Research On Application Of Cement Mixing Pile In Highway Foundation Of Dredger Fill

Dredger soil has the characteristics of poor permeability,low bearing capacity,high compressibility,etc.It is easy to produce a large settlement under the action of additional load,which is very unfavorable for highway engineering construction.Therefore,it is necessary to treat the dredged soft soil foundation to meet the needs of engineering construction.In this paper,the composite foundation of cement mixing piles in the section of Zuncao Highway’s blow-fill area is taken as the research object.According to the results of field monitoring and finite element numerical simulation,the influence of the load on the bearing capacity and deformation of the cement mixed pile composite foundation is studied.In this paper,the bearing capacity mechanism,load transfer mechanism,cushion action mechanism and calculation method of bearing capacity and settlement of composite foundation are summarized.The monitoring points are arranged in the test section of Zuncao Highway reinforced with cement mixing piles.The changes of the settlement in the middle and shoulder of the composite foundation,the lateral displacement of the subgrade slope and the pore water pressure in the foundation soil were measured with the embankment filling process.The change law of monitoring data is analyzed.The finite element software PLAXIS3 D was used to simulate the monitoring section.The stress deformation of cement-mixed pile composite foundation and natural blown-fill foundation under highway load is analyzed to verify the applicability of cement mixing pile in the treatment of road subgrade.Then,based on the original design,the influences of factors such as pile length,pile spacing,pile modulus,cushion modulus,soil filling rate and pavement load on the deformation law and stress characteristics of cement mixed pile composite foundation are simulated by changing a single variable.The research results show that the cement mixing pile is a good way to deal with the roadbed of the Caofeidian filled land area.The composite foundation has obvious effects of reducing settlement and controlling deformation.There are many factors that affect the deformation and deformation of the composite foundation.The influence of pile length,pile spacing and pile modulus on the bearing capacity of composite foundation is significant.When the cushion modulus is large and the filling rate is slow,the post-construction settlement of the composite foundation can be reduced.Pavement load has a greater influence on the deformation and deformation of composite foundation.