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|Fully grouted tensioned bolts provide a desirable compressive of laminated roof and bondage along the entire bolt length, at the same time the entire surface of the hole is protected against penetration of moisture. This is particularly important in shale strata, where, when left unprotected by a partial grout column, moisture penetrates to the annular space, and weathers rock around the bolt hole, having an easy access to the bedding planes which are strongly hydrophilic. The most desirable are thrust tensioned rebar bolts that can be installed with one procedure step, and can secure a desired pre-stressing. Such bolts have a forged conventional head and offer no hazard to miners in low clearance mines, whose number increase constantly due to the depletion of reserves in thicker seams. The presented field-testing program has been based on instrumented bolts allowing for monitoring of tension at installation and at a chosen time interval after. The tested system is based on rebar bolts installed with two speed Fosroc resin (fast at the top and stow at the bottom), and mechanical compression by the bolting machine at installation. Combination of several different washer -- plate arrangements have been tested. The results are reported with their interpretation, and recommendations directly towards strata control requirements, as well as the operational considerations for efficiency of installation.|
Additional chapters/articles from the SME-ICGCM book Proceedings 21st International Conference on Ground Control in Mining
|Pre-Driven Experimental Longwall Recovery Room Under Weak Ro||Longwall Mining-Induced Abutment Loads and Their Impacts on||Influence of Structural Stress Concentration and Structural||The NIOSH Shield Hydraulics Inspection and Evaluation of Leg||Study on Top-Coal Loss and the Optimum Drawing Interval of L||Stress Measurements for Safety Decisions in Longwall Coal||Re-Use of Rectangular Bolted Roadways in a Cover Depth > 100||Numerical Modeling of the Gob Loading Mechanism in Longwall||Deep Cover Pillar Extraction in the U.S. Coalfields||Evaluation of Pillar Recovery in Southern West Virginia||A Case History Investigation of Two Coal Bumps in the Southe||A Linear Coal Pillar Strength Formula for South African Coal||Anchorage Pull Testing for Fully Grouted Roof Bolts||Comparison of Some Aspects of Bolting Mechanisms Between Ful||Eclipse System Improves Resin Anchored Rebar Bolting||Design Considerations for Tensioned Bolts||Field Testing of the Fully Grouted Thrust Tensioned Bolts||Improvement in Pre-Tensioning of Strand Bolts in Australian||The Introduction of Roof Bolting to U.S. Underground Coal Mi||Support of Coal Mines in the United Kingdom||The Use of NDT Methods to Determine the Condition of Rockbol||Rockbolted Support of Retreat Longwall Gateroads at 1000m De||Roof Screening: Best Practices and Roof Bolting Machines||Numerical and Physical Modeling as Planning Tools for Rockbo||Stone Mine Design in Highly Fractured Rock||The Importance of Underground Stone Mine Roof Geology||Utilization of Ground-Penetrating Radar to Determine Roof Co||An Examination of the Loyalhanna Limestone's Structural||Highwall Stability in an Open Pit Stone Operation||Overview of Safety Considerations with Highwall Mining Opera||Highwall Monitoring to Combat Rockfall Accidents at Opencast||Seepage and Reinforcement Behavior of Grouting Into Slaking-||Floor Heave in Shallow Room-and-Pillar Mining||Analysis of a Stability Problem in an Underground Coal Mine||Comparison of Acoustic Emission and Stress Measurement Resul||Acoustic Scanner Analysis of Borehole Breakout to Define the||Estimating Rock Strengths Using Drilling Parameters During R||New developments with the coal mine roof rating||Application of geotechnical and geophysical parameters to im||Development of a Risk Rating System for Use in Underground C||Empirical and analytical design of large openings at a propo||Shear Mechanism for Mining-Induced Fractures Applied to Rock||Evaluating Techniques for Monitoring Rock Falls and Slope St||Developments in Sealant Support Systems for Ground Control||Stability Control of Clusters of Deep Openings Around Shaft||The Use of Pneumatic Stowing in Germany Considering Subsiden||A 3-D Semi-Analytical Method for Subsidence Prediction and S||Theory and Technology of Mining Subsidence Control by Grouti||Surface Subsidence Due to the Combined Effects of Undergroun|