Ground Control - Geomechanics and Ground Control - Mining Engineering Previous Year Questions

The phenomenon of fretting (necking) of pillars in room-and-pillar stoping is common in the pillars formed in

In a longwall mining subsidence phenomenon, the “angle of break” is the angle between

In an underground coal mine, a freshly exposed roof can be supported by a temporary support in the form of

The angle of draw in a trough subsidence helps in determining the

At equilibrium, the thickness of the roof layer supported by the bolt in m is

The roof bolt that follows the principle of point anchorage is

Given S is the setting load and Y is the yield load of a hydraulic prop, the correct relationship is

Massive sandstone in immediate roof delays the local fall in goaf of a coal mine. Under this condition, crushing of the pillars at outbye side is called

The support system followed along the goaf edge in a depillaring panel is

Which one of the following ropes CANNOT be an effective cable bolt?

Exposure of weak roof in junctions of a development district in a coal mine can be decreased by

A coal seam lying at a depth of 200 m is developed by bord and pillar method. Pillars are 30 m centre to centre with a gallery width of 4 m. Unit weight of the overlying strata is 28 kN/m3. If the pillar strength is 9.32 MPa, the factor of safety of pillar is __________.