SOIL COMPRESSION DEFORMATION CHARACTERISTICS OF TYPICAL PROFILES IN THE NORTH CHINA PLAIN

Ground fissure and land subsidence are usually caused by soil mass deformation, which may occur in region of groundwater depression cone formed by overexploitation of groundwater. Soil deformation process is irreversible. It is extremely difficult for deformed soil to restore. Therefore, predicting soil deformation is one of the main researching contents for preventing and controlling ground fissure and land subsidence. In the north China plain, groundwater overexploitation is a very serious problem. A series of environmental geological problems(i.e, ground fissures, and land subsidence) have been caused by the overexploitation of groundwater in the North China Plain. It is very important for researchers to study soil deformation in region of groundwater depression cone in the north China plain. Soil mechanics experiments were carried out with different depths and different soils collected from Shijiazhuang and Hengshui in the north China plain where groundwater were overexploited heavily, and where groundwater depression cone have formed. The results show that the relationship among different soil deformations is clay soils silty clay soils sandy soils; the deeper buried soils are easier to occur deformation; Deformation of shallow clay is increasing with colloidal particles content increasing; Deformation process of deep silty clay is divided into fast and slow-steady two stages. This study of soil deformation has a guiding significance for land subsidence prediction in the North China plain.