摘要
水平土层场地尤其是特殊地形的场地地震响应计算是工程场地安全性评价的重要内容。本文以上海某在建超高层建筑中钢筋混凝土大底盘工程场地为背景,对其深覆盖土层场地进行了地震响应计算分析。为研究地震作用下刚性大底盘可能产生的地震动摆动效应,采用工程场地地震安评报告提供的3条地震波进行了一致激励和行波激励的地震响应分析。计算结果表明,混凝土大底盘具有刚体运动的特点,且具有一定的摆动效应,地震动强度越小,地震波激励方式引起的摆动效应差异越大。行波激励下底盘各点水平加速度响应较一致激励有所减小,按沿基岩一致地震输入进行土层地震反应分析偏于安全。
Seismic response analysis of horizontal soil layer,especially special terrain site,is an important part of seismic safety evaluation of engineering site. In this paper,a soil layer with site reinforced concrete large-base-plate of super high-rise building in Shanghai is taken as background,and seismic response analysis is studied for the deep coverage soil site. To analyze the rocking effect of existing reinforced concrete large-base-plate on the upper structure under the earthquake excitation,three seismic waves from the seismic safety evaluation report are used for the seismic response analysis of the site,and the input is respectively through excitation of uniform wave and traveling wave. The calculation results show that,the reinforced concrete large-base-plate has some rocking effects under the action of earthquake wave. The bigger the intensity of seismic wave,the less the rocking effect difference due to excitation mode. The horizontal acceleration value of the large-base-plate is reduced under traveling wave excitation compare with uniform excitation,so it is safe for seismic response analysis of soil layer site of this engineering under the uniform excitation of seismic wave.
引文
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