中高温三轴应力下鲁灰花岗岩热破裂声发射特征的试验研究

在中高温三轴应力作用下岩石内部物理化学性质和结构特性将发生变化，随着岩石内部结构的变化会引发一系列的声发射现象。通过试验研究了大试件花岗岩在三轴压力状态下声发射随温度的变化规律。试验研究表明：①随着温度升高，岩石的声发射现象是间断发生的；②花岗岩存在一个开始发生热破裂的门槛值温度，其值为120 ℃左右；③试验温度范围内花岗岩热破裂的声发射现象可分为5个阶段，即岩石原生裂隙整合阶段、热破裂前声发射静默阶段、热破裂声发射阶段、大规模热破裂后声发射静默阶段、二次热破裂开始阶段。

Experimental study of acoustic emission characteristics of granite thermal cracking under middle-high temperature and triaxial stress

The interior physicochemical and structural properties of rock change under middle-high temperature and triaxial stress; and all these Changes would make a series of the acoustic emission phenomena. The law of the acoustic emission of granite sample under triaxial stress (axial pressure 860 kN, confining pressure 1 150 kN) with temperature is primarily studied by experiment. It is shown in this research that: ① The acoustic emission phenomena of rock discontinuously occur under the effect of temperature. ② There is the threshold for the beginning of granite thermal cracking, which is around of 120 ℃. ③ There are 5 stages for the acoustic emission phenomena of granite cracking under the effect of temperature: movement stage of the rock's original cracking; stage of the acoustic emission before the thermal cracking; the acoustic emission of thermal cracking stage; still stage of the acoustic emission after the large-scale thermal cracking; second thermal cracking stage.