Constitutive model for rock fractures: Revisiting Barton's empirical model

Dynamic modelling of a mining-induced fault slip

“…The shear strength models reviewed in section 2.2 is applicable only to static conditions; and the initiation of fault-slip can be predicted with the static shear strength models provided that the physical and mechanical properties of causative faults are already known. Although post-peak behaviour of rock joints have been examined in terms of the decrease in a joint roughness coefficient (Asadollahi & Tonon, 2010;Barton et al, 1985) with increasing shear displacements, the dynamic behaviour of fault-slip cannot be adequately described with the studies because other complicated processes, such as the flash heating of microasperity contacts and frictional melting of fault gouge, are involved when fault-slip occurs with high slip rates. To date, quite a few dynamic friction laws allowing for stress changes that take place during faultslip have been proposed mainly in the field of geophysics.…”

“…It is obvious that post-peak behaviour induced by the decrease in a joint roughness coefficient is of paramount importance for the better understanding of fault-slip. Recently, Asadollahi and Tonon (2010) proposed an empirical relationship between the decrease in joint surface roughness and increase in shear displacement on the basis of results obtained from direct shear tests. The proposed equation is expressed as follows:…”

“…Asadollahi and Tonon (2010) has further considered the effect of normal stress acting on the joint as well as joint wall compressive strength on the peak shear displacement. A formula proposed by the authors is given as:…”

Effects of Displacement Velocity on Rock Fracture Shear Strengths under Large Confinements

“…These include, for example, scale effect (Bandis et al, 1981;Fardin et al, 2001;Johansson & Stille, 2014), thermal loading (Stesky et al, 1974;Lockner et al, 1986;Mitchell et al, 2013), cyclic loading (Lee et al, 2001;Kamonphet et al, 2015;Jafari et al, 2003), and water pressure (Stesky, 1978;Yeo et al, 1998). Several criteria and models have been proposed to describe the rock fracture shear strength under these conditions (e.g., Grasselli & Egger, 2003;Asadollahi & Tonon, 2010;Barton, 2013;Usefzadeh et al, 2013). The effects of confining pressure on the shearing behavior of fractures however have rarely been addressed and experimentally investigated.…”

Assessment of frictional resistance of granite rock joints with reference to weathering

“…However, the frictional resistance of rock joints itself is influenced by a number of factors such as magnitude of normal stress, joint roughness coefficient, joint compressive strength, weathering state of discontinuity, shearing rate, scale effect, degree of saturation, nature and thickness of infill material and so on [1]. Over the several decades, a number of research works were carried out in order to study the influence of individual factor or multiple factors controlling shear behavior considering fabricated surfaces made up of POP or cement, mimicked joint planes as well as natural joints by several researchers [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. However, the influence of weathering on the shear strength/frictional resistance of natural unfilled joints does not seem to have been much explored.…”