我国南方地区公路路基土的含水量通常处于随季节降雨而不断变化过程中,土的力学性能随干湿循环而呈现明显的周期性变化.通过进行某路基压实红粘土的干湿循环试验和固结压缩试验,对某路基红粘土湿化膨胀及干燥收缩和力学性能进行了研究.试验结果表明干湿循环过程中压实试样膨胀和收缩变形均随着循环次数的增加而减小;湿化膨胀和干燥收缩过程中累积的塑性变形随着干湿循环次数的增加而减小;初始饱和压实试样的屈服应力为70 kPa,弹性压缩指数为k=0.032,塑性压缩指数为λ=0.179;两次干湿循环后力学参数变大,多次循环后(四次)由于试样中微裂隙的产生导致力学性能变差.%The water content of subgrade soil in southern China is usually in the process of changing with the seasonal rainfall.Therefore,the mechanical properties of soils show obvious cyclical changes with the wetting and drying cycles.According to the wetting and drying cycle tests and consolidation compression test of the compacted red clay.The wet expansion and drying shrinkage and mechanical properties of the compacted soil were studied in this work.The results show that the expansion and shrinkage strain of the compacted specimen decrease with the increase of the number of cycles during the wet and dry cycle.The accumulated plastic deformation during the wetting and drying shrinkage decreases with the increase of the number of wetting and drying cycles.The yield stress of the initial saturated compacted specimen is 70 kPa,the elastic compression index is k=0.032 and the plastic compression index is λ=0.179.After two wetting and drying cycles,the mechanical parameters become larger,and the mechanical properties are deteriorated due to the occurrence of micro cracks in the sample after several cycles (four cycles).
展开▼
