Study Of Passive Earth Pressure Of The Retainning Wall Spinning Around The Bottom Under Non-limit State

The earth pressure calculation of retaining wall is an ancient yet new topic.The classical Coulomb and Rankine earth pressure theories are widely used on retaining wall design, because of its clear mechanics concept. But in the actual cases, the computation results of classical theories are often different from the actual stress distribution of retaining wall, which leads to the actively stress calculation results of retaining wall smaller(unsafe) and the passive stress bigger(uneconomical). Therefore, it is necessary to seek a reasonable method to calculate earth pressure of retaining wall.Existing literature shows that the earth pressure of retaining wall presents non-linear distribution along the height of the wall, and the value of distribution is related to the displacement model, the friction between the soil and the wall,and so on. However, there is no systematic and adequate study of the earth pressure distribution, the size of earth pressure and the action point position with its influence factors.The paper takes the non-limit state passive earth pressure of retaining wall spinning around the bottom as the research object. The large-scale finite elementsoftware ANSYS is selected to simulate the pressure distribution, and single factor analysis method is used to analyze the horizontal displacement field of soil after wall and analyze the specific relationship between the size of the earth pressure, distribution, action point position, the lateral pressure coefficient and the five factors including wall corner(wall top displacement ratio), friction angle between soil and wall(external friction angle), internal friction angle of soil, soil elastic modulus and Poisson’s ratio. The calculation fomula of Rankine’s earth pressure is improved to compare with the ANSYS simulation results in earth pressure. We get the following main conclusions:(1) The size of relative displacement area of soil after wall increases with the increasing of the wall horizontal displacement, internal friction angle,Poisson’s ratio, decreases with the increasing of the external friction angle,elastic modulus.(2) The size of the lateral pressure coefficient and resultant earth pressure of retaining wall increases with the increasing of the five factors including the wall top horizontal displacement, internal friction angle, external friction angle,elastic modulus and Poisson’s ratio.(3) The action point position of the resultant earth pressure increases with the increasing of the wall top displacement ratio, internal friction angle, elastic modulus, and almost has nothing to do with external friction angle, decreases with the increasing of Poisson’s ratio. The passive earth pressure of soil behind retaining wall starting to destruction is about 5 times bigger than the stationarystate, at this time, the resultant force point position is about 0.55 times of the wall height.(4) When calculating the non-limit state of passive resultant earth pressure of retaining wall, the calculation results of improved Rankine’s earth pressure calculation formula are consistent with the ANSYS simulation results proving the rationality of the calculation formula.