Analysis Research On The Deformation Of Layered Soil Under Large Foundation Due To Static Additional Load

It is a general type of problem in civil engineering that the subsidence of subsoil under a large foundation due to static additional load. This issue needs to consider soil constitutive model, physical and mechanical properties of soil, the process of space transmission and the distribution of subsidiary stress on subgrade and so on. With high-rise buildings growing, the value of the load and the size of and foundation is increasing, and the type of the foundation is changing. It is a complete problem that how to calculate the deformation of layered subsoil under large foundation, especially for a large, complicated, and important foundation. It is still a problem which investigates are always trying their bests to solve that how to compute and describe deformation of layered soil subgrade under a large foundation.A new settlement calculation model has been established, which is based on Mohr-Coulomb elastic-plastic constitutive relations and the method of dividing subregion. SSBSMC calculation program has been written via matlab to achieve the subsidence calculation of subsoil under a large foundation. Meanwhile, ABAQUS finite element analysis software and FLAC3D geotechnical analysis software are applyed to calculate the subsidence of subsoil under the same conditions as contrast analysis to prove the rationality of SSBSMC calculating program.Results show that a SSBSMC calculation program is rational in the subsidence calculation of subsoil under a large foundation. When calculating the maximum settlement amount and the point where the maximum subsidence occurred, there is no blindness and the results are much intuitive; Compression modulus of soil can be derived from the definition of compression modulus through the stiffness matrix, when the subsoil is in the elastic state, the compression modulus is just related with the deformation modulus and Poisson’s ratio. When the subsoil is in the plastic state, the compression modulus becomes quite complex, not only related with the deformation modulus and Poisson’s ratio, but also with the vertical stress of soil, coefficient of lateral earth pressure at rest, cohesion and internal friction angle; The more deep foundation soil is, the additional stress value is smaller and more uniform, and contours of stress gradually are approaching the center of the center of the base; Point coordinate of the maximum settlement is not always in common with that of the maximum load putting on the surface of subgrade and the center of the foundation. Thus, it is a certain degree of security risk to calculate the settlement under the center of the foundation only.