Fhwa - Hoek Y Bray - Rock Slopes Engineering

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Transcript of Fhwa - Hoek Y Bray - Rock Slopes Engineering

  • U.S. Departmentof Transportation

    . .


    Publication No. FHWA-TS-89-045September 1989

    ROCK SLOPES:Design, Excavation, Stabilization

    Research, Development, and TechnologyTurner-Fairbank Highway Research Center

    6300 Georgetown PikeMcLean, Virginia 221012296

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  • PB2001-105207



    This documen+ I s dlssemlnated u n d e r t h e s p o n s o r s h l p o f t h e De-partmen+ o f Transportation I n t h e I n t e r e s t o f I n f o r m a t i o n e x -change. The United States Government assumes no llabl I Ity forI ts contents or use thereof .

    T h e c o n t e n t s o f this r e p o r t r e f l e c t t h e views o f Golder Asso-cl&es, which I s r espons lb l e f o r t he f ac t s and t he accu racy o fthe data presented hereln. The conten+s do not necessar I ly re-f lect the of f lclal vlews cr pol Icy of the Department of Trans-p o r t a t l o n .

    Thls report does not constitute a s+andard, speclflcatlon orregula+lon.


    Bolder Associates wishes to express thei r appreclatlon to theFedera I H i g h w a y Adminlstration f o r t h e i r f u n d i n g O f t h epreparat ion of this manual. We also sppreclate the assistanceand advice provided by many members of the Federal and StateGovernment geotechnlcal engineering community with whom we haveworked i n t h e p a s t . I n particular, we acknowledge GerryDiqaggio. D i ck Cheney , Bob Leary, a n d R o n Chassie w i t h t heFederal Highway Administration, and Verne McGuffey (NYDOT), Hal4pgar (NJDOT), Dave Bingham (NCDOT), Bob Smith, Bl I I CaPbul andJ im Winger (IDT). A l Ki I lian and S teve Lowe1 I (USDOT), a n dHarry Moore (TNDOT).

    We al so appreciate the generosi ty of Dr . Ever t Hock and JohnB r a y f o r a l l o w i n g t h e a d a p t i o n o f t h e i r b o o k R o c k S l o p eEngineer ing (publ ished by Inst i tu te of Mining and Metal lurgy,L o n d o n 1 9 8 1 ) a s t h e b a s i s f o r t h i s m a n u a l . Examp I es andexperience quoted in this manual have been drawn from manyorgan iza t ions inc lud ing rallway, h ighway , logg ing and min ingcompanies located in many parts of the world. In addition, wea r e g r a t e f u l t o t h e m a n u f a c t u r e r s o f d r i l l i n g e q u i p m e n t ,explosives and movement monitoring instruments for the use oft h e i r t e c h n i c a l d a t a .


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    T h i s m a n u a l h a s b e e n p r e p a r e d b y Golder A s s o c i a t e s , S e a t t l e ,Washington, i n c o n j u n c t i o n w i t h a s e r i e s o f R o c k S l o p e E n g i -n e e r i n g c o u r s e s s p o n s o r e d b y t h e F e d e r a l H i g h w a y A d m i n i s t r a -t i o n .

    T h e m a n u a l i s b a s e d o n a b o o k e n t i t l e d Rock S l o p e E n g i n e e r i n g a u t h o r e d b y D r . E v e r t H o e k a n d D r . J o h n B r a y . A t h i r d e d i t i o no f t h i s b o o k h a s b e e n p u b l i s h e d i n 1 9 8 1 . The book has beenm o d i f i e d f o r t h e s e c o u r s e s b y e x p a n d i n g t h e c h a p t e r o n B l a s t i n ga n d p r e p a r i n g n e w c h a p t e r s o n S l o e Stabilizalton, M o v e m e n tM o n i t o r i n g a n d C o n s t r u c t i o n C o n t r a c t s a n d S p e c i f i c a t i o n s . Ag l o s s a r y o f e x c a v a t i o n t e r m s , I i st ings and documentation of twos l o p e s t a b i l i t y p r o g r a m s a n d a d a t a c o l l e c t i o n m a n u a l h a v e b e e nadded as appendices. T h e e n t i r e t e x t h a s b e e n e d i t e d t o m a k e i ta p p l i c a b l e t o t r a n s p o r t a t i o n e n g i n e e r i n g .

