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Mechanical significance of probability of failure as an index for prediction of slope failure
67A
This p a p ~ presents a ease study of ellffalde Instability. O e o t e ~ e a l aralyses employir~ field measurements sxzl laboratory test results obtained over a 30 year pe]~.od imdleate that r~simg Ix~e pressures trigger slides alc~1~ the cliff. Visual observation, surveys, amd field e~pl~stion show"%hat most of the lax~slides have wedge-~ype failure geometry. 'Shear occurs t h r o ~ a nearly h~rizontal stratm, of weak slay, brown ~at clay. l~e s t r e ~ of the fat clay decreases with deformation. Fluids gemarated by domestic s ~ Imdus~rial activities have res1~ited in a perch~l water layer- abowe the stratum of fat clay. F ~ more than two de,aries, the Ix~e pressure on top of the fat clay has risen. A wedge type of stability analys~ s can g i v e the c~rect f a c t ~ of safety - is, 1.0 - fo~ the slides which have occurred. Auth.
823157 GEC~4ORPHOI/~ICAL ASPECq'S OF SLOFF~ IN MUDRO~KS IN THE UNITED K I ~ D O M Anderson, M G; Richsrds, K S q J Engng Geol, VI4, N~, i981, F363-372 Discusses the growing use of ~eom~phological studies in the stability ar~lysis of mmdrock slopes and mass movement on the slopes. The geotee/~nical Iroperties of British mudrocks, which determine slope stability amd ~ s s movement, are reviewed. Slope development ar~ mass movement ~re then discussed and erosion we~:thering and high IX~ew~ter press%~es are seen as maJo~ f a c t , s in the failure of the slopes. The use of models for mass reorients is discussed amd slope stability amalysis employing geomorphological investigations is outlined. 66 refs.
8231~
ANALYSIS OF THE STABILITY OF A HIGRWALL IN AN OPEN CL'£ STRIP COAL ~[NE C~, R H T CSIRO Division of Applied Ge~,echanics report GOM 30, AUg 19@1, 195P Ground deformation amd moisture measuring i ~ ments were installed in the hig~wall close to the open cut of Goor~ella Mime in central Queensls~d. The purpose .~s to m o r ~ t ~ cha~ges that would occur as a result of minlmg, overburden ar~ coal blasting, amd possibly hig~wall failures. The b~e~holes w ~ e logged and tri~xlal ar~ shear tests perfumed on the cared samples. The sensitivity of the s~,nple stremgths was related to moisture cor~ent. Two hi~hw~ll failures occurred during the course of the test. The instrument response is amslysed and a meahamdsm for f'~il~re suggested. This is backed up with a parametric study involving the inclination ar~ friction characteristics of' the failure boundaries. The analytical model, based on the method of slices, has been expanded to model d~u~mic behaviour after failure initiation. This approach, based on the energy balance of the moving system, demons't~cates that self-stabilization can occur after significsnt displacement.
823159 MECHANICAL SIGNIFICANCE OF PROBABILYTY OF FAILURE AS AN INDEX F3R I~RH~)ICTIONOF S L O ~ FAIYX~E Matsuo, M; Ueno, M Soils Found, V21, N2_, J1me 1.~8]., P19"3~ Slope fail,me due to heavy r~infa/l is a serious problam in Japex:. A m~thod of preddetion Gf slope f~il~rc is l~oRosed ~hat requires only ra~fall intensity ~:~ information, res~ovlr~ the need Car extensive deformation emd !~zr~ pressure
