...FORMING A VIEW OF THE ROCK MASS STRENGTH OF HAWKESBURY SANDSTONE FROM TUNNELLING CASE HISTORIES R. Bertuzzi PSM & School of Civil & Environmental Engineering, UNSW Australia Sydney, Australia ([email protected]) Innovations in Applied and Theoretical Rock Mechanics Editors Hassani...

... Abstract Rock mass characterization for deep underground construction and mining offers many challenges. This paper first describes some of the key challenges when characterizing highly stressed brittle rocks and then offers some guidance on how to arrive at reliable rock mass strength...

...Harmonising Rock Engineering and the Environment Qian & Zhou (eds) © 2012 Taylor & Francis Group, London, ISBN 978-0-415-80444-8 Fractal approach to determine rock mass strength and deformation M.N. Bagde, A.K. Raina, P.B. Choudhury & A. Sinha* Central Institute of Mining and Fuel Research...

... ABSTRACT: It is generally accepted in rock engineering that the strength of a rock mass decreases as the volume increases. There are two contributors to the rock mass strength: the strength of the intact rock, and the strength of the fractures. When creating a synthetic rock mass, the intact rock is first...

... and fracture strength parameters are determined for two perpendicular foli- ation directions. The input parameters, as listed in Table 1, are used. 3.2.1 Rock mass strength The single plane of weakness theory states that rock sam- ple with a discontinuity should have its weakest direction of 45 + 2) where...

... (Mogi, 1966 in Mogi, 2007), equivalent to = tan(33.06 and examining Figure 4, the following facts emerge: a) Quartzitic sandstone poor rock mass strength becomes ductile for normal stress > 40.7 MPa (upper circle) beyond which H-B strength criterion is no longer valid. 83 b) Quartzitic sandstone...

...Harmonising Rock Engineering and the Environment Qian & Zhou (eds) © 2012 Taylor & Francis Group, London, ISBN 978-0-415-80444-8 Influence of confinement dependent failure processes on rock mass strength at depth Benoît Valley, Bo-Hyun Kim, Fidelis T. Suorineni, Navid Bahrani & Rob P. Bewick...

... ABSTRACT Prediction of squeezing potential is one of the major problems while tunnelling through weak rock mass under high overburden. The present methods in vogue generally compare the rock mass strength with the in-situ stress to resolve this problem. It is suggested in this paper...

... ABSTRACT This paper presents a numerical method for estimating rock mass strength criteria in underground mines. The method is based upon "measuring" selected rock mass failure events, which are then numerically back analyzed to estimate strength criteria. The basis of the numerical method...

... reservoir geomechanics relation Simulation Upstream Oil & Gas scale effect hydraulic fracturing strength rock mass strength fracture rock mass hoek-brown criterion Itasca Consulting Group Reservoir Characterization classification criterion empirical relation SRM model...

... and fracture geomechanical properties, and field test results available on in situ stress for Äspö diorite were used in the said estimations. The mean rock mass strength was found to be 47% of mean intact rock strength of 297MPa at the depth of 485 m. The mean rock mass modulus was found to be 51...

... a potential extension to current guidelines on the use of the Hoek-Brown failure criterion. The paper also outlines kinematic checks to assess the influence of defect clusters on rock mass strength. Das Hoek-Brown Bruchkriterium, das strikte nur fuer isotrope Gefuege gilt, findet oft einen viel weiteren...

... A retrospective analysis of some geomechanical classifications for rock masses is presented. It is shown that estimates of rock mass strength according to geomechanical classifications developed, e.g., for construction of tunnels and for ore mines can differ very much. Development...

... Recent studies by the authors into the behaviour of jointed rock masses using direct shear testing have confirmed that joint spacing has a significant effect on rock mass strength. The rock mass failure envelopes assessed from these tests have been compared to failure envelopes obtained using...

.... The failure criterion shows the important role the intermediate principal stress plays on rock mass strength. Zur Simulation spröder Gesteinsarten wurde ein Modellmaterial aus Dentalgips, Sand und Wasser hergestellt. Daraus wurden Blöcke gegossen, in denen mittels duennen, galvanisierten Blechen Trennflachen...

... locations throug- is dependent on faults or cracks. The thrust of TBM FN is the : hout the 'observed section, causing rock 'mass strength decrease sum of thrust forces F 1 and the torque of TBM T R is the sum' .J,; at 840 m and 860 m. Slate from 900' m to 930 In is fractured and of rolling forces multiplied...

... metals & mining stope knowledge management structural geology dilution strength Reservoir Characterization Upstream Oil & Gas Stability Graph Method instability case study low confinement strike length rock mass tensile strength rock mass strength stope strike length...

... material constant m, for greywacke sandstones and mudstones gives lower typical values (12 and 9 respectively) than the value for greywacke assigned by Hoek & Brown (18). High intact greywacke sandstone strengths also lead to unrealistically high predictions of rock mass strength by the failure...

... metals & mining Rock Deformation rock zone stability Dong main objective earth pressure rock mass strength roadway equation physical state laboratory work objective field measurement thrust displacement support thrust support theory plastic deformation wall displacement...

... types: fracture mode; sliding mode; mixed fracture-sliding mode of (a) and (b). Superposition of joint sets on rock mass strength is only correct for the fracture and the sliding failure modes which the interaction of joints can be ignored. For the mixed failure mode, the strength...