1. STRESS MAPPING FOR
RE- ORIENTATION OF GALLERIES IN
PVK-5 Incl.
Dr.D.N.SHARMA
Dy.General Manager(Geo)
Exploration Division / RG1
• In PVK mine, King Seam workings reached 400m depth.
• Thickness of the King Seam in the study area is about 6.50m with a
gradient of 1 in 8.
• King seam was developed in the Top Section upto 116 Level, with
Sandstone as immediate roof.
• Since there is a problem with sever seepage of water along sandstone
roof , an attempt was made to leave about 3.50m seam portion in the roof.
• In the changed working section, another problem of severe roof
failures in Level galleries cropped out.
1. PROBLEMS IN KING SEAM

2. 2. STRESS MAPPING IN QUEEN SEAM
With a similar problem in overlying Queen Seam workings that is beyond 110
Level at a depth of 350m, Stress mapping was carried out, during June
2004. The inferences of those studies were-
The Major Principal Stress axis inferred from most prominent
Joint set (J1) is perpendicular to Level galleries are contributing
for instability of level galleries.
Minor Principal Stress axis inferred from least prominent Joint
set (J3) is parallel to level galleries.
Conversely, Dip galleries are stable as they are almost (with
about 5 degrees) parallel to the Major Principal Stress axis.
Further, these findings were closely matching with that of
Stress Orientation established earlier in the Queen Seam of
adjacent VK-7 Shaft through similar Stress Mapping technique.

3. CONTOUR DIAGRAM OF JOINTS PLOTTED ON
EQUAL AREA PROJECTION,LOWER HEMISPHERE,
QUEEN SEAM (100 JOINT POLES)
DIRECTION OF STRAIN ELLIPSOID
DEVELOPED IN QUEEN SEAM

4. 3. STRESS MAPPING IN KING SEAM
1. Stress mapping is carried out in the present study area in King Seam.
2. The workings crossed 400 m. depth line and approaching the F16 Fault
(throw 20m) in the dip side property.
3. The details of structural features mapped are as follows -
SL.NO STRUCTURAL FEATURE NO.OF READINGS. MEAN TREND
1 FACE CLEAT
140
N550E
2 BUTT CLEAT N350W
3 MOST PROMINENT SLIPS
40
N450 E
4 LEAST PROMINENT SLIPS N650E
5 MOST PROMINENT JOINTS
27
N550E
6 LEAST PROMINENT JOINTS N650E
3. STRESS MAPPING IN KING SEAM
Contd…
4. The causative factors of unstable roof conditions are due to :
• The most prominent Slips S1 aligned to the greatest principal
stress direction (N450E) is responsible for the roof instability
confined to level galleries.
• Roof strata consists of thin layers and leading to failure in level
galleries with an indication of "Gutter roof". Trend of the "Gutter
roof" ,largely helped to confirm the orientation of principal stress in
the study area.
• As workings are enveloped by Faults, sympathetic slips developed
and contributed for unstable roof conditions.
• These findings are closely matching with that of Stress Orientation
established in the overlying Queen Seam.

5. FACE AND BUTT CLEAT

6. SLIP IN THE PILLAR SHOWING
DISPLACEMENT OF BANDS
J1 JOINT EXPOSED IN THE FLOOR

7. 4. ROCK MASS RATING (RMR)
RMR classified the roof of working section of King Seam (Bottom
Section) as "FAIR“ with a rating of 41, where 40 is border of “Poor”
and “Fair” rock.

8. “ROOF GUTTERING” IN THE CENTER OF LEVEL GALLERY BEFORE
RE-ORIENTATION
5. NUMERICAL MODELLING BY CIMFR
Numerical modelling was taken up by CIMFR and the following conclusions
and recommendations are made:
1. The magnitude of major and minor in situ horizontal stresses in King
seam in the study area are found to be 7.15 Mpa and 3.68 Mpa
respectively.
2. The direction of the major in situ horizontal stress is found to be along
N 450 E , which is almost perpendicular to the level galleries.
3. Keeping the above directions and magnitude of in situ horizontal
stresses in view, level gallery can be driven along N 850 E to
E 50 S (with a stress point of view).

