Mining Publication: Design Parameters of Roof Support Systems for Pre-Driven Longwall Recovery Rooms
Original creation date: February 2004
Authors: SC Tadolini, TM Barczak
NIOSHTIC2 Number: 20024570
2004 SME Annual Meeting, Feb 23-25, Denver, Colorado, preprint 04-54. Littleton, CO: Society for Mining, Metallurgy, and Exploration, Inc., 2004; :1-13
Reduction in the recovery time required and improvements in safety during a longwall face move have compelled coal mine operators to examine and use predriven longwall recovery rooms. The recovery entry is developed at the longwall stop position and supported ahead of time so that the required combinations of standing and internal supports can be installed before the longwall face approaches. A calibrated three-dimensional finite element model, developed in conjunction with an underground test area, provided the critical components and design principles for a comprehensive parametric study. The study indicates that vertical, horizontal, and shear stresses concentrated on the outby abutment pillar corner of the recovery room resulting in deformations in the immediate roof above the primary roof support anchorage level. The results of the numerical model and field site observations indicated that the combination of the internal bolting system and the standing concrete supports are critical for the successful and safe extraction of the longwall equipment. Cable supports installed at and angle over the pillars can help stabilize the disturbed zone above the adjacent fender and outby pillars; however, standing supports are required in most sedimentary roof conditions to increase stability and assure a safe longwall extraction.
NIOSHTIC2 Number: 20024570
2004 SME Annual Meeting, Feb 23-25, Denver, Colorado, preprint 04-54. Littleton, CO: Society for Mining, Metallurgy, and Exploration, Inc., 2004; :1-13
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- Overview of Coal Mine Ground Control Issues in the Illinois Basin
- Overview of Current US Longwall Gateroad Support Practices: An Update
- Performance of Roof Support Under High Stress in a U.S. Coal Mine
- Rock Mass Behavior and Support Response in a Longwall Panel Pre-Driven Recovery Room
- A Study of the Ground Control Effects of Mining Longwall Faces Into Open or Backfilled Entries
- Two Sister Reports of Investigations on Ground Stress Research