城市地铁爆破开挖对浅埋地下大直径管道的安全影响研究

Security Impact of Blasting Excavation of Urban Subway on Shallow Buried Large Diameter Pipeline

在城市浅埋地铁爆破开挖中,经常遇到地下管网、涵洞等构筑物,而爆破地震效应对其影响范围和程度的正确评价就显得尤为重要。本文以长沙地铁爆破开挖为例,以现场实测数据为基础,采用有限单元法,对爆破振动下大直径混凝土污水管道的动力响应、变形和动应力等进行了计算,评价了爆破地震对管道的安全影响。研究表明:管道在控制爆破作用下是偏于安全的;爆心距是影响管道受到爆炸作用力影响大小的最主要因素;对于以实测数据为基础,采用加速度激励的时程分析方法以爆破振动对埋地管道的影响进行评价,是一种可行且较为精确的方法。

In the process of shallow buried underground blasting excavation, there often exists underground pipe network, culverts and other buildings. Therefore, the influence range and degree of accuracy evaluation for the blasting is particularly important. Taking Changsha subway tunnel blasting construction as an example, we used finite element method based on spot-measuring data to calculate the pipeline dynamic response on buried sewage pipeline under tunnel blasting vibration as well as deformation and stress, and to evaluate the safety effect of blasting vibration on pipeline. The results show that the pipelines are basically safe. Blasting distance is the main factor to pipeline affected by explosive force size. Finally, time-history analysis method of acceleration excitation is a feasible and accurate method for evaluating the impact on buried pipeline and blasting vibration.