9. 6. ORIENTATION OF GALLERIES
REFERENCE TO PRINCIPAL STRESS
N
N7°E
N10°E
N24°E
N
55°
E
N 69° E
N
62° W
N
4
7°
W
F5
RE-ORIENTED-1DG
F18
F10
&
J1
&
FC
F9
F16
RE-ORIENTED-1.LG
S1
N
45°
E
N 65° E
S2 & J2
N
35°
W
BC
N 73° E
ORIGINAL DG
N24°W
ORIGINALLG
INDEX
N
45°
W
1
N5°WRE-ORIENTED-2DG
N85°E
RE-ORIENTED-2. LG
S1 MOST PROMINENT SLIP
J1 MOST PROMINENT JOINT
S2- NEXT PROMINENT SLIP
J2 NEXT PROMINENT JOINT
FC- FACE CLEAT
BC-BUTT CLEAT
1- MAJOR PRINCIPAL STRESS
3- MINOR PRINCIPAL STRESS RE-ORIENTED-1 DIP GALLERY
RE-ORIENTED-1.LEVEL GALLERY
ORIGINAL DIP GALLERY
ORIGINAL LEVEL GALLERY
RE-ORIENTED-2 DIP GALLERY
RE-ORIENTED-2. LAVEL GALLERY
EW
3
N/55
N/49
N/46
N/48
N/51
N/46A
N/50
N/29
1IN
5.19
TS
TO
KS
108L
96L
15D
11D
7D
4D
1D
85L
90L
533
.50
55
8.20
527.5
0
543.
45
55
2.06
54
9.5
5
569.3
0
569.
60
N/30
N/47
85L
82L
MID
MWD
88L
TO KS/TS
1 IN 10
LEVELDRIFT
LEVELDRIFT
LEVELDRIFT
1IN6
1IN10
1IN10
1IN10
1 IN 10
1 IN 10
1 IN 6.7
1IN10
2.4M
0.5M
3.2M
0.7M
0.3M
0.2M
1.2M
502.
87
0.8M
1.3M
23D
4M
3.8M
1.2M
25D
27D
30D
92L
578.4
7
F.K.S...... 447.69(5.20)
55
7.40
485
.36
535.98
56
5.5
0
20D
20D
22D
97L
95L
L.T.LINE
HAULER ROOM
SURFACE
150 HP
816.13
816.03
B.M...816.54 M
OFFICE
No 5B INCLINE
11D
7D
T O KS/TS
1 IN 10
TO KS/TS
1 IN 10
TO KS/TS
1 IN 10
1IN4
1IN5
MID
MWD
5B AIR SHAFT
110L
25D
23D
21D
20D
1IN5.19
TSTOKS
512.4
90
DIA: 6.5M
1.2M
3.2M
3
2A
2
33K.V.TR
ANSMISSIONLINE
60
m
B
ARRIE
R
60m
BAR RIER
60
m
BARR
IE
R
60mBAR
RIE
R
1 .20M
3.20M
501.5
95
0.60M
48
2.
49
487
.4
4
483.2
0
508
.0
8
495.5
3
49
4.
44
DEPTH :292M
PVK SHAFT
F1
0
F1
0
D/H
16D
12D
112L BELT LEVEL
48
7.
04
10D
9D
S/22
47
2.
29
0.4
0.250.35
0.1
0.2
2.0
0.1M
0.25M
47
1.7447
3.
08
8D
47
2.
64
80
0.34
803.06
805.16
810.05
T E L L A V A G U
807
.68 HFL
803.72
805.0
0
HFL
HF
LWITHINTH
ENALLAH
T E L L A V A G U
796.6
0
797.2
7
798.0
5
DIVERTED
6D
4D
2D
0R
115L
48
2.52
48
8.
07
47
9.
69
48
8.
28
49
2.64
46
4.
08
5
46
2.
94
46
2.
40
45
8.
77
50
0.
68
6
UG B.H.
TO K.S.
N82°W
N8°E
S5°E
S85°W
N
0 200
43D
45D
116CXCUT
412.53
3
41
9.19
3
404.65
3
40
0.38
8
39
8.57
3
41
5.898
533.339
536.670
539.870
543.450
546.280
543.53
537.45
540.57
530.879
534.18
537.37
540.52
534.00
530.83
528.26
5D
3D
552.03
555.10
551.65
550.44
548.34
546.03
