冻融循环下重塑黄土动回弹模量演化规律

Influence of Freeze-thaw Cycles on Remodeled-loess's Resilience Modulus Evolution Law

为明确季冻区黄土动回弹模量的演化规律,采用动三轴试验,研究了不同冻融循环次数下考虑不同应力条件、不同压实条件及不同湿度条件下重塑黄土动回弹模量的演化规律。结果表明:重塑黄土的动回弹模量随围压的升高而增大,随偏应力的增大而减小,并且围压对动回弹模量的影响大于偏应力。在不同的应力条件下,重塑黄土动回弹模量随冻融循环次数的增加先增大后减小,且减小趋势渐缓。在冻融循环第4～第6次的过程中非最佳含水量的重塑黄土动回弹模量变化较小。另外,综合研究含水量和冻融循环对重塑黄土的动回弹模量的影响,发现在冻融循环N≤6次时,含水量对冻融循环作用下重塑黄土的动回弹模量的演化规律影响较大。

In order to make clear of the evolution of the loess dynamic resilient modulus in seasonally frozen region,the dynamic resilient modulus of remolded loess with different stress conditions,different compaction conditions and humidity conditions under different freeze-thaw cycles was studied by dynamic triaxial test.The experimental results show that dynamic resilient modulus of the remodeled-loess increases with the increase of the confining pressure,decreases with the increase of the partial stress,and the effect of the confining pressure on the dynamic rebound modulus is greater than the partial stress.Under different stress conditions,the dynamic resilience modulus of remolded loess first increases and then decreases with the increase of freeze-thaw cycles,and the trend decreases gradually.During the 4th and 6th cycles of the freeze-thaw cycle,the non-optimal moisture content of the remolded loess dynamic rebound modulus is small.In addition,through a comprehensive study of remolded loess’s water content and freeze-thaw cycles on the influence of the dynamic modulus of resilience,found remolded loess under the action of the freeze-thaw cycle water content had a greater influence on the dynamic resilient modulus evolution law when the freeze-thaw cycle less than or equal to six.