Comparison of Uniform Four-Foot Length,Fully-Grouted Resin Roof Bolts and Alternating Four-and Six-Foot Length,Fully-Grouted Resin Roof Bolts.

摘要

This contract work is the second phase of a project to obtain a comparison of resin and mechanical roof bolting. Phase one resulted in performance characterization of the two bolt types under production conditions. This current phase compared the behavior of two resin systems in high horizontally stressed ground by measurement of bolt loads and roof movement underground in rock of the two systems. Data generated under this project show that there was no discernible difference in the roof support given by uniform four-foot and by alternating four-and six-foot resin bolts in two different ground conditions. The contractor reached the conclusion that,in mine roof support,the particular roof bolt system used is often important but is usually not of controlling importance,rather the dominant factors include the structural geology,the in situ stresses and the interaction of the mine design with these. This contract provided insight on the mechanisms of roof support and its control by rock bolting. The contractor has used the information to improve his roof bolting and mine design practices. The use of four-foot resin bolts has resulted in a cost savings and increased productivity for the company with no sacrifice of safety.