Experimental Study On Pile Forming Mechanism Of High Polymer Bag Grouting Pile

High polymer bag grouting pile is a new technology which combines the traditional bag grouting pile with high polymer slurry,and it is suitable for strengthening the soft foundation of existing buildings.Because of its characteristics of fast construction speed,good reinforcement effect,no water reaction and small construction disturbance,the reinforcement of soil foundation with strong water sensitivity has a good application prospect.However,as a new construction technology,there are many scientific problems worthy of further study in the reinforcement technology of high polymer bag grouting piles,such as pile forming mechanism,construction technology,pile forming law,soil squeezing effect and reinforcement effect.Therefore,in order to improve the understanding of the scientific issues related to the reinforcement technology of high polymer bag grouting piles,based on the previous research results,this paper studies the reinforcement technology of high polymer bag grouting piles through theoretical analysis,model test and numerical simulation.The main research contents are as follows:(1)Through the contrast test,the material of the bag,the form of the grouting pipe and the position of the grout outlet are selected,and a complete set of construction technology of the high polymer bag grouting pile is put forward.(2)Through the model test of pile forming,the law of pile forming of high polymer bag grouting pile in different properties,different densities and different layers of soil is studied.The process of pile forming,the law of pile density distribution,the law of pile forming in different densities of soil and the effect of reinforcement are analyzed.(3)Based on the model pile forming test of muddy soil and the single pile load test after pile forming,this paper studies the soil squeezing effect of polymer bag pile,and analyzes the law of soil squeezing pressure change,the influence range of soil squeezing effect,the law of excess pore water pressure change and the vertical bearing capacity of single pile.(4)Based on ABAQUS finite element numerical analysis software,the reinforcement effect of high polymer bag grouting pile is simulated,and the change of foundation settlement,reinforcement mechanism,change rule of super static pore water pressure and deformation of pile body after reinforcement of soft and hard interlayer soil and saturated muddy soil by high polymer bag grouting pile are studied.