AKADEMIA GÓRNICZO-HUTNICZA
IM. STANISA
AWA STASZICA
W KRAKOWIE
Wydział Górnictwa i Geoinżynierii
Budownictwo
Rok III, Grupa 5
BUDOWNICTWO PODZIEMNE
Wykonał:
Bartłomiej Urbanek
Kraków 2014
Contents
1. Parameters ............................................................................................................................ 3
2. Rock Quality Designation Index (RQD) .................................................................................. 4
3. Rock Mass Rating .................................................................................................................. 4
4. Parameters ............................................................................................................................ 5
4.1. In-situ deformation modulus ................................................................................ 5
4.2. Strength parameters.................................................................................................... 6
5. Rock Tunnelling Quality Index Q ........................................................................................... 6
6. Equivalent dimension De ....................................................................................................... 7
7. Tunnel support (in accordance with the Q Classification) .................................................... 8
8. Parameters ............................................................................................................................ 9
8.1. Deformation modulus ........................................................................................... 9
8.2. Roof pressure............................................................................................................... 9
9. Q  RMR Correlations ............................................................................................................ 9
10. Conclusion ........................................................................................................................... 10
2
1. PARAMETERS
Parametr Wartość lub opis
Lp.
Chamber for the underground parking In the
Shape, size and purpose of tunnel shape of rectangle with vaulted ceiling, 40 m
1.
(cavern) width, 15 m height
2.
Average depth, m 50
General rock mass characteristics in
3.
Compact and block rock mass
the vicinity of tunnel (cavern)
Average compressive strength of
4.
120
surrounding rocks, MPa
Average tensile strength of
5.
13
surrounding rocks, MPa
As in picture below
6.
RQD, % diameter of core 55 mm
Jak na rysunku
Number and average sparing of joint Two discontinuity sets, average spacing is about
7.
sets 1,0 m
Layers in contact, impermeable, natural fill
8.
Characteristic of the discontinuities
gouge
9.
Groundwater conditions Drippings
Discontinuity strike and dip Strike perpendicular to chamber s axis, driver in
10.
orientation the opposite direction (angle 45o)
Blasting
11.
Excavation method
MW
3
2. ROCK QUALITY DESIGNATION INDEX (RQD)
"
- Total length of core run
- Length of core pieces length
3. ROCK MASS RATING
Parameter Value Rating Comment
Uniaxial compressive Determined by linear
1 120 MPa 12,6
strength interpolation
Determined by linear
2 RQD 87 % 19.4
interpolation
Determined by linear
3 Spacing of discontinuities 1,0 m 15.11
interpolation
I do not have any information
Discontinuity length 3-10 m 2 about that parameter so I
chose medium value
4 I have information that layers
Separation None 6 are in contact so I choose the
highest score
Roughness Rough 5 Because of impermeable
4
Discontinuity
characteristics
filling and contacted layers I
choose high roughness
It is a natural filling- hard rock
Hard filling with high strength.
Infilling 4
<5mm Impermeable - so smaller
than 5 mm
Because of impermeable
filling and contacted layers
Weathering Unweathered 6
there is no possibility to
provide weather
There is small amount of
5 Ground water Dripping 4 water in ground so rate is not
too big
Strike
perpendicular to
chamber s axis,
Chamber with unfavourable
6 Strike and dip orientations driver in the -10
strike and dip orientation
opposite
direction (angle
45o)
RMR 64,11
Rock class: II  Good Rock (61-80)
4. PARAMETERS
4.1. In-situ deformation modulus
Bieniawski (1978) and Serafim & Pereira (1983)
for
Hoek and Brown (1997)
( ) ( )
" "
5
Verman (1993)
( ) ( )
4.2. Strength parameters
Hoek (1994):
" "
Aydan & Kawamoto (2000)
( ) ( )
Kalamaras & Bieniawski (1995)
I received different values of the parameters and and I decided to choose the middle
value of each parameters:
(Hoek and Brown)
(Kalamaras & Bieniawski)
5. ROCK TUNNELLING QUALITY INDEX Q
Parameter Value Comment
Good RQD
1 the Rock Quality 90
(between 75 and 90%)
Designation
Two joint sets and there was no
2 4
the joint set number
information about randomness
3 4 Layers in contact, two discontinuity sets
the joint roughness number
6
th
block
Inter-
shear
Block size
streng
The only information which I have is that it
is impermeable and have natural fill
4 0,75
the joint alteration number
gouge, so I chose  Tightly healed, hard,
non-softening, impermeable filling
There are impermeable layers, so it is
5 the joint water reduction 1,0
counted to dry excavation
factor
Single shear zone in competent rock (clay
6 2,5
the stress reduction factor
free). Depth of excavation > 50m (50m).
Rock class: Very Good (40-100)
6. EQUIVALENT DIMENSION D
E
Excavation span
Excavation height
Excavation Support Ratio (I classified underground hall to  sports and public
facilities (excavation category  D)
7
stress
Active
Crown
Walls
7. TUNNEL SUPPORT (IN ACCORDANCE WITH THE Q CLASSIFICATION)
On the basis of the graph results:
Reinforcement category for roof: Systematic bolting (3)
Bolt spacing in unshotcreted area:
Bolting length:
Reinforcement category for walls: Spot bolting (2)
Bolt spacing in unshotcreted area:
Bolting length:
8
Length of bolts:
8. PARAMETERS
8.1. Deformation modulus
Barton (2002)
)# *#
" " for ,
)# *#
Grimstad and Barton (1993)
8.2. Roof pressure
" "
" "
9. Q  RMR CORRELATIONS
9
Source of case Differential between
Result
Correlation studies and correlation and result from
RMR=
reference classification table
New Zealand [55] 65,70 1,59
Diverse Origin [25] 78,84 14,73
Spain [56] 76,22 12,11
South Africa [57] 80,16 16,05
Spain [58] 8,31 -55,80
Spain [59] 82,45 18,34
Canada [60] 71,17 7,06
Canada [27] 71,68 7,57
Canada [52] 77,71 13,60
Supposed location: New Zealand
10. CONCLUSION
We should use the two systems to analyse and to compare the rock mass. In this project I
used the RMR system and Q classification. Both of them are most widely used for the rock
mass classifications. They include geological, geometric and design/engineering parameters to
obtain a value of the rock mass quality.
The results that I have achieved are different. According to RMR, the system rock is good
(RMR=61,11). However, according to Q classification, the system rock is excellent (Q=48).
In my opinion, the difference is caused by the lack of information about the few parameters
(e.g. discontinuity length) and an estimation method.
To conclude, I am able to propose the two ways of a support construction. The first one,
based on the RMR classification involves strengthening the construction by locally bolt in
crown (3 m long), spaced 2,5 m with occasional wire mesh and 50 mm shotcrete in crown
(where required).
The second one, based on Q classification involves strengthening the construction by bolts in
crown (10 m long).
Finally, I have received a various value of the deformation modulus. These parameters are
place a higher worth in Q classification.
10