冻融黏土动态回弹模量演变规律及预估模型

为研究冻融循环影响下路基黏土动态回弹模量的变化规律,开展了不同初始含水率、压实度、冻融循环次数、偏应力及围压条件下的动三轴试验。结果表明:路基黏土的动态回弹模量随初始含水率和偏应力的增加而减小,而与压实度及围压均呈正相关关系;冻融作用导致动态回弹模量发生衰减,而经历5次冻融循环后其值基本稳定。基于此,建立了全面考虑冻融循环影响、物理状态及应力条件的路基黏土动态回弹模量回归模型,预测效果较好。

Evolution Rule and Prediction Model for Dynamic Resilient Modulus of Clay under Cyclic Freezing-Thawing

Dynamic triaxial tests under different deviatoric stresses and confining pressures were carried out to investigate the variations of dynamic resilient modulus of subgrade clay of varied initial moisture content and compaction degree under different freeze-thaw cycles.Results demonstrate that the dynamic resilient modulus of subgrade clay declines with the rising of initial moisture content and deviator stress,but is positively correlated with the degree of compaction and confining pressure.In the mean time,dynamic resilient modulus attenuates under freeze-thaw action,but remains stable after five freeze-thaw cycles.Furthermore,an effective regression model for predicting the dynamic resilient modulus of subgrade clay was established in consideration of the influence of freeze-thaw cycles,physical state and stress conditions.