异跨框架式地铁地下车站结构三维非线性地震响应分析

Three-dimensional Nonlinear Seismic Response Analysis of Unequal-span Frame Underground Subway Station Structure

建立了异形框架式地铁地下结构的三维计算模型,并对异跨框架式地铁车站结构进行数值模拟.计入土体和混凝土的非线性以及土-结构之间接触非线性的效应,对结构关键部位的应力响应、相对位移以及结构层间位移角等变化规律进行了分析.结果表明,结构框架柱底端应力高于顶端应力,底层框架柱应力值高于顶层框架柱应力值;结构整体在与场地相匹配的地震动载荷下,随着载荷的改变,其层间相对位移变化趋势由单一方向的大变形转变为多个方向的大变形;在纵向的不同截面上,结构的地震响应随着主震频率覆盖范围的增加,会出现明显差异.模拟结果可为异跨框架式地铁车站的抗震设计以及相关结构的抗震性能评价方法提供合理的参考依据.

A three-dimensional computational model of the unequal-span underground subway structure is established,and the structure of the unequal-span frame subway station is numerically simulated.Taking into account the effects of the nonlinearity of the soil and concrete and the contact nonlinearity between the soil and the structure,the change laws of the stress response,relative displacement and the inter-story displacement angle of the structure at key parts are analyzed.The results show that the stresses at the bottom end of the structural frame columns are higher than those at the top end,and the stress values of the bottom frame columns are higher than those of the top frame columns;the trend of the inter-story relative displacement of the structure as a whole changes with the change of load under the ground shaking load matching the site;the seismic response of the structure varies significantly with the increase of the coverage of the mainshock frequency in different sections of the longitudinal direction.The simulation results can provide a reference for the seismic design of the unequal-span frame subway stations and the seismic performance evaluation of related structures.