Taking a hydropower slope in Tibet as the study example,the governing equation of rock mass transient tem-perature filed of freezing zone and melting zone are established based on the principle of transient thermal conduction,so as to simulate temperature field response of the slope under low temperature environment. The involution regularity of temperature filed of rock mass with the temperature throughout the year is analyzed and the temperature influence range of cover layer and strong weathering layer in the freezing and melting periods is studied based on the extraction of feature points in different parts of the slope. Based on the above discussion results,the deformation variation characteristics of cover layer and strong weathering layer of the slope under the conditions of thermal effect and freezing-thawing cycles are analyzed by adopting direct coupling method. The study results show that rock temperature of shallow slope has a strong correspondence with the environmental tem-perature,while the rock temperature of slope deep remains at 3~5 ℃,the maximum freezing depth of slope is 4 m;the influ-ence of environmental temperature on deformation of cover layer and strong weathering layer is great,the sinusoidal distribution of the deformations are displayed with the change of time,the variation deformation caused by freezing-thawing cycle is much greater than the one caused by thermal effect from the aspects of influence degree.%针对西藏地区某水电边坡,在瞬态热传导原理基础上,建立了冻结区和融化区岩体瞬态温度场控制方程,模拟了在低温环境下边坡的温度场响应情况;通过在边坡的不同部位提取特征点,分析了岩体温度场随年气温的演化规律,研究了覆盖层和强风化层在冻结期和融化期的温度影响范围.在此基础上,利用直接耦合法分析了热效应和冻融循环情况下,边坡覆盖层和强风化层位移的变化情况.研究结果表明:边坡浅层岩体温度与环境温度有很强对应性,而边坡深层温度则基本保持在3~5℃,边坡冻结最大深度为4m;覆盖层和强风化层位移受环境温度影响较大,其位移均随时间变化呈近似正弦分布;从影响程度上看,冻胀循环引起的位移变化要远大于热效应的影响.
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