Impact and Severity of Deep Excavations on Stress Tensors in Mining
V. Shankar1, D. Kumar2, Ds. Subrahmanyam1
1National Institute of Rock Mechanics, Bangalor, India
2Indian Institute of Technology, Dhanbad, India
Keywords: напряжение, гидравлические испытания существующей трещины, топография, анизотропия, Stress, hydraulic tests on pre-existing fracture, topography, anisotropy
Abstract
Knowledge of the state of stress regime is important to the mine designers for deciding the method of mining and for strategic design in virgin areas. This knowledge helps them in deciding the mining sequence and rock reinforcement for extraction of ores economically and safely. Generally, as excavation progresses to deeper levels, the stress tensors are also equally affected. Elevated stress regime results in concomitant increase in rock fracturing and mining induced deformations. The ambient state of the stress in an element of rock in the ground is determined by the existing loading regime in the rock mass as well as the stress path defined by the cumulative geologic history of the area. Rock failure in the periphery of the excavation is somewhat stress related, and it is therefore important to ascertain the extent of stress levels within a given rock formation. In this paper, the role of stress regime in pre and post mining stages is discussed by referring available and validated data inputs from in-situ stress measurements conducted at deeper levels in mines. Further, the authors also tried to ascertain the redistribution of the stresses due to mining or perturbation due to various other geological factors and any re-orientation of the stresses when compared to pre-mining stress tensor. The generation of post - mining stress data helps in understanding the impact of mining on the stress and could be used for design and sequencing of the mining operations for safe and optimum extraction of the ore/mineral.
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