地铁车站内爆炸引起的地面震动分析

ANALYSIS ON GROUND VIBRATION INDUCED BY INTERNAL EXPLOSION IN SUBWAY STATION

地铁车站内部爆炸及产生的爆炸冲击波将在结构周围的土体中产生巨大的应力波,并向外传播,进而引起地铁车站周边地面的强烈震动,对地面建筑结构造成危害。该文以天津某典型地铁车站为例,对车站内发生意外爆炸后,应力波在周围土体内的传播过程,引起的周边地面震动的特性及其衰减规律进行了数值分析;同时针对国内典型地铁车站,研究了车站埋深、炸药量等参数对地铁车站周边地面震动的影响规律,进而提出了考虑车站埋深和比例距离变化的地铁车站周边地面典型位置的地面震动主要参数的计算公式。该文的研究成果可用于评估恐怖爆炸情况下地铁车站周边建筑的抗震安全性,也可为地铁车站抗爆设计中车站埋深的选取提供理论依据。

Once an internal explosion happened in a subway station, strong stress wave will occur in the surrounding soil, which will spread to the surface causing strong vibration of the buildings. In this paper, a case study of typical subway station in Tianjin is carried out to analyze the responses of surrounding soil induced by an internal explosion, including the propagation of shock wave in the soil, characteristics of ground vibration and its attenuation law. For a typical subway station in China, parametric studies are carried out to investigate the influences of explosive weight and structure buried depth on ground vibration surrounding the subway station. Further, a series of formulas concerning scaled distance and structure buried depth are derived to calculate the main parameters of ground vibration at typical positions surrounding the subway station. The results of the research can be used both to estimate the vibration safety of buildings surrounding the subway station under terrorist bombing attack, and to provide theoretical basis for the determination of structure buried depth in blast-resistant design of subway stations.