Research On Bearing Character And Engineering Application Of Cfg Pile Composite Ground

CFG pile composite ground is a new foundation treatment technic. It is extensive used, but the theory isn't fully researched. This assignment approaches CFG pile's bearing capacity, settlement and pore-forming stability from theory. It is proved by instance and comparised with numerical modeling.According to the particularity about equal settlement surface of CFG pile, the two shear failure model is first brought out. It will make composite ground failure theory perfect. Combining with new model, over studying star point theory, cushion thickness, axial stress near star point, and new method about bearing capacity. The new model's reliability and trueness are proved by instances.This assignment introduces the standard settlement computing methods which are analysis, numerical and empirical formula. It discusses empirical formula of CFG pile composite ground, and contrastes these methods. The calculation method and the formulas of pile-soil stress ratio considering the interaction of pile-soil-cushion are deduced. They are based on the settlement model of CFG pile composite ground.Attain this important coefficient using normal triaxial consolidation undrained test and measuring pore pressure. Utilizing capillary phenomenon and equilibrium rule, the paper deduced computation formula for pore pressure coefficient of saturated soil. This assignment discusses the direct pore-forming stability of CFG pile, and calculates maximal drilling depth when drilling. Then it analyses stability about wall of hole by muddy water protection, and researches the aging stability when drilling by using the formula for pore pressure coefficient of saturated soil.Using the Drucker-Prager elastic-plastic model which is offered by ANSYS, this assignment builds model with CFG pile's features, calculates the CFG pile's bearing capacity and settlement by finite element method, the result can compare with theory.The new Shen yang train carriage works is buildding. Geological conditions of new factory are complex. Bearing capacity of natural foundation is not enough, it need disposed. Seven projects are brought forward. According to comparing with economy and technic, the best foundation treatment which is CFG pile composite ground is selected from the first electing programmes.