CDC STACKS serves as an archival repository of CDC-published products including scientific findings, journal articles, guidelines, recommendations, or other public health information authored or co-authored by CDC or funded partners.
As a repository, CDC STACKS retains documents in their original published format to ensure public access to scientific information.
i
New Developments With The Coal Mine Roof Rating
-
2002
-
Source: Proceedings of the 21st International Conference on Ground Control in Mining, August 6-8, 2002, Morgantown, West Virginia. Peng SS, Mark C, Khair AW, Heasley KA, eds., Morgantown, WV: West Virginia University, 2002 Aug; :294-301
[PDF-150.12 KB]
Details:
-
Personal Author:
-
Corporate Authors:
-
Conference Authors:
-
Description:The Coal Mine Roof Rating (CMRR) was first presented at this Conference nine years ago. Since its introduction, the CMRR has been incorporated into many aspects of mine planning, including longwall pillar design, roof support selection, feasibility studies, and extended cut evaluation. It has also become truly international, with involvement in mine designs and funded research projects in South Africa, Canada, and Australia. The purpose of this paper is to bring the mining community up to date with recent improvements and applications of the CMRR. The most important new development is a streamlined process for determining the CMRR from exploratory drill core. Just three types of information are now required: •Fracture spacing (or RQD) •Uniaxial compressive strength (or axial Point Load Testing) •Diametral Point Load Testing The moisture sensitivity adjustment has also been changed, and new research has related the immersion test to slake durability. Most recently, the CMRR has been implemented in a computer program, which can be obtained from NIOSH free of charge. The program facilitates calculation of the CMRR from either underground or drill core data. Values from many locations can be saved in a single file, and an interface with Autocad allows CMRR contour plots to be integrated into mine planning.
-
Subjects:
-
Source:
-
Document Type:
-
Genre:
-
CIO:
-
NIOSHTIC Number:nn:20024703
-
Collection(s):
-
Main Document Checksum:
-
Download URL:
-
File Type: