基于非线性Pushover分析的单桩横向受力特性研究

Research on Lateral Load Bearing Behavior of Single Pile Based on Nonlinear Pushover Analysis

为了研究地基土以及桩身在进入非线性状态下的单桩水平极限承载能力及变形能力,采用分布塑性铰模型模拟桩身的弹塑性,以p-y曲线模拟桩侧地基土水平抗力,对固定桩头单桩基础进行了静力非线性推倒分析。结果表明:(1)桩身轴压比对结构水平极限承载能力及位移延性影响显著;(2)随着地基土抗剪强度的增大,桩顶极限位移减小,但水平极限承载能力增大;(3)提高桩身配箍率,桩顶极限位移增加较明显;(4)轴压比较小时,在桩头及地面以下桩身均可能产生塑性铰,但轴压比较大时,仅在桩头产生塑性铰。

In order to study the horizontal ultimate bearing and deformation capacity of pile under the condition of the nonlinearity of pile and subsoil, the plastic hinge distribution model is adopted to simulate the elastoplasticity of pile shaft, p-y curve is used to simulate the horizontal soil resistance of pile side soil, and non-linear static pushover analysis is performed on single pile with the boundary constraint at pile head. The result shows that （ 1 ） axial compressive ratio of pile shaft has a significant influence on the horizontal limit bearing capacity and displacement ductility of the structure; （2） with the increase of shear strength of foundation soil, the ultimate displacement of the pile top reduce, but the horizontal limit bearing capacity increases; （3） after incresing stirrup ratio of pile shaft, the ultimate displacement of the pile top increases greatly; （4） when axial compressive ratio is small, plasticity hinges maybe produced at the location of pile head and pile shaft below ground line, but when axial compressive ratio is larger, plasticity hinges will only generated at the location of pile head.