k_0固结饱和黏土的循环强度特性

Cyclic Strength of k_0-Consolidated Saturated Clay

通过k0固结饱和黏土的循环三轴试验,研究了固结压力、不排水增量静偏应力对k0固结饱和黏土循环强度的影响.结果表明,同一增量静偏应力比下,不同固结压力对应的循环强度曲线有良好的一致性;当增量静偏应力比从0.15增至0.7时,同一循环破坏次数下的循环强度增大18%左右;由于土样破坏时的应力圆与Mohr-Coulomb强度包线之间有良好的相关性,所以可利用Mohr-Coulomb强度关系描述无应力反向时k0固结饱和黏土循环强度的变化;若略去增量静偏应力的影响,则按照较小增量静偏应力对应的Mohr-Coulomb循环强度指标分析循环荷载作用下土体的稳定性可以得到偏于安全的结果.

Effects of consolidation pressure and static cyclic strength of k0-consolidated saturated clay were incremental deviatoric stress under undrained conditions on the studied using cyclic triaxial tests. Following conclusions were obtained based on test results. Cyclic strength curves under different consolidated pressures are basically the same for a specified static incremental deviatoric stress ratio. The cyclic strength increases by about 18% for the specified num- ber of cycles to failure when the incremental deviatoric stress ratio increases from 0.15 to 0.7. Because of the good correlation between stress circles corresponding to failure states of triaxial specimens and Mohr-Coulomb strength lines, the Mohr-Coulomb strength criterion can be used to describe the cyclic strength of k0-consolidated triaxial specimens without stress reverse. If the effect of static incremental deviatoric stress on cyclic strength is neglected, Mohr-Coulomb cyclic strength parameters corresponding to small static incremental deviatoric stress ratio will be used to analyze the stability of clays with cyclic loads, and the results will be safer.