Based On The Soil The Maximum Pressure Limit Of The Nonlinear Failure Criterion

A linear Mohr-Coulomb failure criterion is used for the traditional method of calculating earth pressure.Based on the nonlinear failure criterion,some scholars have also used the single tangent method to calculating earth pressure.The single tangent method assumption that filling behind the retaining wall is in a single state of stress.Did not consider that filling in different locations have the different normal stress. Different from the normal stress lead to different values of C_t,andφ_t. This paper is based on nonlinear damage criteria,taking into account the filling in different locations,the value of C_t,andφ_t,are different.A multi-tangent method are adopted when sloving earth pressure behind a rigid retaining wall by using limit analysis upper bound theory.The main research work and conclusions are as follows:Firstly,based on the nonlinear failure criterion,a multi-tangent method and a multi-blocks method are adopted when sloving earth pressure behind a rigid retaining wall by using limit analysis upper bound theory.The optimal upper bound solution is obtained after optimizing the divisions of the filling elements and the volocity field by using sequential quadratic programming method.Secondly,both multi-tangent method and singal tangential method. are used for calculating earth pressure which is follow a nonlinear yield criterion.It is found that the method used multi -tangent is more effective than singal tangential method.The results for used multi-tangent method is closer to the real value.From the results,the results of passive pressure which is used the single-tangent method in significantly more than the results for used the multi-tangent method,the biggest difference can be reached 19.82%.The results of active earth which is used the multi -tangent method in significantly more than the results for used the single-tangent method,the biggest difference can be reached 21.39%.Finally,the impact of K,nonlinear parameter m,overloading and initial cohesion on earth pressure is discussed.As the results shows,along with the increase of K calculated results tend to converge,earth pressure growing closer to the upper limit of the real value.Nonlinear parameter m,overloading and initial cohesion have an important impact on the earth pressure.Active earth pressure increases and passive pressure reduce with the increasing of m.With the increasing of C₀ active earth pressure reduce and passive pressure ncreases.