浅谈电力盾构隧道抗震分析

Discussion on seismic analysis of electric shield tunnel

简要介绍两种常见的地下结构抗震分析方法,以实际盾构隧道工程为例,分别采用手算和一维自由场分析计算三大地震力(强制位移、地层剪力、加速度)。经对比,手算结果与一维自由场分析计算结果相近,计算精度满足设计要求,在地质资料不全时可用该方法初步估算地震作用。分别利用反应位移法和时程分析法对盾构隧道进行了抗震分析,可以得出利用反应位移法得到的弯矩和剪力值要大于时程分析法得到的弯矩和剪力值,而轴力值要小于时程分析法。盾构隧道抗震计算可以以反应位移法为主、时程分析法为辅进行设计。

This paper briefly introduces two common seismic analysis methods for underground structures.Taking the actual shield tunnel project as an example,the three major seismic forces(forced displacement,formation shear force and acceleration)are calculated by hand calculation and one-dimensional free field analysis respectively.By comparison,the hand calculation results are similar to the one-dimensional free field analysis calculation results,and the calculation accuracy meets the design requirements.This method can be used to preliminarily estimate the seismic action when the geological data is incomplete.The seismic analysis of the shield tunnel was carried out by using the response displacement method and the time-history analysis method respectively.It can be concluded that the bending moment and shear force obtained by the response displacement method are larger than those obtained by the time-history analysis method,while the obtained axial force value is smaller than the time-history analysis.The seismic calculation of shield tunnels can be designed mainly by the response displacement method,supplemented by the time-history analysis method.