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

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

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Acknowledgements

The authors express their thanks to the Imensazan Consultant Engineers corporation staff. Engineering Staff, Moshanir Cu. Engineering Staff, Dezab Cu. Engineering Staff for providing data support, and Isfahan University of Technology, where the study was carried out.

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2014 Higher Education Press and Springer-Verlag Berlin Heidelberg