应力历史对重塑红黏土动力特性影响的试验研究

土体动力特性是影响工程稳定性的重要因素。大量试验研究表明应力历史对红黏土静力特性有较显著影响,但目前研究应力历史对红黏土动力特性影响的成果甚少。为进一步揭示应力历史对红黏土动力特性的影响,对承受过不同应力历史的重塑红黏土土样进行了大量动三轴试验,得到了不同应力历史条件下重塑红黏土的动应力应变骨干曲线及动模量变化曲线,分析了不同应力历史对重塑红黏土的影响规律。试验结果表明：在不超过重塑红黏土强度的范围内,提高土体压实度、围压、固结比和振动频率,有利于提高土体动强度和动弹性模量。为给相关工程提供基础数据及参考,建立了重塑红黏土动力指标与应力历史因素的经验公式。

Experimental study on influence of stress history on dynamic properties of remolded red clay

The dynamic characteristics of soils are important factors affecting the engineering stability. Experimental studies have shown that the stress history has a more significant impact on the static characteristics of the red clay. However, there are few research achievements from the studies on the influence of the stress history on the dynamic properties of the red clay. In order to further reveal the effect of the stress history on the dynamic characteristics of the red clay, a large number of dynamic triaxial tests are performed on the remolded red clay samples with different stress histories. The dynamic stress-strain bone curve and the dynamic modulus variation curve of the remolded red clay under different stress histories are obtained. The influence laws of the stress history on the remolded red clay are analyzed. The test results show that in the range not exceeding the strength of the red clay, improving the soil compactness, confining pressure, consolidation ratio and vibration frequency is beneficial to enhancing the dynamic strength and elastic modulus of the soils. In order to provide basic data and references for the relevant projects, several empirical equations for the dynamic indexes and stress history factors of red clay are established.