Face Stability in Heavy Clay: Theory and Practice
M. O. Lebedev1, M. A. Karasev2, N. A. Belyakov2, L. A. Basova2
1Lenmetrogiprotrans Research, Design and Exploration Institute, Saint-Petersburg, Russia
2Saint-Petersburg Mining University, Saint-Petersburg, Russia
Keywords: Tunnels, rock deformation, advanced face reinforcement, fiberglass rock bolts, numerical modeling
Abstract
The authors focus on feasibility of reducing deformation of surrounding rock mass around underground structures by means of advanced reinforcement of tunnel headings in claystone. The reinforcement efficiency is estimated in 3D calculations. The factors to influence deformation in rock mass ahead of tunnel faces include: rock bolt length, rock bolting system stiffness and the bolt pattern. An additional factor of concern is the mechanical characteristics of claystone. The implemented research shows the highest influence is exerted on deformation in rock mass by the bolt pattern and the rock bolting system stiffness. The efficient design of advanced rock bolting is determined.
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