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A G H 2010 Badania Polowe Teoria, Metodologia i Praktyka Profesor Zdzisław Bieniawski 1 2 3 “Idea” #1 Badania polowe w Geoinżynierii 4 Plate jacking tests 5 Another well-known in situ test Large Flat Jack (LFJ) test 6 Other types of large in situ tests Tri-axial block test Coal mine pillar test 7 RMR versus Rock Mass Modulus Em from penetrometer tests (Galera 2005) RMR versus ratio Emass/Eintact (penetrometer data after Galera 2005) 10 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 12 Rock Mass Modulus versus RMR and Q (check correlation) Rock Mass Strength Kalamaras, 1995 14 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) sMASS = sc 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 Ei sM sc 2/3 16 Warning! concerning Rock Mass Strength This expression: EM Ei sM sc 2/3 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 17 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 19 20 21 22 World Record! The largest Tunnel Boring Machine (T B M) cannot function without Rock Mechanics! 23 Uniaxial compressive strength of intact rock [0 – 25 points] sci (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 Homogeneous Ratings 10 No. of joints per metre Orientation versus tunnel axis Mixed 0-4 4-8 8-15 15-30 0 5 10 20 15 >30 Perpendicular Oblique Parallel 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 Ratings for Rock Mass Excavability index (RME): Input parameters Roof Span versus Stand Up Time as function of RMR and Q Correlation between Rock Mass Excavability index (RME) and Average Rate of Advance (m/day) for Double Shield TBMs 26 60 ARAT(m/day) NO DATA ARE AVAILABLE FOR RME < 10 FOR sci < 45 MPa 50 ARAT = 0,661RME - 20,4 R = 0,867 40 30 20 10 0 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 RME Abdalajís Gilgel Gibe II - Inlet Double Shield TBMs Guadarrama σci < 45 MPa 85 90 95 100 “Idea” #3 Maszyny tarczowe TBM 28 Kraków Badania polowe w geoinżynierii Profesor Z.T. Bieniawski A G H 2010 Dziękuję za słuchanie