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借助自主设计的由加载控制系统、应变采集系统、电阻同步采集系统以及红外成像系统等组成的多参数、同步监测系统,研究了充填体在单轴压缩过程中的应力-应变、电阻率以及温度变化规律,分析了充填体在破坏失稳应力-应变、电阻率以及热效应异常前兆特征,并对比了不同监测信息对同一事件破坏的敏感度和差异性。结果表明:充填体的电阻率和热红外信息时空演化进程与其压缩变形破坏整个过程基本相符,且具有明显的阶段性;在整个加载破坏过程中,观测到的电阻率前兆信息点要早于热红外前兆点、应力前兆点;与应力-应变、温度变化相比,电阻率变化规律具有明显的反对称性;电阻率变化规律能详细地表现充填体受压过程中每个阶段内部结构变化特征,而热红外信息则主要体现充填体塑性屈服前的表面结构温度演化特性。运用多参数评价充填体加载破坏前兆特征,能克服单纯考虑某一参数变化方法预警可信度低、错误率高的缺点。该方法是一种能全面、精准地掌握采场充填体稳定状态的有效方法。
With the self-designed multi-parameter and synchronous monitoring system consisting of load control system, strain collection system, resistance synchronous acquisition system and infrared imaging system, the stress-strain, resistivity and temperature of the filling body during uniaxial compression were studied. The regularity of failure, instability, thermal resistivity and thermal anomalies were analyzed. The sensitivity and difference of different monitoring information to the same event were also compared. The results show that the temporal and spatial evolution of the resistivity and thermal infrared information of the filling body basically coincide with the whole process of its compressive deformation and failure, and have obvious phases. During the entire loading failure, the observed resistivity precursory information point is earlier than that of the hot Infrared precursor point and stress precursor point. Compared with stress-strain and temperature change, the variation law of resistivity has obvious antisymmetry. The variation law of resistivity can show the variation of internal structure in each stage of filling process , While thermal infrared information mainly reflects the temperature evolution of the surface structure before plastic yielding. Using multiple parameters to evaluate the characteristics of preloading damage precursors can overcome the shortcomings of low reliability and high error rate of early warning based on simply considering the change of a certain parameter. This method is an effective way to grasp the steady state of stope filling body comprehensively and accurately.