SHEAR CREEP PROPERTY AND CONSTITUTIVE MODEL FOR SOFT SOIL OF LITTORAL AREA IN TIANJIN

To describe the stability and operation safety of buildings on soft soil area, this article carries out a series of shear creep tests of soft soil in Tianjin littoral area. Different vertical loads and load ratios are adopted in the shear creep instrument. It obtains the relationship of stain and stress and time in different conditions. It analyzes the structural effect and influence factors of the shear creep properties. It then establishes the corresponding constitutive model. The test results show that the shear creep properties of Tianjin littoral soft soil are obviously restricted by stress. The soil turns up attenuation creep and steady creep in low stress and destructive creep in high stress. The stress-strain presents a linear characteristics in lower stress and shows the nonlinear creep characteristics in higher stress. The smaller load ratio can not only reduce the final creep, but also improve the soft soil capacity. The nonlinear creep constitutive equation of Tianjin littoral soft soil is established with the theory of half experience and half theoretical method. The equation has the character of simple to understand, less parameters and strong practical. The model can well fit the Tianjin littoral soft soil creep characteristics through the compared analysis of experimental results and the creep model.