变荷载下一维热固结特性剖析.doc

变荷载下一维热固结特性分析 摘要：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本文解答的正确性，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。 关键词：热固结；耦合；变荷载；温度；超静孔压 ONE-DIMENSIONAL THERMAL CONSOLIDATION UNDER TIME-DEPENDENT LOADING Wang Sihai1，Yang Kangcheng3，WANG Xudong3 (1 JiangSu college of Engineering and Technology,Jiangsu NanTong 226014 2 724 Research Institute China Shipbuilding Industry Corporation,Jiangsu Nanjing 210003 3 Nanjing University of Technology,Jiangsu Nanjing 210009) Abstract：Based on fully coupled thermal-hydraulic-mechanical formulation of saturated porous media, the model under time- dependent loading is established. By finite Fourier transform and Laplace transform,the general solution of one-dimensional thermal consolidation under variable load is given..A degraded solution is used to verify the correctness of the general solution and another solution under Single-stage uniform load is given for discussing the characteristic of pore-water pressure and temperature. Researches show that the closer to the drainage surface the smaller the excess pore-water pressure is when the ramped loading is ended. The bigger the initial loading, the greater the rate of soil consolidated. The faster the loading rate, the faster the pore pressure increasing rate in the soil and pore pressure dissipation rate is faster at the time of sustaining loading. Besides, on the influence of the initial loading or loading rate, the change of the temperature in the soil can be ignored. Key words：thermal consolidation;coupling;time-dependent loading;temperature;excess pore-water pressure 1 引 言 随着国民经济的飞速发展和城市化、工业化的进程的加快，使得环境岩土问题日益加剧。人们逐渐认识到热-水-力耦合问题研究在岩土工程和环境工程中的重要性。如核废料处理、地热开发、石油库封存、城市热岛效应、软土地基热辅助处理等课题[1-3]已成为岩土工程与环境科学领域的重要研究方向。这类问题都涉及到岩土体的热-水-力耦合问题，对于土体而言，称为热固结。 Passwell[4]通过刚性环状固结仪在恒定荷载条件下的加热试验，发现体积随时间的压缩变化曲线与固结曲线相