地铁隧道下穿砖混结构建筑物爆破振动控制

Blasting Vibration Control of Subway Tunnels Under Brick-Concrete Structures

武汉地铁27号线纸地区间段为暗挖隧道,下穿3层砖混结构建筑物,埋深为16~26m。为了使地铁隧道安全地下穿砖混结构建筑物,通过减小最大单段药量、多分段和增加上下台阶的距离来优化爆破方案。将监测点沿着径向布置在地表,对爆破方案优化前与优化后测点所测的振动峰值速度和频率进行对比分析。结果表明:优化后的爆破振动峰值速度显著降低,频率明显增大,使建筑物更为安全;爆破方案优化后,当工作面位于建筑物外墙正下方时,振动峰值速度最大;从工作面后方到工作面前方,地表质点振动峰值速度先增大后减小,空洞效应和应力波的绕射现象明显,为类似工程的修建提供参考。

The metro section of Wuhan Subway Line 27 ranging from Zhifang to subway town is a subsurface tunnel which is underneath a three-story brick-concrete structure building with a buried depth of 16~26 meters.In order to make the subway tunnel safely underpass the brick-concrete structure,the blasting scheme was optimized by reducing the maximum single detonating charge,increasing the detonation sections,increasing the distance between the upper and lower steps.The monitoring points were arranged on the surface in the radial direction,and the comparison of the vibration peak velocity and frequency of the surface particles between pre-optimization and post-optimization of the blasting scheme was made.The results show that the blasting vibration velocity after optimization of the blasting scheme is significantly reduced,and the frequency is significantly increased,making the building more secure.After the blasting scheme is optimized,when the working surface is directly below the outer wall of the building,the blasting vibration velocity is the largest.From the back of the working face to the front of the working face,the blasting vibration velocity of the surface particles increase first and then decrease,and the hollow effect and the stress wave diffraction phenomenon are obvious.the study can provide reference for similar projects.