| With the rapid growth of the national economy,railway engineering construction has entered a period of rapid development.China has a vast territory and a relatively wide area of soft soil.So,Railway engineering construction in China often requires targeted foundation reinforcement measures.The characteristics of soft soil are generally high water content,low permeability,high compressibility and long consolidation time.When the subgrade of the railway project is built on soft soil,diseases such as excessive settlement and insufficient bearing capacity often occur,which has great harm to the safe and efficient operation of the railway project.There is a large area of soft soil along the Zhengzhou-Xuzhou high-speed railway,and the distribution depth is thin and uneven,targeting soft soils of different thicknesses and geological conditions.Therefore,combined with experience,this paper proposes three types of foundation reinforcement modes,namely pipe pile,CFG pile and plain concrete pile.The finite element software is used to numerically simulate the three reinforcement schemes,and the field comparison data is used to compare the schemes.And the construction optimization measures of the three foundation strengthening modes were studied respectively.Finally,the applicability of various pile types under different conditions is obtained for reference and reference of similar projects.This article mainly draws the following conclusions:(1)Under the same conditions,the ratio of the bearing capacity of the pile-net structure is lower than the pile-raft structure.For the design calculation of the bearing capacity of the composite foundation,the influence of the rigidity of the superstructure must be considered.(2)The industrial waste fly ash is added to the CFG pile body material,which reduces environmental pollution and achieves the purpose of material waste utilization.It has significant economic and social benefits.(3)The plain concrete piles constructed by long spiral squeezing rock drilling rigs ensure the construction quality of the pile foundation,save the construction time,speed up the construction progress,reduce the loss of labor costs,and bring a better economy Benefits,social benefits,has a good promotion prospects.(4)CFG piles and plain concrete piles have the highest working efficiency.In the case of tight construction period,CFG piles and plain concrete piles are preferred for construction,which can greatly reduce the construction time.The construction technology of prestressed pipe pile is the simplest and the construction quality is the easiest to control. |
