Prediction of geomechanical behavior of deep-level rock mass in the Zun-Kholba deposit

Zun-Kholba is a steeply dipping gold ore body developed by the underground method in difficult ground conditions. For the efficient ground control during heading and stoping, the geomechanical behavior of deep-level rock mass was studied. The analysis of the geological structure of the gold ore body and the rock mass tectonics is presented. The rock mass stability is determined as moderate to unstable. The physical and mechanical properties of rocks, as well as their proneness to dynamic events of rock pressure are investigated. The maximum tolerable stresses are determined for ore and rocks. Natural stresses in rock mass are analyzed based on the measurements using the method of borehole slotter. The calculations show that rock mass experiences high gravitational tectonic stresses. Using the finite element-based mathematical modeling, the induced stresses in rock mass around development drifts and stopes are studied. The main patterns of the induced stresses in roof, corners and walls of the drifts are determined versus the mining depth (800–100 m) and the stope–drift spacing. The abutment pressure zone is found in the stoping area. The modeling also shows that stresses in pillars exceed the tolerable values, which results in the pillar failure. Prediction of the geomechanical behavior of deep-level rock mass in the course of mining is performed.

Pavlov A. M. Prediction of geomechanical behavior of deep-level rock mass in the Zun-Kholba deposit. MIAB. Mining Inf. Anal. Bull. 2020;(5):105-114. [In Russ]. DOI: 10.25018/0236-1493-2020-5-0-105-114.

A.M. Pavlov, Dr. Sci. (Eng.), Professor, Irkutsk National Research Technical University, 664074, Irkutsk, Russia, e-mail: go_gor@estu.edu.

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