基于桩侧砂土三维圆锥型应变楔的变形特征,提出砂土中水平受荷桩的非线性p-y曲线。构建圆锥型楔形体前表面应力体系并引入土体应力-应变双曲线模型,进而考虑应变楔的水平受力平衡得到桩侧土反力的表达式。在此基础上,结合弹性地基梁有限差分数值分析,建立了水平受荷桩非线性p-y曲线的理论推导方法。将该理论用于钻孔桩和打入桩模型试验的算例分析,结果表明:相对于API规范的p-y曲线、双曲线型p-y曲线以及传统非圆锥型应变楔模型得到的p-y曲线,本文方法得到的非线性p-y曲线与模型试验结果更为接近。通过比较本文圆锥变形模式与传统非圆锥型应变楔模式的差异以及桩-土参数的影响分析,进一步论证了该方法的优点。
Based on the deformation features of three-dimensional conical strain wedge of pile side sand, the nonlinear p-y curve of laterally loaded pile in sand was obtained. Constructing the stress system of the front surface of the conical wedge and introducing the hyperbolic stress-strain model of the soil, the expression of lateral soil resistance was derived by considering the horizontal force balance in the plane of the strain wedge. On this basis, the theoretical derivation method of nonlinear p-y curve of laterally loaded pile was established by combining with the finite difference numerical analysis of a beam on elastic foundation. The case analysis of bored and driven model piles using the proposed method shows that the nonlinear p-y curves obtained by the proposed method are closer to the model test results than the p-y curves of API code, hyperbolic p-y curves and the p-y curves obtained by traditional non conical strain wedge model. By comparing the difference between the conical deformation mode and the traditional non conical strain wedge mode and analyzing the effects of pile-soil parameters, the advantages of this method are further demonstrated.
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