Controlled Blasting Techniques in Tongzilin Tunnel on Lanzhou-Chongqing Railway Over-crossing Existing Tunnels
(1 LYJL-13 Lot Supervision Station of Lanzhou-Chongqing Railway, Beijing Tiecheng Supervision Company, Chongqing 400711;
2 Construction Headquarters of Lanzhou-Chongqing Railway Co., Ltd., Nanchong 637500)
Abstract：
Tongzilin tunnel over-crosses two existing tunnels with small clear distances, high requirements for blasting are required for its construction. By means of four-part excavation, multi-cycling with shallow bore holes of explosion, differential controlled blasting and vibration velocity control, it over-passed the existing tunnels safely and smoothly.
2011, Vol. 48 