基于FLAC3D的单桩静载模拟桩土接触面参数敏感性研究

原位静载试验结果与数值模拟结果常出现较大偏差，原因是计算模拟中桩土接触面参数取值不准确，且不同参数对计算结果敏感性不同。为使模拟结果对实际工程具有更强的实践意义，应逐一研究桩土界面参数对计算结果的影响规律，针对性地提高桩土界面参数取值的准确性。基于FLAC3D，控制改变接触面单元黏聚力c、内摩擦角φ、接触面刚度Kn和Ks取值，获得每个参数对静载试验结果的敏感程度。结果表明:桩土界

FlAC3D-based Study on Sensitivity of Pile-soil Interface Parameters by Static Load Test of Single Pile

There often occurs large discrepancy between the results of in-situ static load test and numerical simulation, which is due to the inaccurate values of pile-soil interface parameters taken in the simulated calculation, and the different sensitivities of these parameters to the calculation result. In order to make the simulation result more significance in practice, how the pile-soil interface parameters influence the calculation result should be studied respectively so as to improve the accuracy of the parameter values. Depending on FLAC3D, the values of cohesion c and internal friction angle φ of the interface element, and the interface stiffness values Kn and Ks, were changed under control so as to obtain the sensitive degree of each parameter to the result of static load test. The result shows that the value of cohesion c of the pile-soil interface has significant influence on the calculation result, the values of interface stiffness Kn and Ks have the influence to certain extent, and the value of internal friction angle φ has minor influence. Therefore, the value selection of the cohesion c of pile-soil interface should be focused in practical simulation.