Analysis Of Static Characteristics And Optimization Of Design Parameters Of Reinforced Soil Embankment With Wrapped Face

Reinforced soil embankment with wrapped face is a new type of reinforced soil structure,which replaces the facing panel with a wrap-around segment,and enhances the lateral confinement and friction of the embankment by the wrap-around segment,thus controlling the embankment displacement and improving the overall stability.It has the advantages of light weight,strong adaptability,good seismic resistance,etc.In recent years,this structure has been applied in engineering projects,but due to the complexity of the stress transfer mechanism,the research on the design calculation method and stress-deformation characteristics of wraparound reinforced soil embankment still cannot meet the engineering practice requirements.Based on the above understanding,this paper studies the stress,deformation and stability characteristics and influencing factors of reinforced soil embankment with wrapped face based on the theoretical analysis of the stress,displacement calculation method of wrap-around reinforced soil embankment,taking the high fill reinforced soil embankment with wrapped face in Xianhu Road reconstruction project in Yichang City as an example,and optimizes the design parameters with multiple objectives,aiming to provide references for the optimization design and construction of similar projects.The main research work are as follows:(1)According to the structural characteristics of reinforced soil embankment with wrapped face,based on the conventional stress calculation method of reinforced soil embankment,the stress calculation formula of reinforced soil embankment with wrapped face is derived;using the method of composite calculation of reinforced soil,considering the relative displacement of reinforced soil,the composite modulus and strength parameters of reinforced soil are obtained;combining the stress calculation formula with the composite modulus,the lateral displacement and vertical displacement of wrap-around reinforced soil embankment are calculated.(2)Based on a specific engineering project,numerical simulation is carried out to study the deformation and stress characteristics of reinforced soil embankment with wrapped face during layered filling process,as well as the variation characteristics of stability and potential sliding surface.The numerical simulation data are compared with the field monitoring data to verify the reliability of the numerical simulation model.The results show that: The maximum lateral deformation of reinforced soil embankment with wrapped face occurs near H/3 height slope surface,showing obvious “bulging” effect;affected by the compensation effect of layered filling,the maximum vertical displacement occurs in the middle part of embankment;The reinforcement in the middle and lower part of embankment contributes more to improving embankment stability,controlling embankment displacement and stress than that in upper part.(3)The orthogonal test method and control variable method are used respectively to explore the significance of various design parameters on reinforced soil embankment with wrapped face displacement,stress and safety factor.The recommended selection range of various design parameters is obtained.The research results show that: The design parameters with the greatest impact on each evaluation index are fill elastic modulus and embankment slope;When slope ratio is less than 1:1.5,it has little significance for improving embankment safety,but it will increase slope space;Too long and dense high elastic modulus reinforcement may cause “over-reinforced” phenomenon which reduces safety factor and increases risk of tensile failure.(4)Taking recommended parameter selection range as constraint,a prediction model based on genetic algorithm(GA)and BP neural network is constructed to optimize design parameters.After verification,it is found that GA-BP neural network model can simulate nonlinear implicit relationship between various design parameters and evaluation indexes of reinforced soil embankment with wrapped face accurately.It shows good performance in multi-objective optimization problems and provides certain reference value for optimizing design parameter selection of reinforced soil embankment with wrapped face.