CAN ANY BODE GIVE THE SOLUTION OF QUESTION OF FIRST CLASS MINE MANAGER CERTIFICATE COAL 2013
Q4. A coal seam, 3 m thick dipping at 1 in 7 towards S 23°15' E was being developed by bard and
pillar method at a depth of 250 m deploying LHDs directly loading on to belts. Pillars were
45 m x 45 m centre to centre developed along strike and dip, with galleries of 4.8 mx 3.0 m
cross section. The immediate roof is shaley sand stone having adjusted RMR as 32. Full
column resin grouted roof bolts of 1.8 m in length were being used to support the roof as
per the designed SSR, keeping factor of safety as 2. Deteriorations in roof were noticed e.g.,
crushing, bulging, deformation, etc., in bearing plate and also slipping of nuts of roof bolt
even after 5 m of progress in development gallery. After a scientific investigation it was
found that direction of horizontal stress was S 43°25' E and is 1.86 times higher than vertical
stress. Suggest methods to improve the roof condition to continue development of the
seam in safe manner.
pillar method at a depth of 250 m deploying LHDs directly loading on to belts. Pillars were
45 m x 45 m centre to centre developed along strike and dip, with galleries of 4.8 mx 3.0 m
cross section. The immediate roof is shaley sand stone having adjusted RMR as 32. Full
column resin grouted roof bolts of 1.8 m in length were being used to support the roof as
per the designed SSR, keeping factor of safety as 2. Deteriorations in roof were noticed e.g.,
crushing, bulging, deformation, etc., in bearing plate and also slipping of nuts of roof bolt
even after 5 m of progress in development gallery. After a scientific investigation it was
found that direction of horizontal stress was S 43°25' E and is 1.86 times higher than vertical
stress. Suggest methods to improve the roof condition to continue development of the
seam in safe manner.
NUTAN PRAKASH
Sr. Officer Mining
N.C.P.H. Old Mines
Chirimiri Area
S.E.C.L.
Sr. Officer Mining
N.C.P.H. Old Mines
Chirimiri Area
S.E.C.L.
__._,_.___
Posted by: NUTAN PRAKASH <nutan_prakash786@yahoo.co.in>
| Reply via web post | • | Reply to sender | • | Reply to group | • | Start a New Topic | • | Messages in this topic (6) |
_________________________________________________________________
Directorate General of Mines Safety, Ministry of Labour & Employment, Govt. of India
Websites: http://www.dgms.net and http://www.dgmsindia.in and http://www.dgms.gov.in
--------------------------------------------------------------------------------------------------------
If for any reason you wish to unsubscribe from DGMS Mailing List, send an email to:
dgms_mail_list-unsubscribe@yahoogroups.com
Directorate General of Mines Safety, Ministry of Labour & Employment, Govt. of India
Websites: http://www.dgms.net and http://www.dgmsindia.in and http://www.dgms.gov.in
--------------------------------------------------------------------------------------------------------
If for any reason you wish to unsubscribe from DGMS Mailing List, send an email to:
dgms_mail_list-unsubscribe@yahoogroups.com
.
__,_._,___
0 comments:
Post a Comment