基于温度场时空分布特征的寒区隧道冻胀模型

寒区隧道冻胀力随时间和隧道进深呈三维时空分布，为建立描述冻胀力时空效应的简化模型，首先以某寒区隧道温度场测试成果为基础，建立了三维温度场模型，通过Stephen公式得到围岩冻结深度变化规律，以围岩冻结深度为参数，结合冻融圈整体冻胀模型和风化层冻胀模型建立了新的冻胀模型。分析结果表明：围岩冻结深度受温度场影响呈三维时空分布，随隧道进深逐渐减小，随时间呈弦函数变化；考虑风化层和破碎层建立冻胀模型，当冻结深度小于风化层厚度时，冻胀力只由风化层产生，冻结深度大于风化层厚度时，冻胀力由风化层和扰动层叠加产生；冻胀力时空分布规律与围岩冻结深度变化规律一致。

A frost heave model based on space-time distribution of temperature field in cold region tunnels

Frost heaven force, related with tunnel axial length and time, has three dimensional space-time characteristics in cold region tunnels. In order to establish a frost heave model for studying the change rule of frost heaven force, three dimensional temperature field model of cold region tunnels was firstly established based on the field test results, and the changing law of surrounding rock frozen depth was obtained by Stephen formula. On this basis, a new temperature-frost heave model was established in combination with freeze-thaw circle theory and weathering layer theory. The results show that the frozen depth of surrounding rock influenced by environment temperature has a trend of decrease with the increase of tunnel axial length and changes periodically with time. According to this new model, when the frozen depth is smaller than the weathering layer depth, the frost heaven force is only induced by the weathering layer; when the frozen depth is bigger than the weathering layer depth, the frost heaven force in induced by both the weathering layer and freeze-thaw circle. The change rule of frost heaven force is similar with the change rule of surrounding rock frozen depth.