Three-dimensional Nonlinear Finite Element Numerical Simulation Of Embankment On Soft Ground Treated By Drainage Consolidation And Mixing Pile Method

As China's transportation infrastructure construction continues to expand,it is necessary to seek a more scientific and effective soft land-based treatment.The design theory of drainage consolidation method and powder jetting pile composite foundation method is relatively perfect,and the construction is fast and simple.It is widely used in engineering practice,but both methods still have their inevitable shortcomings.The new soft soil foundation combined treatment method combining the advantages of both,that is,the long-slab-shock composite foundation has been successfully applied,but most of the researches have focused on indoor model tests and field tests,and the numerical simulation analysis of refinement has not been carried out in depth.In this paper,the three-dimensional nonlinear refinement finite element numerical simulation is carried out for the engineering characteristics and influencing factors of the long-slab-shock composite foundation.The main work is as follows:(1)Through literature research and engineering investigation,the composition,arrangement form,construction method and construction procedure of the long-slab composite foundation are introduced.(2)The three methods and analysis principles of finite element numerical simulation of composite foundation under the action of embankment load are discussed.The representative software packages are introduced and the advantages and disadvantages of various methods are analyzed.In the finite element simulation of long-slab-shock composite foundation by plane analysis method,the spatial variation method of plastic drainage board and powder jet pile with spatial distribution and its applicable conditions are introduced in detail.(3)Based on the finite element software PLAXIS 3D of geotechnical engineering,three-dimensional nonlinear limited construction of long-slip-shock composite foundation,powder-jet composite foundation,plastic drainage board treatment foundation and untreated foundation were constructed.The meta-value model compares the settlement,consolidation characteristics,stability safety and pile-soil stress ratio of four working conditions,and explores the respective roles of powder-jetting piles and plastic drainage boards in the long-slab-shock method.(4)Using the finite element software PLAXIS 3D of geotechnical engineering,the multi-group numerical model of the long-short pile composite foundation in the main design parameters of the powder-jetting pile was established,and the long-short pile composite foundation was compared and analyzed.The influence of pile length,pile diameter and pile spacing on foundation settlement,lateral displacement,excess pore water pressure were discussed.