The excavation damaged zone (EDZ) can be defined as a rock zone where the rock properties and conditions have been changed due to the processes related to an excavation. This zone affects the behavior of rock mass surrounding the construction that reduces the stability and safety factor and increase probability of failure of the structure. In this paper, a methodology was examined for computing...

The geomechanical classification SMR (Slope Mass Rating) enables the preliminary assessment of the susceptibility of rock slopes to failure. The SMR index is obtained from Bieniawski’s basic RMR (Rock Mass Rating) through an “adjustment factor” and an “excavation factor”. Since its appearance in 1985, this classification has been used for appraisals and preliminary studies in many countries. Th...

The in situ block size of the rock mass may be the single most important parameter influencing the stability and strength of some underground openings. Rock masses can often reasonably be characterized by a simple size-strength classification. The actual block size distribution is the product of the interaction between the joint orientation, spacing and persistence of that rock mass. Despite th...

Underground longwall mining of coal causes large scale disturbance of the surrounding rock mass. The disturbance can increase the rock mass permeability through a reduction on the stress as well as formation of new fractures in the rock. Methane gas contained in the disturbed rock mass can migrate towards the low pressure mine workings and present an explosion hazard. This paper describes the a...

Large volumes of naturally jointed Precambrian crystalline rock can be stably maintained at pressures considerably above the least principal earth stress in the surrounding rock mass. At Los Alamos National Laboratory’s Fenton Hill hot dry rock (HDR) geothermal test site, tests carried out for a cumulative period of 11 months in the deeper and larger of the two HDR reservoirs showed no evidence...