应变控制下深层黏土动弹性模量与阻尼比试验研究

Experimental Study of Dynamic Elastic Modulus and Damping Ratio of Deep Clay under Strain Control

为研究天津滨海新区深层黏土动力特性,借助GDS动三轴仪器对应变控制条件下天津滨海新区深层黏土的动弹性模量及阻尼比的变化规律进行研究。每组试验中将相应深度土体上覆土层压力作为试验围压,其间只改变控制应变进行循环三轴试验。试验结果表明,土体动弹性模量、阻尼比受围压影响有一个限值,超过这个限值(约3倍参考围压),围压对土体动弹性模量、阻尼比影响很小,但土体动应变对其影响较大。

To research the dynamic properties of the deep clay in the Binhai new area,Tianjin,changes in the dynamic elastic modulus and damping ratios of the deep clay under strain control were studied using GDS dynamic triaxial apparatus.In every group of tests,the pressure of the overlaying soil at corresponding depth was set as the confining pressure,with the controlled strain as the only variable.Test results showed that the dynamic elastic modulus and the damping ratio of the soil were affected by the confining pressure in a fixed scope,while out of the scope(about three times referenced confining pressure),the influence of the confining pressure could be neglected.However,the influence of the dynamic strain of the soil on the dynamic elastic modulus and damping ratios was significant.