重交通荷载作用下港区地基工作区深度研究

STUDY OF WORKING DEPTH IN PORT GROUND UNDER HEAVY VEHICLE LOAD

基于重交通荷载作用下港口地基工作区深度现场试验,采用有限差分软件FLAC3D建立重交通荷载作用下港口地基的数值模型。通过现场试验监测结果验证了数值模型的合理性,并对重交通荷载作用下港区地基工作机制进行深入研究。最后,针对港区地基设计计算中砂垫层厚度、接地面积和轮压等重要参数进行系统分析。研究结果表明:重交通荷载作用下,港区地基附加应力与自重应力比等于0.2和0.1的深度分别约为1.63和2.03 m;竖向应变在淤泥质黏土层顶部最大;侧向位移沿深度和水平方向呈先增大后减小;随着砂垫层厚度的增加,地基中的最大竖向应变和最大侧向位移逐渐减小,当砂垫层厚度为1.25 m时,地基工作区深度恰好位于砂垫层底部;随着接地面积和轮压的增大,地基工作区深度和地基中的最大竖向应变和最大侧向位移均逐渐增大。

A three-dimensional numerical simulation was conducted by FLAC3D software to simulate the field test. A model calibration was conducted to ensure that the numerical modeling was a realistic representation by the measured data. Finally,a sensitivity analysis was performed to investigate influence factors,such as the thickness of sand cushion,area of thrust surface and wheel pressure. The research results indicated that:(1) Under the vehicle load,when the ratio of additional stress to gravity stress was equal to 0.2 and 0.1,the corresponding depths were 1.63 and 2.03 m,respectively.(2) The maximum vertical strain occurred at the top of the mucky clay.(3) The lateral displacement increased first and then decreased along the depth and horizontal direction.(4) With the increase of thickness of sand cushion,the maximum vertical strain and the largest lateral displacement of the ground increased firstly and decreased lastly.(5) When the thickness of medium-coarse sand was about 1.25 m,the working depth was right at the bottom of medium-coarse sand.(6) The working depth,the maximum vertical strain and the maximum lateral displacement of ground increased with the increase of the area of thrust surface and wheel pressure.