SOILS AND FOUNDATIONS Lesson 04 667 Geotech Design... · SOILS AND FOUNDATIONS Testing Experience...

SOILS AND FOUNDATIONSSOILS AND FOUNDATIONS

Testing

Experience

Theory

Lesson 04Lesson 04Chapter 4 Chapter 4 –– Engineering Description, Classification and Engineering Description, Classification and

Characteristics of Soils and RocksCharacteristics of Soils and Rocks

TopicsTopics

gg Topic 1 (Section 4.0, 4.1)Topic 1 (Section 4.0, 4.1)-- Engineering description of soilsEngineering description of soils

gg Topic 2 (Section 4.2)Topic 2 (Section 4.2)-- Engineering classification of soilsEngineering classification of soils

gg Topic 3 (Section 4.3, 4.4, 4.5) Topic 3 (Section 4.3, 4.4, 4.5) -- Engineering characteristics of soilsEngineering characteristics of soils

gg Topic 4 (Section 4.6)Topic 4 (Section 4.6)-- Engineering description of rock and rock mass Engineering description of rock and rock mass

classificationclassificationgg Topic 5 (Section 4.7)Topic 5 (Section 4.7)

-- Subsurface profile developmentSubsurface profile development

Engineering Description, Engineering Description, Classification and Characteristics Classification and Characteristics

of Soils and Rocks of Soils and Rocks

Lesson 04 Lesson 04 -- Topic 1Topic 1Engineering Description of SoilsEngineering Description of Soils

(Section 4.0, 4.1)(Section 4.0, 4.1)

Learning OutcomesLearning Outcomes

ggAt the end of this session, the participant will At the end of this session, the participant will be able to:be able to:-- Compare soil, rock and intermediate Compare soil, rock and intermediate

geomaterialsgeomaterials ((IGMsIGMs))-- Contrast identification, description and Contrast identification, description and

classificationclassification-- Perform engineering description of soilPerform engineering description of soil

Rock, Soil and IGMRock, Soil and IGM

ggWhat is Rock?What is Rock?ggWhat is Soil?What is Soil?ggWhat is Intermediate What is Intermediate GeoMaterialGeoMaterial (IGM)?(IGM)?

Identification, Description and Identification, Description and Classification of SoilsClassification of Soilsgg IdentificationIdentification

-- Process of determining the components of a given soil, Process of determining the components of a given soil, e.g., gravel, sand, silt, clay, etc.e.g., gravel, sand, silt, clay, etc.

gg DescriptionDescription-- Process of estimating the relative percentage of each Process of estimating the relative percentage of each

component of soilcomponent of soil-- Description includes identificationDescription includes identification

gg ClassificationClassification-- Laboratory based process of grouping Laboratory based process of grouping geomaterialsgeomaterials with with

similar engineering characteristics into categoriessimilar engineering characteristics into categories

Soil DescriptionSoil Description

ggSystematic naming of individual soils in both Systematic naming of individual soils in both written and spoken formswritten and spoken forms

ggASTM D 2488, AASHTO M 145ASTM D 2488, AASHTO M 145ggSoil Soil decriptiondecription is used in the field during is used in the field during

logginglogging


ggApparent consistency (e.g., soft, firm)Apparent consistency (e.g., soft, firm)ggWater content (e.g., dry, moist)Water content (e.g., dry, moist)ggColor Color ggMain soil type (e.g., Sand)Main soil type (e.g., Sand)ggDescriptive term for main soil type (e.g., fine, Descriptive term for main soil type (e.g., fine,

medium, coarse, wellmedium, coarse, well--rounded)rounded)ggParticleParticle--size distribution (e.g., uniform, wellsize distribution (e.g., uniform, well--

graded)graded)


gg Plasticity adjective (e.g., high, low)Plasticity adjective (e.g., high, low)gg Soil texture (e.g., rough, smooth, waxy)Soil texture (e.g., rough, smooth, waxy)gg Descriptive term for minor soil Descriptive term for minor soil type(stype(s) (e.g., with, ) (e.g., with,

some, trace, etc.)some, trace, etc.)gg Minor soil type name with “y” (e.g., Minor soil type name with “y” (e.g., siltysilty))

