兰青复线虎头崖隧道微振动爆破技术研究

Small-vibration Blasting Technology in Construction of Hutouya Tunnel of LanQing Double Line

新建兰青复线虎头崖隧道出口段（DK60＋590～DK60＋710）与既有隧道线间距11．6～40m。为保证既有隧道正常行车安全，对新建和既有虎头崖隧道进行支护加固并采用微振动爆破技术施工。同时采用4C型振动测试仪对隧道爆破振动进行监测，根据监测结果并结合新建隧道确定下一次爆破的参数，对爆破设计进行优化。通过合理选择爆破时差、最大装药量、微差起爆、掘进进尺、预裂爆破等5个方面的振动控制技术措施，使该隧道开挖施工爆破中的既有隧道振动速度值控制在安全范围以内。最后，利用微振动爆破技术保证了虎头崖隧道开挖作业安全、顺利地进行。

The exit section （DK60 ＋590 -DK60 ＋710） of the new constructed Lan-Qing double line, Hu- Tou-Yan tunnel is 11.6 to 40 meters apart from the old tunnel. To ensure the traveling safety of the old tunnel, the new and the old tunnel is reinforced and the blasting vibration monitoring is performed in the job site by means of DSVM-4C vibration signal automatic recording instrument and, on basis of the monitoring results and via regression analysis, the blasting design is optimized. At the same time, such technologies as the reasonable blasting time difference, the maximum charge quantity, the millisecond blasting, the excavation plan and springing blasting are adopted so as to control the vibration velocity of ground within safety range in the process of the tunnel excavation construction, consequently the safety of old tunnel of construction segment and blasting work of this tunnel project was finished safely and smoothly.