Submitted By

Nandan Kumar
2011MT0134

Co Guided by
Er. R. D. Dwivedi
Principal Scientist
CSRI-CIMFR
,Regional Centre,

Gu...
Objective
Study of Classification of Rock Mass according to




Q- values
RMR values
GSI values

Calculation of drill...
Outline Of Project
 Literature survey
 Site Selection

 Design of Experiment

 Field work and Data collection
 Data A...
Literature Survey
 Drill Blast Tunnelling Method
 The Himalayan Tunnelling

 Rock Mass Classification System

 Bieniaw...
ROCK MASS RATING:

 RMR value : It is the geo mechanical classification developed by

Bieniawski (1973)
 For application...
The rating of six parameters of the
RMR system
PARAMETER
Intact Rock UCS(MPa)
Rating

Assessment of values and Rating
>250...
Rock Tunnelling Quality Index, Q

 RQD   Jr   Jw 
Q
 

 Jn   Ja   SRF 

Where
 RQD = Rock Quality De...
GSI
 Hoek and Brown(1997) introduced the GSI both for hard and weak

rock masses
 It is based on visual inspection of ge...
GSI SHEET
Drill blast cycle
STEPS

Unit Operation Time

1
2

Face mapping, Profile making
Face Drilling

3
4
5

Blasting
Supporting
...
Drill – Blast Cycle
Project Overview
• Construction of a two lane 9km main

tunnel and parallel one lane escape tunnel,
involving major slope ...
Chenani Nashri Tunnel Project,
J&K
North Portal

South Portal
Geometrical & Functional characteristics of CHENANI
NASHARI Tunnel
Tunnel Name

Chenani-Nashri

Length

Approx.9000m

Type...
Typical cross section of Escape
Tunnel
Typical cross section of
MainTunnel
NATM(New austrian tunneling method)

 NATM is not a method of tunneling but a strategy for

tunneling which does have a c...
Correlation among rock class description as per
NATM
and behavioural categories as per Geodata
Engineering approach
Rock c...
Drilling Time Data
Boomer XE3 C : Used at Main Tunnel
Drilling time : 70 Minutes ( Hole Depth : 2.5M ) Rock
Class : B2
Dri...
Drill Pattern

Escape Tunnel

Main
Tunnel
Jumbo
BLASTING PATTERN PARAMETER
MAIN
TUNNEL(TOP
HEADING)

ESCAPE
TUNNEL

Contour

30

22

Stoping

38

26

Cut

18

16+2(large ...
Blasting Pattern in
Main Tunnel
Blasting Pattern in Escape Tunnel
Data collection
 Under this project data has been collected from

Chenani

Nashri Road Tunnel, Jammu
 It includes data r...
Representation of Cycle Time
Main Tunnel

SCALING
11%

Escape Tunnel

GM
4%

SCALING
11%

GM
4%

GM
SUPP
MUCK
18%

GM
SUPP...
Drill Blast Cycle Time
PULL
(M)

Geo
Mapping
(Min)

SUPP.
Time
(Min)

PROF
Making
(Min)

Drilling
Time
(Min)

Charging
Tim...
Lithological Distribution of Rock Type in
Main Tunnel
Clayey
siltstone,
sandstone and
sandy siltstone
38%

Sandstone,
clay...
Lithological Distribution of Rock Type in
Escape Tunnel
Sandstone and clayey
siltstone
9%

Sandstone
9%

Siltstone
11%

Si...
FACE GEOTEC HNICAL DESCRIPTION
ESCAPE TUNNEL
FACE

GEOTECHNICAL DESCRIPTION
Main Tunnel
Rock mass quality
FROM

TO

Q-Value

RMR

GSI

RQD

STRENGTH

1389.50

1392.50

1.015

47

42

45.7

48

1392.50

1395.10
...
5
4.5
4
3.5
3
2.5
2
1.5
1
0.5
0

Chainage no. vs RMR
Values

Rock mass Quality in Main
tunnel

60

50

40

30

20

10

0

...
GSI Values in Main
Tunnel
50
45
40
35
30
25
20
15
10
5
0

Rock Mass
Quality

Q Values

Range

0.52 to 2.6
42 to 51

GSI Va...
Chainage No vs Q values

4

3.5

3

2.5

2
30

1.5

1

0.5

0
2164.6
2191.5
2219.5
2244
2372.70
2408.20
2440.80
2491.5
253...
Chainage No. Vs GSI
values

