遥感-岩石力学(IV)--岩石压剪破裂的热红外辐射规律及其地震前兆意义

完整岩体压剪破裂失稳是构造地震的另一种可能孕震机制。以此为模拟对象,采集中国首都圈地区的5种典型岩石,进行了岩石压剪破裂过程的红外辐射成像实验。研究发现:(1) 岩石压剪破裂过程存在热弹和摩擦热两种热-力耦合效应,且压剪作用越强,压剪破裂过程中红外辐射升温现象就越明显。(2) 压应变占优势时,岩石压剪破裂存在红外辐射异常破裂前兆。(3) 压剪破裂前兆有明显的“时空”特征,即:时间上,当载荷增加到约80%破坏应力时,沿剪切区域的平均红外辐射温度开始出现加速升温前兆,且压剪比越高,出现前兆的时间越早;空间上,破裂前沿剪切区域出现的高温异常条带具有前沿推进即“由一端向另一端迁移、扩展”的特点。本研究结果对地震、岩爆、矿爆、边坡滑移等自然与岩石工程灾害的遥感与预报具有重要的基础意义。

REMOTE-SENSING-ROCK MECHANICS(Ⅳ)--LAWS OF THERMAL INFRARED RADIATION FROM COMPRESSIVELY-SHEARED FRACTURING OF ROCK AND ITS MEANINGS FOR EARTHQUAKE OMENS

The fracturing of initial rock mass is another mechanism of tectonic earthquake. Taking it for experimental modeling object,five kinds of typical rocks were collected from the capital area of China,Beijing,and thermal infrared (TIR) radiation imaging experiments were conducted in condition of compressively-sheared rock fracturing. It is discovered from the experimental study that:(1) there are two thermal-stress coupling effects,thermoelastic effect and friction-heat effect,in the process of compressively-sheared rock fracturing,and the higher the ratio of compressive stress to shearing stress is,the more obvious the TIR radiation temperature increment is,(2) in condition of dominating compressive strain,there exists abnormal TIR radiation omen of rock fracturing,(3) the TIR omen of rock fracturing is of obvious temporal-spatial features,i.e.,the average TIR radiation temperature of rock surface increases rapidly as the load reaches to about 80% of the compressive-shear strength,and the higher the ratio of the compressive stress to the shearing stress is,the earlier the appearance of the TIR omen is,and the front edge of the abnormal high temperature strip along the shearing face will move forward until fracturing. The results are basically meaningful for the remote sensing and the forecast of some natural and rock engineering disasters,such as earthquake,rock burst,mine burst and landslide.