粉砂岩破裂失稳过程的红外高温区域异常前兆

临破裂岩石自身突变所引起的红外温度场异常可能主要集中于某一较小区域内。为从局部层面探寻岩石破裂失稳过程的红外异常前兆,进行了粉砂岩单轴压缩下的红外监测实验,根据直方分布特征将红外温度场划分为包括高温区域在内的三个温度区域,并以高温区域特征值变化异常为重点展开研究。结果表明:粉砂岩破坏失稳过程中存在红外高温区域异常前兆,其表征形式主要包括高温区域面积比、温均面积比(面积比/极差)等形式;面积比、温均面积比异常前兆表现为临破裂突增异常,出现频率分别可达80%和60%;另外,高温区域异常前兆普遍晚于峰值应力出现。研究结果对岩石受力灾变的红外监测及预警具有一定的工程应用价值。

Abnormal precursor of high infrared temperature zonein the process of siltstone rupture instability

Abnormity of Infrared Temperature Field(ITF)approaching instability caused by mutations in the rock itself may focused on a small area .To explore the infrared anomalies precursor in the process of rock rupture instability, we conducted a siltstone infrared monitoring experiment under uniaxial compression. After dividing ITF into three areas including the high temperature zone,the study focuses on analyzing the abnormal characteristic of high temperature zone. The results show that in the process of siltstone rupture instability statistics abnormal precursor of high temperature zone is more obvious than average infrared temperature anomalies precursor, and the higher frequency of occurrence; that abnormal precursor of high temperature zone is characterized by four forms including area ratio, range, maximum, area ratio of degree Celsius ; that for the abnormal precursor of area ratio and area ratio of degree Celsius which all manifestsSas sharpSrise near instability, the frequency of occurrence can respectively reach up to 80% and 60%, while the abnormal performance for temperature range and maximum of high temperature zone is fast-falling near instability and the frequency of occurrence is only 40 %; in addition, the abnormal precursor emergence of high temperature zone is generally later than peak stress. The results have some value for the infrared monitoring and early warning of rock catastrophe.