以南宁地区粉砂岩+泥岩+粉砂岩互层边坡为原型,采用温湿耦合理论对极端气候下互层边坡的温湿度场进行了分析,得到了不同气候组合条件下,互层边坡土体温湿耦合特性、温湿度场的变化规律以及稳定性的影响。结果表明:①短时间急剧的气候变化对土体表层的温度场与湿度场的影响较大,而对比较深层的土体的影响有限,长时间的气候作用,比如干旱,对深层土体将产生较大的影响;②降雨对土体温度场的影响较小,在降雨过后的蒸发作用过程中,对于边坡的中部来说,处于下层的土体在一定深度内的含水量会有一定程度的升高,这种现象在长时间干旱发生的过程中会慢慢消散;③边坡的稳定系数在蒸发作用下会明显升高,短期的高温蒸发作用下,互层边坡的稳定性高于无互层的边坡,长时间的蒸发条件下则是无互层的边坡更加稳定。
Abstract
The temperature field and moisture field of typical siltstone and mudstone interbedded slope in Nanning under extreme climates are analyzed by means of numerical simulation based on soil moisture-heat coupling theory. The moisture-heat coupling behavior, the temperature-moisture filed variations and the impact on slope stability under different combinations of extreme climates are obtained. Results show that dramatic climate change in short time has large impact on the temperature and moisture fields of surface soil; while long-term climate such as arid has great effect on the temperature and moisture fields of deep soil. Rainfall has small influence on temperature field; and during the evaporation after rainfall, the moisture content at a certain depth in the lower part of middle slope increases to some extent, which would disappear in long-term drought. Moreover, the slope's factor of safety increases apparently under the action of evaporation. In particular, in short-term evaporation with high temperature, interbedded slope is more stable than homogeneous slope; while in long term evaporation, homogeneous slope is more stable.
关键词
互层边坡 /
极端气候 /
温湿耦合 /
稳定性分析 /
体积含水量
Key words
interbedded slope /
extreme climate /
moisture-heat coupling /
slope stability analysis /
volumetric water content
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