温度循环作用后蚀变岩力学参数劣化规律的探究

STUDY ON DETERIORATION LAW OF ALTERED ROCK UNDER CYCLIC TEMPERATURE

为了研究温度周期循环作用对蚀变岩力学性质的影响,以蚀变岩为试验对象进行了温度周期循环条件下的岩石力学试验,在分析试验数据的基础上建立了函数表达式来描述温度作用下蚀变岩力学参数劣化的规律。试验结果表明:在温度周期循环作用下蚀变岩力学参数发生劣化现象,且温度周期循环次数越多劣化现象越明显;随着温度周期循环次数的增多,峰值强度、弹性模量和抗拉强度均减小,泊松比基本不变;蚀变、碎裂程度越大的岩石对温度周期循环作用越敏感,循环20次后,抗拉强度累积损伤率最大为42.38%,峰值强度累积损伤率最大为34.69%,弹性模量累积损伤率最大为29.57%;蚀变岩力学参数值及其累积损伤率随温度周期循环次数的变化关系均服从指数分布。

This paper aims to examine the effect of cyclic variation of temperature on rock mechanical property. Altered rock are selected and rock mechanics test is carried out to examine the effect of different temperature circulating frequencies. Based on the analysis of experimental data, the function is established to describe the variation pattern of mechanical properties of altered rock by cyclic temperature. It is shown that the mechanical properties of the altered rocks are obviously weakened by temperature cycle effects. With the increase of temperature cycle times, the peak strength, elastic modulus and tensile strength are decreased and the Poisson’s ratio is almost constant. As the degree of alteration and fragmentation increases, the degree of damage increases. For the cyclic temperature to the mechanical properties of rock the phenomenon is more obvious. After 20 times, the damage rates of tensile strength, peaky peak intensity and elastic modulus can reach 42.38%, 34.6 9 % and 29. 57% respectively. The variation of the mechanical parameters of the altered rock and the cumulative damage rate with the change of the temperature cycle times are all subject to the exponential distribution.