systems, were tested before being shipped to the jobsite. For a time lapse video of the Onsite First Time Assembly at Sleemanabad, visit:
The tunnel will have a finished diameter of 9.2 m and is expected to be operational in 2013.
Updates of this project will be posted as boring continues.