Study On The Bearing Characteristics Of Composite Ground Of Pulverized Clay-Geosynthetic Encased Stone Columns

Due to its excellent replacement function,drainage characteristics,crowding effect and ability to reduce ground liquefaction,the geosynthetic encased stone column is widely used in the reinforcement treatment of special ground,but the application of the geosynthetic encased stone column in powder clay ground and the study of the change law of super static pore water pressure in composite ground of geosynthetic encased stone column are rarely reported.According to the characteristics of the actual road ground project,the force transfer law and deformation law of the composite ground treated with inlaid bulk material pile reinforcement in powdered clay ground were studied by using indoor model static load test method,and the simulation calculation was carried out by using ABAQUS software,and the numerical analysis results were compared with the test results.Then,the bearing capacity calculation method and construction technology points of composite ground reinforced by encapsulated bulk material pile on powder clay ground are summarized and summarized.The paper mainly achieved the following research results.(1)The force transfer law and the method of determining the ultimate bearing capacity of composite ground of powder clay wrapped bulk material pile were obtainedBased on the test results of different reinforcement forms of composite grounds,the bearing capacity,pile-to-soil stress ratio and pile axial force transfer efficiency of composite grounds of the geosynthetic encased stone columns are analyzed with the changes of tensile strength of encapsulated materials and pile encapsulation length.Meanwhile,with reference to the existing research,the method of determining the bearing capacity of composite ground after reinforcement treatment with full-length wrapped bulk material pile is discussed according to the stress-displacement curve of load test.(2)The development law of super-static pore water pressure in composite ground is determinedThe super-static pore water pressure of different reinforcement forms grows non-linearly with the increase of stress.At the early stage of loading,the super-static pore water pressure grows faster,and the growth becomes slower at the later stage and will tend to stabilize.Among them,the geosynthetic encased stone column is a good drainage channel,and its composite ground has the best drainage effect and the fastest dissipation rate of pore water pressure,so the bearing capacity of the composite ground is the largest,followed by the partially wrapped bulk material pile composite ground and gravel pile composite ground respectively.(3)The bearing capacity calculation method and construction technology points of composite ground with loose material pile wrapped with powder clay are summarized.Based on the damage patterns of the composite grounds with different reinforcement forms obtained from the indoor model tests,the bearing capacity and settlement calculation methods and the main construction technology points of the composite grounds with the reinforcement treatment of encapsulated bulk material piles on the powdered clay ground are summarized with reference to the previous design calculation methods of the geosynthetic encased stone columns and the building ground design code...