干-湿循环条件下压实宽级配砾质土SWCC研究  

Study on Soil-Water Characteristic Curve of Compacted Wide Grading Gravelly Soil with Wet-Dry Cycles

作　　者：李雨佳[1] 王红雨[1] 杨旭[1] 

机构地区：[1]宁夏大学土木与水利工程学院,宁夏银川750021

出　　处：《人民黄河》2014年第2期107-108,111,共3页Yellow River

基　　金：国家自然科学基金资助项目(41062004)

摘　　要：采用压力膜仪法测定了压实宽级配砾质土干-湿循环后的脱湿土壤水分特征曲线,总结了压实宽级配土样随干-湿循环次数的增加其土壤水分特征曲线的变化规律。试验结果表明:第1次至第3次脱湿SWCC测定中,土样的饱和含水率随着干-湿循环次数的增加明显增大,但是增加幅度逐渐减小,经第4次脱湿后,饱和含水率下降,但仍明显大于未经干-湿循环的土样;第2次至第5次脱湿曲线与第1次脱湿曲线的交点随着干-湿循环次数的增加不断向左移动;在曲线末端,相同基质吸力下随着干-湿循环次数的增加,含水率明显减小;在基质吸力大于50 kPa时,SWCC随着干-湿循环次数的增加整体下移,但变化幅度逐渐减小。Abstract： It revealed the water conservation function of geo-textiles betonies layer in composite impervious system of landfill site wide grading grav- elly soil as a protective layer, used pressure membrane method to determine the compaction of wide grading gravelly soil dehydration soil water char- acteristic curve after dry-wet cycles and summed up the change laws of soil water characteristic curve of the compaction wide grading soil samples with the increase of the dry-wet cycles. Experimental results show that in the first 3 times determination to take off the wet of SWCC, the saturated moisture content of soil samp]e obviously increases with the number of dry-wet cycles, but the increase rate decreases, after 4 times to take off the wet, saturated moisture content decreases, but still significantly greater than the samples without the dry - wet circulation; The intersection of the second to the fifth dehydration curve and the first dehydration curve is moving to the left with the increase of dry-wet cycles ; In the end of the curve, under the same matric suction, with the increase of dry-wet cycles, moisture content significantly decreases; After the matrix suction of 50 kPa, SWCC overall down with the increase of dry-wet cycles, but the change is getting smaller gradually.

关 键 词：土壤水分特征曲线 宽级配砾质土 干-湿循环 饱和含水率 

分 类 号：TU411.99[建筑科学—岩土工程]