Range

60

Rock Mass
Quality

50

Q Values

1.90 to 4.13

RMR Values

47 to 53

GSI Values

42...
Correlation of data (Main
Tunnel)
 Correlation between

6.6
y = -0.3841Q2 + 1.48 Q + 4.73
R² = 0.44

Cycle time and Q-val...
Main Tunnel

 Correlation between

7
CT0.33 = -0.0182(RMR)2 + 1.84(RMR) - 39.9
R² = 0.72

Cycle time and RMRvalue in main...
Main Tunnel

 Correlation between

7.00
CT0.33 = 1.13(GSI)0.45
R² = 0.86

Cycle time and GSI-value
in main tunnel

6.50

...
Correlation of data (Escape
Tunnel)
Cycle time vs Q values
(Q < 6)
2.92

Cycle time vs Q values
(Q>6)
2.80

2.76

2.84

2....
Correlation of data (Escape
Tunnel)
Cycle time vs RMR values Cycle time vs RMR values
(RMR > 49)
(RMR <49 )
240

180

CT =...
Correlation of data (Escape
Tunnel)
Cycle time vs GSI
value(GSI< 43)

Cycle time Vs GSI
value(GSI > 43)
180
CT = -0.246(GS...
Conclusion
From the undertaken study conclusion may be as follows:

1.The change in Rock mass quality direct influence on ...
Contd……
4. This indicates that the specific charge , design and
sequence need to be changed with change in rock

mass qual...
Thank You
M Tech Presentation on "Effect of Rock Mass Quality on Drill Blast Cycle Time in a Himalayan Tunnelling Project" BY NANDAN
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M Tech Presentation on "Effect of Rock Mass Quality on Drill Blast Cycle Time in a Himalayan Tunnelling Project" BY NANDAN

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M Tech Presentation on "Effect of Rock Mass Quality on Drill Blast Cycle Time in a Himalayan Tunnelling Project" BY NANDAN

