Download GTU (Gujarat Technological University) BE/BTech (Bachelor of Engineering / Bachelor of Technology) 2019 Winter 7th Sem New 2172207 Rock Fragmentation Previous Question Paper
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ? VII (New) EXAMINATION ? WINTER 2019
Subject Code: 2172207 Date: 30/11/2019
Subject Name: Rock Fragmentation
Time: 10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
MARKS
Q.1 (a) Explain the purpose of drilling & factors influencing the selection of drill machine. 03
(b) Discuss the type of drilling methods based on their principle of working. 04
(c) Define drillability and explain the four phases of rock breakage during percussive
drilling.
07
Q.2 (a) Write a note on ANFO explosive. 03
(b) Explain the principle of operation of jack hammer drill used in underground coal
mining.
04
(c) Define explosive & its basic composition. Briefly explain the properties of explosive. 07
OR
(c) Explain different types of drill bits used in drilling with neat sketch.
07
Q.3 (a) Differentiate between low explosive & high explosive with suitable examples. 03
(b) Write a note on down the hole hammer drill machine. 04
(c) A project in granite rock will have an average bench height of 20 feet. An explosive
having a specific gravity of 1.2 has been proposed. A drill machine can easily drill 3.0
inch diameter of holes. Assume diameter of explosive will be 2.5 inch and delay
blasting technique will be used. Develop a blast design for the project. Take specific
gravity of granite is 2.8.
07
OR
Q.3 (a) What do you mean by safety fuse and detonating fuse? 03
(b) Differentiate between the term slurry explosive and emulsion explosive. 04
(c) What are the blast design parameters? Explain briefly.
07
Q.4 (a) Explain permitted explosive and its type 03
(b) What are electric and non-electric methods of blasting system? 04
(c) Write note on Hydraulic Drilling and Long Hole Drilling. 07
OR
Q.4 (a) Write a note on wagon drill machine. 03
(b) Explain delay detonator and its type with neat sketches. 04
(c) What do you mean by powder factor?
Calculate the powder factor, if the bench height is 6.5 m, subgrade drilling is 0.3 m,
stemming height is 1.5 m, burden is 2 m and spacing is 3 m. Take specific gravity of
explosive is 1.2 and loading rate of explosive per meter is 7.5 kg.
07
Q.5 (a) What do you mean by boring in rocks? 03
(b) Write the advantage and disadvantage of delay blasting technique. 04
(c) Explain the recent developments in explosive and blasting techniques. 07
OR
Q.5 (a) Write a short note on nuclear blasting. 03
(b) Explain novel methods of drilling. 04
(c) What is ground vibration and air blast? Explain its causes and impacts. 07
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This post was last modified on 20 February 2020