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Results 31 - 40 of 45
Longwall Tailgates: The Technology for Roof Support Has Improved, but Optimization is Still Not There6/1/2003 - Conference papersThe primary objective of the paper will be to discuss strata mechanics and ways in which the support and strata interaction can be evaluated to provide an optimized secondary support design, particularly standing support systems, for longwall tailgates.
8/1/2001 - Conference papersA state-of-the-art, three-dimensional, full waveform, microseismic system was used to analyze the rock failure around a deep bump-prone longwall panel. Analysis of the recorded events is discussed.
8/1/1999 - Conference papersThis paper discusses a design methodology for standing secondary tailgate supports, using the performance characteristics generated in the NIOSH Mine Roof Simulator (MRS) to match load characteristics of various supports to ground reaction behavior.
3/1/1999 - Conference papersThis paper presents several case studies in which a mechanics-based boundary-element program is used to back-calculate the surface subsidence associated with various panels at several northern Appalachian coal mines.
3/1/1999 - Conference papersTwo types of airflow splitting methods for improving longwall dust control were investigated by NIOSH's Pittsburgh Research Laboratory. These methods included a transducer mesh barrier and a staged spray barrier system.
1/1/1998 - Conference papersUnusual circumstances sometimes require a longwall retreat into/through a previously driven room, with the potential for failures and roof fall hazards. To determine the failure factors, NIOSH compiled an international database of 130 case histories.
11/1/1997 - Technology NewsA method is described for allowing operators to predict methane emissions from panels with increased face width.
Analysis and Prediction of Longwall Methane Emissions: A Case Study in the Pocahontas No. 3 Coalbed, VA2/1/1997 - Conference papersIncreasing longwall panel dimensions, particularly face width in gassy coalbeds, may result in unexpected increases in methane emissions. To investigate this problem, continuous longwall face emission monitoring studies were conducted at two adjacent mi...
Technology News 445 - Updated Analysis of Longwall Pillar Stability (ALPS) Computer Program Incorporates New Coal Mine Roof Rating (CMRR)2/1/1995 - Technology NewsThe objective of this work is to develop a comprehensive, practical method for designing longwall gate entries that considers coal pillar size, mine roof quality, and artificial support in an easy-to-use computer program.
1/1/1995 - Reports of InvestigationsSubsidence data gathered by the U.S. Bureau of Mines over a series of longwall panels in the Pittsburgh Coalbed were studied to obtain insight as to the role of time in the subsidence process. These results were then compared to data from three other si...