冻融循环下石灰处治软土动态回弹模量试验研究

Experimental Study on Dynamic Resilient Modulus of the Lime Modified Soft Soil Under Freeze-Thaw Cycle

通过重复加载动三轴试验测定石灰处治软土在不同含水率、压实度、应力状态、掺灰比和冻融循环次数下的动态回弹模量值,分析了石灰处治软土的动态回弹模量受各因素的影响规律和不同影响程度。以此为基础对优选的现有模型进行改进,建立了冻融循环作用下考虑因素较为全面的经验方程以预测石灰处治软土的动态回弹模量值。研究显示:掺灰比、压实度、围压的增大,以及冻融循环次数、含水率、偏应力的减小均导致石灰处治软土动态回弹模量的提高,且对其不同影响程度排序依次为压实度、围压、掺灰比、含水率、冻融循环次数、偏应力。此外,所建立的模型形式易于接受且预测精度较高,可推广应用于实际工程。

The repeated loading dynamic triaxial tests were carried out to determine the dynamic resilient modulus of lime modified soft soil under different water content,compaction degree,stress state,ash mixing ratio and freeze-thaw cycle times.The influence of various factors on the dynamic resilient modulus of lime-treated soft soil and its degree of influence were analyzed.Based on the results,the preferred existing model for predicting resilient modulus is improved.A empirical model considering more comprehensive factors was established to predict the dynamic resilient modulus of lime-treated soft soil under freeze-thaw cycles.The results of this study show that the increase of ash mixing ratio,compaction,confining pressure and the decrease of freeze-thaw cycles,water content,and partial stress all lead to the improvement of the dynamic resilient modulus of lime modified soft soil.The order of its different influences is in order of compaction degree,confining pressure,ash mixing ratio,water content,freezing and thawing cycles,partial stress.In addition,the established model form is easy to accept and has high prediction accuracy.This model can be generalized and applied to actual projects.