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Pillars are key structural columns in underground mining. They are usually made of in situ intact ores and do not have additional reinforcements. Their main function is temporary or permanent support of ore ceiling of rooms during excavation and mining. Coal pillar strength is usually estimated according to empirical formulae obtained from field observations. Todays, numerical models have found increasing use in pillar design. The FLAC3D Software based Mohr-Coulomb Strain Softening (MCSS) failure criterion was use...

Ventilation networks in underground mines may be affected by items such as: locating of objects in air path or destruction of support systems which would result in pressure loss and distortion of air flow. By considering the necessity of keeping the network performances at appropriate level in such conditions, in this study, definition of ventilation network evaluation has been proposed which indicates the network reliability in an uncertain situation. Economic and safety concerns in mines involve this fact that t...

The First step in analysis of slope stability in open pit mines is punctual definition of rock mass characteristics. Several rock mass classification systems have been presented so far in the area of geomechanics. One of the most widely used rock mass classification systems are the geomechanics classification (RMR) by Bieniawiski. The RMR classification is based on the definition of classic membership functions. So characterization of rock masses and determination of their strength may involve some uncertainties d...

Characterization of rock masses is one of the fundamental aspects of rock engineering. Particularly, as a rock mass characteristic, determination of the strength of jointed rock masses is difficult since the size of representative specimens including discontinuities is too large for laboratory testing. This problem can be overcome by using the Hoek– Brown empirical failure criterion in conjunction with the Geological Strength Index (GSI) classification system. However, characterization of rock masses and determi...

Most of water resources in Iran are flowing in the west, south-west, north districts of country and, on the other hand, providing of water the central districts of Iran, for a long term, had been a critical problem to Iran water industry since long ago. Accordingly, many water transferring projects have been proposed between different zones to remove this problem. Transferring water from of Dez river to central districts of Iran is one of these projects that water transfer tunnel from Anvaj river to Qomrud is its ...

Mine ventilation has a key role to improving underground working conditions. Ventilation is required to clear dust, gas and toxic fumes from blasting and removing exhaust fumes from diesel equipments and also required for cooling the workplace for miners in deep hot mines. Ventilation systems need to take many possible modern mining scenarios into account, and costly infrastructure is needed to serve future ventilation and cooling requirements. To enable the practical and economical design of mine ventilation syst...

Coal is an important energy resource in world. Coal mine exploitation with nonmechanized methods, need expert labors and with out them, mining process will be deranged so the labors and their safety is really important. In many industrial countries the accidents are the most important cause of person’s death. According to I.L.O (International Labor Organization) reports 120,000,000 accidents occur per year and 210,000 people die in these accidents. It means more than 500 people per day. In order to decreasing th...

For opening of blocks No. 7 \& 8 of Golbini mine in Bauxite Jajarm region (Northern- Khorasan province, Iran) a tunnel is excavated with horse shoes shape with 800 m length. In this paper firstly, the tunnel section was modeled by FLAC2D software and secondly the stability analysis were studied. Then a composition of shotcrete and steel frame was offered. To reach an appropriate safety factor the shotcrete with 20 cm thickness which utilized with steel bars IPE-140, IPE-160 and IPE-180 established and amounts of s...

Methane drainage and utilization can be a profitable activity for gassy underground coal mines, also it protects our environment by decreasing “greenhouse” gases. One of the key parameters for methane drainage is permeability of coal. The flow of gas and water through coal samples was studied to investigate its permeability to methane and water. A relationship was found between the coal permeability to methane, and its permeability to water. As the measurements of permeability should be in-situ representative,...