Development of a new method for RMR and Q classification method to optimize support system in tunneling

Asghar RAHMATI^*, Lohrasb FARAMARZI, Manouchehr SANEI

Department of Mining Engineering, Isfahan University of Technology, Isfahan, Iran

Doi. 10.1007/s11709-014-0262-x

ABSTRACT

Rock mass classification system is very suitable for various engineering design and stability analysis. JH classification method is confirmed by Japan Highway Public Corporation that this method can figure out either strength or deformability of rock mass, further appropriating the amount of rock bolts, thickness of shotcrete, and size of pitch of steel ribs just after the blasting procedure. Based on these advantages of JH method, in this study, according to data of five deep and long tunnels in Iran, two equations for estimating the value of JH method from Q and RMR classification systems were developed. These equations as a new method were able to optimize the support system for Q and RMR classification systems. From JH classification and its application in these case studies, it is pointed out that the JH method for the design of support systems in underground working is more reliable than the Q and RMR classification systems.

KEYWORDS: JH classification, Q and RMR classification, new method