对桩承结构上下部水平抗震理解的联合预估

结合平面动力有限元与简化三维集中质量法(S-R模型)对水平地震作用下的群桩-土-结构体系的动力性能进行了理论预测,可用来计算不同构型、桩数、土层属性下的结构系统动力反应。算例分析表明,由于土与基础的参与,考虑相互作用后结构位移及层间位移反应增大;受结构、桩基础及土层属性等多因素影响,结构内力在某些地震频谱作用下反而会有所增加,而固基情形下的加速度反应谱曲线对相互作用的反应结果并不一定形成包络,两种方法在对相互作用结构进行动力反应的量化数值分析和定性评价上均有良好的一致性。

Combination evaluation of horizontal aseismatic performance based on pile-supported upper structures

The theoretical evaluation for the dynamic behavior of pile-soil-structure under horizontal seismic load was conducted based on the combination of plane dynamic FEM and simplified 3D concentrating-mass method(S-R model).The structural dynamic response with different types,number of pile-group and soil properties could be expediently educed.With a computation example,it was indicated that structural and interstorey displacement should augment considering the effect of interaction due to the participation of relative flexible soil-foundation,but internal structural forces under some seismic frequency-spectrum would increase owing to varied pile-soil-structure system properties.In addition,an acceleration response spectrum curves on condition of fix-base did not necessarily include that on condition of soil-pile-structure interaction.These two methods were consistenty for the quantitative numerical analysis and qualitative evaluation on responses of interaction structures.