研究目的:受线路位置的限制,处于市区的浅埋隧道往往近距离穿越一些地表建筑物,施工环境十分复杂。爆破开挖会影响到建筑物的安全,引发工程爆破事故纠纷。本文以杭州市钱塘江引水入城工程浅埋段爆破为例,分析电子雷管爆破震动和普通雷管爆破震动的特点,为解决复杂环境条件下控制爆破问题提供依据。研究结论:通过对杭州市钱塘江引水入城工程浅埋段爆破震动测试数据分析,得出:(1)电子雷管爆破震动峰值震速低、持续时间短、波形均匀、稳定性好,减震效果明显;(2)电子雷管爆破震动频带范围宽,呈现多峰特征,高频成分相对较多,其时能密度曲线峰值多而密集,无明显分离的突峰点,逐孔起爆的干扰和叠加作用明显;(3)电子雷管精度高、安全性能好,能够有效改善爆破效果和降低炸药单耗,综合效益显著;(4)本工程所采取的控制爆破和隧洞支护措施取得了较好的应用效果,对城市浅埋段控制爆破有一定的参考意义。
Research purposes: The shallow tunnels in urban areas, which are close to some surface buildings, are usually excavated by blasting because of line positions. Thus, the construction conditions are very complex. The vibration effects produced by blasting will endanger the safety of bulidings close to tunnels and will lead blasting accident disputes. This paper, taking the shallow tunnel of Qiantang River diversion project as an example, the vibration characteristic of electronic detonator blasting and millisecond detonator blasting and their varying laws are studied so as to offer the basis for the decision -making on controlled blasting under complicated environment conditions. Research conclusions:For the research on the analysis of measured data of blasting vibration, some useful results can be concluded. Firstly, the maximum vibration velocity of Electronic Detonator Blasting (EDB) is smaller than that of Millisecond Detonator Blasting (MDB) , and EDB has a relative short sustained time. Secondly, the wave of EDB is well - distributed and steady. The frequency coverage of EDB is wider and has multiple peaks, the high - frequency components of EDB are more abundant than that of MDB. The time - energy density curve of EDB doesn' t have the abrupt and separated fluctuation, which indicates the interference and superposition of EDB are very distinct. Moreover, Electronic Detonator has high precision and good safety performance, and it can effectively improve the blasting effect and reduce the consumption of explosives. The controlled blasting and tunnel support measures of this project have achieved a good effect, which provide the valuable reference to the study on controlled blasting for shallow tunnels in urban areas.