Infrared Precursor Experiment to Predict Water Inrushes in Underground Spaces Using a Multiparameter Normalization

Abstract

Rock failure is the root cause of geological disasters such as slope failure, civil tunnel collapse, and water inrush in roadways and mines. Accurate and effective monitoring of the loaded rock failure process can provide reliable precursor information for water inrushes in underground engineering structures such as in mines, civil tunnels, and subways. The water inrush may affect the safe and efficient execution of these engineering structures. Therefore, it is essential to predict the water inrush effectively. In this paper, the water inrush process of the roadway was simulated by laboratory experiments. The multiparameters such as strain energy field and infrared radiation temperature field were normalized based on the normalization algorithm of linear function transformation. On the basis of analyzing the variation characteristics of the original parameters, the evolution characteristics after the parameters normalization algorithm were studied, and the precursor of roadway water inrush was predicted comprehensively. The results show that the dissipation energy ratio, the infrared radiation variation coefficient (IRVC), the average infrared radiation temperature (AIRT), and the variance of successful minor infrared image temperature (VSMIT) are all suitable for the prediction of roadway water inrushes in the developing face of an excavation. The intermediate mutation of the IRVC can be used as an early precursor of roadway water inrush in the face of an excavation that is being developed. The inflection of the dissipation energy ratio from a declining amount to a level value and the mutation of VSMIT during rock failure can be used as the middle precursor of roadway water inrush. The mutation of AIRT and VSMIT after rock failure can be used as the precursor of roadway imminent water inrush. Combining with the early precursor and middle precursor of roadway water inrush, the graded warning of “early precursor–middle precursor–final precursor” of roadway water inrush can be obtained. The research results provide a theoretical basis for water inrush monitoring and early warning in the sustainable development of mine, tunnel, shaft, and foundation pit excavations.

Experimental Study on the Response of Cracked Sandstone to the Intermediate Principal Stress Coupled with Pore Pressure

“…With the exhaustion of shallow energy resources and sustainable utilization of underground space, human endeavors have inevitably extended into deeper regions of the Earth. − The rock masses in deep underground engineering are characterized by inherent heterogeneity, often containing an abundance of structural planes such as joints, fissures, and faults. , Meanwhile, the intricate geological structures typically subject the fractured rock underground to true three-dimensional stress with high geostress and elevated pore pressure . The presence of pore pressure in the cracked causes a decrease in the strength of the rock masses, reducing its stability and increasing its susceptibility to failure under stress perturbations. , During the rock failure process, the water diffusion volume change (i.e., Δ V ) can potentially lead to water inrush disaster, significantly jeopardizing the safe construction of underground engineering. Therefore, it is crucial to investigate the mechanical and Δ V characteristics in the failure process of cracked rocks under the influence of true triaxial stress and pore pressure.…”

“… 2 The presence of pore pressure in the cracked causes a decrease in the strength of the rock masses, reducing its stability and increasing its susceptibility to failure under stress perturbations. 6 , 7 During the rock failure process, the water diffusion volume change (i.e., Δ V ) can potentially lead to water inrush disaster, significantly jeopardizing the safe construction of underground engineering. Therefore, it is crucial to investigate the mechanical and Δ V characteristics in the failure process of cracked rocks under the influence of true triaxial stress and pore pressure.…”