多向地震作用下土-框筒结构动力响应试验研究与数值模拟

为研究土—框筒结构动力相互作用体系在多向地震作用下的动力响应,对20层框筒结构的土—结构动力相互作用(SSI)模型和刚性基础(FB)模型分别进行了多向地震作用的振动台试验。通过试验数据的模态识别,分析了SSI和FB两种模型在不同工况下的固有频率、阻尼比和振型的差别。将不同烈度地震作用下SSI模型上部结构水平方向的峰值加速度、最大层间位移、最大层间位移角以及最大动应变进行对比,分析了单向水平和多向地震作用下SSI模型水平方向动力响应的差别;通过对比SSI和FB两种模型在多向地震作用下上部结构的竖向峰值加速度和层间位移,分析了土对结构竖直方向动力响应的影响;采用有限元软件ANSYS对试验模型和工况进行数值模拟,验证了试验结果的可靠性。研究成果可为框筒结构高层建筑的抗震性能研究提供参考。

Experimental and numerical investigation on the dynamic response of a frame-core tube structure under the excitation of multi-direction seismic waves considering the soil-structure effect

To investigate the dynamic response of a frame-core tube structure under the excitation of multi-direction seismic waves,with the consideration of soil-structure interaction(SSI)effect,shaking table tests were conducted on a SSI model and a fix-based(FB)model,with its superstructure of 20 floors frame-core tube construction.The differences of natural frequency,damping ratio,and mode shape between the SSI and FB models were analyzed under different conditions by the modal identification using the test data.The difference of dynamic responses of the SSI model in horizontal direction between the excitation of single horizontal direction and multi-direction seismic waves was analyzed by comparing the peak acceleration,maximum story displacement,maximum story drift,and maximum dynamic strain of the superstructure in horizontal direction under different seismic magnitudes.The influence of soil on the dynamic responses of the superstructure in vertical direction was analyzed by comparing the peak accelerations and story displacements in vertical direction of the SSI and FB models.Moreover,the test models were simulated by the finite element software(ANSYS)to verify the reliability of the test results.The study results could provide a reference to the study of the seismic performances of frame core tube high-rise buildings.