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Drilling and Blasting for Surface Excavations


Quiz Questions

1.Fig2-1 illustrates _____________.
Zones of fracturing and deformation around an explosion in rock
Combined Role of expanding gases
None of the above
2. A chemical explosive is a compound or a mixture of compounds which, when subjected to heat, impact, friction, or shock, undergoes very rapid, self-propagating, heat- producing decomposition.
Chemical explosive
Hydrogen Peroxide
Water
3.Important properties of explosives are weight strength, cartridge strength, detonation velocity, density, detonation pressure, water resistance, and fume class.
True
False
4.An electric blasting cap consists of two insulated leg wires inserted in an insulated metal capsule and connected by a thin-filament bridge tire as shown in page 40.
True
False
5.The ___________ as seen in Fig. 4-4 imparts two basic actions through the bit into the rock: axial thrust and torque.
Rotary drill
Rotary drag bit
None
6.A single wagon drill can drill from ________of hole in a 9-hr shift as seen in page54 in the course.
200 to 400 ft
150 to 300ft
None
7.Figure 4-14 represents _____________.
Rotary- percussive drill bit
Churn drill bit
None of the above
8.A basic coyote layout consists of a main adit driven perpendicular to the face with wing tunnels driven left and right at 90 deg as seen in page 70.
True
False
9.Rocks cannot be classified for blasting purposes according to their seismic velocity as seen in the rock types in page 84.
True
False
10.Fig. 6-5 represents ___________.
Variation of shear strength with inclination to schistosity
Effect of dipping strata on stability of excavation
None of the above
11.Damage to nearby surface structures, such as buildings, bridges, concrete foundations, etc can result from air blasts, ground vibrations, and fly rock.
True
False
12.The processes as discussed in pages 100 & 101 in Chapter7 talk about______________.
Airborne Vibrations and Air blasts
Ground Vibrations
None of the above Vibrations
13.The quantity (D/W1/2) in the general propagation relation for ground vibrations from blasting denotes ___________.
Scaled distance
Particle Velocity
14.The sample record of blasting is represented in figure___________.
Figure 8-1
Figure 8-2
Figure 7-1
15.Fig. 4-8 shows a _____________.
Wagon Drill
Churn Drill
Hammer Drill
16.Blasting gelatin is a rubber- textured explosive made by adding nitrocellulose (guncotton) to nitroglycerin.
True
False
17.Straight gelatin is a dense, plastic explosive consisting of nitroglycerin or other explosive oil gelatinized with Nitro cellulose, an antacid, sodium nitrate, carbonaceous fuel, and sometimes sulfur.
True
False
18.Advantages of insensitive dry blasting agents are their safety, ease of loading, and low price.
True
False
19.Slurries are also called water gels.
True
False
20.A primer is a cartridge of explosive used in conjunction with a cap or detonating fuse to initiate the detonation of a blasting agent.
True
False