高温环境岩石力学性质损伤效应试验研究

Experimental Study on the Damage Effect of Mechanical Properties of Rock in High Temperature Environment

高温环境中,岩石结构的渐变或突变导致岩石力学性质的变化。对经历高温环境的岩石进行轴向压缩试验,结果表明:岩石单轴抗压强度、弹性模量随温度升高呈现负指数规律减小,岩石的软化系数及弹性模量劣化度随温度升高逐渐增大;岩石的抗剪强度参数随温度升高逐渐减小,分析粘聚力、内摩擦角与温度变化规律,可表征为三次多项式变化关系。为定量分析岩石力学性质的热损伤特征,分别求得岩石抗剪强度参数损伤变量,损伤变量值随温度升高而逐渐增大。高温对岩石的力学性质产生明显的损伤,研究成果可以为高温环境岩体失稳预测分析提供依据。

In high temperature environment, the gradual or abrupt change of rock structure would result in the changes of mechanical properties of rock. Therefore, the axial compression tests for the rock experienced high temperature environment were carried out. The results showed that with the increase of temperature, the uniaxial compressive strength and the elastic modulus of rock presented the decrease of negative exponential law, the softening coefficient and the deteriorative degree of elastic modulus of rock gradually increased, and the shear strength parameter of rock decreased gradually. Besides, the change rules between cohesive force and internal friction angle with temperature were analyzed, which could be characterized as a cubic polynomial. In order to quantitatively analyze the thermal damage characteristics of mechanical properties of rock, the damage variables of shear strength parameters of rock were respectively obtained, which increased with the temperature increase. High temperature would cause obvious damage on the mechanical properties of rock. The study provided a basis for instability prediction and analysis of rock mass.