黄土地区地下道路结构地震反应分析

Seismic Response Analysis of Underground Road Structures in Loess Area

以地下道路结构为研究对象,通过文献查阅获取西安地区典型黄土地层参数。基于Midas-GTS有限元分析软件,建立地下道路横断面的二维平面有限元分析模型。对土体和结构材料本构模型及相关参数、黄土地基计算范围的选取、阻尼以及边界条件设置等系列问题进行探讨。对黄土场地地下道路结构进行初始应力的地震时程反应数值分析,得到黄土场地地下道路结构的内力分布。分别利用时程分析的结果和规范推荐的简化方法,求得地下道路结构横断面反应位移法计算所需的基本参数。基于Midas-Gen有限元分析软件,采用反应位移法对地下道路结构横断面进行分析。计算结果表明,2种方法结果差异较大,直接影响结构配筋的控制工况。因此,在对西安黄土地区地下道路结构进行设计时,有必要对地震作用进行专门的计算,并且不建议采用规范推荐的简化方法。

Taking the underground road structure as the research object, the typical loess stratum parameters in Xi'an area are obtained through literature review. Based on Midas-GTS finite element analysis software, a 2D plane finite element analysis model of underground road cross-section is established. The soil, constitutive model of structural materials, related parameters, the selection of calculation range of loess foundation, damping & setting of boundary conditions are discussed. Seismic time history response numerical analysis of initial stress of underground road structure in loess site is carried out, and internal force distribution of underground road structure in loess site is obtained. Based on the results of time history analysis & the simplified method recommended by the code, the basic parameters for the calculation of cross-section response displacement method of underground road structure are obtained. Based on Midas-Gen finite element analysis software, the response displacement method is used to analyze the cross-section of underground road structure. The results show that the results of the two methods are quite different, which directly affects the control conditions of structural reinforcement. Therefore, when designing the underground road structure in Xi'an loess area, it is necessary to calculate the seismic action specially, and the simplified method recommended by the code is not recommended.