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    Chapter 1:

    Chapter 2:

    Chsptor 3 :

    Chaptw 4: Coological data col lect ion 4.1

    Principles of rock slope engineering for highways 1.1

    Economic consequences of instabi I ity 1.1Planning stability investigations 1.6Chaptar I r*ferencos 1.11

    Basic machanics of slope failure 2.1

    Continuum mechanics approach to slope stabilityMaximum slope height - slope angle relationship for oxcavatod slopesRole of discontinuit ies in slope fai lureFriction, cohesion and unit weightSliding due to gravitational loadingInfluence of water pressure on shear strengthThe effective stress lawThe effect of water pressure in a tension crackReinforcanent to prevent slldlngFactor of safety of a slopeSlope failures for which factors of safety can be calculatadCritlcal slope height versus slope angle relationshipsSlopes for which a factor of safety cannot ba calculatedProbabilistic approach to slope designChapter 2 roferoncas .82 . 92 .

    Graphical prosantation of geological data 3.1

    Doflnition of geological termsD e f i n i t i o n o f gwnetrical termsGraphical tochniquos for data presentationEqual-aroa projectionConstruction of a great circle and a pole reprosonting a planeIkt*rmination of the Ilna of intersection of two planesTo dotormine the angle batwoon two specific llnosAltarnativo n&hod for f inding the l ine of intersection of two pianosPlott ing and analysis of f ield maasuromentsEvaluation of potential slope problemsSuggostmd method of date presentation and analysis for highway designChaptor 3 refwancos

    Regional geological investigations 4.1Mapp Ing of exposed structures 4 .2Photograph Ic mapping of axposed structures 4 .6Measuromont of surface roughness 4 .8Diamond drilling for structural purposes 4.8Prosontation of geological information 4.16Chapter 4 rafwences 4.18

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    Chapter 5: Shear strength of rock

    Shear strength of planar discontinuitiesInfluence of water on shear strength of planar discontinuitiesShearing on an inclined planeSurface roughnessShear testing of discontinuities in rockEstimating joint compressive strength and friction angleShear strength of filled discontinuitiesShear strength of closely jointed rock massesTesting closely jointed rockShear strength determination by back analysis of slope failuresSample collection and preparationChapter 5 references

    Chapter 6: Groundwater flow; permeability and pressure

    Groundwater flow in rock massesFlow netsField measurement of permeabilityMeasurement of water pressureGeneral comnentsChapter 6 references

    Chapter 7: Plane failure

    General conditions for plane failurePlane failure analysisGraphical analysis of stabilityInfluence of aroundwater on stabilityCritical tension crack depthThe tension crack as an indicator of instabilityCritical failure plane inclinationInfluence of undercutting the toe of a slopeReinforcement of a slopeAnalvsis of failure on a rough planePractical example No. 1Practical example No. 2Practical example No. 3Practical example No. 4Practical example NO. 5Chapter 7 references

    Chapter 8: Wedge failure

    Definition of wedge geometryAnalysis of wedge failureWedge analysis including cohesion and water pressureWedge stability charts for friction onlyPractical example of wedge analysisChapter B references











    Chapter 9: Circular failure 9.1

    Conditions for circular failureDerivation of circular failure chartGroundwater flow assumptionsProduction of circular flow chartsUse of the circular failure chartsLocation of critical failure circle and tension crackPractical example No. 1Practical example No. 2Practical example No. 3Bishop's and Janbu's methods of slicesChapter 9 references



    Chapter 10: Toppling failure 10.1

    Types of toppling failureAnalysis of toppling failureFactor of safety for limiting eouilibrium analysis of


    topoling failures 10.13General comnents on toppling-failure 10.13Chapter 10 references 10.14

    Chapter 11: Blasting 11.1

    1 Principles of blastingMechanism of rock failure by explosiveProduction blastingBlast designEvaluation of a blastModification of blasting methodsII Controlled blasting to improve stabilityLine drillingCushion blastingPreshear blastingBuffer blastingControlled blasting: construction practices and economicsIII Blast damage and its controlStructural damageControl of flyrockAirblast and noise problems associated with production blastsChapter 11 references

    Chapter 12: Stabilization and protection measures 12.1Stabilization methods 12.2I Stabilization methods that reduce driving forces 12.3II Reinforcement and support stabilization methods 12.8III Protection measures 12.18Example of slope stabilization project 12.24Chapter 12 references 12.32

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    Chapter 13: Slope movement monitoring

    Methods of measuring slope movementsSurface methodsSubsurface surveying methodsInterpreting movement resultsChapter 13 references

    Chapter 14: Construction contracts and specifications

    Selecting the type of construction contractWrltlng speclficatlonsTypical specif IcationsChapter 14 references

    Appendix 1:

    Appendix 2:

    Appendix 3:

    Appendix 4:

    Appendix 5:

    Appendix 6: