桩-土相互作用弹簧对倾斜液化场地-群桩-上部结构体系的影响  

The influence of pile-soil interaction springs on the inclined liquefied site-group pile-supertructure system

作　　者：王知扬 贾科敏 许成顺[1] 杜修力[1] Wang Zhiyang;Jia Kemin;Xu Chengshun;Du Xiuli(Key Laboratory of Urban Security and Disaster Engineering of the Ministry of Education,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学城市与工程安全减灾教育部重点实验室,北京100124

出　　处：《地震科学进展》2024年第2期125-134,共10页Progress in Earthquake Sciences

基　　金：国家自然科学基金面上项目(52078016)资助。

摘　　要：桩-土-上部结构体系的动力相互作用是一个复杂的过程,尤其是在倾斜液化侧向扩展流动(侧扩流)场地中,由于地震过程中场地产生地面永久大变形,桩土间有可能产生错动滑移与开裂等非线性反应,因此桩-土相互作用模拟至关重要。为了探究桩-土非线性接触对倾斜液化场地-群桩基础-上部结构体系动力响应的影响,本文基于OpenSees分别建立了考虑桩-土相互作用弹簧和桩土结点之间直接绑定的有限元数值模型。结果表明:考虑桩-土相互作用Pyliq弹簧时,土体加速度幅值略微降低,桩基对土体的约束明显变弱,土体残余位移增大。同时,具有Pyliq弹簧的模型能较好地模拟桩的曲率响应,而采用桩土结点直接绑定的模型高估了桩顶曲率,进而无法准确估计桩基抗弯最不利位置。桩-土相互作用弹簧对上部结构动力响应的影响较小。The dynamic interaction of pile-soil-superstructure system is a complex process,especially in inclined liquefaction-induced lateral spreading site.Due to the permanent large deformation of the ground generated during the earthquake,nonlinear reactions such as sliding and cracking may occur between piles and soil.Therefore,the simulation of pile-soil interaction is crucial.In order to explore the influence of nonlinear contact between pile and soil on the dynamic response of the inclined liquefied site-group pile-supertructure system,the finite element numerical models considering the pile-soil interaction springs and the direct binding between the pile nodes and soil nodes were established based on OpenSees.The results indicate that when considering the Pyliq springs for pile-soil interaction,the amplitude of soil acceleration is slightly lower,the constraint of the pile foundation on the soil becomes significantly weaker,and the residual displacement of the soil increases.Meanwhile,models with Pyliq springs can better simulate the curvature response of piles,while models that directly bind pile nodes and soil nodes overestimate the curvature of the pile top,making it difficult to accurately estimate the most unfavorable position of pile bending resistance.The influence of pilesoil interaction springs on the dynamic response of the upper structure is relatively small.

关 键 词：数值模拟 倾斜液化侧扩流场地 桩-土相互作用 Pyliq弹簧 

分 类 号：P315.8[天文地球—地震学]