Self Drilling Ground Anchor in TBM Construction Tunnel
After a 4-month break, here’s the Delhi Metro Phase 3 tunneling update for December 2016. In the past month, final TBM breakthroughs have been achieved on the Pink Line & Magenta Line leaving just 1 more TBM breakthrough pending on the Dwarka –Najafgarh line. In late November, the DMRC bizarrely announced that Phase 3’s tunneling works are over.
According to the DMRC, 48.06 km of the 190 km Phase 1 & 2 network is underground. In Phase 3,53.835 km of the 160.574 km project is being built underground. Phase 3 includes a total of 40 sections of which 38 will be built using a Tunnel Boring Machine (TBM). That’s a total of 76 tunneling drives and with some places requiring multiple TBMs to build 1 tunnel (e.g. Vasant Vihar – Munirka’s down-line tunnel required 2 TBMs & both tunnels of Mukundpur-Azadpur required 4 TBMs) – that brings it up to a total of 80 tunneling drives.
Self drilling ground anchor is generally adopted to support tunnel when TBM is excavating. It can provide immediate reinforcement and have functions of security and high efficiency. Besides, self drilling ground anchor combines drilling, grouting and anchoring together, which can take place of other supporting methods.
