超大型地下交通枢纽结构关键断面抗震性能分析

Seismic performance analysis of key sections of super-large underground transportation junctions

地下结构特别是大型断面地下结构在地震中的安全性受很多因素影响,如结构断面尺寸,结构构造形式,工程场地条件等。目前地下结构在地震作用下的安全性研究大多针对一些结构断面尺寸较小,且工程场地较简单的研究模型,基本没有对超大断面地下框架结构在复杂多层成层土层场地中结构的破坏形式与重要节点的研究。以某超大断面地铁车站为例,根据地勘报告提供的土层场地信息将长提条件简化为13层水平成层土层,通过对拟建超大断面与周围边界土体的ABAQUS数值建模分析,采用人工生成的地震动模拟地震动输入和土体粘弹性边界定义,并应用土体线性化方法充分考虑了土体在动力荷载作用下非线性特性。结果表明,设计结构断面在小震、中震和大震作用下均满足工程规范要求。

The safety of underground structures,especially those with large sections,is affected by many factors,such as the size of the structure section,the structure form and the condition of the engineering site.At present,most of the research on the safety of underground structure under earthquake action is focused on some models with small section size and simple engineering site,and there is almost no research on the failure forms and important nodes of super-large section underground frame structure in complex multi-layer soil site.Taking a subway station with a super-large section as an example,according to the soil site information provided by geological survey report,the long uplift condition is simplified to 13 layers of horizontal stratified soil.Through ABAQUS numerical modeling analysis of the proposed super-large section and the surrounding boundary soil,artificial ground motion simulation ground motion input and soil viscoelastic boundary definition are adopted.The nonlinear characteristics of soil under dynamic load are fully considered by using soil linearization method.The results show that the cross-section of the designed structure meets the requirements of engineering specifications under small,medium and large earthquakes.