Viscous Elasto-plastic Analysis Of Soft Foundation Soils With Laying On Structures And Its Engineering Applications

Because of the special geological property of saturated cohesive soft soils, the large construction projects face much problem, such as treatment of soft foundation, prediction and control of long-term settlement of the soft soils and so on. The mayor factors, which have very significant influence on the construction on soft soil, can be attributed to the elasto-plasticity and the rheological property. Consequently, the long-term settlement of the foundation and the momemt distribution of the structure will be predicted, based on stress-strain-time behavior of soft soil, using numerical method in the paper to provide some scientific basis for design and construction.Based on the BIOT consolidation theory, an expansion model was established, which could simulate the coupling effect of rheological action of soft soil and seepage effects of groundwater. In the paper, a three-dimensional finite elememt analysis software was programmed, which could analyze viscous elasto-plastical problem of soft foundation, to study the deformation principle of different simulation model and to predict the time-dependent differential settlement. Finally, some exploratory research on the longitudinal moment of the structure was considered to describe the changes of the moment with time.The evolution of long-term settlement and pore-pressure with time was simulated with previous numerical way. And a multiple-step numerical procedure was design to simulate different behavior. In addition, some different numerical models were taken into consider to describe deformation procedure and pore-pressure distribution in different computational conditions. In the paper, the influence of drainage condition of the foundation on the evolution of long-term surface settlement as well excess pore pressure has been mainly discussed.The evolution of long-term settlement and long-term differential of segmental homogeneous foundation was predicted on the basis of interaction theory between structure and soil, and the evolution of longitudinal moment of structure with time was also provided. A satisfied agreement was obtained between the analysis result and the actual measurement data of the soil foundation.