旨在介绍一个描述非饱和土孔隙气、水、汽、热耦合运动的理论模型。该模型假定孔隙气和孔隙水运动分别遵循达西定律 ,而影响水蒸汽运动的两种主要因素分别是分子扩散和孔隙气运动 ,其中受分子扩散影响的孔隙水蒸汽运动可用Fick定律描述。热转移则主要包括了三种形式 ,即传导、对流和汽化潜热。根据有限单元法 ,编制了一个三维的计算机程序用以模拟非饱和土孔隙气、水、汽、热的耦合运动。通过数值分析与干沙试验结果之比较 ,验证了文中之理论模型和计算机程序的可靠性 The purpose of this paper is to introduce a theoretical model that describes pore-gas, water, vapor, and thermal coupling in unsaturated soils. The model assumes that pore gas and pore water movement follow Darcy’s law, respectively. The two main factors affecting water vapor movement are molecular diffusion and pore gas movement, respectively. The pore water vapor movement influenced by molecular diffusion can be described by Fick’s law. Heat transfer is mainly composed of three forms, namely, conduction, convection and latent heat of vaporization. According to the finite element method, a three-dimensional computer program was developed to simulate the coupled movement of pore gas, water, vapor and heat in unsaturated soil. By comparing the numerical analysis with the dry sand test results, the reliability of the theoretical model and the computer program are verified