大坪隧道掘进中爆破震动的控制

重庆轻轨大坪车站隧道最小埋深仅4m,地面人口密集,建筑物林立。采用了浅孔、多循环和楔形掏槽的分步开挖方式;根据被保护建筑物的安全振速确定最大一段药量;采用了增设减振孔的光面爆破技术;同时严格控制单孔药量。在开挖施工过程中还进行了爆破震动监测。上述技术措施有效地控制了爆破的地震强度,保证了开挖施工的安全,地表建筑物没有损坏。

CONTROL OF BLASTING VIBRATION IN EXCAVATION OF DAPING TUNNEL

In Chongqing light railway project,Daping station tunnel has a minimum buried depth of only four meters and dense population and constructions on surfaceThe stepped excavation mode with short hole,multi round and V shaped cut were adoptedThe maximum charge weight of one delayed interval was determined from the permitted vibration velocity for the construction to be protectedThe smooth blasting technology with adding vibration reduction holes was usedAt the same time,the charge weight per hole was strictly controlledAlso,the monitoring of blasting vibration was carried out in excavation of the tunnelThe strength of blasting vibration was effectively under control through taking above mentioned technological measuresSo,the constructing safety in excavation of the tunnel was ensured and the constructions on surface were in good condition