  1. 1. Submitted By Nandan Kumar 2011MT0134 Co Guided by Er. R. D. Dwivedi Principal Scientist CSRI-CIMFR ,Regional Centre, Guided by Dr. A. K. Mishra Associate Professor Dept. of Mining Engineering
  2. 2. Objective Study of Classification of Rock Mass according to    Q- values RMR values GSI values Calculation of drill blast cycle time which includes     Drilling and charging time Ventilation time Loading and hauling time Scaling and rock support time Investigation of correlations between rock mass quality and drill blast cycle time
  3. 3. Outline Of Project  Literature survey  Site Selection  Design of Experiment  Field work and Data collection  Data Analysis  Result  Conclusion
  4. 4. Literature Survey  Drill Blast Tunnelling Method  The Himalayan Tunnelling  Rock Mass Classification System  Bieniawski’s RMR Classification  Rock Tunnelling Index, Q  Geological Strength Index (GSI)  Drill-Blast Cycle
  5. 5. ROCK MASS RATING:  RMR value : It is the geo mechanical classification developed by Bieniawski (1973)  For application of RMR a given site should be divided into a number of geological structural units.  The following six parameters are determine for each structural unit       UCS (uniaxial Compressive Strength) RQD (Rock Quality designation) Joint or Discontinuity Spacing Joint Condition Ground Water condition and Joint Orientation
  6. 6. The rating of six parameters of the RMR system PARAMETER Intact Rock UCS(MPa) Rating Assessment of values and Rating >250 100-250 15 RQD% >90 Rating 50-100 12 7 75-90 20 25-50 1-25 4 50-75 1 25-50 <25 17 13 8 50-200 mm 8 <60 mm 0.6-2 m 3 Mean Fracture Spacing Rating >2m 20 15 200-600 mm 10 Fracture conditions Rating Rough tight 30 Open<1 mm 25 Weathered 20 Gouge< 5 mm 10 Gouge>5 Groundwater state Rating Dry Damp Wet Damping Flowing Fracture orientation Rating Very favorable 0 15 10 favorable 7 Fair -2 5 4 Unfavorable -7 -15 0 0 Very unfavorable -25
  7. 7. Rock Tunnelling Quality Index, Q  RQD   Jr   Jw  Q     Jn   Ja   SRF  Where  RQD = Rock Quality Designation  Jn = Joint set number  Jr = Joint roughness factor  Ja = Joint alteration and clay fillings  Jw = Joint water inflow or pressure  SRF = stress reduction factor Range: 0.0001 < Q <1000 1 – 20 1-4 1 – 20 1 – 20 10 - 100 0.1– 1
  8. 8. GSI  Hoek and Brown(1997) introduced the GSI both for hard and weak rock masses  It is based on visual inspection of geological conditions GSI = RMR -5 for GSI >18 or RMR > 23 = 9 ln Q’ + 44 for GSI < 18  RQD   Jr  Where Q’ = modified tunneling quality index     Jn   Ja  = RMR = rock mass rating according to Bieniawski (1989)
  9. 9. GSI SHEET
  10. 10. Drill blast cycle STEPS Unit Operation Time 1 2 Face mapping, Profile making Face Drilling 3 4 5 Blasting Supporting Firing 6 7 8 Ventilation Mucking Scaling
  11. 11. Drill – Blast Cycle
  12. 12. Project Overview • Construction of a two lane 9km main tunnel and parallel one lane escape tunnel, involving major slope cutting and embankment filling works. • Two bridges of 40 m and 50 m span (two lanes on each bridge). • Buildings: Two tunnel control buildings, ventilation and power buildings, administrative and maintenance building. • MEP works: power distribution, ventilation, lighting, fire control system, video surveillance, traffic control, emergency call and communications. • Approach roads to the Tunnel at both the ends.
  13. 13. Chenani Nashri Tunnel Project, J&K North Portal South Portal
  14. 14. Geometrical & Functional characteristics of CHENANI NASHARI Tunnel Tunnel Name Chenani-Nashri Length Approx.9000m Type Single bore, bi-directional double lane with parallel escape tunnel, crosspassages (pedestrian and vehicular) every 300m H = 5m; W = 9.35m; tolerance 0.05m Clearance traffic envelope Lateral walkways 1.2m (W) x 2.20m (H) 6.65m Inner radius Min. curvature radius 300m Max. overburden Approx.1000m Tapered with max. slope 0.5% Profile Excavation method as per Tender documents D&B (NATM) Lay-bys Safety and fire niches on both sides Every 600m staggered Every 150m Underground pump rooms No Electrical underground substations (technical rooms) Ventilation Every 2400m inside the cross passages Transverse with air ducts above road level
  15. 15. Typical cross section of Escape Tunnel
