STRUCTURING EXPERIMENTAL DATA ON THE PERFORMANCE OF ARCH SUPPORTS FOR PROBABILISTIC ASSESSMENT OF THE STATE OF RETRACTABLE DRIFTS

Abstract

Purpose. Structuring of experimental data of mine observations of the performance of arched flexible supports to establish a probabilistic assessment of the state of haulage drifts of steep coal seams in the excavation areas of a coal mine. Methods. The methodological basis of the research is an integrated approach, including the analysis and generalization of scientific achievements on the problem under study; mine observations of the state of development workings; analytical calculations using the basic provisions of probability theory, mathematical statistics using differential equations. Results. A probabilistic assessment of the state of the haulage drift under different protection methods, used to predict the stability of section development workings, was obtained from the experimental data of mine observations (observation time t = 4280 hours) of the performance of the arched pliable lining installed in the working along the length of the excavation section. After the sample was formed, the calculation of a statistical assessment of the reliability of the support operation was performed: the indicators of the failure rate λ and the recovery rate μ were established. Dependencies are obtained that allow assessing the state of development workings along the length of the excavation section and in the zone of influence of the stopping operations. It is proved that in the steady mode of operation of the haulage drift, with an increase in the failure rate of the arch support by 5 times, the availability factor, as a function of the reliability and maintainability of the support, changes from 0.9 to 0.5, which leads to a deterioration in time, approximately by 60 %, operational characteristics of the support in the supported development. Novelty. The probabilistic assessment of the loss of stability of the haulage drift along the length of the excavation section is based on the structuring of the data on the performance of arched supports and depends on the method of protection of the working, the intensity of failures of the arched supple support and the frequency of its damage, when in the desired interval of observations when forming the sample, the position of the stopping front is taken into account. Practical relevance. For the reuse of development workings with a store method of preparing steep seams and a descending order of mining floors, a conceptual model is proposed that allows predicting the state of haulage drifts along the length of the excavation area, taking into account the method of protection.