Experimental study on compression deformation characteristics of soils under seepage

To understand the compression deformation characteristics of soils influenced by groundwater level decline and seepage, the pore pressure-controlled compression tests satisfing the stress state of soil in dewatering site and the stress path of water level drop and seepage are designed by using the Rowe consolidation instrument. The representative fine sand, silty and silty clay from a subway station site are selected to carry out compression tests to simulate the groundwater level decline by reducing pore pressure and the seepage by applying pore pressure difference. The test results show that all the three types of soils exhibit compression deformation under the action of pore pressure difference, and the compression deformation of soils caused by the pore pressure difference decreases with the increasing consolidation pressure. There is a good linear relationship between the compression coefficient and hydraulic gradient of soils. The silt still shows the phenomenon of compression deformation when the pore pressure difference decreases, which indicates that there is the possibility of ground settlement when the groundwater level recovers. The compression deformation of soils caused by seepage should be considered as appropriate in engineering practice.