TBM RECORDER Breaking excavation records in the HimalayasDec 2012
Seli News Release
A new excavation record of 816m in a single month is set at Kishanganga in India by SELI.
November's remarkable progress rate is credited by SELI to highly-specialised personnel and a double shield universal (DSU) TBM designed especially for the challenging geological and environmental conditions of the job site.
6.18m DSU TBM for Kishanganga
Kishanganga work site in the Himalayas
The TBM, with a diameter of 6.18m, is operating beneath the Himalayas under an overburden of between 750m and 1,000m and at an altitude of 2,430m. It began its 14km drive in June 2010 and is currently more than 7,000m into the task using trains of skips and a twin set of tracks through the full length for muck haulage and erecting the segments of a hexagonal lining system. The total 23.5km headrace tunnel, with drill+blast progressing from the upstream portal, is part of the 330MW hydropower scheme in the northern Indian states of Jammu and Kashmir.
Another factor in the record-breaking efficiency of the TBM is credited to the TBM's specifications, which were developed and implemented to handle variable and exceptional working conditions, including a 19in cutterhead design; 350mm of maximum total overcutting adjustable depending on geology; and the ability to rotate the cutterhead even in the presence of collapsing faces.
The TBM also features 8 x 325kW motors for an installed power of 2,600kW and 12 auxiliary cylinders for additional thrust capacity of 4,427 tonne.
The main contractor for the Kishanganga hydro project is HCC Hindustan Construction Company, a long-time partner of SELI in the Indian market. It awarded a €36.6 million (US$50 million) subcontract for fabrication of the TBM and back-up and the supply of specialised personnel and technical support in 2009, with the machine arriving on site in May 2010.
The SELI team working on the Kishanganga project was featured in the ITA video produced to promote engineering careers in tunnelling and underground space. TunnelTalk sends congratulations to the team and wishes it every good fortune for the second half of the long drive that is blazing a trail for mechanised tunnelling through the Himalayas.
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