循环加卸载充填体围岩组合体红外辐射特征

Infrared characteristics of combination of surrounding rock and backfilling body under cyclic loading and unloading

为研究矿山充填后围岩和充填体的破裂损伤,设计了充填体围岩组合体模型,采用红外辐射、场应变设备对双轴循环加卸载的组合体进行监测,揭示组合体模型表面的平均红外辐射温度(AIRT)及红外热像图随加卸载的变化规律。研究结果表明:加载过程组合体超过上次最高承载力会产生新裂隙,AIRT发生骤降;开始卸载时裂隙发生张拉,AIRT再次骤降。弹性能和摩擦热效应导致加卸载过程AIRT整体表现出升温现象;加卸载过程由红外热像图的变化可以推测出围岩从张性破裂转变为压剪破裂。研究结论证明红外热像技术可以预测充填体围岩组合体破裂的产生及发展。

In order to study the fracture damage of the surrounding rock and filling body after mining filling,a model of the combination of surrounding rock and backfilling body was designed.Infrared radiation and field strain equipment were used to monitor the biaxial cyclic loading and unloading of the combination body.The changes of infrared radiation temperature(AIRT)and infrared thermal image with loading and unloading were revealed.The results show that when the combination during the loading process exceeds the previous maximum bearing capacity,new cracks will occur and AIRT will experience a sudden decrease.At the beginning of unloading,the cracks undergo tension,and AIRT suddenly drops again.The elastic energy and frictional heat effect cause the overall temperature rise of AIRT during the loading and unloading process;the change in infrared thermography during the loading and unloading process can infer the transformation of the surrounding rock from tensile fracture to compressive shear fracture.The research conclusion proves that infrared thermal imaging technology can predict the occurrence and development of fractures in combination of surrounding rock and backfilling body.