-- If fineIf fine--grained minor component <30%, >12%grained minor component <30%, >12%gg Descriptive adjective “with” if fineDescriptive adjective “with” if fine--grained grained

component is between 5 and 12%component is between 5 and 12%gg Inclusions (e.g., concretions, cementation)Inclusions (e.g., concretions, cementation)gg Geological name (e.g., Holocene, Jurassic)Geological name (e.g., Holocene, Jurassic)

Soil DescriptionSoil DescriptionExamplesExamplesggFineFine--grained soilsgrained soils

-- Soft, wet, gray, high plasticity CLAY, with f. Sand Soft, wet, gray, high plasticity CLAY, with f. Sand (Alluvium)(Alluvium)

ggCoarseCoarse--grained soilsgrained soils-- Dense, moist, brown, Dense, moist, brown, siltysilty mm--ff SAND, with f. SAND, with f.

Gravel to c. Sand (Alluvium)Gravel to c. Sand (Alluvium)

Apparent Density of CoarseApparent Density of Coarse--Grained Grained Soils (Table 4Soils (Table 4--1)1)

N60 Apparent Density Relative Density, %

0 – 4 Very loose 0 – 20

>4 - 10 Loose 20 – 40

>10 - 30 Medium dense 40 – 70

>30 - 50 Dense 70 – 85

>50 Very Dense 85 – 100

The above guidance may be misleading in gravelly soils.

N60 Consistency Unconfined Compressive Strength, qu, ksf (kPa) Results of Manual Manipulation

<2 Very soft < 0.5 (<25)

Specimen (height = twice the diameter) sags under its own weight; extrudes between fingers when squeezed.

2 - 4 Soft 0.5 – 1 (25 – 50)

Specimen can be pinched in two between the thumb and forefinger; remolded by light finger pressure.

4 - 8 Medium stiff

1 – 2(50 – 100)

Can be imprinted easily with fingers; remolded by strong finger pressure.

8 - 15 Stiff 2 – 4(100 – 200)

Can be imprinted with considerable pressure from fingers or indented by thumbnail.

15 - 30 Very stiff 4 – 8(200 – 400)

Can barely be imprinted by pressure from fingers or indented by thumbnail.

>30 Hard > 8>400

Cannot be imprinted by fingers or difficult to indent by thumbnail.

Note that N60-values should not be used to determine the design strength of fine grained soils.

Water ContentWater Content

Description Conditions

DryNo sign of water and soil dry to touch

MoistSigns of water and soil is relatively dry to touch

WetSigns of water and soil definitely wet to touch;

granular soil exhibits some free water when densified

Particle Size DefinitionParticle Size DefinitionDescribing Size DistributionDescribing Size DistributionggTable 4Table 4--44

ggTable 4Table 4--55

Simple Tests for Soil TypeSimple Tests for Soil Type-- CoarseCoarse--Grained SoilsGrained SoilsggFeel and smear testsFeel and smear testsggSedimentation testSedimentation testggVisual characteristicsVisual characteristics

Simple Test for Soil Type Simple Test for Soil Type -- FineFine--Grained SoilsGrained SoilsggShaking (Shaking (dilatancydilatancy) test) testggDry strength testDry strength testggThread testThread testggSmear testSmear test

Field Methods to Describe PlasticityField Methods to Describe Plasticity(Table 4(Table 4--6)6)

Plasticity Range Adjective Dry Strength Smear Test

Thread Smallest Diameter, in

(mm)

0 Nonplastic none - crumbles into powder with mere pressure

gritty or rough ball cracks

1 - 10 low plasticity low - crumbles into powder with some finger pressure

rough to smooth

1/4 – 1/8(6 to 3)

