Rock mechanics for design of Brisbane tunnels and implications of recent thinking in relation to rock mass strength  

作　　者：L.B.McQueen A.Purwodihardjo S.V.L.Barrett 

机构地区：[1]Golder Associates Pty Ltd.,124 Pacific Highway,St.Leonards,NSW,2065,Australia [2]Golder Associates Pty Ltd.,147 Coronation Drive,Milton,Queensland,4064,Australia [3]Golder Associates Pty Ltd.,Building 7,Botanicca Corporate Park,570 e 588 Swan Street,Richmond,Victoria,3121,Australia

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2019年第3期676-683,共8页岩石力学与岩土工程学报（英文版）

摘　　要：This paper explores the potential implications of recent thinking in relation to rock mass strength for future tunnelling projects in Brisbane,Australia,particularly as they are constructed within deep horizons where the in situ stress magnitudes is larger.Rock mass failure mechanisms for the current tunnels in Brisbane are generally discontinuity controlled and the potential for stress-induced failure is relatively rare.For the road tunnels which have been constructed in Brisbane over the last 12 years,the strength of the more massive rock masses for continuum analysis has been estimated by the application of the Hoek-Brown(H-B)failure criterion using the geological strength index(GSI)to determine the H-B parameters mb,s and a.Over the last few years,alternative approaches to estimating rock mass strength for‘massive to moderately jointed hard rock masses’have been proposed by others,which are built on the work completed by E.Hoek and E.T.Brown in this area over their joint careers.This paper explores one of these alternative approaches to estimating rock mass strength for one of the geological units(the Brisbane Tuff),which is often encountered in tunnelling projects in Brisbane.The potential implications of these strength forecasts for future tunnelling projects are discussed along with the additional work which will need to be undertaken to confirm the applicability of such alternative strength criteria for this rock mass.This paper explores the potential implications of recent thinking in relation to rock mass strength for future tunnelling projects in Brisbane, Australia, particularly as they are constructed within deep horizons where the in situ stress magnitudes is larger. Rock mass failure mechanisms for the current tunnels in Brisbane are generally discontinuity controlled and the potential for stress-induced failure is relatively rare. For the road tunnels which have been constructed in Brisbane over the last 12 years, the strength of the more massive rock masses for continuum analysis has been estimated by the application of the HoekBrown(H-B) failure criterion using the geological strength index(GSI) to determine the H-B parameters mb, s and a. Over the last few years, alternative approaches to estimating rock mass strength for ‘massive to moderately jointed hard rock masses’ have been proposed by others, which are built on the work completed by E. Hoek and E.T. Brown in this area over their joint careers. This paper explores one of these alternative approaches to estimating rock mass strength for one of the geological units(the Brisbane Tuff), which is often encountered in tunnelling projects in Brisbane. The potential implications of these strength forecasts for future tunnelling projects are discussed along with the additional work which will need to be undertaken to confirm the applicability of such alternative strength criteria for this rock mass.

关 键 词：Rock mass strength Hoek-Brown(H-B)failure criterion Triaxial testing BRITTLE FAILURE BRISBANE TUFF 

分 类 号：O3[理学—力学]