“…The shear characteristic of rock fractures influenced by a large extent on several phenomena and many effective factors including wall strength and weathering state [ Barton , ; Bandis et al ., ], boundary conditions and normal stresses [ Haberfield and Johnston , ; Haberfield and Seidel , ; Haque , ; Jiang et al ., ; Leichnitz , ; Pereira and de Freitas , ; Saeb and Amadei , ; Seidel and Haberfield , ; Sun et al ., ], time [ Dieterich , ; Ruina , ], deformation history [ Babanouri et al ., ; Belem et al ., ; Boulon et al ., ; Chern et al ., ; Dowding et al ., ; Huang et al ., ], fracture geometry and roughness [ Archambault et al ., ; Barton , ; Barton et al ., ; Gentier et al ., ; Goodman , ; Grasselli et al ., ; Huang et al ., ; Karami and Stead , ; Kwafniewski and Wang , ; Lopez et al ., ; Park and Song , ; Zhang et al ., ; Zhao , ], shear direction [ Jing et al ., ], and scale [ Bandis et al .,1981; Barton and Bandis , ; Barton et al ., ]. From these, fracture geometry and surface roughness play a key role in the shear characteristic of rock fractures.…”