The Coefficient of the Lateral Earth Pressure of Khon Kaen Loess Soil in Compacted Condition

Abstract

This research studied the active pressure behavior and coefficient of active earth pressure of compacted Khon Kaen loess soil under wet and dry conditions. Two earth pressure cell were used to measure the lateral pressure. The soil sample was compacted in a mold size of a cubic meter  at 90% of maximum dry density on a wet side by the modified proctor method. The soil sample size was 0.6 meters in thickness, 0.5 meters in width, and 1.0 meters in length. The foundation size 0.2x0.2x0.1 m was seated on the ground surface 0.25 m away from the cut edge. The test result shows an excellent linear relationship between the vertical and stresses horizontal stress at a depth of 1.5B until a soil reached the failure. Then the horizontal stress is gradually reduced. However, the vertical and stress horizontal stress relationship at a depth greater than 1.5B is non-linear. Therefore the coefficient of the active earth pressure increased with the applied stress until failure was reached. Then the coefficient of the active earth pressure was dropped. The failure plane has occurred from the edge of the foundation to the depth of 1.5B. The soil pressure coefficient in dry and wet baking is different. With the same load weight, the soil pressure coefficient in the wet test is greater than the soil pressure coefficient in the dry test.