关键词: 真空预压, 热固结, 饱和土, 大变形, 数值模型

Abstract: A large strain nonlinear radial consolidation model RVTCS for saturated soil foundation under vacuum preloading combined with heating is developed by using piecewise-linear difference method. This model couples radial heat conduction in a soil layer with large-strain thermo-consolidation. It accounts for thermal stress and thermal expansion during consolidation, self-weight, radial and vertical seepage, time-dependent heat-source temperature, nonlinear relationships between compressibility and permeability, and rebound–recompression behavior. The model can analyze large-strain thermo-consolidation under various combinations of vacuum preloading and heating. The model is verified by large-scale vacuum preloading combined with heating consolidation test, and the RVTCS numerical solution of settlement is in good agreement with the indoor test results. The variation laws of excess pore water pressure, settlement, degree of consolidation, temperature and energy consumption under different combined conditions are deeply studied through the analysis of numerical examples. The combination of vacuum preloading and heating can significantly improve the settlement and consolidation rate of soil layer.

Key words: vacuum preloading, thermo-consolidation, saturated soil, large strain, numerical model