通过声发射仪、红外热像仪观测有水压条件下的花岗岩试样单轴加载实验,研究加载过程中试样的声发射与红外辐射特征以及花岗岩破裂与渗水的红外及声发射异常前兆。研究结果显示:随着应力的逐步增加,试样的红外辐射表现为早期均匀上升、中期局部高温异常、后期渗水区低温异常;在破裂及渗水过程中,红外辐射表现为高温辐射场包围低温辐射场;花岗岩破裂一渗水的红外异常前兆为渗水点出现明显的“先升后降”红外辐射现象;32~128kHz频段是花岗岩破裂渗水时声发射信号的特征频带,且在渗水前夕该频带能量呈百分比下降趋势,并在渗水发生时降至最低点。上述实验结果对巷道开挖过程中透水事故的遥感监测预警具有重要的意义。
By observing the uniaxial loading tests of a granite under water pressure with infrared radiation(IR) and a- coustic emission ( AE), the characteristics of infrared radiation (IR) and acoustic emission ( AE ) of granite as loading and some abnormal phenomenon of infrared radiation(IR) and acoustic emission(AE) as granite fracturing and water seepage process are investigated. The experimental results show that with the stress increasing, IR radiation of the sample~ surface rises evenly in early term, local high temperature in medium term, and low temperature in the late water seepage area. Dur- ing the fracture and water-seepage process, the IR radiation indicates that low-temperature radiation field is surrounded by high-temperature radiation field. The anomaly features of IR radiation when granite rupture or seepage show that the infrared radiation reflects as "first increase and then decrease" at water seepage point; 32 -128 kHz band is the characteristic band of acoustic emission signals as granite fracture and water seepage, and the band energy showed a trend of decline with percentage before seepage and declined to the lowest when water seepage occurs. The test results above is of great signifi- cance to remote sensing monitoring and early warning of flooding accident in the tunnel excavation process.