Highway Subgrade Design And Foundation Treatment Method In Soft Soil Area Application Research

China's vast territory,soft soil foundation is widely distributed in our country,but because of the high water content,compressibility and low shear strength of soft soil,the safety and stability of road builded in soft soil area will be serious influenced.so,In order to build high quality roads,especially highways in soft soil area,conduct research about soft soil Foundation treatment technology is very important.In this paper,the geological characteristics and hydrological characteristics are investigated,and the engineering properties of soft soil are analyzed from the causes of soft soil,and the adverse effects of soft soil foundation on highway engineering are analyzed.The roadbed involved in the project is studied,and the design of soft soil foundation is analyzed,Including settlement standard,stability and safety checking coefficient,design load,preloading period,preload construction height and loading rate;Based on the study of commonly used soil release method,deep density method,lateral restraint method,geotextile reinforcement method,drainage consolidation method and chemical reinforcement method,summarize the scope of application of each method according to its characteristics;The classification of soft soil subgrade involved in engineering is studied,and the applicable methods of different soft soil foundation sections are studied and the construction technology is studied according to the material technical requirements of the selected treatment method.By analyzing the general rule of settlement of soft soil subgrade and the factors influencing settlement,combined with the settlement observation data of this project,the effect of soft soil foundation treatment in this project is analyzed and evaluated,Finally,in this project culverts and bridge in soft soil section of this project with CFG piles compound Foundation treatment,general sections with plastic drainage Board in soft soil and surcharge preloading method and so on,enhance the overall stability of the embankment,makes an average settlement of subgrade and bridge transition section significantly decreased,reduction the phenomenon of jumping car,comprehensive effect is remarkable,and st the same time provide reference for the same type of soft soil subgrade design and construction.