大空间地下结构地震响应混合试验研究

Seismic response hybrid simulation of large space underground structure to earthquake excitation

基于OpenSees-OpenFresco-MTS混合试验系统,选取关键构件底层中柱,进行大空间地下结构地震响应混合试验研究。在混合试验过程中,取结构底层中柱为试验子结构,取结构剩余部分与土体为数值子结构。为了满足试验要求,开发了一种专用于混合试验的可变刚度钢构件。通过更换柱脚螺杆改变试验装置侧向刚度。在混合试验前,根据数值模型中对应单元侧向刚度确定钢构件侧向刚度;根据幅值比和相位差等频域指标评价混合试验结果。试验结果显示:在上海人工波工况、El Centro波工况和Kobe波工况中,理论结果与试验结果匹配良好。在以大空间地下结构地震响应为研究对象时,基于OpenSees-OpenFresco-MTS的混合试验系统具有良好的稳定性与精确性。

In order to study the seismic performance of a large space underground structure under earthquake action,this paper adopts central column as experimental substructure by using OpenSees-OpenFresco-MTS hybrid test system.In the hybrid simulation process,the central column is adopted as experimental substructure,the remaining part of the structure and soil are adopted as numerical substructure.In order to meet the test requirements,a variable stiffness steel specimen dedicated to the hybrid simulation was developed.The lateral stiffness of the steel specimen could be changed by changing the screws located at the foot of the specimen.Before hybrid simulation process,the lateral stiffness of the steel specimen was determined based on the lateral stiffness of the corresponding elements in the analytical model.The test results were evaluated based on the frequency domain index amplitude ratio and phase angle.The test results show that the analytical results and the test results are well matched during the whole vibration process in Shanghai artificial wave condition,El Centro wave condition and Kobe wave condition.The hybrid test system based on OpenSees-OpenFresco-MTS system is stable and accurate.