交通荷载作用下非饱和土的动力特性试验研究

Experimental Study on the Dynamic Characteristics of Unsaturated Soils under Traffic Loading

通过泥浆固结法制备大量均一试样,基于改进的可控制吸力式非饱和土C.K.C循环三轴仪进行了动三轴试验,研究了非饱和粉质粘土在交通荷载长期作用下的动强度和变形特性,同时分析了在饱和条件下反复干湿循环对其动强度的影响。结果表明:基质吸力的增加提高了土体抵抗变形的能力,相同动应力及振次条件下,土体的累积塑性应变随着基质吸力的增加而减小;土体的临界循环动应力以及动强度随着基质吸力的增加而增大,但动强度随基质吸力增加而增大的速率随基质吸力的增加而减小;干湿循环对粉质粘土的动强度有显著影响,使得土体的动强度提高。

Based on the modified unsaturated C. K. C cyclic loader triaxial testing system, a series of dynamic triaxial tests were performed on the slurry consolidated specimens. The dynamic be- havior and deformation characteristics of silt clay under traffic loading were studied. The effect of drying and wetting on the dynamic strength of saturated silt clay was also analyzed. The test re- sults show： the accumulated plastic strain of the specimens decreases with the increase of matric suction under the same dynamic stress and cyclic loading number; the critical dynamic stress and dynamic strength increase with the increase of matric suction, however, the dynamic strength growth rate with the increase of the matric suction decreases with the increase of matric suction; drying and wetting has significant influence on dynamic strength of silt clay, the dynamic strength increases after drying and wetting.