基于Winkler地基梁模型的高桩码头非线性时程分析

Nonlinear time-history analysis of pile-supported wharf based on model of beam on Winkler foundation

基于Winkler地基梁模型,考虑高桩码头结构的非线性,进行了高桩码头的非线性时程分析。采用的Winkler地基梁模型由并联的弹簧和阻尼器组成,弹簧和阻尼器分别用于模拟桩侧土抗力和土体辐射阻尼。通过岸坡自由场地震反应分析获得结构地震动输入,并将计算得到的位移时程施加在弹簧末端以计算码头动力反应。另外,通过去除模型中的阻尼器以研究辐射阻尼对高桩码头地震反应的影响。研究表明,Winkler地基梁模型可以很好地模拟码头在地震作用下的受力状态,得到桩基塑性铰出现次序、内力及变形;辐射阻尼会减弱码头地震反应,影响结构破坏程度,在工程设计中应予以重视。

Based on the model of beam on Winkler foundation, we carried out nonlinear time-history analysis to investigate the laterally seismic response of pile-supported wharf by inputting the outcome of free-field analysis of the slope. The model applied consists of a spring which simulates the reaction of soil surrounding the pile and a dashpot which interprets the radiation damping in parallel to the spring. Through excluding the presence of dashpots in the model, we analyzed the influences of radiation damping. The results show that the behavior of wharf, for instant, sequence of plastic hinges, internal forces and deformations, during earthquake can be accurately simulated by Winkler model. Radiation damping weakens the response of wharf and reduces the damage, so it should be treated carefully in engineering design.