The Study Of Deformation Characteristic On Expansive Soil Foundations

The swelling soil in Hefei zone was formed at the Q3 epipleistocene of the 4th subage or before. It belongs to the type of Huaihe alluviation and diluvion. The principal ingredient of the swelling soil is glimmertion, with a small quantity of kaolinite, minim vermiculite and montmorillonite. Its hydrophilic nature is between the hydrophilic nature of montmorillonite and kaolinite. Swelling after absorption and shrinking after dehydration are the main characters of the swelling soil. Because of the change of climate and alternation of seasons, the foundation soil will be swelled and shrink from up to down and the building on it will be damaged and be not easy to repaired. Firstly, from the characters of swelling soil and the water ratio of soil layer, ground temperature, engineering geology and hydrogeology, different index points of soil layer with the variety of vertical depth and climate conditions, the atmospheric influence region of swelling soil and the depth of soil layer are studied in this paper. The relation between swelling distortion magnitude of different depth soil layer measured under the pressure plate prototype soaking test and the theoretical swelling distortion magnitude measured under the prototype soaking test indoor with the same initial water ratio condition is obtained to seek the rules of difference between the theoretical computed values and practical observed values, and then the empirical coefficient