A G H 2010 Profesor Zdzis ł aw Bieniawski 1. 2 3.
-
Upload
joy-gallagher -
Category
Documents
-
view
214 -
download
0
Transcript of A G H 2010 Profesor Zdzis ł aw Bieniawski 1. 2 3.
Rock mass deformation Modulus (GPa)
EMASS = 10 [(RMR - 10)/40] and for RMR > 50: EMASS = 2 RMR – 100
Latest correlations (Galera 2008):
EMASS = 147 e [(RMR - 100)/24] - 0.2 RMR Alternatively for RMR < 50: EMASS = 0.09 RMR
and for
RMR > 50: EMASS = 0.09 RMR + 1.06 (RMR-50) + 0.015(RMR-50)2 Correlation coefficient: R = 0.89.
11
Rock mass deformation Modulus
Another correlation by Galera 2008:
EMASS = Eintact e [(RMR - 100)/36]
For full range of RMR
15
Rock mass strength (MPa)
MASS = c intact e [(RMR - 100)/24] Kalamaras [1995]
As per the last correlation of Galera 2008:
EMASS = E intact e [(RMR - 100)/36]
it follows:
EM M
Ei c
2/3
16
17
This expression:
EM M
Ei c
is preferable to the Hoek – Brown criterion in which:
m/mi = e [(RMR - 100)/28] and s = e [(RMR -
100)/9]
Due to uncertainty of mi values and equating RMR with GSI
2/3
W a r n i n g !
Example of needed Rock Mechanics focus
Mechanized excavation in Mining and Tunneling
deserves special attention in Rock Mechanics today
Consider the case of TBM tunneling: determination of rock mass excavability
(TBM rate of advance)
18
Ratings for Rock Mass Excavability index (RME): Input parameters
Uniaxial compressive strength of intact rock [0 – 25 points]ci (MPa) < 5 5-30 30-90 90-180 > 180
Ratings 4 14 25 14 0
Drillability – Drilling Rate Index [0 – 15 points]DRI > 80 80-65 65-50 50-40 < 40
Ratings 15 10 7 3 0
Discontinuities at excavation front [0 – 40 points]Homogeneity No. of joints per metre Orientation versus tunnel axis
Homogeneous Mixed 0-4 4-8 8-15 15-30 >30 Perpendicular Oblique Parallel
Ratings 10 0 5 10 20 15 0 5 3 0
Stand up Time [0 – 25 points]Hours < 5 5-24 24-96 96-192 > 192
Ratings 0 2 10 15 25
Groundwater inflow [0 – 5 points]litres/sec > 100 70-100 30-70 10-30 < 10
Ratings 0 1 2 4 5
Correlation between Rock Mass Excavability index (RME) and Average Rate of Advance (m/day) for Double Shield TBMs
26
Double Shield TBMs σci < 45 MPa
0
10
20
30
40
50
60
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
RME
ARAT(m/day)
Abdalajís Gilgel Gibe II - Inlet Guadarrama
ARAT = 0,661RME - 20,4R = 0,867
NO DATA ARE AVAILABLE FOR RME < 10 FOR
ci < 45 MPa