喷混凝土边坡温度场与应力场耦合的有限元时效分析

由于混凝土材料与岩土材料的热传导系数、比热容与热膨胀系数的差异，在温度的循环变化下使得喷射混凝土边坡容易于喷层与岩土层的结合面处产生应力集中而开裂。采用有限元的方法，考虑地应力与温度应力的耦合作用，分析了在一定的边界温度作用下不同时刻边坡喷层面的水平位移，以及喷层与岩层结合面处的剪应力的分布规律；指出在温度应力与地应力的共同作用下，喷混凝土边坡坡顶与坡脚均为容易发生破坏的地方，通常坡顶的破坏型式为拉张破坏而坡脚则为剪切破坏；边坡内的温度分布、边坡表面的位移与应力的变化均存在一定的时间效应，这一规律与实测规律比较吻合。分析结果表明，当温度变化剧烈时边坡的防护必须考虑温度应力的影响。

Finite element analysis of time effect for coupled problem of temperature and stress fields in slope supported by shotcrete

Due to the difference of heat conduction coefficient, specific heat capacity and expansion coefficient between concrete and rock, under cyclic variation of temperature, the junction plane is liable to crack in the slope supported by shotcrete. Using FEM, the coupled action of thermal stress and crustal stress has been taken into account. The regularities of distribution of the horizontal displacement of surface of slope and the shear stress of junction plane between shotcrete and rock are discussed too. According to the analysis, under the combined action of thermal stress and crustal stress, top and foot of slope are liable to be destructed. Ordinary, the destructional form of the top is tensile failure and the bottom is shear failure. There are some time effect of displacement and stress in the surface of slope and distribution of temperature in slope, which agrees with actual measured rules. The results reveal that when temperature fluctuation is large, the effect of thermal stress should be taken into account to prevent the slope.