Rock Mechanics Questions and Answers - 1

1. what is the name of associated support installing system with continuous miner

1. plough
2. quad bolter
3. drop war wick
4. tugger

2. cross bars or Safari supports are set on the side clamps made in both side walls and the minimum depth of such holes is given by

1. 20 cm
2. 30 cm
3. 40 cm
4. 50 cm

3. on receiving approved SSR which of the following is the main duty of colliery manager

1. send a copy to DMS
2. send a copy to DM
3. handover copy to supervisory officials and assistant manager
4. give a copy to area safety officer

4. minimum length of cogging sleepers that is used as members of cog is

1. 0.6 m
2. 1.2 m
3. 1.8 m
4. 2.4 m

5. after every round of blasting, support of roof and sides shall be tested at places in the zone of influence of blasting. who decides the zone

1. overman
2. assistant manager (blasting)
3. colliery manager
4. agent

6. as per DGMS circular 7/2002 which out of the following shall be responsible to assess the requirements of support in underground

1. overman
2. mining sirdar
3. shotfirer
4. colliery manager

7. in order to maintain support performance what minimum percentage of installed bolts shall be subjected to Anchorage testing randomly

1. 4%
2. 6%
3. 8%
4. 10%

8. what is the minimum length of roof bolt used in underground coal mine?

1. 1/2 of the width of roadway
2. 1/3rd of the width of roadway
3. equal to the width of roadway
4. double the width of roadway

9. the minimum Anchorage strength of bolt after 30 minutes and 2 hours of setting shall be

1. 1 ton and 2 ton
2. 2 ton and 3 ton
3. 3 ton and 4 ton
4. 3 ton and 5 ton

10. As per guidelines given in support plan the bolting density at junction should be increased by

1. 15%
2. 20%
3. 25%
4. 40%