地震对地下硐室围岩动压力的影响  

Influence of earthquake on rock dynamic pressure of underground chambers

作　　者：孙有为[1,2] 薄景山[2,1] 李平[1,2] 郭晓云[2] 蔡晓光[2] 

机构地区：[1]中国地震局工程力学研究所,黑龙江哈尔滨150080 [2]防灾科技学院,河北三河065201

出　　处：《地震工程与工程振动》2010年第3期171-177,共7页Earthquake Engineering and Engineering Dynamics

基　　金：国家科技支撑项目(2008BAC44B02-0201);地震行业专项(200708039)

摘　　要：地下硐室围岩压力在地震荷载作用下的表现是岩土地震工程领域当前的热点问题之一。本文简述了目前我国隧道工程抗震规范关于地下硐室围岩动压力的确定方法,以四川黄草坪隧道的资料为例,利用有限差分法分析在不同峰值加速度的水平地震动输入下,硐室围岩压力对地震输入的响应,并与围岩静压力进行了对比分析。结果表明:随着输入地震动加速度峰值的增加,地下硐室围岩最大主应力峰值的增大;围岩最大主应力的地震反应峰值与输入地震动的加速度峰值有一定的关联;在加速度峰值小于0.2 g的地震动作用下,硐室围岩的最大主应力峰值变化较小,硐室结构一般不会发生破坏;地震作用时,硐室的斜上和斜下侧壁是整个结构的薄弱部位;衬砌结构对于地下硐室围岩最大主应力地震反应峰值的控制和硐室结构抗震性能的增强有极为重要的作用。The rock pressure of underground chamber,which is affected by the earthquake,is a popular topic of current geotechnical earthquake engineering.This article introduces the methods which are advised on China tunnel seismic design codes to determine the dynamic pressure of the rock around underground chamber.Using Sichuan Huangcaoping tunnel as an example,the authors analyse the rock pressure of underground chamber wall,which is caused by different levels of peak ground motion acceleration,with the help of finite difference method.Then the authors compare all the responses with static pressure of wall rock.The result shows that with the increase of peak ground motion acceleration,the peak of maximum principal stress of underground chamber wall rock increases.To a certain extent,the peak of maximum principal stress of wall rock is determined by the peak ground motion acceleration.In some earthquakes,the peak ground motion acceleration is less than 0.2g,the peak of maximum principal stress of underground chamber wall rock changes within a small range.The chamber structure is not damaged normally in this case.In an earthquake,chamber ramp sidewall and under oblique sidewall are the weak parts of the whole structure.The lining structures are very important in controlling the peak of maximum principal stress of underground chamber wall rock and enhancing the earthquake-resistant capability of the chamber structure.

关 键 词：地下硐室 围岩动压力 地震动 数值模拟 

分 类 号：P453.2[天文地球—大气科学及气象学]