Study On The Force And Failure Mechanism Of Lateral Restrained Sand Pile

Soft soil foundation in our country categories,wide distribution,high permeability,low permeability,long consolidation and long duration,how to improve the soft soil characteristics,make it meet the engineering requirements become an important issue in the design and construction.In the past ten years,sand pile method has been widely used in soft soil foundation treatment because of its simple construction,low cost,good reinforcement effect and no pollution.However,due to the complexity of the interaction mechanism between the bulk material and the soil,and the limitation of the test method,the bearing mechanism and the calculation theory of the composite foundation of the bulk material pile are still in the exploratory stage,especially for the sand pile After the application of the side effect(hoop),the bearing capacity of the sand pile and how to change the damage pattern of the study is rarely published.According to the sand pile composite foundation pile soil interaction mechanism,adopt different tensile strength of sheet material as package material made into a closed cylinder mold,inside the cylinder mold and fill sand production of sand pile model pile.The cylindrical mold provides lateral force for the internal filling sand,which is used to replace the lateral restraining force of the sand pile in the composite foundation of the sand pile.Based on the static load test of the single pile,the following research is carried out:1?The effect of the strength of the wrapping material,the compaction density of the filling material and the cross-sectional area of the hoop on the vertical bearing capacity of the model pile and the failure of the model pile are studied by using the self-designed indoor loading device to load the pile.And the rationality of model pile design and model test is verified.2?Was studied by tensile test the tensile strength of different package materials,with different tensile strength of the package material made of sand pile model has carried on the static load test,discusses the tensile strength of package materials and the relationship between the model pile failure mode;3?The influence of the stiffness of the holding layer,the compaction density of the sand,the length of the pile and the pile diameter on the ultimate bearing capacity and the compression deformation of the sand pile model are discussed by using a series of laboratory tests of the sand pile model piles made of the same wrapping material.