Practical Rock Mechanics

An Ideal Source for Geologists and Others with Little Background in Engineering or Mechanics Practical Rock Mechanics provides an introduction for graduate students as well as a reference guide for practicing engineering geologists and geotechnical engineers. The book considers fundamental geological processes that give rise to the nature of rock masses and control their mechanical behavior. Stresses in the earth’s crust are discussed and methods of measurement and prediction explained. Ways to investigate, describe, test, and characterize rocks in the laboratory and at project scale are reviewed. The application of rock mechanics principles to the design of engineering structures including tunnels, foundations, and slopes is addressed. The book is illustrated throughout with simple figures and photographs, and important concepts are illustrated by modern case examples. Mathematical equations are kept to the minimum necessary and are explained fully—the book leans towards practice rather than theory. This text: Addresses the principles of rock mechanics as it applies to both structural geology and engineering practice Demonstrates the importance of and methods of geological characterisation to rock engineering Examines the standard methods of rock mechanics testing and measurement as well as interpretation of data in practice Explains connections between main parameters both empirically as well as on the basis of scientific theory Provides examples of the practice of rock mechanics to major engineering projects Practical Rock Mechanics teaches from first principles and aids readers’ understanding of the concepts of stress and stress transformation and the practical application of rock mechanics theory. This text can help ensure that ground models and designs are correct, realistic, and produced cost-effectively.

Introduction to rock mechanicsIntroductionDifferentiating between soil and rockMechanics of failureClassification of intact rockCompressive strength of weak rockOrigins of shear strength in intact rockShear strength parameters for the sample in FigureStability of a cut slope in weak rockDiscontinuities in rock massesThe importance of discontinuities to stabilityEarly lessons and the relevance of rock mechanicsApplication of rock mechanicsHistory of the subject areaRock mechanics as a scientific disciplineLoad changesFundamental mechanicsDefinitionsMohr circle representation of stress-stateStress concentration in underground openingsStresses below foundationsEffective stressRock deformation and behaviourDirect shearSimple shear and associated rock structuresSurface features on rock fracturesConclusions to this sectionGeological processes and the nature of rock massesIntroductionEarth stressesFaultsFoldingRock textures, fabrics and effect on propertiesRock joints and other discontinuitiesMajor geological structuresHydrogeology of rock massesIntroductionFundamental concepts and definitionsHydraulic conductivity and permeabilityMeasuring hydraulic conductivityTypical parametersUnconfined and confined aquifers and storageCompartmentalisation, aquicludes and aquitardsFlow pathsCharacterisation and prediction of hydrogeological conditions for projectsGroutingHydrogeological modellingCharacterising rock for engineering purposesIntroductionInitial stages of site investigationField mappingTrial excavationsDiscontinuity surveysRemote measurementInterpretationRose diagramsStereographic interpretationRoughness measurementGround investigation techniquesDescription and classification of rocksRock mass classificationsInterpreting ground conditions and reportingContracts for constructionInstrumentation and monitoringProperties and parameters for designIntroductionSamplingRole of index testingBasic characterisationRock strength and its measurementRock deformabilityRock shear strength at mass scaleHydraulic conductivity and related parametersFoundations on rockIntroductionDesign of shallow foundationsDifficult sitesDeep foundationsCase example: The Izmit Bay crossing: Rock engineering for the anchorage of a major suspension bridgeSite formationRock slopesengineeringDesign of engineering worksSlope formationQuarryingOpen-pit slopesUnderground excavationsIntroductionDifference between tunnels and cavernsStability categories for underground excavationsInvestigationDesignConstructionCavern constructionConversion factors (to two decimal places)References

Steve Hencher is research professor in engineering geology at the University of Leeds, UK, and an honorary professor in the Department of Earth Sciences at the University of Hong Kong. Up until recently, he was a director of Halcrow (China) and head of Geotechnics in the Hong Kong Office for approximately ten years. Previously, he worked with Bechtel on the design of the high-speed railway in South Korea and for the Geotechnical Control Office of the Hong Kong Government. He also spent 12 intervening years teaching an MSc course in engineering geology and conducting research at the University of Leeds.