软土地基单桶基础循环承载力研究

在不固结不排水条件下对软粘土进行了大量循环三轴试验。通过分析试验结果,阐明了软粘土在静、动荷载共同作用下的破坏遵循Mises屈服准则。因此,可以依据Mises屈服准则和循环三轴试验结果确定一般应力状态下土单元的循环强度。建议了一种依据土单元循环强度评价地基循环承载力的方法,该方法考虑土单元的静应力对其循环强度进而对地基循环承载力的影响。利用这一方法分析了软土地基上单桶基础的循环承载力。结果表明,单桶基础的竖直和水平循环承载力取决于所受到的静荷载大小。当静荷载是静承载力的0.3倍时,竖向循环承载力达到最大,为竖向静承载力的0.43倍;当静荷载是静承载力的0.5倍时,水平循环承载力达到最大,为水平静承载力的0.79倍。

Cyclic bearing capacity of single bucket foundation on soft clay strata

A large number of cyclic UU triaxial tests of the soft clay were conducted,showing that the failure of the soft clay with static and cyclic loads obeyed Mises criterion by analysis of test results.The cyclic strength of soil element in general stress states could be determined according to Mises criterion and cyclic triaxial test results.A method evaluating cyclic bearing capacity of foundation based on cyclic strength of soil element was further suggested,with consideration of effect of different cyclic strengths of element in different static stresses on the cyclic bearing capacity.The cyclic bearing capacity of a single bucket foundation was then evaluated using it.Results show that the vertical and horizontal cyclic failure loads depended on static loads.When the vertical static load was 0.3 times of the static bearing capacity,the maximum vertical cyclic failure load was 0.43 times of vertical static bearing capacity.When the vertical static load was 0.5 times of the static bearing capacity,the maximum horizontal cyclic failure load was 0.79 times of horizontal static bearing capacity.