Hard rock pillar is a crucial mass structure to maintain the stability of underground mine. It needs special attention analyze its from point quality. In this paper, geological strength index (GSI) representing quality hard examined as new influence factor stability, and combined with conventional parameters (uniaxial compressive (UCS) intact mass, width (w), height (h), ratio (w/h)) complete s...

This article introduces a new non-pillar coal mining technology (i.e., Gob-side Entry Retaining by Roof Cutting (GERRC)) under the condition of thick and hard roofs. First, we theoretically analyzed solution to large suspension span roof in mining. Three-Zone pre-split blasting design for roofs was proposed, based on principles rock mechanics. After field experiments, successfully applied huge ...

A recent experimental pillar extraction project at a UG2 bord-and-pillar mine presented unique opportunity to compile new database. Currently, the South African hard rock mines are designed using Hedley and Grant formula with modified K-value. This empirically derived was developed for uranium in Elliot Lake district of Canada. The use this design pillars Africa is questionable. Very few failur...

Given the complexity and uniqueness of underground hard rock mines, application design fire scenario approach is recommended when evaluating safety in mines. Providing a full set scenarios – ensuring that several important life aspects are covered for mine can be challenging. The question whether catalogue potential clusters could developed, covering found underground? general lack research int...

This paper proposes a coupled thermal-hydrological-mechanical damage (THMD) model for the failure process of rock, in which coupling effects such as thermally induced rock deformation, water flow-induced thermal convection, and rock deformation-induced water flow are considered. The damage is considered to be the key factor that controls the THM coupling process and the heterogeneity of rock is...

A number of shallow coal or hard rock mines employ pillar mining systems as a strategy for roof failure control. In certain platinum mine layouts, pillars are designed to 'crush' in stable manner they become loaded the panel back area. The correct sizing demands some knowledge strength and overall layout stress distribution. It is particularly important understand impact geometry on effective r...

A new theoretical/empirical model has been developed for performance prediction of hard rock TBMs. The model uses information on the rock properties and cutting geometry to calculate TBM rate of penetration. The model can also be used for TBM butterhead design optimization to achieve maximum performance in a given geology.

Theoretical analysis and numerical simulation were conducted to study the disaster-causing mechanism of structural instability overlying strata induced by water–rock coupling effectively prevent control powered support jammed accident during mining below unconsolidated confined aquifer. The influencing factors on stability structure analyzed, method aquifer was designed. evolution process stres...