TEST RESEARCH ON DEFORMATION OF COARSE-GRAINDE SOIL WITH WEAK ROCK DUE TO WETTING-DRYING CYCLE

摘要

The wetting-drying cyclic tests are tried for coarse-grained soil with weak rocks using iron wire mesh as outer boundary, wetting by steaming and drying by hot-dry wind. Main tests organized as wetting-drying tests under different constant stress state, wetting-drying tests with various moistened water content under certain stress state and second time wetting-drying test under changed stress state. The test results indicate that there are three existent states of water in coarse-grained soil and their action and affection on humidification deformation are different; the deformation in first cycle is notable, after several wetting and drying cycles, the deformation in a wetting and drying cycle becomes stable and the deformation in drying is more outstanding than that in wetting; in second time wetting-drying test, increased stress induces considerable deformation and decreased stress induces negligible deformation. The test results are important for realizing the microscopic mechanism of the humidification and dehumidification of coarsegrained soil and the long time behavior of high earth-rock dams. The test results supply a reference for the design and construction of high earth-rock dams.