549.12
542.67
544.78
546.92
554.30
540.62
538.53
535.85
532.0
548.42
544.86
42
2.05
42
6.84
42
0.55
41
3.39
415.19
40
9.25
404.69
42
6.55
JH
GH
GH
47D
49D
43
0.83
5
42
4.33
5
41
8.50
5
40
8.26
5
42
0.03
5
42
8.27
558.55
560.35
556.85
558.84
554.17
549.535
552.38
544.145
542.42
536.285
538.825
38D
521.984
12D
9D
517.534
519.614
510.674516.579
513.749
40
5.59
6
1.8m
526.869
524.914
518.859
42
4.11
403.15
6
41
0.266
533.339
523.924
524.984
7D
40D
38D
116BXCUT
GH
B. H. No..A/326
F.K.S...... 541.60(5.35)
DEPTH....310.00
28D
GH
GH
GH
506.53
504.38
488.75
473.67
51
2.
83
8
50
9.
58
8
51
3.
04
3
52
4.31
8
51
9.
08
8
52
2.63
51
1.
65
6
50
4.
93
6
502.09
505.899
497.899
494.804
483.759
BE
LT
RO
AD
434.
00
41
9.
61
396
.9
6
401.4
2
39
6.5
4
405
.7
2
39
4.0
39
4.36
39
1.43
48
9.
23
48
1.
04
49
0.5
9
46
6.
75
45
7.
26
45
4.61
47
5.
92
22D
3.5m
410
.4
1
41
8.3
3
393.3
4
39
5.
87
3.5m
4.5m
4.5m
49
4.8849
5.
53
24D
26D
23D
24D
26D
28D
30D
32D
34D
36D
GH
452.72
459.66
457.95
458.29
1.6
2
0.7
0.8 1.20.6
0.4
0.8
0.7
0.6
2
2
UG B.H.
TO K.S.
50
1.
32
49
4.
99
471.03
469.04
467.46
452.21
107L
48
8.4
1
0.8
0.8
0.7
0.7
441
.9
7
435
.9
4431
.6
9
424
.8
0
42
0.2
3
JHw
96L
0.6
0.4
B. H. No..A/324
S.L.... .....802.21
DEPTH....365.00
DIA.. ......10CM
F.K.S...... 444.71(7.70)
484.50
478.48
487.26
461.73
460.4
1
458.0
5449
.4
7
506
.5
3
49
4.
66
6.5m
PANEL No.S-21
1.4m
1.4m
0.5m
0.5m
0.2M
0.3M
0.3M
0.45M
12D
16DN
18D
20D
119L
15D
16DS
BELT LEVEL
BELT
DIP
BELTDIP
407.2
9
436
.2
8
40
3.95
40
8.18
41
5.50
41
2.01
1m
120L
120L
120L
22D
GH
GH
GH
GH
GH
GH
HAULAGE
DIP
HAULA
GE
DIP
39
4.59
39
9.34
40
4.46
39
7.7 39
7.69
403.4
8
404.5
1
41
3.
67
425
.0
943
1.
97
43
7.
97
447.4
8
400
.5
403.5
3
400.
92
122L
GH
GH
122L
16BD
1.6m
2m
1.6m
16DN
16AD
18D
19D
94L
91L
5D
3D
1D
MID
122L
123L
39
7.36
39
5.55
39
2.38
40
0.
47
403.7
9
410.5
1
1m
1m
1.6m
D/H
E/H
D/H
13D
EH
END LESS HAULAGE
END LESS HAULAGE
J/H
123L
392.62
2.5m
39
4.1
8
400.4
7
395.6
8
408.5
1
410
.2
3
417
.7
1423.
33
428
.3
5
47
4.
68
47
8.
52
46
3.10
463
.35
44
9.23
43
9.2
0
527.
47
474
.7
6
465
.3
7
3
2A
2
3
2A
2
B.H. No..A/342
FKS-382.10
BOUNDARY
3
2A
2
FKS-....429.39
B.H. No..A/306
P BORE HOLE
DEPTH....240
DIA........10CM
B.H. No. .A/320
DEPTH....310.00