m a a s u r ~ n t s from slopes. The method is based on the relationship between probability of fail~re a~i slope d ~ r m a t i o n . The validity of the m t h o d is shown, based on a r ~ i e s l results of failed amd nora-failed slopes, and the meaha~leal significance of l~obability of failure is verified by lab(~atc~y and field tests. 823160 TENSILE STRENGTH, TENSION CRACES, AND SI'ABII,I'I'Y OF ~IDPES Baker, R Soils Found, V21, N2, June 19~!, Pl-17 Describes a procedtu-e, based on the variational aplroach to llmitir~ equilibrium problems, far the evalt~tlo~ ~f the effect of tensile stremgth on the cracking and stability of slopes. It is possible to esthete the depth of tension cracks and their affee~ on stability in a eonsi~en% mamne~. Fc~m~lae a~1 charts fc~ the determination of crack depth a~d stability number far varylmg slope a*~le, mobilised friction and tensile strer~th are given. It is comeluded from this study that the maximum d e l ~ of tension cracks is 2~ per sent of slope height, add that the increase in stability rammer c~respomdir~ to a msximm~ crack is about 20 per cent (far cracks not filled with water). 82316] RISK ANALYSIS FOR ROCK SLOPES IN OPEN PIT .MINES
(~ 8 PA~S) Einstein, H H; Baecher, G B; Vsmeziano, D US Bureau of Mines repcrts OFR ~6(i-8)-81,
Nov 1979, 19~P Coml~Ises the followimg 8 parts: (i) distribution of rock mass properties, (2) limit equilibrium amalysis fc~ rock wedge stability, (3) reliability analysis of rock slope s~ability, (4) field expl~ation to determlme rock mass properties, (5) probabillstic models of Jointed rock mass defa~matlon amd their impllcations, (6) executive s , ~ r y , introduction and teehm~cal summary, bibllograDhy, (7) Appemd~ces A-M, detslled geologic data ~de~lylr~ developments, (8) ApperzLix UM, use~ ms~mmls f ~ emmputer programs. Avail: NTIS, Sprimgfleld, Va, 22161 USA
( ~ 81-201~ zer the se%)
Hydraulic structures 823162 WAVE-INDUCED STRESSES AROUND A PIPE M I D ON A PORO-ELASTIC SEA ~ED
Mel, C C; Fodaj M A Geotemh~lque, V~I, ~ , Dec 19@i, P509-517 The dynamic equations of p~o-elasticity by Biot~ who existed T e ~ z a ~ ' s one-d~mensional theory of soll consolidation, are used to study the local stresses ir~uced by sea waves ~assimg a circ~tlar pipe fixed on the sea bed. These equations couple the motion of the pore f l ~ d a~d the solid skeleton, ar~ are in g e ~ a l difficult to solve analytic~lly. An analytical approximation is applied amd solutions are presented in explicit fo~ms. The aPlroximation makes use of the i/a,~lly I ~ permeability of the sea bedj and is applicable when drainage is appreciable only near the m~[ line in a layer of thickness much less th~n than the pipe diamet.~. Auth.
This p a p ~ presents a ease study of ellffalde Instability. O e o t e ~ e a l aralyses employir~ field measurements sxzl laboratory test results obtained over a 30 year pe]~.od imdleate that r~simg Ix~e pressures trigger slides alc~1~ the cliff. Visual observation, surveys, amd field e~pl~stion show"%hat most of the lax~slides have wedge-~ype failure geometry. 'Shear occurs t h r o ~ a nearly h~rizontal stratm, of weak slay, brown ~at clay. l~e s t r e ~ of the fat clay decreases with deformation. Fluids gemarated by domestic s ~ Imdus~rial activities have res1~ited in a perch~l water layer- abowe the stratum of fat clay. F ~ more than two de,aries, the Ix~e pressure on top of the fat clay has risen. A wedge type of stability analys~ s can g i v e the c~rect f a c t ~ of safety - is, 1.0 - fo~ the slides which have occurred. Auth.
823157 GEC~4ORPHOI/~ICAL ASPECq'S OF SLOFF~ IN MUDRO~KS IN THE UNITED K I ~ D O M Anderson, M G; Richsrds, K S q J Engng Geol, VI4, N~, i981, F363-372 Discusses the growing use of ~eom~phological studies in the stability ar~lysis of mmdrock slopes and mass movement on the slopes. The geotee/~nical Iroperties of British mudrocks, which determine slope stability amd ~ s s movement, are reviewed. Slope development ar~ mass movement ~re then discussed and erosion we~:thering and high IX~ew~ter press%~es are seen as maJo~ f a c t , s in the failure of the slopes. The use of models for mass reorients is discussed amd slope stability amalysis employing geomorphological investigations is outlined. 66 refs.
