变荷载下土体一维热固结特性分析

Analysis of one-dimensional thermal consolidation characterisitcs under time-dependent loading

基于热弹性多孔介质热-水-力完全耦合的控制方程,假定无热源和流源,忽略强迫热对流,建立了变荷载下饱和土一维热固结模型。通过有限Fourier变换及Laplace变换给出了变荷载下的一维热固结普遍解答。利用退化解答验证了所提出方法的正确性,同时给出了单级等速加载下的热固结解析解,并探讨了土体内部温度、孔压的变化特征。研究表明:等速加载结束时,靠近排水面处土体明显较远离排水面处土体超静孔压小;初始荷载越大,土体固结速率越快;加载速率越快,土体中的孔压增大速率也越快,持载阶段孔压消散速率也越快;初始荷载及加载速率对温度影响可以忽略不计。

Based on fully coupled thermal-hydraulic-mechanical formula of thermoelastic porous media,one-dimensional thermal consolidation model under time-dependent loading is established on the assumption that thermal source and stream source is absent and forced thermal convection is ignored. By finite Fourier transform and Laplace transform,the general solution to one-dimensional thermal consolidation under variable load is given. A degraded solution is used to verify the correctness of the general solution proposed and the solution under single-stage uniform load is given for discussing the characteristic of pore-water pressure and temperature. The results show that the excess pore-water pressure of the soil close to the drainage surface is smaller than that of the soil far away from the drainage surface,when the uniform loading is finished; the bigger the initial loading,the greater the soil consolidation rate is; the faster the loading rate,the faster the pore pressure increasing rate and pore pressure dissipation rate in sustaining loading stage is. Besides,influence of the initial loading or loading rate on the soil temperature can be ignored.