| 摘要: |
| 【目的】研究桩-土体系地震响应特征,为工程抗震研究提供参考。【方法】基于动力平衡方程，推导黏弹性土介质的波动方程，利用伽辽金加权余量法，建立波动方程时域的离散形式；借助ABAQUS软件,采用有限元和无限元耦合的数值方法，对水平地震作用下桩的动力响应进行数值计算；分析桩的长径比、上部结构质量和桩-土接触面不同时,桩-土体系对地震波的响应特征。【结果】桩的长径比越小，桩的变形越大；上部结构质量越大，惯性力越大，对桩顶部附近桩身的影响越大；桩-土接触面有滑移无开裂时桩的加速度响应明显较无滑移无开裂时大。【结论】水平地震作用下桩土体系中的桩体横向地震响应受桩的长径比、上部结构质量、桩-土接触面特性等因素的影响。在今后的桩基抗震设计中，可以根据桩体横向变形的规律，针对这些因素合理地选择桩基设计方案，从而提高桩体及其上部结构的抗震性能。 |
| 关键词: 桩-土相互作用 黏弹性本构关系 地震波 有限元-无限元耦合分析 |
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| 基金项目:陕西省教育厅专项科研项目“三维桩 土体系的地震波响应研究”（08JK341）;西安建筑科技大学基础基金项目“基础结构体的地震响应研究”（JC0821） |
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| Numerical analysis of seismic response in wave theory based pile soil system |
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| Abstract: |
| 【Objective】The research was conducted to study the seismic response characteristics of the pile soil system to offer some reference for research on earthquake resistance of engineering structure.【Method】Based on the dynamic equilibrium equation,the wave equation of visco-elastic soil medium is derived;Using Galerkin Weighted Residual Method,the discrete form of wave equation in time-domain is established;With the software ABAQUS,adopting the finite element and infinite element coupled numerical method,the dynamical response of piles on horizontal seismic is calculated;Seismic wave response characteristics are analyzed in the pile-soil system in different situations of slenderness ratio,superstructure mass or interface between pile and soils.【Result】The smaller the pile’s slenderness ratio is,the bigger the pile’s deformation is;The bigger the superstructure mass is,the bigger the inertial force and the effect of the top part of the pile is;The acceleration response of the pile with slippage and without cracks on pile soil interface is significantly higher than the case without slippage and cracks.【Conclusion】The factors such as pile’s slenderness ratiois,superstructure mass and the behavior of interface between pile and soils all affect the horizontal response of pile in pile soil system under horizontal seismic.So,in the future pile foundation aseismatic design,we can reasonably choose the design for the above factors according to the law of pile’s lateral deformation,so as to improve the aseismatic performances of the pile and superstructure. |
| Key words: pile-soil interaction visco-elastic constitutive relation seismic wave analysis of finite element and infinite element coupling |