F.K.S......516.23(5.35)
B. H. No..A/323
DEPTH.. ..367. 00
F .K.S......449.25(6.80)
B.H. No..A/286
DEPTH..365.93
F.K.S.... 448.68(6.86)
B.H. No.. A/285
DEPTH....407.55
F.K.S...... 403.80(5.45)
B.H. No..KSB-7
DEPTH....431.92
F.K.S......409.61(6. 05)
B.H. No.. A/311A
DEPTH....375.00
B.H. No.. A/316
DEPTH....435.00
F.K.S......383.44(5.60)
B.H
. No..A/11
5
DEPTH
....396.2
4
F.K
.S......52
0.6
5(5
.37
)
B.H. No. .KSB-5
DEPTH....339.38
B.H. No.. A/119
DEPTH....262.1
B.H. No..KSB-14
S.L.... .....804.07
DEPTH....153M
DIA.. ......10CM
B.H. No..A/319
DEPTH....236
B.H. No..A/338
DEPTH....216.50
B.H. No..A/337
DEPTH....216.50
B.H. No..A/336
DEPTH.... 213.00
B.H. No.. A174
B.H. No.. A178
B.H. No.. A175
DEPTH....159.50
B.H. No.. A157
DEPTH....161.85
DIA...... .....15CM
DEPTH....115.06
NO 1 ... 727.44 (19.58)
S.L........ ....798.84
DIA...........15CM
DEPTH....65.68
NO 1SEAM ...780.210 (13.72)
S.L.. ..........803.070
B.H. No. . A183
DEPTH....56.80
B.H. No.. A118
DEPTH.... 169.840
B.H. No.. A185
DEPTH....53.03
B.H. No.. A/313
DEPTH.... 420.00
F.K.S......391.85(5.90)
B.H. No..A/350 (MPBX)
DEPTH....285.00
B.H. No..A/340
46
2.
39
44
7.36
439
.5
7
442.98
454
.2
6
52
5.5
5
430
.9
44
44
1.1
2
42
9.12
43
4.18
3
44
7.
97
45
3.64
3M
2M
0.8
M
115L
117L
115L
117L
41
9.07
417.23
42
2.
71
426.2
3
454
.9
2
443
.6
0
434
.6
8
41
6.
36
119L
417.2
3
412
.2
5
1.4m
1.2m0.4M
0.4 1m
1.4m
1.4m 0.5m
0.65m
0.6m
0.8m
562.13
563.38
559.72
539.48
541.26
563.658
561.313
565.412
567.242
567.102
562.972
558.625
554.563
549.663
547.228
550.298
555.503
570.537
566.498
545.818
113L
42
3.03
1
43
1.35
1
42
7.74
6
421.03
6
42
4.486
41
6.91141
9.021
PANEL STD. ON 20-05-11

10. STABLE ROOF IN THE LEVEL GALLERY AFTER RE ORIENTATION
7. SUMMARY AND CONCLUSIONS
1. PHYSICAL MAPPING LARGELY HELPED TO DERIVE STRESS
ORIENTATION IN THE STUDY AREA TO BE N450E.
2. THE DATA IS VALIDATED WITH THAT OF OVERLYING QUEEN
SEAM AS WELL AS ADJACENT BLOCK i.e. VK-7 SHAFT.
3. FURTHER IT IS VALIDATED WITH NUMERICAL MODELLING DATA.
4. FINDINGS OF ALL THE ABOVE STUDIES ARE IN GOOD
AGREEMENT WITH EACH OTHER.
5. BASED ON THE RECOMMANDATIONS (to drive Level Galleries in
N850E) OF ABOVE STUDIES, STABLE ROOF CONDITIONS COULD
BE ESTABLISHED.
******