Upper Bound Solution For Ultimate Bearing Capacity Of The Reinforced Grounds

With the acceleration of China's new urbanization,more and more new city region will be located in the suburbs.Yet on the outskirts of the terrain is rugged,and its bearing capacity and stability cannot meet the new requirements of the project.Therefore,it is necessary to treat the soft foundation before construction.The horizontal reinforcement is one of the effective method to reinforce the soft ground.Because of the complex interactions between horizontal reinforcement and soil,its theoretical research has lagged behind in engineering application.At present,there is still no clear calculating formula in the current specification about the special case mentioned above.Therefore,it is of great theoretical and engineering significance to study the reinforcement mechanism,failure mode and bearing capacity calculation method suited to the engineering characteristics.First,based on the analysis and comparison of the existing reinforced grounds,its failure mechanism,the reinforcement mechanism and the interaction mechanism of reinforcement and soil have been discovered preliminarily when there is load of horizontal reinforced grounds.At the same time,based on the analysis of relevant limit equilibrium analysis on the advantages and disadvantages of limit equilibrium method,the basic ideas of using limit analysis method to solve its ultimate bearing capacity have been raised,which lays a theoretical foundation for the establishment of the calculation method of energy dissipation for the level reinforcement considering the influence of the coordinate deformation between soil and the horizontal reinforcement.Then,based on summing up the existing calculation method of energy dissipation for the level reinforcement,a new method was established,in which the influence of the coordinate deformation between soil and the horizontal reinforcement is considered.This method avoids solving complex mechanics,can reflect the reinforcement design parameters effect on the failure mode and its ultimate bearing capacity,and is more convenient for engineering practice.Finally,combined with the engineering characteristics of reinforced grounds,a movable failure mode changing with the parameters of the level reinforcement is established by a deeply research on classic earth pressure theories.Based on the research above,with the upper limit analysis,the ultimate bearing capacity calculation formula of reinforced grounds was put forward by focusing on the calculation method of energy dissipation for the level reinforcement.Then by introducing the sequential quadratic programming optimization algorithm,a new approach for determining the ultimate bearing capacity of the reinforced grounds is proposed respectively.At last,by comparison with experimental results,it is found that this proposed method is reasonable,feasible and superior to other existing methods.Meanwhile,the sensitivity analysis for tensile strength of reinforcement material,reinforcement spacing,and filling properties has given some beneficial conclusions.