地铁车站钢筋混凝土中柱试件抗震混合试验研究

Hybrid simulation for aseismic performance of subway station with its RC central column as test specimen

地下结构抗震性能试验中同样存在缩尺比问题。以地铁车站结构钢筋混凝土中柱为足尺试验对象,进行地铁车站结构抗震混合试验研究。试验中的试验子结构取为车站中柱,该试件采用MTS作动器加载通过OpenFresco从数值子结构获得地震作用;取车站结构剩余部分与车站周围土体为数值子结构,数值子结构采用OpenSees模拟,地震激励由数值子结构底部输入。试验结果显示:随着地震动加速度峰值(PBA)增加,试验构件进入损伤状态,侧向刚度降低;在输入基岩波为上海人工波时,在弹性工作状态下纯数值模型的层间位移和水平剪力与试验结果匹配较好,表明采用的OpenSees,OpenFresco,MTS混合试验系统在测试地下结构地震响应时具有良好的稳定性与准确性。

The scale ratio problem exists in aseismic performance tests of underground structures. Here, hybrid simulation wasadopted to study structural aseismic performance of a subway station. Its central column was selected as a full-scale specimen of the substructure to be tested, the remaining parts of the station structure and soil surrounding itwere taken as the numerical substructure simulated with the software OpenSees. The specimen was loaded using MTS actuator and obtain seismic action from the numerical substructure through the software OpenFresco. The seismic excitation was input into the bottom of the numerical substructure. The hybrid simulation results showed that with increase inpeak base acceleration(PBA), the specimen enters a damage state and its lateral stiffness decreases;when input bedrock wave is Shanghai artificial one, the horizontal shear force and interlayer displacement obtained usingthe pure numerical model under elastic working state match betterthoseobtained with the hybrid simulation, so theproposed hybrid simulation system based on OpenSee, OpenFresco, and MTS has good stability and accuracy when applied in underground structure seismic response tests.