冻土路基应力变形数值模型

Stress-strain numerical model for frozen soil subgrade

冻土路基中水、热随气候的变化是不均匀的 ,由此引起的土性变化也是不均匀的 ,土性的不均匀变化导致路基不均匀变形 ,当路基中的不均匀变形超过容许值时 ,路基便产生破坏 ,冻土路基土性的动态变化及由此引起的变形差异 ,是冻土路基设计中应注意的关键问题。基于此 ,在现有土力学弹塑性理论和流变理论的基础上 ,模拟水、热及土性的动态变化 ,建立了冻土路基应力及变形的二维数值模型 ,模型考虑了冻土的流变变形、自身体积变形和瞬时变形 。

Changing process of water content and temperature distribution in permafrost embankment is unequal,which results in non uniform changes in soil property, with the result that the deformation in permafrost embankment is unequal. If the non uniform deformation is greater than allowable value,the embankment will be in collapse state. The changing process in soil property and the non uniform deformation should be significantly taken into account in permafrost embankment design.Based on the elasto plasticity theory and rheology theory,by simulating the changing process of water content and temperature distribution and soil property,this paper establishes a two dimensional model to calculate the stress and deformation in permafrost embankment. In this model the creep deformation,the temperature caused volumetric deformation and the transient deformation are considered,especially the creep and transient deformation behaviours in the condition of soil property changes with time is studied. Based on the elasto plasticity theory and rheology theory,this paper establishes a two dimensional model to calculate the stress and deformation of frozen soil subgrade.In this model the great change in soil property caused by water and temperature conditions,the significant creep behavior, the temperature caused self volume deformation and the transient deformation resulted from applied loads are all considered.