Study On Non-limitinging Earth Pressure Of Rigid Retaining Wall Based On Steel Rod Similar Soil

In the actual operation process,retaining wall is affected by various loads and environmental factors,and is often in the state of non-limiting displacement.However,engineering design mostly adopts Coulomb and Rankine linear earth pressure theory based on limit equilibrium theory for design calculation,resulting in mismatch between engineering design results and actual stress characteristics of retaining wall.At present,most of the researches on this aspect adopt indoor model tests,and the packing is mostly sandy soil.However,due to the fact that the compactness of sandy soil is difficult to control and easy to deform during the actual loading process,the reliability of experimental results is difficult to be guaranteed.In order to overcome the test defects,the steel rod similar soil has been gradually applied in the research due to the characteristics of controllable test conditions and no compression deformation.Therefore,on the basis of fully l iterature investigation,this paper uses the steel bar as similar soil wall after packing,consider translation(T),around the wall rotation(RT)and the wall around a point on the top of the rotation(RTT)three displacement modes,against the rigid retaining wall displacement condition limit earth pressure distribution in the model test,and introduces a particle image velocimetry(PIV)is used to capture the wall after filling displacement vector and the failure surface evolution process,set up the limit displacement mode of earth pressure calculation model.According to the research of this paper,the main conclusions are as follows:1)Through the direct shear test of steel rod similar soil,the internal friction Angle of steel rod similar soil with different particle size combinations was obtained,and the functional relationship between the internal friction Angle and the average particle size of steel rod was established.The test data was verified by particle discrete eleCent software PFC2D,providing basic data for theoretical analysis.2)The model test of the translational(T)displacement mode of the rigid retaining wall was carried out to reveal the distribution law of the earth pressure on the wall back under the Non-limiting displacement mode,and the feasibility of the steel rod similar soil as the filler of the retaining wall model test was verified.3)Indoor model tests were carried out under the modes of non-limit rotation(RT)of rigid retaining wall around the top and rotation(RTT)of a certain point on the top of the wall.The distribution characteristics of soil pressure on the back of the wall under different displacements,the change rules of resultant force and resultant point and the filling failure surface were analyzed,and two practical calculation models of soil pressure under the modes of non-limit displacement were established.