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Currently, the implementation of a coal mine production safety monitoring system, capable of real-time monitoring of the safety condition of large coal mine equipment and timely dispatch management, is crucial for the efficient and safe operation of coal mine enterprises. This paper designs the coal mine major equipment failure process based on the rolling bearing’s vibration mechanism, analyzes the major equipment’s failure signal using both time domain and frequency domain analysis methods, and employs the intelligent fuzzy control method to identify the major equipment failure. We have designed and practically applied a real-time, multi-threaded, and comprehensive fault diagnosis and prediction system for coal mine major equipment, combining information from coal mine safety, production, and operation. The results show that the normal state’s time-domain amplitude approximates (-0.2, 0.2), and the time-domain waveforms all display periodic shock signals when the bearing sustains damage. The faulty vibration amplitude of the inner ring is within 0.08 ms2 and the faulty vibration amplitude of the outer ring is within 0.44 ms2, and the diagnostic accuracy using the method of this paper reaches 97.2%. This study demonstrates the effectiveness of remote monitoring and fault analysis of major equipment in coal mines, which effectively improves the equipment start-up rate and ensures coal mine production safety.

The degradation of simulated methyl red dye wastewater in a concentric tubular reactor using dielectric barrier discharge low-temperature plasma technology was studied. The effects of discharge power, initial solution concentration, initial pH, treatment time, and atmospheric conditions on the degradation efficiency were studied. The color, pH, and absorbance of methyl red at 521 nm were used to detect the dye concentration, analyze the degradation process, and propose a degradation mechanism for methyl red. The results indicate that (1) in this experiment, the discharge power affects the degradation of methyl red but is limited by temperature and humidity, such that there is no positive correlation between the discharge power and the treatment effect. Therefore, the treatment of the solution at a low discharge power of 115 W is preferable; (2) the higher the initial concentration, the longer the time needed to achieve the same degradation rate as that achieved at lower concentrations; and (3) under the same conditions, a low pH is conducive to the degradation of methyl red, and acidic conditions are conducive to the bond breaking of methyl red.

The performance of three adjacent 48 m depth concrete diaphragm wall panels in silty soils is measured throughout the complete process of the wall installation including trench excavation, trench concreting, and concrete hardening. The analysis of the field measurement data shows that the ground movement induced by the wall installation is a function of construction activities. The maximum lateral movement occurs during the trench excavation. The trench concreting reduces the lateral movement. Field measurement at the end of wall installation may not catch the value of the maximum lateral movement. The ground settlement continues to increase during the complete process of panel installation, but with a decreasing rate. Roughly 90% of the settlement occurs during the trench excavation. The ground movement is also closely related to the properties of subsurface strata. The weak superficial fill materials sustain high disturbance, which consequently results in relatively large ground movement. With current engineering means and methods and good construction workmanship, the ground movement can be well controlled. In the current project, the maximum lateral ground movement was controlled within 2.0 cm and the maximum settlement was controlled within 0.05% of trench depth. Key words: concrete diaphragm wall, trench excavation, field instrumentation, lateral ground deformation, settlement. La performance de trois panneaux des paroi en beton adjacent d'une profondeur de 48 m dans des sols limoneux est mesuree a partir du processus d'installation de la paroi, y compris l'excavation de la tranchee, le betonnage et le durcissement du beton. L'analyse des donnees issues de mesures de terrain montre que le mouvement du sol induit par l'installation de la paroi depend des activites de construction. Le mouvement lateral maximal se produit lors de l'excavation de la tranchee. Le betonnage reduit le mouvement lateral. Les mesures sur le terrain a la fin de l'installation de la paroi peuvent ne pas correspondre a la valeur du deplacement lateral maximal. Le tassement du sol continue a augmenter lors du processus d'installation des panneaux, mais a un taux decroissant. Presque 90 % du tassement se produit lors de l'excavation de la tranchee. Le mouvement du sol est egalement etroitement lie aux proprietes des strates souterraines. Les materiaux de remplissage superficiels faibles subissent de fortes perturbations et entrainent par consequent un mouvement du sol relativement important. Avec les moyens et methodes d'ingenierie actuels et une bonne finition, le mouvement du sol peut etre bien controle. Dans le projet actuel, le mouvement lateral maximal du sol etait controle a 2,0 cm et le tassement maximal a 0,05 % de la profondeur de la tranchee. [Traduit par la Redaction] Mots-cles : paroi moulee en beton, excavation de tranchee, instrumentation de terrain, deformation laterale du sol, tassement., 1. Introduction Large underground structures, such as subway stations, are typically constructed using open-cut or cut-and-cover. Concrete diaphragm wall (CDW) is one of the most widely used support techniques during [...]