【作者】 何开明；

【导师】 曾国熙； 王兰民；

【作者基本信息】 浙江大学 ， 岩土工程， 2001， 博士

【摘要】 用二维有限元方法对黄土碎石桩复合地基的抗液化性状进行了数值分析。结果表明，碎石桩在黄土地基中具有明显的抗液化效果，但由于黄土的低渗透性，即使增加碎石桩的直径，其抗液化影响范围也很有限。 在野外人工饱和黄土地基上实施了液化爆破试验，获得了在爆破地震波作用下人工饱和黄土地基中的超孔隙水压力和加速度资料。 对野外人工饱和黄土液化爆破试验进行了室内模拟和数值分析。对比分析显示，由室内模拟试验和数值分析给出的孔压比和应变与野外爆破试验的结果很接近。同时，等幅循环荷载与野外爆破地震荷载在荷载类型、荷载强度和频率方面对试验结果有一定的影响。 采用现场试验和室内动力试验，对强夯法、化学灌浆法、挤密桩法、换土垫层法和预浸水湿陷处理后的黄土地基的液化性状进行了综合研究。结果表明，只有化学灌浆处理法能在减少黄土的震陷性、湿陷性和提高黄土地基的承载力的同时，能彻底消除黄土的液化势并能增强黄土地基的抗变形能力。更多还原

【Abstract】 The anti-liquefaction behavior of loess ground improved by gravel columns is studied by 2D finite element method. It shows that the effect of gravel columns on anti-liquefaction is obvious, but the improved area is quite limited even increasing the diameters of the gravel columns because of the low permeability of loess.An explosion test was carried out on an artificially saturated loess ground. Acceleration and pore water pressure data are collected.A lab simulation experiment of explosion test on artificially saturated loess and its numerical analysis are made. By comparison, it is seen that the pore pressure ratio and strain by lab simulation and numerical analysis are very close to those obtained by explosion test. Meanwhile, the effects of load types, load strength and frequencies of the uniform cyclic load and the field explosion load on the test results are of importance.Liquefaction behavior of the loess ground improved by dynamic tamping, chemical grouting, compaction pile, replacement and pre-immersion methods are synthetically studied by field tests and lab dynamical experiments. It shows that only chemical grouting can completely eliminate liquefaction potential in loess and strengthen the loess capability of anti-deformation, meanwhile it can reduce seismic settlement and subsidence due to wetting of loess ground and improve the bearing capacity of loess ground.更多还原