隧道爆破地震波作用下砌体建筑物振动响应分析

为研究隧道爆破地震波作用下砌体建筑物的振动响应,以青岛地铁3号线下穿某砌体建筑物爆破施工为背景,通过现场爆破振动监测和有限元数值模拟,对砌体结构的爆破振动速度和主振频率随楼层的变化规律进行研究。结合数值计算,进一步分析隧道埋深、单段最大装药量,装药结构等不同因素下砌体建筑物的振动响应。分析表明:在隧道爆破地震波作用下砌体结构在垂直方向的振动响应强度明显大于水平方向,并且存在一定的高程放大效应,在爆破施工时应加强对砌体结构顶层的防护;隧道下穿砌体建筑物施工时,爆破地震波的主频率主要集中在10～60 Hz内,建筑物自振频率则大多为3.0～3.5 Hz,该砌体建筑物与爆破地震波较难发生共振;砌体结构动力响应强度随着不耦合系数的增加而逐渐降低,随单段最大装药量增加近似呈线性关系,改变装药结构及控制单段最大装药量是控制爆破振动的有效措施;爆破振动速度对隧道的埋深响应敏感,在数值上出现数量级的变化。通过对多层砌体结构振动响应分析,有利于不断提高与完善现有的爆破技术与减振措施。

Analysis of Vibration Response of Surface Masonry Buildings under Tunnel Blasting Seismic Wave

In order to study the vibration response of masonry buildings under the action of tunnel blasting seismic waves, taking the blasting construction of a masonry building under the Qingdao Metro Line 3 as the background, the blasting vibration velocity and the main vibration frequency of the masonry structure are studied with the change of the floor by on-site blasting vibration monitoring and finite element numerical simulation. Combined with the numerical calculation, the vibration response of masonry buildings under different factors such as tunnel buried depth, single-stage maximum charge and charge structure was further analyzed. The analysis shows that the vibration response strength of the masonry structure in the vertical direction is obviously larger than the horizontal direction under the action of tunnel blasting seismic wave, and there is a certain elevation amplification effect. The protection of the top layer of the masonry structure should be strengthened during blasting construction; In the construction of tunnel undergoing masonry buildings, the main frequency of blasting seismic wave is mainly concentrated in the range of 10~60 Hz, while the natural frequency of buildings is mostly 3.0~ 3.5 Hz, which makes it difficult for buildings and blasting seismic wave to resonate; The masonry structure dynamic response strength decreases with the increase of the uncoupling coefficient, which is approximately linear with the increase of single-stage maximum charge. Changing the charge structure and controlling the single-stage maximum charge is an effective measure to control blasting vibration. The blasting vibration velocity is sensitive to the buried depth response of the tunnel, and there is an order of magnitude change in the value. Through the analysis of the multi-story masonry structure vibration response, it is conducive to continuously improve and perfect the existing blasting technology and vibration reduction measures.