Numerical Simulation Study On Load-bearing Characteristics Of Bagged Sand Foundation

Under the vertical uniform distributed load, the natural foundation shows bearing load property of the large settlement of the middle part and the small settlement of the edge of the surrounding areas. Under the condition of complete half space, the settlement of the middle part is 2 times of the settlement of the edge of the foundation. In order to change the mechanism and reduce the foundation settlement influence on the upper structure, in the traditional foundation reinforcement method, develop the thinking and innovation, a new type of bagged sand composite foundation is proposed.This paper from the numerical analysis point of view, bagged sand composite foundation in the control effects of the total settlement and uneven settlement, sandbags and sandbags,sandbags and soil interaction mechanism were studied. At the same time, the results of numerical simulation and model test results were compared, in order to increase the reliability and stability of the test results. According to their sandbags pile section and buried depth, the 9 groups of bagged sand model scheme and 1 group of no enhancement model scheme were established. In 9groups of bagged sand foundation reinforcement model, model 1, model 2 and model 3 are adopt to tile sandbag and gradually increase in the sand tile layer; model 5 and 8 models are using to pile sandbags like arch structure with single span; model 4, model 6, model7 and model 9 are using to pile sandbags like arch structure with double spans. Simulation results of different groups of bagged sand reinforced foundation show that, after the sand bags buried in the soil,sandy soil foundation of the overall settlement has been very good control, but different sandbag stacked form and sand bags buried depth have being certain difference for the overall control of the foundation settlement and uneven settlement. Compared with the settlement characteristics of the non-enhanced body model, the settlement of the soil in the process of the distribution of the sand in the bag has obvious effect. By adjusting the sandbags the depth and change sand section for adjusted foundation rigidity distribution and control the uneven settlement is practical.Numerical analysis of the results that increasing the Foundation Center site sand buried depth is particularly important, bagged sand like arched double cross form foundation treatment superiority of relatively strong. Through the comparison of the results of 10 groups of numerical simulation results, the model 9 is the best group and the effect of improving the bearing capacity of the foundation is the most prominent.Through numerical calculation results with the model test results contrast, with the changing load, each group of test model of the foundation center point and edge load settlement curve is consistent, which deviation, both of the data in a reasonable range, indicating that the bagged sand foundation reinforcement method is feasible. At the same time, the test scheme can effectively improve the soft foundation soil, and achieve the design goal of the foundation,which provides a good data support and theoretical support for the follow-up study.