The 4.3km long TBM driven section of the 9.6km long Chimay hydroelectric tunnel in Peru has been completed. On March 4 2000, the TBM broke through into a completed 3km long drill+blast drive.
Contractor Cartellone del Peru, a subsidiary of Jose Cartellone Construcciones Civiles of Argentina, took approximately ten months to complete boring with a Robbins Jarva Mk 15, 5.7m diameter TBM. This was the contractor’s first experience of TBM tunnelling.
The tunnel was excavated from four faces: the recently completed TBM drive and three drill+blast drives. The latter consist of one at the opposite end of the tunnel to the TBM drive and two in opposite directions from an adit approximately 7.5km from the TBM end. The final and longest drill+blast drive, 3km long from the adit back to the TBM was finished at the end of February.
Joe Roby, vice president of the Robbins Company, says of the completion, "exceeding 190m of excavation in one week, as well as negotiating several areas of very weak rock, and maintaining a high average monthly advance are excellent records for any contractor, but are especially so for a contractor using a TBM for the first time!"
