Gebirgsmechanische Betrachtung und Beschreibung des Festenverhaltens in einem tiefen österreichischen Hartgesteinsbergbau
Research output: Thesis › Master's Thesis
In a deep Austrian hard rock mine sublevel stoping is applied. Currently there is a project regarding the rock mechanical optimization of the mining layout ongoing. Due to the circumstance that pillars ensure the local and regional stability, their behavior is a key issue. The pillar system behavior is amongst other things depended on the pillar strength, pillar stiffness and the pillar loading mechanism. In the thesis the existing pillar system is back analyzed to determine the pillar behavior. In numerical simulations different parameters are investigated to evaluate their influence on the behavior of the pillars as well as on the regional stress redistribution. The parameters are rock mass properties, pillar strength and pillar stiffness. The results of the numerical simulations are evaluated against the real life behavior of a mine tunnel, which was situated in the abutment zone and subjected to increased stress levels resulting from the approaching pillar mining area. The investigation is subdivided into two different cases. The first case assumes that the pillar system does not contribute to regional stability. In this case, the pillars are considered as mined out as well. The influence of varying hanging wall compositions, the rock mass parameters, the mining panel width, the number of pillars as well as different shale thicknesses are examined. The second case builds on the results of the first case, considering the pillars to be supporting structures, which provide local and at least to some extend regional support to the surrounding rock mass. The pillar loading mechanism is modeled as a bending beam, which is formed by the immediate hanging wall layers, and as a dead weight load of the immediate hanging wall shale. To evaluate the effects of varying pillar behavior a variation of the pillar stiffness based on a change of their modulus of elasticity on the one hand as well as different constant pillar stresses on the other hand are considered. The results are used to discuss the effect of a changed pillar geometry. The parametric study supported by the observation of pillar behavior has provided into the complex behavior of limited span pillar mining areas.
|Translated title of the contribution||Rock mechanical analysis of the pillar behavior in a deep Austrian hard rock mine|
|Award date||14 Dec 2018|
|Publication status||Published - 2018|