受周边地上建筑影响地铁车站的抗震设计方法

A seismic design method of subway stations affected by surrounding buildings

基于地上建筑-土-地铁车站整体模型的动态平衡特性,分析得到地上建筑对地铁车站地震响应影响的机制,并以此为依据进一步推导出受周边建筑影响地铁车站的简化抗震设计方法。取包含地铁车站和地上建筑的近场进行动态平衡分析,并将其与仅有车站的情况进行对比,得到地上建筑的地震作用力通过基础和场地的传递最终作用在地铁车站上,从而引起车站地震响应的变化。由于地上建筑的地震作用力主要为惯性力,且该作用力可由反应谱法进行计算,以此为基础可简化地铁车站的地震响应分析,得到一种简化抗震设计方法。该方法采用拟静力建模计算地铁车站动力响应,能大幅度地减少分析时间。与此同时,为了验证该方法的正确性并分析其计算精度,建立了一系列数值模型试验进行分析。计算结果表明:以动力时程的结果为基准,简化方法在计算结构内力响应时误差能控制在7%以内;而计算结构顶底相对变形的误差均在5%以内,由此得到简化方法是一种计算精度较高的方法。

The mechanism of surrounding buildings on the seismic response of subway stations was investigated based on the dynamic equilibrium characteristics of the building-soil-subway station model and a simplified method for the seismic design of subway stations considering the effects of surrounding buildings was proposed in this paper.A near-field model including a subway station and a surface building was established firstly.Comparing the dynamic characteristics of the near-field model to the model without surface building,we found that the seismic forces of surface building induced in an earthquake would be passed to subway station through the foundation and field.Since the main seismic forces of surface building were inertia forces which could be calculated using the response spectrum method,a simplified method was derived.Owing to acquiring the dynamic response of subway stations via static modeling and calculating,the method proposed herein consumes less analysis time and cost.Furthermore,a series of numerical simulation experiments was conducted to verify the simplified method and further evaluate its computational accuracy.The results of those tests revealed that:compared to the results of dynamic time history,errors in internal forces and deformations of the simplified method are less than 7%and 5%,respectively.Therefore,the simplified method has a high accuracy in engineering design.