干湿循环下南水北调中线工程压实壤土物理力学性质研究  

Research on physical and mechanical properties of compacted loam of Middle Route Project of South-to-North Water Diversion under drying-wetting cycles

作　　者：占世斌 张胜军[2] 何娇[2] ZHAN Shibin;ZHANG Shengjun;HE Jiao(Yangtze River Engineering Construction Bureau,Changjiang Water Resources Commission,Wuhan 430010,China;Changji-ang Institute of Survey Technical Research of Ministry of Water Resources,Wuhan 430011,China)

机构地区：[1]长江水利委员会长江工程建设局,湖北武汉430010 [2]水利部长江勘测技术研究所,湖北武汉430011

出　　处：《水利水电快报》2022年第4期113-117,共5页Express Water Resources & Hydropower Information

摘　　要：南水北调中线工程黄河以北的膨胀岩土边坡一般采用壤土换填方法进行处理。由于降雨及蒸发等周期性变化原因,压实壤土经常处于干湿交替状态,使壤土换填层产生一系列变形失稳现象。选取壤土扰动样,制成最优含水率下不同压实度的样品,并开展干湿循环试验,以模拟野外土体含水率反复变化的条件;通过分析不同压实度、不同压力条件下样品物理力学特性随时间的变化规律,研究了干湿循环作用对压实壤土物理力学特性的影响。研究结果表明:干湿循环对不同初始压实度壤土的抗剪强度所造成的影响不同;不同初始压实度下,随着干湿循环次数增多,壤土黏聚力和内摩擦角均不断减小并最终趋于稳定。研究成果可为渠坡稳定性研究提供参考。For Middle Route Project of South-to-North Water Diversion,the expansive rock-soil canal slope in the north of the Yellow River is generally replaced with loam.Due to the periodic changes of rainfall and evaporation,the compacted loam is often in a wet-dry cycling condition which causes a series of phenomena such as deformation and instability of the loam replacement layer.By selecting disturbed samples of loam,different compaction samples under the optimal moisture content are prepared for the drying-wetting cycles test to simulate the repeated changes of moisture content of soils in the field.The physical and mechanical properties of the samples under different compaction and pressure conditions are analyzed,and the effects of drying-wetting cycles on the physical and mechanical properties of compacted loam are studied.The results show that:under different initial compaction degrees,the cohesion and internal friction angle of loam decrease continuously and eventually tend to be stable with increase of drying-wetting cycles;the effects of drying-wetting cycles on the shear strength of loam are different under different initial compaction degrees.

关 键 词：压实壤土 干湿循环 物理力学性质 南水北调中线工程 

分 类 号：TU452[建筑科学—岩土工程]