An empirical method for design of grouted bolts in rock tunnels based on the Geological Strength Index (GSI)

摘要: The procedure presented in this paper has been developed for the design of grouted rock bolts tunnels during preliminary stage. proposed approach provides a step-by-step to set up series practical guidelines optimum pattern bolting variety mass qualities. For purpose, new formula estimation load (support pressure) is recommended. Due its wide-spread acceptance field engineering, Geological Strength Index (GSI) adopted support pressure equation. poor and very where GSI < 27, use Modified-GSI is, instead, supporting action assumed be provided by carrying total defined height. mechanism rely on roof arch forming suspension principle. Integrated with function, bolt density parameter modified order provide an optimized any shape tunnel. can also used analysis reinforced tunnel terms Ground Reaction Curve (GRC) such way as evaluate convergence. By doing so, effectiveness well evaluated. based believed overcome constrains limitations existing empirical methods RMR or Q-system, which are doubtful usage. applicability method illustrated stability rail-road Turkey.