Calculation Of Bearing Capacity Of Unsaturated Soil Foundation Based On Slip Line Method

In this paper,the matrix suction and effective stress parameters are introduced into the slip line equation,and the two-group slip line equation of unsaturated soil foundation is derived.Based on the theoretical solution of the unsaturated soil slip line equation,the ultimate bearing capacity of the unsaturated soil flat foundation and slope foundation is theoretically calculated and qualitatively analyzed programming.The effects of groundwater depth,vertical unsaturation flow rate of groundwater,cohesion and internal friction angle on the ultimate bearing capacity of unsaturated soil foundation are analyzed.For the unsaturated slope foundation,due to its certain shape characteristics,the analysis of its slope is added.In this paper,when the slip line of unsaturated soil foundation is derived,the matrix suction and effective stress parameters are related to the saturated soil slip line equation by the seepage model.The bearing capacity of the unsaturated soil foundation under steady state permeation(water absorption)and steady state evaporation(water loss)was calculated.Then,the possible reasons for the different bearing capacities in the two states are analyzed.In unsaturated soil flat foundation,groundwater depth,cohesion and internal friction angle have a great influence on its bearing capacity,while the vertical unsaturated flow rate of groundwater has little influence on its bearing capacity.In the unsaturated soil foundation of the slope,the influence of the first three influencing factors on the bearing capacity is similar to that of the flat foundation.The steeper the slope,the smaller the bearing capacity of the calculated unsaturated soil slope foundation.At the same time,the paper also analyzes the influence of various factors on the plastic slip line field under the foundation.