部分排水条件下饱和红黏土循环试验研究

Cyclic triaxial tests on saturated red clay under partially drained condition

为了研究交通荷载作用下路基天然黏土层的长期动力特性,采用GDS循环三轴系统,对赣南地区的路基红黏土开展部分排水条件下大次数循环荷载试验.研究部分排水条件下红黏土的孔压累积和模量变化情况,分析循环应力比、平均初始固结压力、初始固结应力比对红黏土累积变形的影响.研究结果表明,红黏土的最终竖向累积变形随循环应力比和初始固结应力比的增大而指数型增大,随平均初始固结压力的增大而线性增大,提出考虑循环应力比、平均初始固结压力、初始固结应力比和循环次数的累积应变模型,通过不同动应力状态下红黏土累积应变随循环次数发展曲线的归一化表明了该累积应变模型的正确性.

Series of cyclic triaxial tests were conducted on saturated red clay derived from GanNan area in partially drained condition with large-number cycles in order to analyze the long-term behavior of saturated red clay in subgrade under traffic load.Pore pressure accumulation and rebound modulus were analyzed,and special attention was paid on the axial strain accumulation of saturated red clay under different cycle stress ratios,average initial consolidation pressures and initial consolidation stress ratios.Results show that the final axial strain accumulation exponentially increases with increasing cycle stress ratio and initial consolidation stress ratio,and linearly increases with increasing average initial consolidation pressure.An axial strain accumulation model was proposed considering cycle stress ratios,average initial consolidation pressures and number of cycles.The normalization of axial strain accumulation suggested the correctness of proposed model.