Experimental Study On Earth Pressure Of Retaining Wall With Relief Shelf

Retaining wall with relief shelf is a new type of retaining structure,which is widely used in practical projects in the fields of hydraulic engineering,port industry,highway,railroad,etc.By utilizing the relieving effect of the shelf,the application of the relief shelf can reduce the total lateral earth pressure on the wall below the relief shelf greatly.Meanwhile,the overall displacement of the retaining wall is also limited effectively by introducing an additional downward bending moment,so that the internal force distribution of this kind of retaining wall is more reasonable.Compared with the traditional gravity retaining wall,a retaining wall with relief shelf has many unique advantages.However,the method for calculating earth pressure for this type of retaining wall is not yet mature,and there is no common specification for reference.Moreover,less research has been done on the earth pressure distribution of the wall both above and below the relief shelf in the passive state.Further research on the interaction process between the retaining wall and the filling behind the wall is needed.In this paper,the stress and deformation characteristics of retaining walls with relief shelf are studied by model test,and the experimental basis for further improving for relevant design theory is provided.The main purpose of this paper is to design and pour a retaining wall model and a model box to go with it.The multi-group model test is carried out by adjusting the width of the relief shelf while keeping the installation position of the relief shelf unchanged.In this study,the distribution of the earth pressure on the retaining wall model under the initial state and RB model is measured;the surface stress on both the upper and lower surfaces of the relief shelf,as well as the connection parts of the shelf and the retaining wall,is monitored during the loading period;and the changes in the filling behind the wall are also observed.Finally,the FEM is adopted to verify the test results.The adoption of the relief shelf has a substantial impact on the earth pressure on the wall both above and below the relief shelf in both the initial and passive states,according to the test results.The empirical formulas for calculating the earth pressure on the upper and lower walls of the retaining wall under the initial state are given based on the data measured from the model test.Furthermore,the optimum location for the installation of the relief shelf and the corresponding shelf width is suggested to minimize the lateral thrust on the retaining wall.The calculation method for the resultant force of the passive earth pressure on both upper and lower walls,as well as the corresponding action point of the resultant force,is proposed for the passive state,under RB movement mode.During the loading period,the vertical load on the upper surface of the relief shelf,the surface stress on the relevant parts,and the change of the filling behind the wall with various conditions of the width of the relief shelf are analyzed and compared,and the relevant experience is summarized.