Numerical simulation of rock burst processes treated as problems of dynamic instability

63A

842195 Vardo Tunnel - an undersea unlined road tunnel Norwegian

deformatmn and floor swelhng to be ehmmated

style Martin, D

842200 Stress distribution in a jointed and fractured medium

In: Norwegian Hard Rock Tunnelling. Norwegian Soil and Rock Engineering Association Publication N I, P IO0-102 Publ Trondhe:m Tapir Pubhshers, 1982

Lemos, J V, Brady, B H G

An underground road tunnel between Vardo and Norway is being constructed using drill and blast techniques from both ends It passes through faulted ground under the sea, but only a small stretch is fully lined w~th concrete The rest ~s supported entirely by shotcrete and/or rock bolts with hghtwelght alumlmum panels for interior protection

A hybrid boundary element-distract element computatmnal model for the stress analysis of jointed or fractured rocks has been developed The far-field response is modelled with boundary elements and is assumed to be hnear elastic The near-field response, incorporating the nonhnear behavtour of the discontinuities, is modelled with distract elements The model has been vahdated against simple classical solutions

In-situ stresses and stress around underground openings

842201

See also 842042, 842340 842196 Changes in strata stress and indications from a borehole probe (In Polish) Zorychta, A

Arch Gorn V27, N4, 1982, P361-369 In order to determine stresses and dtslocatmns occurnng w~thm a borehole, an analytical solution was derived which takes account of an adhering layer and of rhcologlcai properties of the strata The solutmn provides formulae for the dctermmatmn of changes m stresses from the borehole probe mdlcatmns

842197 Stress-strain relations applicable to overcoring techniqdes in transversely isotropic rocks van Heerden, W L

lnt J Rock Mech Min Sci V20, N6, Dec 1983, P277-282 Stress-strata equatmns for use with stress measurement overcoring techmques arc gwen for transversely lsotrop~c materials The equatmns are gwen for the CSIR tnaxml strata cell and the CSIRO HI cell for two borehole onentatmns relatwe to the ~sotrop~c plane Determmatmn of the elastic material properties reqmred Is discussed and an example of measured results evaluated m terms of the theory ~s gwen Auth.

Proc 24th US Symposium on Rock Mechanics, College Station, Texas, 20-23 June 1983 P53-59 Publ AEG, 1983

Stress changes induced by fluid injection in a porous layer around a wellbore Bouteca, M, Less/, J, Sarda, J P

Proc 24th US Symposium on Rock Mechanics, College Station, Texas, 20-23 June 1983 P99-106 Publ AEG, 1983 It ~s shown that flmd reJeCtion can alter the stresses considerably and that It stdl has influence at large distances (500 to 600 t~mes the well radms)

842202 Applicability of borebole stress measurement instrumentation to closely jointed rock Gregory, C, Cramer, M, Ames, R, McHenry, J

Proc 24th US Symposium on Rock Meclumics, College Station, Texas, 20-23 June 1983 P283-285 Publ AEG, 1983 An abstract of a paper presented at the Symposium The borehole deformation gauge (BDG) and the vibrating wire stress meter (VWS) have been adapted and developed for use m temperature and hydrologic conditions to be found m nuclear waste repositories Results of their applicability indicate good agreement while the rock exhibits hnearly elastic behawour Stress results from the VWS are generally m closer agreement to the apphed stresses than those from the BDG

842203 Development of the Serata stress-mensuring system for application to both hard-brittle and soft-ductile grounds Serata, S, Bellman, g A

842198 Numerical simulation of rock burst processes treated as problems of dynamic instability

Proc 24th US Symposium on Rock Mechanics, College Station, Texas, 20-23 June 1983 P343-358 Publ AEG, 1983

Zubelewlcz, A, Mroz, Z

Deformation behavlour of a borehole being destroyed by hydrauhc loading applied through a soft but leakproof plastic cylinder is directly related to m~tlal stress states m both hardbrittle and soft-ductile grounds. The existence of such a relation is hypothesized first and demonstrated later by fimtc element analysis using a rheologlcal constRutlve model, which is capable of simulating both hard-bnttle and soft-ductile behavlour of earth matermls The relation is further demonstrated experimentally m laboratory and underground tests Based on this work, the Serata Stress-Mcasunng System (S-100) has been developed, as a computerized instrumentatmn system capable of determining ln-sltu stress at a site without reqmrlng the tedious operations of overconng or hydrofracturmg Auth

Rock Meek Rock Engng VI6, N4, Nov 1983, P253-274 The phenomenon of rock burst occurs when the static stability conditions of the rock mass are vmlated and the dynamic fadure process proceeds starting from the eqmhbrmm state In wew of the difficulties m determining numerically the mstabd~ty point, an alternative approach ~s advocated here. after solving the m~tlal static problem the mode and onset of dynamic failure are studied by 3uperposltmn o f dynamic disturbances In this way quant~tatwe analyses of rock burst phenomena may be handled m a relatwely simple manner Auth 842199 Stress control around mine roadways (In Russian) Lltvmskn, G G

Ugoi Ukr NIO, Oct 1982, P6-8 Strata control m mine roadways by stress reductmn using camouflet blasting, ts described The distribution, length and dmmeter of boreholes for explosive fractunng are shown lnvest~gatmns of camouflet blasting m rock strata surrounding underground workings showed convergence of the roof and floor to be reduced by an order of magnitude and support

842204 Investigation of the accuracy and reliability of in situ stress measurements using hydraulic fracturing in perforated cased boles Warplnskl, N R

Proc 24th US Symposium on Rock Mechanics, College Station, Texas, 20-23 June 1983 P773-786 Publ AEG, 1983