>10 - 20 medium plasticity

medium - breaks into pieces or crumbles with considerable finger pressure

smooth and dull

1/16(1.5)

>20 - 40 high plasticity

high - cannot be broken with finger pressure; spec. will break into pieces between thumb and a hard surface

Shiny 0.03(0.75)

>40 very plasticvery high - can’t be broken

between thumb and a hard surface

very shiny and waxy

0.02(0.5)

Highly Organic SoilsHighly Organic Soils

gg Dark gray and black (sometimes dark brown)Dark gray and black (sometimes dark brown)-- Not all dark colored soils are organicNot all dark colored soils are organic

ggWhen exposed to air, color of sample surface When exposed to air, color of sample surface changes from darker to lighterchanges from darker to lighter-- Pull apart sample to verify darker color insidePull apart sample to verify darker color inside

gg Characteristic odorCharacteristic odorgg FriableFriablegg SpongierSpongiergg DO NOT CONFUSE TOP SOIL WITH ORGANIC DO NOT CONFUSE TOP SOIL WITH ORGANIC

SOILS OR PEATSOILS OR PEAT

Minor Soil TypesMinor Soil Types

ggTrace (between 1 to 12%)Trace (between 1 to 12%)ggSome (between 12 to 30%)Some (between 12 to 30%)

InclusionsInclusions

ggDescribed using “with”Described using “with”ggExamplesExamples

-- With With petroluempetroluem odorodor-- With organic matterWith organic matter-- With foreign matter (roots, bricks, etc.)With foreign matter (roots, bricks, etc.)-- With shell fragmentsWith shell fragments-- With micaWith mica-- With With parting(sparting(s), ), seam(sseam(s) etc. of (give soil’s ) etc. of (give soil’s

complete description)complete description)

Layered SoilsLayered Soils(Table 4(Table 4--7)7)gg PartingPartinggg SeamSeamgg LayerLayergg StratumStratumgg PocketPocketgg LensLensgg VarvedVarvedgg OccasionalOccasionalgg FrequentFrequent

Geological NameGeological Name

ggPotomac Group FormationPotomac Group FormationggYorktown FormationYorktown FormationggCoconino SandstoneCoconino Sandstone


ggAt the end of this session, the participant will At the end of this session, the participant will be able to:be able to:-- Compare soil, rock and intermediate Compare soil, rock and intermediate

geomaterialsgeomaterials ((IGMsIGMs))-- Contrast identification, description and Contrast identification, description and

classificationclassification-- Perform engineering description of soilPerform engineering description of soil

Any Questions?Any Questions?

THE ROAD TOUNDERSTANDING

SOILSAND

FOUNDATIONS



Lesson 04 Lesson 04 -- Topic 2Topic 2Engineering Classification of SoilsEngineering Classification of Soils

(Section 4.2)(Section 4.2)


ggAt the end of this session, the participant will At the end of this session, the participant will be able to:be able to:-- Describe Unified Soil Classification System Describe Unified Soil Classification System

(USCS)(USCS)-- Explain soil plasticity chartExplain soil plasticity chart-- Discuss the AASHTO soil classification systemDiscuss the AASHTO soil classification system

Soil ClassificationSoil Classification

ggUnified Soil Classification System (USCS)Unified Soil Classification System (USCS)ggAASHTO Soil Classification AASHTO Soil Classification SytemSytem

ggClassification of the soils is performed in the Classification of the soils is performed in the laboratorylaboratory

ggGrouping of soils in terms of engineering Grouping of soils in terms of engineering characteristicscharacteristics

USCS (Table 4USCS (Table 4--8, Table 48, Table 4--9)9)

