软岩动参数统计及地基动力反应分析

Research on Dynamic Parameter and Seismic Response of Soft Rock Foundation

软岩作为核电厂地基的适宜性研究是实施“核电走出去”战略的重要课题。本文基于对国内大型建筑场址动力学参数的调研,采用数理统计方法对软岩动力学特性进行分析,得到了软岩剪切波速、容重、动剪切模量比和阻尼比、以及动泊松比随埋深的变化规律,初步建立了软岩地基动参数模型。通过构造水平成层软岩地基模型,采用等效线性法对软岩地基进行动力反应分析。结果表明,软岩地基对地表加速度峰值具有明显放大效应,加速度反应谱峰值响应频率随基岩埋深增大而逐渐减小。

The study of adaptability of soft rock as the foundation of nuclear power plant is an important issue.In this paper,based on the investigation of dynamic parameters of large building sites,the dynamic characteristics of soft rock of shear wave velocity 500m/s~600m/s are analyzed by mathematical statistics method,and the variation laws of shear wave velocity,bulk density,dynamic shear modulus ratio,damping ratio and dynamic Poisson`s ratio with buried depth are obtained,and the dynamic parameter model of sotf rock foundation is preliminarily established.By constructing the horizontal layered soft rock foundation model,the dynamic response analysis of the soft rock foundation is carried out by using the equivalent linear method.The result shows that the peak response frequency of the acceleration response spectrum decreases with the increase of the buried depth of the bedrock.