Study On Optimization Of Variable Stiffness Reinforcement Design Based On Uneven Soft Soil Foundation Of Highway In Lake Area

With the development and improvement of my country’s traffic road network,the design,construction and maintenance of highway engineering are becoming more and more difficult.In actual engineering,soft soil foundation and uneven geology may appear at the same time in some special sections,which often brings great trouble to engineering design and construction.In order to meet the needs of engineering stability,it is necessary to take corresponding measures to prevent or reduce the adverse effects of soft soil foundation and uneven geology on engineering.In this paper,taking the reinforcement treatment of uneven soft soil foundation of a highway project as the background,on the basis of extensively reviewing and summarizing relevant literature on soft soil foundation at home and abroad,combined with the finite element simulation and orthogonal experiment method,the stress and deformation of the subgrade in the uneven soft soil foundation after the pavement construction is completed are studied,and the finite element model is verified from the actual monitoring data and the hyperbolic analysis method.According to the finite element model,the influencing factors of the post-construction settlement of the pavement in the uneven soft soil foundation are studied,and then the variable stiffness reinforcement design scheme of the uneven soft soil foundation is optimized,and the optimization scheme of variable stiffness reinforcement design for uneven soft soil foundation with better economic and safety reserves is determined.The main research contents and corresponding results are as follows:(1)The common soft soil foundation reinforcement treatment methods and settlement calculation theory are expounded,and the settlement calculation methods commonly used in practical engineering are introduced.(2)After collecting and sorting out the data of a highway engineering in the lake area,analyzing and processing the actual monitoring data,and comparing the calculation results of the finite element model with the monitoring data and the calculated values of the hyperbolic analysis method,the rationality and reliability of the finite element model are verified,and the model is used for subsequent soft-base simulation calculations.(3)Under the action of simplified traffic load,the settlement and stress analysis of the subgrade after 15 years of operation are carried out.The results show that: in general,the settlement of the pavement and subgrade is large on the left side and small on the right side,and the settlement distribution of the road surface is similar to An inclined straight line;the base stress is small on both sides and large in the middle,and the maximum value appears near the uneven geological boundary;depending on the different design parameters,near the right end of the underside of subgrade,there may be a slight tensile stress in the soil mass on the subgrade,and its value is about several kilopascals.(4)In general,the pressure on the top of the single pile on the left side of the powder injection pile under the right subgrade is relatively large,and the pressure on the top of the single pile on the right side is relatively small.(5)In terms of single-variable analysis,the replacement height of light soil for the left subgrade and the elastic modulus of the soft soil layer on the left side of the foundation have a great influence on the bearing performance of uneven soft soil foundations.The light soil replacement height of the right subgrade and the width of the left back pressure berm have a certain influence on the bearing performance of the uneven soft soil foundation,while the width of the right side back pressure berm has relatively little effect on the bearing performance of uneven soft soil foundations.(6)Through the orthogonal experimental analysis,the sensitivity of the maximum post-construction settlement of the uneven soft soil foundation to the various influencing factors is arranged in descending order: the height of the left light soil replacement,the elastic modulus of the left soft soil layer,the width of the left back pressure berm,the width of the right back pressure berm,the replacement height of the right light soil.