  16. 16. Typical cross section of MainTunnel
  17. 17. NATM(New austrian tunneling method)  NATM is not a method of tunneling but a strategy for tunneling which does have a considerable conformity and sequence  The basic principle of NATM are 1.mobilisation rock mass strength 2. Shotcrete protection to preserve the load carrying capacity of the rock mass 3. monitoring the deformation of the excavated rock mass 4.Providing flexible but active supports and
  18. 18. Correlation among rock class description as per NATM and behavioural categories as per Geodata Engineering approach Rock class description as per NATM Geo data Quantitative approach Qualitative approach (Geo consult, 1993 ) Class Description (Russo & Grasso, 2007) Geo structural condition (typical RMR class) A1 Stable I A2 Slightly over breaking II B1 Friable III B2 Heavily friable IV C1 Pressure exerting/squeezing Heavily pressure exerting/heavily squeezing Loose ground/shortterm stable with low cohesion III-IV C2 L III-IV-V V
  19. 19. Drilling Time Data Boomer XE3 C : Used at Main Tunnel Drilling time : 70 Minutes ( Hole Depth : 2.5M ) Rock Class : B2 Drilling Time : 100 Minutes ( Hole Depth : 3.5M ) Rock Class : B1 Cross Section Area : 76m No. of hole : 150 Rock Bolting Time : 20 Minutes ( 9 nos. , 5.0 depth Swellex bolt ) Fixing & expansion of bolt : 15 minutes. Machine Navigation : 5-7 Minutes E2C : Using at Escape Tunnel Drilling Time : 1:30 ( Rock Class : B1 ) Hole Depth : 4.0M Cross Section Area : 36m2 Rock Bolting Time : 15 Minutes ( 6 nos. 3.0 depth
  20. 20. Drill Pattern Escape Tunnel Main Tunnel
  21. 21. Jumbo
  22. 22. BLASTING PATTERN PARAMETER MAIN TUNNEL(TOP HEADING) ESCAPE TUNNEL Contour 30 22 Stoping 38 26 Cut 18 16+2(large hole102114mm) Floor 15 6 Total no of holes 101 72 No of Holes Average round length 2.3 m 2.3 m Total Excavation(m3) 226.71 79.6 Total explosive(Kg) 292.88 115.4 Powder 1.45 1.29
  23. 23. Blasting Pattern in Main Tunnel
  24. 24. Blasting Pattern in Escape Tunnel
  25. 25. Data collection  Under this project data has been collected from Chenani Nashri Road Tunnel, Jammu  It includes data related to geology and cycle time of different activities of escape tunnel and main tunnel
  26. 26. Representation of Cycle Time Main Tunnel SCALING 11% Escape Tunnel GM 4% SCALING 11% GM 4% GM SUPP MUCK 18% GM SUPP MUCK 20% PROF SUPP 40% FDT SUPP 37% PROF FDT CH T VENT VENT 3% CH T VENT MUCK CH T 9% SCALING VENT 2% MUCK CH T 9% SCALING FDT 14% FDT 12% PROF 3% PROF 3%
  27. 27. Drill Blast Cycle Time PULL (M) Geo Mapping (Min) SUPP. Time (Min) PROF Making (Min) Drilling Time (Min) Charging Time (Min) VENT. Time (Min) Mucking Time (Min) Scaling Time (Min) Cycle Time (Min) 4 20 60 15 60 40 10 130 60 395 2.9 20 60 15 60 45 15 180 60 455 3.5 30 185 15 120 75 15 240 45 725 4 30 65 15 115 60 10 170 120 585 3 25 135 40 75 60 15 165 60 575 3 30 90 30 150 75 10 275 30 690 3.5 15 90 15 70 45 25 245 30 535 3 30 60 20 100 75 10 180 60 535 4 20 120 20 130 60 10 200 30 590 4 20 45 15 90 60 10 200 30 470
  28. 28. Lithological Distribution of Rock Type in Main Tunnel Clayey siltstone, sandstone and sandy siltstone 38% Sandstone, claystone, clayey siltstone and siltstone 7% Sandstone, claystone and clayey siltstone 21% Siltstone, clayey siltstone, Sandy sandy siltstone siltstone, and sandstone sandstone 19% and claystone 3% Sandy siltstone, sandstone, claystone and clayey siltstone 12%
  29. 29. Lithological Distribution of Rock Type in Escape Tunnel Sandstone and clayey siltstone 9% Sandstone 9% Siltstone 11% Siltstone, intermixed siltstone and claystone 7% Siltstone, silty sandstone, sandstone 6% Siltstone, silty claystone, silty sandstone, sandstone 6% silty sandstone, sandstone 21% Siltstone and clayey siltstone, sandysiltstone and Sandstone 20% Sandstone and Siltstone 3% Sandstone, siltstone and a thin strip of claystone 2% Siltstone and Sandy siltstone 4% Siltstone and clayey siltstone, sandysiltstone 2%
  30. 30. FACE GEOTEC HNICAL DESCRIPTION ESCAPE TUNNEL
  31. 31. FACE GEOTECHNICAL DESCRIPTION Main Tunnel
