利用真空预压方法制备了一个大尺寸软黏土模型试验土池,进行了不同竖向静荷载与水平循环荷载共同作用下软土中单桶基础承载力的模型试验,研究了竖向静荷载与水平循环荷载对基础承载力的影响。结果表明,基础的水平循环承载力小于静承载力;导致基础破坏的循环荷载与循环次数取决于竖向静荷载。竖向静荷载越大,与同一循环破坏次数对应的循环荷载就越小。依据模型试验土的循环强度变化关系,采用弹塑性有限元计算方法对模型试验进行了数值模拟,计算与试验结果基本吻合,表明可以依据软黏土的循环强度变化关系,通过弹塑性有限元数值计算评价软土地基中桶型基础的水平循环承载力。
The soft clay stratum is prepared to use vacuum preload method in a large-scale model test tank. Model tests of a bucket foundation in the stratum are conducted to research its bearing capacity under different vertical static and horizontal cyclic loads. Research results show that the bearing capacity of the foundation under horizontal cyclic loads is less than that of under horizontal static load. The cyclic load and cycle-index which lead to foundation failure depend on vertical static load. The larger the vertical load is; the less the failure of horizontal cyclic load corresponding to the number of cycles is. According to model test condition, the simulation calculations are performed by using the cyclic strength relationship of the stratum and elasto-plastic FEM. Calculating results are in good agreement with test results, which show that the horizontal cyclic bearing capacity of the bucket foundation in the soft clay can be evaluated by using elasto-plastic FEM based on the cyclic strength relationship.