Lacustrine Soft Soil Physical And Mechanical Properties And Creep Characteristics Of Study

Post-construction settlement plays a significant role in line smoothness, driving comfort and safety of railway. Creep of soft soil is an important factor leading to post-construction settlement. Therefore, it is significant to study the engineering property of soft soil as well as its creep. Based on the background of high-speed railway, a series of tests were conducted to investigate the properties of soft clay in Yangcheng Lake area. On the basis of the test results, the engineering properties and creep of soft soil in YangCheng Lake area were studied systematically and the achievements were obtained as follows:(1) Based on least square principle and with the method of mathematical statistical analysis, the correlations among physical properties index and mechanical properties index of soft soil in Yangcheng Lake area were analyzed. Accordingly, the correlation equation among these parameters was obtained.(2) On the basis of the one-dimensional compression creep test, the factors which impact the secondary consolidation coefficient of soft soil were analyzed. The research result show that:①the secondary consolidation coefficient of soft soil in this area had no significant correlation with pre-consolidation pressure;②The curves of relationship between secondary consolidation coefficient and consolidation pressure can be better fitted with a hyperbolic curve;③The secondary consolidation coefficient decreases with load ratios increase;④Preloading can reduce the secondary consolidation coefficient significantly;⑤Secondary consolidation coefficient decreases with the extension of the load time interval.(3) According to one-dimensional compression creep test results, the model was established to simulate the secondary consolidation of soft soils creep. The comparison of experimental values and calculation values was conducted to analyze the reason that preloading with overload make the secondary consolidation settlement decreased. Further, the analysis results show that the new presented model can reflect the creep property of secondary consolidation of soft soil, also can predict the development of secondary consolidation settlement with time.(4) Based on one-dimensional generalized Kelvin creep model at stress state and the least square principle, the inverse analysis was conducted to analyze parameters of the generalized Kelvin creep models at 3d stress state. The physical meaning of this method is clear, and this study provides a new way to analyze the 3d creep parameters of soft soil.