基于广义热弹性理论的多孔地基在移动荷载作用下的特性研究

 基于广义热弹性理论，引入热松弛时间，对Biot波动方程进行修正，建立了考虑温度效应的多孔饱和地基在移动荷载作用下的动力控制方程。利用Fourier变换方法，得到地基中温度增量、应力、位移和孔隙水压力在变换域中的一般解，结合热源输入条件和地基边界条件，确立时域内的温度增量、应力、位移和孔隙水压力的积分形式解答。利用Fourier逆变换方法和自适应数值积分算法得到了相应的数值结果。结果可退化为静荷载作用下的弹性地基解答，并与经典Flamant解进行比较，显示出较好的一致性。通过数值计算讨论不同的热源输入对地基温度增量场、应力场、位移场以及孔隙水压力的影响。结果表明：温度增量场受热源输入条件的影响很小，而应力、位移和孔隙水压力受热源输入的影响很明显。

RESEARCH ON CHARACTERISTICS OF POROUS FOUNDATION SUBJECTED TO MOVING LOADS BASED ON GENERALIZED THERMOELASTIC THEORY

The characteristics of porous elastic medium subjected to harmonic strip moving load are investigated analytically in the context of generalized thermoelastic theory by introducing relaxation time. The material of foundation,obeying Biot's dynamic poroelastic theory,is idealized as a uniform,fully saturated poroelastic half- space stratum. The coupled thermo-hydro-mechanical governing equations are derived by modifying Biot's dynamic poroelastic theory. The general solutions of temperature increment,stress,displacement and pore water pressure are obtained by employing Fourier transform. Considering the heat source acted on the surface of foundation and mixed boundary condition,analytical solutions in the form of integral are derived using the inverse method. Numerical results are obtained by using inverse Fourier transform and adaptive quadrature algorithm. The calculating results can be degenerated to the corresponding classical Flamant solution of static problem. Furthermore,the influence of the different heat source conditions on the temperature increment,stress,displacement and pore water pressure is discussed. Computing results show that the temperature increment is slightly affected by the heat source condition;and the distributions of stress,displacement and pore water pressure are obviously influenced by the heat source.