Rock bolts have been widely used as rock reinforcing members in underground coal mine roadways and tunnels. Failures of rock bolts occur as a result of overloading, corrosion, seismic burst and bad grouting, leading to catastrophic economic and personnel losses. Monitoring the health condition of the rock bolts plays an important role in ensuring the safe operation of underground mines. This wo...

background:  the prevalence of obesity in the elderly is increasing worldwide. obesity greatly impacts quality of life(qol). the present study aimed to investigate the association between obesity and qol among the elderly, in tehran, iran. methods:  this cross-sectional study (observational) was conducted in 2014 in tehran, iran. a total of 421 elderly people aged ≥ 60 years old were recruited ...

Block volumes are generally estimated by analyzing the discontinuity spacing measurements obtained either from the scan lines placed over the rock exposures or the borehole cores. Discontinuity spacing measurements made at the Mesozoic limestone quarries in Karaburun Peninsula were used to estimate the average block volumes that could be produced from them using the suggested methods in the lit...

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...

Annotation In terms of mining and geological structure, ore deposits are complex-structured composed single, parallel-contiguous bodies. The reserves barren or inclusions with the useful component content less than cut-off grade deposit on whole make 5-12% for natural-rich ores, 10-15% natural-lean ores. Application conventional systems to areas underground reduces iron in mined mass by 3-6% re...

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...