Research On Bearing Capacity And Reliability Analysis Of Soil-cement Mixing Pile Composite Foundation

The soil-cement mixing pile composite foundation which constructed conveniently and cost lowly is a method for ground treatment. In use, there are some problems about the bearing capacity of soil-cement mixing pile was understand faintly and short of research. They include:(1)Characteristic value of composite foundation bearing capacity can be determined with experience by the static load test of reinforcement body and the characteristic value of soil around the pile bearing capacity in the new standard.(2) Cement-soil mixing pile engineering was acceptance generally just depend on the static load test of single pile composite foundation, and its test conditions has a great difference with the actual stress state.(3) There is a problem which bearing capacity of composite ground is short of researching based on the new standard.Basing on the new technical code for ground treatment of buildings(JGJ79-2012), we do some research on bearing capacity of soil-cement mixing pile composite foundation. The method we used include the engineering test research, finite element simulation and theoretical analysis, specific research contents include:1. For a certain soil-cement mixing composite foundation engineering in Cangzhou,we do the single pile static load test and single pile composite foundation static load test research. According to the method provided with technical code for ground treatment of buildings(JGJ79-2012),we get the single pile composite foundation bearing capacity characteristic value and characteristic value of bearing capacity of single pile, and verify the rationality of the calculation formula.2. Based on the measured parameters, we use the finite element software ABAQUS simulate the static load test of soil-cement mixing pile, soil around piles and single pile composite foundation. we verify the correctness of the finite element calculation model and method by comparing with the measured results. Then simulate under the same pressure, 2-pile composite foundation,, 4-pile composite foundation and 8-pile composite foundation regular of settlement.3.We analyze the characteristics of the soil-cement mixing pile composite foundation,and determine the bearing capacity limit state equation. The monte-carlo method is used to calculate the composite foundation reliability of engineering we collected, then we get the reliability indexes.