在建筑物密集且部分建筑物抗震性能差的城镇地区地下,进行浅埋隧道爆破开挖施工,只有采用减振控制爆破技术才能使地表建(构)筑物免受爆破振动的危害。以重庆在建的渝利铁路长洪岭隧道下穿江池镇区间为工程背景,针对地表民房密集、房屋抗振等级低,爆破控制标准要求严格,通过数码电子雷管和非电毫秒雷管爆破对比试验,形成数码电子雷管减振爆破技术,保证隧道安全快速通过江池镇。试验表明:数码电子雷管引起的爆破振动降低50%~60%,炮孔利用率达到98%,全断面爆破进尺控制在3m左右,不仅降低了振速,而且改善了爆破块度,还保证了施工进度。
Blasting shock absorption technology is only adopted to make surface buildings avoiding damage caused by blasting vibration, when blasting excavation of shallow-buried tunnel is constructed in the town with crowded buildings. In the blasting excavation of Changhongling tunnel under-traversing Jiangchi town at Chongqing city, according to the dense residences, the building with low resistance seismic level, and the strict blasting control standard, the blasting shock absorption technology of the digital electron detonator was form by the comparative tests between ordinary detonator and digital electron detonator, which guaranteed Chang-Hongling tunnel to pass through Jiangchi town safely. The test indicated that blasting vibration could be reduced 50%-60%, utilization ratio of the bore-hole reached 98%, and fullface blasting footage was about 3m by using the digital electron detonator. So the blasting shock absorption technology not only reduced vibration velocity but also improve blasting fragment and guaranteed the speed of construction.