Earth Pressure Analysis Method Of Retaining Wall Considering Influence Of Uneven Interfacial Stress Distribution

The research on earth pressure of retaining wall is of great significance to engineering practice.The classical earth pressure theory is widely used because of its clear concept and simple calculation,but the linear distribution of earth pressure obtained by its calculation is inconsistent with the actual engineering.A large number of field observations and laboratory tests have found that the earth pressure behind the retaining wall presents a nonlinear distribution and is related to the friction between the wall and the soil.At present,most of the research on the calculation of earth pressure of retaining wall adopts the layered element method for analysis and calculation,and the interface stress,as a load directly distributed on the calculation element,has an important influence on the equilibrium condition of the calculation element,and further affects the calculation of earth pressure.The results have an important impact.In the existing research,the horizontal shear stress on the interface of the calculation element is generally ignored and the vertical normal stress is assumed to be uniformly distributed,which is obviously inconsistent with the actual situation.In view of the above deficiencies,this paper starts from the friction effect of the wall and soil and combines the action mechanism of the soil arch effect,and uses the local wedge element to carry out the force analysis,and fully considers the influence of the uneven distribution of the interface stress on the calculation results of the earth pressure.(1)Establish a reasonable earth pressure analysis model of the retaining wall,conduct the overall force analysis of the sliding wedge behind the retaining wall,and obtain the calculation of the inclination angle of the sliding surface under the active and passive limit states according to the static equilibrium conditions of the sliding wedge.formula.Then,on the basis of analyzing the mechanism of soil arching effect,the stress state of the soil at the back of the wall and the slip surface is determined according to the shear strength criterion,and the stress state and Principal stress deflection law.(2)Select the local wedge element for force analysis,analyze the interface stress distribution form on the interface of the element,and derive the earth pressure acting on the retaining wall by the local wedge element according to the static equilibrium condition of the local wedge element;Then,through differential calculation,the expression form of active and passive earth pressure distribution is deduced,and then the resultant force of active and passive earth pressure and the position of the action point of the resultant earth pressure are calculated.By comparison,the rationality and superiority of the method in this paper are verified,and the parameter analysis is carried out by the control variable method,and the influence law of the wall-soil friction angle and the fill internal friction angle on the calculation results of active and passive earth pressure is discussed.(3)Based on the local wedge element method in this paper,the influence of uneven interfacial stress distribution on the calculation results of earth pressure is discussed.The expression form of the resultant vertical normal stress and the resultant horizontal shear stress is derived;then the parameter sensitivity analysis is carried out on the resultant vertical normal stress and the resultant horizontal shear stress,and the influence of the internal friction angle of the filling soil and the friction angle of the wall and soil on their distribution law is studied.Finally,by comparing the calculation results of earth pressure in three cases considering the influence of vertical normal stress and horizontal shear stress,only considering the influence of vertical normal stress,and not considering the influence of vertical normal stress and horizontal shear stress.The effects of stress and horizontal shear stress are analyzed.