单轴加载下花岗岩温度响应规律实验研究

Experimental study on granite temperature response under uniaxial loading

岩体动力灾害预测预报技术中,通过实时监测岩体受力破裂时变形场、温度场信息,揭示岩石损伤破裂特征是重要研究手段之一。采用接触式定点测温法和红外热成像非接触式全场测温法相结合,对花岗岩试件进行单轴压缩试验,引入回归模型和相关系数定量地描述了应变应力场和温度场的变化差异程度,研究了试件加载变形破裂过程中应变应力场和温度场的演化规律及破裂前兆异常特征,并探索全场信息之间的相关度。结果表明:在加载过程中,花岗岩表面实测温度与应力呈线性相关关系,与应变呈指数相关关系。据此,本文给出了花岗岩表面实测温度与应力、应变的定量关系式,其中,花岗岩表面实测温度变化随应变呈现出‘平缓—缓慢上升—快速上升—突增’四个阶段;花岗岩试件在破裂前出现温度突增的现象,可作为破裂温度前兆。

Real time detecting the deformation field and temperature field changes of rock mass under stress is considered to be an important technical means for predicting rock mass dynamic disasters.In this paper,fixed point temperature measurement and non-contact infrared thermal imaging technology are used to test the parameters related to the uniaxial compression test process of granite specimens.Regression models and quantitative descriptions of correlation coefficients have been used to describe the degree of variation differences between the strain stress field and the temperature field.The evolution of the strain stress field and temperature field during the loading,deformation,and fracture process of rock masses,as well as the characteristics of precursoranomalies,have been analyzed.The results show that,during rock loading process,the kinetic temperature of the granite surface is linearly correlated with stress,and exponentially correlated with strain.The quantitative relationship between the kinetic temperature of the granite surface and stress and strain was established.The measured surface temperature of granite exhibits four characteristics as a function of strain:gentle,slow,rapid,and sudden increase.The granite specimen exhibits a sudden increase in temperature before fracture,which can be used as a precursor to fracture.