Transcription
Introduction toSoil MechanicsGeotechnical EngineeringDr. Attaullah Shahground1SIVA
Soil Mechanics Soil Mechanics Branch of Science dealing with the structure,Engineering properties and reactions (behavior) of soilsunder loading and weathering.Which studies theoretically and practically soils forbuilding of structures over it.Knowledge of physics, mechanics, and hydraulicsapplied to study the behavior of soils.Also called Geo-Technique ( Geo-Tech Engineering)Studies the mutual interaction of soils and structure.The practice of Engineering which applies the principlesof soil mechanics to the design of engineeringstructures is called soil mechanics Engineering or Geotechnical Engineering.2
Objectives of Soil Mechanics To perform the Engineering soil surveys.To develop rational soil sampling devices and soilsampling methods.To develop suitable soil testing devices and soil testingmethods.To collect and classify soils and their physicalproperties on the basis of fundamental knowledge of soilmechanics.To investigate the physical properties of soil anddetermine the coefficients to characterize theseproperties.To evaluate the soil test results and other applicationsas a construction material.To understand various factors such as static and3dynamic loads, water and temperature.
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Shallow Foundations for transferring building loads to underlying ground mostly for firm soils or light loadsfirmgroundbed rock5
Shallow Foundations
Deep Foundations for transferring building loads to underlying ground mostly for weak soils or heavy loadsPILEweak soilbed rock7
Deep FoundationsDriven timber piles, Pacific Highway8
Retaining Walls for retaining soils from spreading laterallyretainingwallRoadTrain9
Earth Dams for impounding waterreservoirclaycoreshellsoil10
Concrete Damsreservoirconcrete damsoil11
Concrete DamsThree Gorges Dam, Hong Kong12
Concrete Dams13
Earthworks preparing the ground prior to constructionRoadwork, Pacific Highway14
Construction hazard an unwelcome visitor at an earthwork site.What does it haveto do with Geo?#!A dead Anaconda python (courtesy: J. Brunskill)15
Geofabrics used for reinforcement, separation, filtration anddrainage in roads, retaining walls, embankments Geofabrics used on Pacific Highway16
Reinforced Earth Walls using geofabrics to strengthen the soil17
Soil Nailing steel rods placed into holes drilled into the wallsand grouted18
Sheet Piles sheets of interlockingsteel or timber driven intothe ground, forming a continuous sheetwarehouseshipsheet pile19
Sheet Piles resist lateral earth pressures used in excavations, waterfront structures, .20
Sheet Piles used in temporary works21
Sheet Piles interlocking sections22
Cofferdam sheet pile walls enclosing an area, toprevent water seeping in23
Landslides24
Shoringpropping and supporting the exposed walls toresist lateral earth pressures25
Tunneling26
BlastingFor ore recovery in mines27
Ground ImprovementImpact Roller to Compact the Ground28
Ground ImprovementSheep foot Roller to Compact Clay Soils29
Ground ImprovementSmooth-wheeled Roller30
Ground ImprovementBig weights droppedfrom 25 m, compactingthe ground.Craters formed in compaction31
Environmental GeomechanicsWaste Disposal in Landfills32
Instrumentation to monitor the performances of earth andearth supported structures to measure loads, pressures, deformations,strains, 33
Soil TestingCone Penetration Test Truck – Lavarach Barracks, Townsville
Soil TestingVane Shear TestStandard Penetration TestMore Field Tests
Soil TestingTri-axial Test on Soil Sample in Laboratory36
Soil TestingVariety of Field Testing Devices37
Typical Safety FactorsType of DesignSafetyFactorProbability ucturesFoundations 2.0-3.01/15001/500038
Great Contributors to the Developmentsin Geotechnical Engineering39
Karl Terzaghi1883-1963L. 14-WJM 2-1981G.A. Leonards401921-1997
Geotechnical Engineering Landmarks41
Leaning Tower of PisaOur blunders become monuments!42
Hoover Dam, USATallest (221 m) concrete dam43
Tallest buildings in the worldPetronas Tower, Malaysia44
Monumentsand .45
Some SuggestionsAttend the lectures.It takes longer to understandfrom the lecture notesDevelop a good feel for the subject.It is practical, interesting andmakes lot of sense.46
Course PlanTeachingWeekTopics to be coveredOne- Introduction to the subject.- Soil and its constituents: Weathering of rocks andtypes of soil, Physical properties, e.g., water content, voidratio, porosity, degree of saturation, specific gravity, andunit weight and their determination, Mass Volumerelationships.TwoSoil Classification:Importance of soil classification, Atterberg limits, grain sizedistribution, sieve analysis.Follow upAssignment#1.Write a note on the importance of thesubject of Soil Mechanics for CivilEngineeringThreeSoil ClassificationHydrometric analysis, Unified and AASHTO classificationand description of their subgroupsAssignment#2FourSoil Exploration:Purpose of soil exploration, soil exploration methods,probing test, trenches and pits,Five1st Quiz- Auger boring, Wash boring, Rotary drilling, Soil samples,Distributed and undistributed samples.SixPermeability and capillarity:Definition, Darcy's law, Factors affecting permeability,Laboratories and field determination of permeabilityAssignment#3SevenCapillarity and effects, bulking of sand, slabing of clay,frost heave and its prevention, Theory of flow nets.Assignment#447
EightMid Term TestNineCompaction:Definition, Compaction fundamentals, Moisture densityrelationship, Compaction standard.TenFactors affecting compaction, Field control andmeasurements of in-situ density, Effect of compaction onproperties of soilEleven2nd QuizShear Strength:Concept, Shear strength parameters, Coulomb's law,shear strength of cohesive and non-cohesive soils,TwelveSimple laboratory and field tests for determination ofshear strength of soils.ThirteenConsolidation:Mechanics of consolidation, Theory of one dimensionalconsolidation, assumptions andValidity.FourteenOedometer test and graphical presentation of data,Compression index, Coefficient of compressibility.Fifteen3rd QuizTime factor, Co-efficient of volume change and degree ofconsolidation,SixteenPrimary and secondary consolidationSeventeenPrimary and secondary ent#6Assignement#7Assignment#8Comprehensive Assignment48
Distribution of Marks: Sessional Marks: 60, as per following details:Assignments: 10Quiz: 10Mid Semester Exam: 20Practical/Viva voce Exam: 20Final End Semester Exam: 4049
Some SuggestionsWork in groups.50
Some SuggestionsThou shall not wait till the last minute.51
Exams“Exam is like a box of chocolates; younever know what you are gonna get”52
3 Objectives of Soil Mechanics To perform the Engineering soil surveys. To develop rational soil sampling devices and soil sampling methods. To develop suitable soil testing devices and soil testing methods. To collect and classify soils and their physical properties on the basis of fundamental knowledge of soil mechanics. To investi
