基于p-y曲线法的深埋桩桩-土相互作用研究

Study on Deep Buried Pile-soil Interaction based on p-y Curve Method

为了研究超长桩在承受水平荷载下的桩侧水平位移和桩侧土压力的理论计算方法,根据有限杆单元的等效荷载求解原理得到与p-y曲线相适应的非线性弹簧的设置方法,建立了超长桩非线性有限杆单元的理论模型;以实际工程为建模背景,通过ABAQUS软件模拟受到水平荷载时的桩侧水平位移和桩侧土压力,并与实际测得的数据进行对比,以验证数值模拟计算结果的准确性。结果表明:当桩端受到水平荷载作用时,桩侧土压力呈“M”型分布;数值模拟结果与实际工程测量数值之间误差较小,通过数值模拟计算得到的桩侧水平位移和桩侧土压力与实测值之间的相对误差分别在5%和2%以内;通过p-y曲线模型计算得到的桩侧土压力曲线与桩侧水平位移曲线与数值模拟计算得到的各点之间的相关系数R^(2)分别为0.97和0.92,两种方法得到的计算结果基本一致;且利用p-y曲线模型进行计算比通过ABAQUS三维有限元软件计算节约了将近60%的计算时间。在实际工程中,可考虑p-y曲线模型作为超长桩的分析计算模型或作为一种辅助验证方法用以验证通过其它方法计算的准确性。

In order to study the theoretical calculation method of pile side horizontal displacement and pile side earth pressure under horizontal load,the theoretical model of nonlinear finite rod element of ultra-long pile is established according to the equivalent load solution principle of finite rod element to obtain the setting method of nonlinear spring corresponding to p-y curve.Based on the actual engineering modeling background,the horizontal displacement of the pile side and the earth pressure on the pile side under horizontal load are simulated by ABAQUS software,and the actual measured data is compared to verify the accuracy of the numerical simulation calculation results.The results show that when the pile end is subjected to horizontal load,the soil pressure on the pile side shows an“M”type distribution.The error between the numerical simulation results and the actual engineering measurement values is small,and the relative errors between the horizontal displacement of the pile side and the soil pressure on the pile side and the measured values calculated by the numerical simulation are within 5%and 2%respectively.The correlation coefficients R^(2) between the pile side soil pressure curve and the pile side horizontal displacement curve calculated by the p-y curve model and the points calculated by the numerical simulation are 0.97 and 0.92,respectively,and the calculation results obtained by the two methods are basically the same.The use of p-y curve model for calculations saves nearly 60%of the calculation time compared to calculations by ABAQUS 3D finite element software.In practical engineering,the p-y curve model can be considered as an analytical calculation model for ultra-long piles or as an auxiliary verification method to verify the accuracy of calculations by other methods.