循环荷载作用下水泥土桩复合地基模型试验研究

Model testing study on composite foundation of cement-soil pile under cyclic loading

设计并完成了循环荷载作用下水泥土桩复合地基的模型试验。对水泥土桩复合地基的竖向附加应力、桩土应力比、孔隙水压力及沉降等问题进行了研究讨论。结果表明,(1)水泥土桩加固饱和软基后发生了应力重分布;(2)循环荷载作用卜复合地基桩土应力比受加荷周数、循环应力比和置换率等因素的影响较显著;(3)水泥土桩加固饱和软基降低了孔压值,减小了由于孔隙水压力的消散而产生的工后沉降;(4)水泥土桩复合地基在循环荷载作用下桩顶和桩间土变形并不协调,桩顶永久沉降小于桩间土永久沉降,且加荷周数越大这种趋势越显著。

Model tests on composite foundation of cement-soil pile under cyclic loading were conducted.The vertical additional pressure,stress ratio of pile and soil,the pore water pressure,and the settlement of composite foundation of cement-soil pile,etc. were discussed.The test results show that (1) the saturated soft foundation improved with cement-soil piles occurred redistribution of stresses;(2) the effects of cyclic stress ratio,number of loading cycle and replacement ratio on the stress ratio of pile to soil of composite foundation were remarkable;(3) the saturated soft foundation improved with cement-soil piles decreased the pore water pressure value and the settlement of back work;(4) the vertical deformation of the top of piles and pile-surrounding soil is not coordinative.The permanent settlement of the pile top piles is less than that of pile-surrounding soil;and this tendency is more remarkable with increasing number of loading cycle.