[关键词]
[摘要]
基于多相流及多场耦合理论,采用有限单元法计算了三峡库区木鱼包滑坡体温度随气温变化情况,进而依据温度与水体粘滞性的相关关系分析气温变化对坡体渗流的影响。计算表明,坡内温度受气温影响仅限于坡体浅层区域,距地表深度越深,影响程度越小,在时间上的滞后性越大。温度变化可改变水的粘滞性,进而引起土体渗透参数的改变,计算表明因气温变化引起的坡体渗透性改变较为显著。坡体渗透系数受气温变化的影响随深度呈非线性分布,距地表越深受气温变化的影响越弱,通常大于雨水最大入渗深度以后,坡体渗透系数不再发生显著变化。另外,坡体渗透系数随气温呈现季节性变化规律,夏季气温高于坡内土体温度,渗透系数随深度的增加而减小;冬季坡体内温度高于气温,渗透系数随深度的增加而增加。
[Key word]
[Abstract]
Based on the multi-phase flow & multi-field coupling theory, this paper adopted the finite element method to calculate the temperature distribution of Muyubao landslide as the atmospheric temperature changes. Further, it analyzed the influence of atmospheric temperature changes on the slope seepage according to the correlation between temperature and viscosity of water. The results of calculation showed that the effect of atmospheric temperature on temperature of the slope body is limited to the shallow surface; as the depth increases, the influence decreases and the hysteresis increases concurrently. The mobility of the water is affected by the change of the slope body’s temperature and it can change the water permeability in the inner slope. The effect of atmospheric temperature on permeability coefficient of the slope has a nonlinear relationship with depth. The effect of atmospheric temperature on the permeability coefficient declines as the depth increases. Generally, the permeability coefficient of the slope no longer change significantly when the depth is deeper than the maximum depth of infiltration. The permeability coefficient of the slope shows seasonal variation with the atmospheric temperature. The permeability coefficient decreases with the increase of depth when the atmospheric temperature is higher than the soil in summer. In contrast, the permeability coefficient increases with the increase of depth in winter.
[中图分类号]
[基金项目]
国家自然科学基金(51279090)