基于CPTU测试的海相软土刚性桩复合地基承载特性研究

Bearing characteristics of rigid pile composite foundation in marine soft soil based on CPTU

通过现场CPTU(孔压静力触探)测试,运用专门解译CPTU数据的分析软件对测试数据进行解译,并利用CPTU方法对场地进行土质分类与土层划分,计算工程区土体的物理力学参数。通过与室内试验结果对比,证明CPTU技术在深厚海相软土地区工程勘察的适用性。基于CPTU方法从理论上预测桩基的竖向承载力,建立刚性桩复合地基的数值模型,并模拟了现场静载荷试验。通过理论计算、数值模拟与现场静载荷试验分别评价复合地基单桩竖向极限承载力,并讨论刚性桩复合地基的破坏形式,提出复合地基单桩承载力特征值的确定方法,研究复合地基桩土相互作用机理以及设计荷载作用下的工作性状。

Through on-site CPTU testing,software which interprets CPTU data was used to interpret the test data,and CPTU method was used to classify the site and stratify the soil layer.The physical and mechanical parameters of the soil in the engineering area were calculated,and the applicability of CPTU technology in deep marine soft soil area was proved by comparing the indoor test results.The CPTU method was used to predict the vertical bearing capacity of pile foundation theoretically.The numerical model of rigid pile composite foundation was established,and the field static load test was simulated.The results of single pile vertical ultimate bearing capacity of composite foundation obtained by theoretical formula calculation,numerical simulation and field static load test were compared and analyzed,and the failure forms of composite foundation are discussed.On this basis,the determination of bearing capacity characteristic value of single pile in composite foundation was deeply studied and the interaction mechanism between pile and soil in composite foundation and the working behavior under design load were studied.