Evaluation of rock mass classifications for supporting TBM tunnels

In this presentation, the history of the rock mass classifications, which is applied to support system for TBM tunnel, is generally discussed. Since the development of Terzaghi’s Rock-Load Classification System, different scholars have introduced quite different classification systems for use in the design of ground support for underground structures. Most common rock classification systems for use in design of ground support for underground structures are evaluated those systems are: Terzaghi’s Rock-Load Classification, Stand-up Time Classification, New Australian Tunneling Methods (NATM), Rock Quality Designation (RQD), Rock Structure Rating System (RSR), Rock Mass Rating System (RMR), Rock Tunneling Quality index (Q). In conclusion, the rock mass classification systems are going to be discussed in terms of ground support design for underground structures and also objectives, advantages and disadvantages of the rock mass classification systems are discussed.