Which of the following is not considered in Bieniawski's geo-mechanics classification?
Select an option to see the answer and solution.
Mining Engineering · all questionsRock Mechanics and Roof Supporting
Rock Mechanics and Roof Supporting
practice.
Practice every MCQ with options. Use Show answers when you want the correct option and solution.
56
Questions
1/3
Page
Pick an option on a question to see the right answer and solution.
What is the expected range of LBC of a 2.5 m long, 15 cm diameter timber prop?
Select an option to see the answer and solution.
Which of the following test may be used to provide an indirect estimate of uniaxial compressive strength?
Select an option to see the answer and solution.
A piece of coal sample weighs 10 kg in air and 2 kg when immersed in water. The specific gravity of the coal sample is
Select an option to see the answer and solution.
A dry rock sample of diameter 50 mm and length 100 mm weighs 300 g. After saturating in brine solution of specific gravity 1.05, its weight increased to 330g. The porosity of the rock sample in percentage is
Select an option to see the answer and solution.
A core of 10 cm height and 5.4 cm diameter is subjected to diametrical point loading. The ram of the hydraulic jack has a cross sectional area of 12.5 cm2 and the dial gauge reading is 3 MPa. What is the point load strength?
Select an option to see the answer and solution.
The grain density and bulk density of a dry coarse gained sandstone rock sample are 3.0 gm/cc and 2.7 gm/cc respectively. The void ratio of the sample in percentage is
Select an option to see the answer and solution.
Objectives of roof supporting in underground is
Select an option to see the answer and solution.
During setting of supports in underground, a lid is used over the prop. The length of such lid shall not be less than
Select an option to see the answer and solution.
Which of the following diagram can represent one aspect of bi-axial stress acting on a point with respect to a set of reference axes?
Select an option to see the answer and solution.
The rock mass classification system that considers 'active stress' factor is
Select an option to see the answer and solution.
The rock specimen obtained from the overlying strata in a coal mine were tested in uni-axial compression and the following results were obtained at 50% of average compressive strength
Longitudinal strain = 0.06 and Lateral strain = 0.012
The ratio of vertical to horizontal stress in the mine is
Longitudinal strain = 0.06 and Lateral strain = 0.012
The ratio of vertical to horizontal stress in the mine is
Select an option to see the answer and solution.
A rock specimen of average thickness 0.8 cm failed at an applied load of 1000 kg during determination of shear strength by the punch test. The diameter of the punch is 2.8 cm, The shear strength of the rock specimen in kg/ cm2 is
Select an option to see the answer and solution.
Rock mass parameters for a shale rock, mb, s, and a of the Hoek and Brown failure criterion as given in the equation are 2.4, 0.01 and 0.52 respectively. The uni-axial compressive strength (σCi) of intact sh!le is 50 MPa.
The global rock mass strength of shale in MPa is
The global rock mass strength of shale in MPa is
Select an option to see the answer and solution.
Below mentioned are some features or cases of roof bolting. Identify one of such case where use of roof bolting may be ineffective?
Select an option to see the answer and solution.
From the stress-strain diagram shown below, the tangent and the secant moduli of elasticity in GPa are
Select an option to see the answer and solution.
The grain size distribution of soil is known as
Select an option to see the answer and solution.
Chimney caving involves the progressive migration of an unsupported mining activity and the sudden mode of formation rather than progressive one is known as
Select an option to see the answer and solution.
Name the diagram where the strikes of discontinuities are oriented at about 5° interval?
Select an option to see the answer and solution.
In the Mohr's scale of hardness, the minerals in increasing sequence of hardness are
Select an option to see the answer and solution.