1. Aydan O, Ulusay R, Kawamoto T (1997) Assessment of rock mass strength for underground excavations. Int J Rock Mech Min Sci 34:18.e1–18.e17
2. Barton N, Lien R, Lunde J (1974) Engineering classification of rock masses for the design of tunnel support. Rock Mech 6:189–236
3. Chen G, Jia ZH, Ke JC (1997) Probabilistic analysis of underground excavation stability. Int J Rock Mech Min Sci 34:51.e1–51.e16
4. Chryssanthakis P, Barton N, Lorig L, Christianson M (1997) Numerical simulation of fiber reinforced shotcrete in tunnel using the discrete element method. Int J Rock Mech Min Sci 34:54.e1–54.e14
5. Cundall PA (1971) A computer model for simulating progressive, large-scale movements in blocky rock systems. In: Proceedings of the international symposium rock fracture. ISRM Proceedings, vol 2, pp 129–136