Settlement Calculation Of Two-way Reinforced Embankment Based On Double Beam Theory

The horizontal reinforced cushion layer + granular material pile is a two-way reinforced composite foundation,which is a new type of soft soil foundation treatment technology.It is widely used in the field of railway,highway,and construction etc.However,the theoretical research on composite foundation of the horizontal reinforced cushion layer + granular material pile is still in the initial stage at present,and there is no unified method to calculate the deformation.Deformation including the total settlement and differential settlement is one of the most important parameters in the design of subgrade,and more and more attention has been paid to it.Therefore,in this paper,I combine the theoretical analysis and practical application to study in-depth about settlement of the two-way reinforced composite subgrade:The horizontal reinforced cushion layer + granular material pile.The main contents and work as follow:Firstly,this paper analyzes the strengthening principle of composite foundation of the horizontal reinforced cushion layer + granular material pile.It synthesizes the advantages of the vertical and horizontal reinforcement composite foundation.The vertical reinforcement is used to improve the bearing capacity of soft soil itself,and the horizontal reinforcement is used to improve the external load environment of the soft soil.They act as a whole,to work consistently and share the load.Thus,to a large extent,it can reduce the settlement of composite foundation,improve the bearing capacity of the composite foundation,and gain the technical and economic benefits.Secondly,on the basis of the analysis of the reinforcement and bearing deformation mechanism of composite foundation of the horizontal reinforced cushion layer + granular material pile,treating granular material pile composite foundation as composite soil,Starting from the load transfer reality,that is,the vehicle load act on the road surface structure immediately,and through the embankment fill to the grid room reinforced cushion,and then to the composite soil.Considering the influence of the interaction among the road surface,the embankment,the geocell reinforced cushion and the composite soil on the deflection of geocell.Deriving the differential equation of flexural deflection of geocell reinforcement,and at last we obtained the analytical solution.Comparing the calculation results of the method used in this paper with that of the method by traditional elastic foundation beam,thus to verify the feasibility of the calculation method used in this paper.On this basis,we analyzed four factors:the stiffness of geocell reinforcement,embankment stiffness,composite soil stiffness,degree of consolidation,which have an influence on the deformation of pavement structure and geocell reinforced cushion.Then,considering the nonlinearity of composite soil,treating the composite soil as ideal elastoplastic model,we got three differential equation of deflection of geocell reinforcement under different conditions,through the step by step calculation method,and studied the new calculation method of deformation reinforcement of the composite soil under elastoplastic condition.At the same time,we analyzed four factors:the stiffness of geocell reinforcement;composite soil stiffness;the yield displacement of composite soil;degree of consolidation;which have an influence on the deformation of pavement structure and geocell reinforced cushion.Finally,combining the engineering examples,comparing the method used in this paper with the measured values and other method,we verified the rationality and feasibility of the calculation method of biaxial reinforced composite foundation deformation,thus to provide useful reference for practical engineering.