# VTU B.E Mining Drilling and Blasting Engineering 2015 Question Paper

VTU Question Paper
Department of Mining
B.E. Degree Examination
Fourth Semester
Drilling and Blasting Engineering
June / July 2015 Question Paper
Max. Marks:100
Time: 3 Hours

Fourth Semester B.E. Degree Examination, June/July 2015
Drilling and Blasting Engineering
Time: 3 hrs. Max. Marks: 100
Note: Answer any FIVEfull questions, selecting
atleast TWO questions from each part.
1
PART-A
a. Detail discussion on principle ofrock drilling (Rotary and percussive). (10 Marks)
b. Calculate the rotary power of the drill. If the rotation speed of the drill is 300 rpm torque is 20 lb/ft, diameter of the drill hole is 13Smm and pull down force is SkN. Find the constant 'K' of rock formation. (10 Marks)
2 a. Explain the types of thrust, feed and rotation mechanism. (10 Marks)
b. Explain the causes of alignment and deviation in drilling. (10 Marks)
3 a. Explain the testing of permitted explosives and break gallery test. (10 Marks)
b. Explain general test procedure of explosive. (10 Marks)
4 a. Explain the types of detonators and its uses. (10 Marks)
b. Explain the types of exploders and its functions. (10 Marks)

PART-B
a. In an underground coal mine, during shot firing, a detonator fails to explode. What is the reason, how will you handle the situation? (10 Marks)
b. Difference between:
i) Misfire and hangfire
ii) Blown out shot and blown through shot. (10 Marks)
6 a. Explain the importance and construction of magazine, discuss about storage of explosive. (10 Marks)
b. Explain pulse infused shot frring. (10 Marks)
7 a. Explain rock breakage mechanism. (10 Marks)
b. If the length of the hole is 12m, spacing is 3m and burden is 2m, and specific gravity is 3 t/m^3, the charge per hole is 30kg. Determine the powder factor and charge factor. (10 Marks)
8 a. Discuss about controlled blasting methods/techniques.
b. Explain the causes and remedies of ground vibration and flu rock.

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