  32. 32. Rock mass quality FROM TO Q-Value RMR GSI RQD STRENGTH 1389.50 1392.50 1.015 47 42 45.7 48 1392.50 1395.10 2.45 46 40 49 45 1395.10 1397.00 2.3 44 40 46 45 1397.00 1399.50 1.015 47 42 45.7 47.5 1399.50 1402.50 2.3 44 40 46 45 1402.50 1405.00 1.08 44 42 49 45 1405.00 1408.00 2.6 50 40 52 45 1408.00 1410.00 1.235 49 45 56 55 1410.00 1412.50 1.235 49 45 55.6 55 1412.50 1415.00 2.6 49 40 52 45 1415.00 1417.70 1.01 46 40 45.7 45 1417.70 1421.00 2.6 48 40 52 45 1421.00 1423.50 0.76 46 40 45.7 45 Rock Class B1 B1 B1 B1 B1 B1 B1 B1 B1 B1 B1 B1 B1
  33. 33. 5 4.5 4 3.5 3 2.5 2 1.5 1 0.5 0 Chainage no. vs RMR Values Rock mass Quality in Main tunnel 60 50 40 30 20 10 0 1389.50 1408.00 1426.00 1446.50 1465.50 1484.50 1563.20 1577.30 1591.30 1604.50 1625.80 1650.50 Chainage No vs Q values 1389.50 1408.00 1426.00 1446.50 1465.50 1484.50 1563.20 1577.30 1591.30 1604.50 1625.80 1650.50
  34. 34. GSI Values in Main Tunnel 50 45 40 35 30 25 20 15 10 5 0 Rock Mass Quality Q Values Range 0.52 to 2.6 42 to 51 GSI Values 1389.50 1408.00 1426.00 1446.50 1465.50 1484.50 1563.20 1577.30 1591.30 1604.50 1625.80 1650.50 RMR Values 35 to 45
  35. 35. Chainage No vs Q values 4 3.5 3 2.5 2 30 1.5 1 0.5 0 2164.6 2191.5 2219.5 2244 2372.70 2408.20 2440.80 2491.5 2533.2 2565 2657.5 4.5 2164.6 2191.5 2219.5 2244 2372.70 2408.20 2440.80 2491.5 2533.2 2565 2657.5 Rock mass Quality in Escape tunnel Chainage No Vs RMR Values 60 50 40 20 10 0
  36. 36. Chainage No. Vs GSI values Range 60 Rock Mass Quality 50 Q Values 1.90 to 4.13 RMR Values 47 to 53 GSI Values 42 to 50 40 30 20 10 2164.6 2191.5 2219.5 2244 2372.70 2408.20 2440.80 2491.5 2533.2 2565 2657.5 0
  37. 37. Correlation of data (Main Tunnel)  Correlation between 6.6 y = -0.3841Q2 + 1.48 Q + 4.73 R² = 0.44 Cycle time and Q-value in main tunnel T0.33 6.2 5.8 5.4 5.0 0 0.5 1 1.5 Q 2 2.5 3
  38. 38. Main Tunnel  Correlation between 7 CT0.33 = -0.0182(RMR)2 + 1.84(RMR) - 39.9 R² = 0.72 Cycle time and RMRvalue in main tunnel T0.33 6 5 4 42 44 46 48 RMR 50 52
  39. 39. Main Tunnel  Correlation between 7.00 CT0.33 = 1.13(GSI)0.45 R² = 0.86 Cycle time and GSI-value in main tunnel 6.50 T0.33 6.00 5.50 5.00 4.50 30 35 40 GSI 45 50
  40. 40. Correlation of data (Escape Tunnel) Cycle time vs Q values (Q < 6) 2.92 Cycle time vs Q values (Q>6) 2.80 2.76 2.84 2.72 T0.2 T0.2 2.88 y = 0.0131x + 2.5654 R² = 0.9147 2.80 2.68 y = -0.0203x + 2.9136 R² = 0.7724 2.76 2.64 2.72 2.60 0 2 4 Q2 6 8 0 5 10 Q2 15 20
  41. 41. Correlation of data (Escape Tunnel) Cycle time vs RMR values Cycle time vs RMR values (RMR > 49) (RMR <49 ) 240 180 CT = 3.305(RMR)2 - 316.5(RMR) + 7750 R² = 0.73 CT = 0.216(RMR)3 - 35.36(RMR)2 + 1927(RMR)34825 R² = 0.96 Cycle time per metre pull Cycle time per metre pull 220 200 180 160 140 120 160 100 140 44 45 46 47 RMR 48 49 47 49 51 53 RMR 55 57
  42. 42. Correlation of data (Escape Tunnel) Cycle time vs GSI value(GSI< 43) Cycle time Vs GSI value(GSI > 43) 180 CT = -0.246(GSI)2 + 25.76(GSI)- 507.56 R² = 0.89 260 CT = 1.292(GSI)2 - 111(GSI) + 2526 R² = 0.70 160 Cycle time per pull Cycle time per m pull 220 180 140 120 140 100 100 34 36 38 40 GSI 42 44 30 40 50 GSI 60
  43. 43. Conclusion From the undertaken study conclusion may be as follows: 1.The change in Rock mass quality direct influence on cycle time of Tunnel which has been true for both the tunnel(Main & Escape Tunnel). 2.In case of Main Tunnel(Diameter 14.02 m) Cycle time is directly proportional to Rock mass quality upto a certain range and after that range the cycle time becomes constant. 3. In case of escape tunnels (diameter 6.55 m), the cycle time is inversely proportional to rock mass quality It may be due to change in degree of fragmentation, which influenced the dig rate as for the lower value of rock mass quality (Q<2.45,RMR values <48.6 and GSI values < 43 ) degree of fragmentation was good whereas for higher values of rock mass quality i.e. (Q >√6,RMR >48.6 and GSI >43) the degree of fragmentation was bad. The specific charge was same for all cases.
  44. 44. Contd…… 4. This indicates that the specific charge , design and sequence need to be changed with change in rock mass quality to suite the excavator and achieve the desire efficiency. 5.From the undertaken study it may be concluded that for varying rock mass quality specific charge, design and sequence need to be change to keep the same face advancement and the efficiency of excavation.
  45. 45. Thank You

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