基于盆地效应的抗震设防研究之若干进展

Some advances in research on seismic fortification based on basin effect

沉积盆地能够加重震害,在抗震设防中需要定量考虑盆地效应。本文叙述了盆地效应的主要表现形式以及对震害的影响;详细介绍了盆地效应的研究方法以及取得的研究成果,同时也指出了各个方法的优缺点;讨论了抗震设防中对盆地效应考虑的必要性;着重回顾和总结了当前在抗震设防中考虑盆地效应的两种方法:(1)在场地地震动预测模型中加入盆地基底埋深项。(2)求取盆地模型相对一维层状模型的附加放大因子,提出针对当前抗震设防规范中地震动参数的校正系数。最后指出开展盆地抗震设防研究面临的问题及工作展望。

Sedimentary basins can aggravate earthquake damage,and the basin effect needs to be quantitatively considered in seismic fortification.This paper describes the main manifestations and the impact on earthquake damage of the basin effect;introduces the research methods of the basin effect and the research results obtained in detail,meanwhile points out the advantages and disadvantages of each method;discusses the necessity of considering the basin effect in seismic fortification;emphatically reviews and summarizes the current two methods to consider basin effect in seismic fortification,the methods are as follows.(1)add the burying depth term of the basin basement to the site attenuation relationship,(2)to obtain the aggravation factor which expresses the additional effect of the response at different locations along the basin with respect to the corresponding 1D response,and proposes correction coefficients for ground motion parameters of the current seismic fortification code.Finally,this paper points out the problems and prospects of the research on the seismic fortification of the basin.