Study On Treatment Effect And Evaluation Technology Of Lacustrine Soft Soil Foundation Of Expressway

Along with the increasing demand of the expressway,the problems exposed gradually increased,especially the damage of the subgrade,slope failure and bumping at bridge-head.As an important part of the soft soil in the system,the problem of lacustrine soft soil is particularly obvious.Therefore,in order to meet the new requirements of modern people,the settlement of the soft soil foundation of the highway becomes the most important problem to be solved.Relying on the second stage of the project between Xingtai and Hengshui,the following work is carried out in this paper:(1)The course and the trend of the development of the expressway,the characteristics of soft soil,the research status at home and abroad and the research purpose of the soft soil foundation treatment methods are briefly introduced;(2)The general situation of the project and the monitoring scheme for subgrade settlement of Expressway on lacustrine soft soil foundation are summarized in the paper,which is based on the summary of the second stage of the Xingtai-Hengshui project;(3)The reinforcement mechanism,construction technology and the control points of the surcharge preloading,surcharge drainage preloading,composite foundation of cement-soil mixing pile and CFG pile,which are usually widely used in the lacustrine soft soil foundation treatment,are analyzed by combining the practical engineering.The post construction settlement is predicted by using different treatment methods in order to prove the feasibility of that treatment method,the advantages and disadvantages,as well as the technical assessment of the four different methods are concluded combining field data at the same time;(4)PLAXIS finite element software is used to simulate the CFG pile construction and the cement soil mixing pile,the simulation results are compared with the measured data,and the construction scheme of the CFG pile is optimized.