Argillisation of surrounding rock due to water seepage and anchorage performance protection

Abstract

Impacts of argillisation of surrounding rock due to water seepage on roadway bolting were investigated. First, the microstructure and mechanical properties of argillaceous rock were studied to show the water weakening effect on rock strength. Then contrastive tests were made on the anchorage performance of bolted areas and the permeability of argillaceous rock, with and without water seepage. Surrounding rock stability of a typical argillaceous roadway Tailgate 721 in Qi’nan Mine was numerically simulated. Serious bolting failure and roof fall could be attributed to the chain reaction of water seepage. The key to the problem lies in the effective fracture sealing by grouting. Seepage characteristics highlighted by three‐directional seepage provided valuable information for the determination of grouting length, time and layout. Finally, the bolting principle and control methods by resin grouting were presented and successfully used in the above roadway.

Keywords:

• Argillisation
• Surrounding rock
• Fracture water seepage
• Anchorage performance
• Bolting
• Grouting

We express our appreciation to State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology (project no. SKLCRSM09X03), the New Century Excellent Talents in University (program no. 06‐0478) and the National Basic Research Program of China (project no. 2007CB209408) for their financial support.