Research On Critical Height Of Reinforced Earth Retaining Wall

With the gradual popularization of the application of the reinforced structure,the demand height of the reinforced earth retaining wall is more and more great,so the research on the critical height of the reinforced earth retaining wall becomes an important issue gradually.The research methods mainly include classical plasticity theory,generalized plasticity theory and limit analysis method.Although there were much research on the critical height of reinforced earth retaining wall based on these methods,most of them ignored the objective factor of the friction loss between the reinforcement and the soil that is difficult to agree with the actual results.In this paper,the reinforcement mechanism is analyzed based on the limit analysis method,and the energy loss of reinforcement and soil on velocity discontinuity and the friction loss between them are given full consideration when the internal failure of reinforced earth retaining wall occurs,then the formula of critical height of reinforced earth retaining wall is derived and verified by various methods.The main work and conclusions are as follows:(1)The soil reinforcement mechanism and several failure modes are analyzed,and the shape of the failure surface is assumed to be logarithmic spiral surface when the internal failure occurs;(2)Total internal energy loss rate includes energy loss rate of reinforcement and soil on velocity discontinuity and the friction loss rate between them when the internal failure occurs based on limit equilibrium method according to the research idea supported by professor Wang Zhao(Wuhan University).The external power is supplied by the gravity of the rotating soil and the analytical equation is established and the computational formula of critical height of reinforced earth retaining wall is derived;(3)The critical height of the reinforced slope is solved through half graph method used the model test parameters experienced by foreign scholar Porbaha A,and the results is basically consisted with test results,and then the rationality of formula of critical height of reinforced earth retaining wall is verified considering the friction loss between the reinforcement and soil;(4)The analysis model is established used the SLOPE module in Geo-Studio software according to the test parameters in the model,and then the reinforced earth retaining wall is filled layer by layer,and the height of the reinforced earth retaining wall is obtained at the critical state(Fs=1),which further confirmed the formula rationality.(5)The formula of critical height of reinforced earth retaining wall is applied to engineering practice,and the formula is solved by half graph method combined with the related parameters of slope design in the study area,and then the maximum height of the reinforced earth retaining wall is 72.6 m when the loess is used as the filling material of reinforced retaining wall under the corresponding conditions,and after that typical section less than this height is conducted on the stability analysis,it is concluded that the results meet with the requirements of standard,so the formula is of great guiding significance.