One of the main problems facing mining engineers when dealing with deep, hard rock mines is to prevent and/or reduce rockburst hazard around mine openings. Rockburst is a phenomenon which is characterised by violent rock failure. The current research focuses on the assessment and control of rockbursts in deep, hard rock mines. / Strainbursts, or strain-type rockbursts, occur in the vicinity of mine openings and are generally provoked by high stress conditions in a brittle rock mass. A new theory has been developed for the assessment of the potential of violent rock failure by strainburst, in underground hard rock mines. In this theory, the mining-induced energy parameters are used to calculate the so-called burst potential index (BPI). When the BPI reaches or exceeds 100%, the method predicts a burst prone situation. One of the most commonly used methods to control strainbursts in hard rock mines is destress blasting. / Motivated by the lack of a dedicated analysis tool to help assess destress blasting, a new, geomechanical model was developed. The technique employs two newly introduced parameters, alpha, a rock fragmentation factor, and beta, a stress dissipation factor, inside the modelled, fractured zone. Implemented in a 3-dimensional finite element code developed by the author, the new model simulates the damage zone induced by destress blasting of a mining face to help evaluate the efficiency of destress blasting. Extensive model verification and parametric studies have been undertaken. The effects of the destress blasting pattern, premining stresses and their orientation, and the two destress blasting factors (rock fragmentation factor, and stress dissipation factor) are studied. The model has been applied successfully to Canadian mine case histories. A detailed case study of a cut-and-fill mine stope involving crown and sill pillar destressing has been carried out. It is shown that the new method can be useful in the assessment of destress blasting in deep drift face development and the crown/sill pillar problems in cut-and-fill mine stopes.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.36717 |
| Date | January 2000 |
| Creators | Tang, Baoyao, 1963- |
| Contributors | Mitri, Hani S. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Mining and Metallurgical Engineering.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001762208, proquestno: NQ64678, Theses scanned by UMI/ProQuest. |
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