8231~
ANALYSIS OF THE STABILITY OF A HIGRWALL IN AN OPEN CL'£ STRIP COAL ~[NE C~, R H T CSIRO Division of Applied Ge~,echanics report GOM 30, AUg 19@1, 195P Ground deformation amd moisture measuring i ~ ments were installed in the hig~wall close to the open cut of Goor~ella Mime in central Queensls~d. The purpose .~s to m o r ~ t ~ cha~ges that would occur as a result of minlmg, overburden ar~ coal blasting, amd possibly hig~wall failures. The b~e~holes w ~ e logged and tri~xlal ar~ shear tests perfumed on the cared samples. The sensitivity of the s~,nple stremgths was related to moisture cor~ent. Two hi~hw~ll failures occurred during the course of the test. The instrument response is amslysed and a meahamdsm for f'~il~re suggested. This is backed up with a parametric study involving the inclination ar~ friction characteristics of' the failure boundaries. The analytical model, based on the method of slices, has been expanded to model d~u~mic behaviour after failure initiation. This approach, based on the energy balance of the moving system, demons't~cates that self-stabilization can occur after significsnt displacement.
823159 MECHANICAL SIGNIFICANCE OF PROBABILYTY OF FAILURE AS AN INDEX F3R I~RH~)ICTIONOF S L O ~ FAIYX~E Matsuo, M; Ueno, M Soils Found, V21, N2_, J1me 1.~8]., P19"3~ Slope fail,me due to heavy r~infa/l is a serious problam in Japex:. A m~thod of preddetion Gf slope f~il~rc is l~oRosed ~hat requires only ra~fall intensity ~:~ information, res~ovlr~ the need Car extensive deformation emd !~zr~ pressure
m a a s u r ~ n t s from slopes. The method is based on the relationship between probability of fail~re a~i slope d ~ r m a t i o n . The validity of the m t h o d is shown, based on a r ~ i e s l results of failed amd nora-failed slopes, and the meaha~leal significance of l~obability of failure is verified by lab(~atc~y and field tests. 823160 TENSILE STRENGTH, TENSION CRACES, AND SI'ABII,I'I'Y OF ~IDPES Baker, R Soils Found, V21, N2, June 19~!, Pl-17 Describes a procedtu-e, based on the variational aplroach to llmitir~ equilibrium problems, far the evalt~tlo~ ~f the effect of tensile stremgth on the cracking and stability of slopes. It is possible to esthete the depth of tension cracks and their affee~ on stability in a eonsi~en% mamne~. Fc~m~lae a~1 charts fc~ the determination of crack depth a~d stability number far varylmg slope a*~le, mobilised friction and tensile strer~th are given. It is comeluded from this study that the maximum d e l ~ of tension cracks is 2~ per sent of slope height, add that the increase in stability rammer c~respomdir~ to a msximm~ crack is about 20 per cent (far cracks not filled with water). 82316] RISK ANALYSIS FOR ROCK SLOPES IN OPEN PIT .MINES
(~ 8 PA~S) Einstein, H H; Baecher, G B; Vsmeziano, D US Bureau of Mines repcrts OFR ~6(i-8)-81,
Nov 1979, 19~P Coml~Ises the followimg 8 parts: (i) distribution of rock mass properties, (2) limit equilibrium amalysis fc~ rock wedge stability, (3) reliability analysis of rock slope s~ability, (4) field expl~ation to determlme rock mass properties, (5) probabillstic models of Jointed rock mass defa~matlon amd their impllcations, (6) executive s , ~ r y , introduction and teehm~cal summary, bibllograDhy, (7) Appemd~ces A-M, detslled geologic data ~de~lylr~ developments, (8) ApperzLix UM, use~ ms~mmls f ~ emmputer programs. Avail: NTIS, Sprimgfleld, Va, 22161 USA
( ~ 81-201~ zer the se%)
Hydraulic structures 823162 WAVE-INDUCED STRESSES AROUND A PIPE M I D ON A PORO-ELASTIC SEA ~ED
Mel, C C; Fodaj M A Geotemh~lque, V~I, ~ , Dec 19@i, P509-517 The dynamic equations of p~o-elasticity by Biot~ who existed T e ~ z a ~ ' s one-d~mensional theory of soll consolidation, are used to study the local stresses ir~uced by sea waves ~assimg a circ~tlar pipe fixed on the sea bed. These equations couple the motion of the pore f l ~ d a~d the solid skeleton, ar~ are in g e ~ a l difficult to solve analytic~lly. An analytical approximation is applied amd solutions are presented in explicit fo~ms. The aPlroximation makes use of the i/a,~lly I ~ permeability of the sea bedj and is applicable when drainage is appreciable only near the m~[ line in a layer of thickness much less th~n than the pipe diamet.~. Auth.