Multi-approach back-analysis of a roof bed collapse in a mining room excavated in stratified rock

Factors predictive of roof instability in addition to the existing CMRR criteria at two case study coal mines

“…In a more mathematical approach, Alejano et al (2008) used different back analysis approaches to better understand the causes of a roof bed failure in an underground mine and to define the most significant parameters affecting the failure.…”

“…Discrete element method codes such as UDEC can also be used to solve the Voussoir beam problem numerically (Alejano et al, 2008 Although their study focused only on intersection stability and not the mine roof as a whole, LaPointe and Clark (2015) also looked at common data mining techniques such as multivariate linear regression, multinomial logistic regression, decision trees and probabilistic neural nets as possible methods to establish correlation between stability and the other variables they examined. They found decision trees and multinomial logistic regression to be the most successful and showed that several factors impacted intersection stability, including overburden thickness, initial opening area and intersection type.…”

“…However, the geomechanical parameters of the rock and discontinuities input need to be realistic for the model to give worthwhile results. For this reason,Alejano et al (2008) recommend a combination of analytical methods and numerical methods Sherizadeh and Kulatilake (2016). also used the discrete element method to assess roof stability in a room and pillar coal mine in Pennsylvania.…”

Analytical approaches for studying the stability of laminated roof strata

“…As mentioned previously, the stress distribution at the crosscut joint is triangular. The maximum stress, s m , at the abutment is calculated by Alejano et al 23 suggested the crushing strength of a beam is approximately 50% of the uniaxial compressive strength of the rock, i.e. r ¼0.5.…”

DEM modelling of a jointed rock beam with emphasis on interface properties

“…To account for the influence of jointing more directly, several investigators have used discontinuum analysis (i.e. the DEM or discontinuous deformation analysis (DDA) (Hatzor & Benary, 1998;Tsesarsky & Hatzor, 2006;Tsesarsky & Talesnick, 2007;Alejano et al, 2008;Bakun-Mazor et al, 2009;Barla et al, 2010;Hatzor et al, 2010) but, until now, these studies have been limited to simple contact models between rock joints. Talesnick et al (2007) measured the horizontal thrust and the vertical deflection of a voussoir beam subject to increasing levels of gravitational acceleration.…”