Classification of CoarseClassification of Coarse--Grained Grained SoilsSoilsggCoarseCoarse--grained soils are those in which 50% grained soils are those in which 50%

or more by weight are retained on the #200 or more by weight are retained on the #200 sievesieve

ggFlow chart in Figure 4Flow chart in Figure 4--11

ggALWAYS REVIEW THE GRAIN SIZE ALWAYS REVIEW THE GRAIN SIZE DISTRIBUTION CURVEDISTRIBUTION CURVE

Flow Chart for Classifying CoarseFlow Chart for Classifying Coarse--Grained Soils (Figure 4Grained Soils (Figure 4--1)1)

Study GSD Study GSD CurvesCurvesggFigure 4Figure 4--22

Curve A Curve B

Curve C

D60 = 0.6 mm

D10 = 0.075 mm

D30 = 0.2 mm

10

60u D

DC =

1060

230

c DxDD

C =

Classification of FineClassification of Fine--Grained SoilsGrained Soils

ggFineFine--grained soils are those in which 50% or grained soils are those in which 50% or more by weight pass the #200 sievemore by weight pass the #200 sieve

ggDetermine Atterberg Limits, LL, PLDetermine Atterberg Limits, LL, PLggCompute PICompute PIggUse plasticity chart to classify fineUse plasticity chart to classify fine--grained grained

soilssoils

Plasticity ChartPlasticity Chart

Flow Chart for Classifying FineFlow Chart for Classifying Fine--Grained Soils (Figure 4Grained Soils (Figure 4--4b)4b)

Flow Chart for Classifying Organic Flow Chart for Classifying Organic Soils (Figure 4Soils (Figure 4--4a)4a)

Typical Soil Plasticity DescriptorsTypical Soil Plasticity Descriptors(Table 4(Table 4--11, Table 411, Table 4--12)12)

Adjective for Soil Type, Texture, and Plasticity Chart Location

PlasticityIndex Range

Plasticity Adjective ML & MH

(Silt)CL & CH

(Clay)OL & OH

(Organic Silt or Clay)1

0 nonplastic - - ORGANIC SILT1 - 10 low plasticity - silty ORGANIC SILT

>10 - 20 medium plasticity Clayey silty to no adj. ORGANIC clayey SILT

>20 - 40 high plasticity Clayey - ORGANIC silty CLAY>40 very plastic Clayey - ORGANIC CLAY

1 Soil type is the same for above or below the “A”-line; the dual group symbol (CL-OL or CH-OH) identifies the soil types above the “A”-line.

AASHTO Soil Classification SystemAASHTO Soil Classification System

ggUseful in determining the relative quality of Useful in determining the relative quality of the soil material for use in earthwork the soil material for use in earthwork structures particularly embankments, structures particularly embankments, subgradessubgrades, , subbasessubbases and basesand bases

ggSoil is classified in seven major groupsSoil is classified in seven major groups-- AA--1 to A1 to A--77

AASHTO Soil Classification SystemAASHTO Soil Classification System

ggSoil is classified in seven major groupsSoil is classified in seven major groups-- AA--1 to A1 to A--77

ggAA--1, A1, A--2 and A2 and A--3 are granular soils (<35% 3 are granular soils (<35% pass #200 sieve)pass #200 sieve)

ggAA--4, A4, A--5, A5, A--6 and A6 and A--7 are soils where more 7 are soils where more than 35% pass the #200 sievethan 35% pass the #200 sieve-- Silt and claySilt and clay--type materialstype materials

ggTable 4Table 4--1313

Quality of the Highway Subgrade Quality of the Highway Subgrade MaterialMaterialgg Use Group Index (GI)Use Group Index (GI)

gg If GI<0, use GI=0If GI<0, use GI=0gg Round GI to the nearest whole number, e.g., GI=3.4 Round GI to the nearest whole number, e.g., GI=3.4

to 3; 3.5 to 4to 3; 3.5 to 4gg No upper limit to GINo upper limit to GIgg Quality of performance as a subgrade material is Quality of performance as a subgrade material is

inversely proportional to the GIinversely proportional to the GI-- Higher GI means poorer materialHigher GI means poorer material

GI = (F-35)[0.2+0.005(LL-40)] + 0.01(F-15) (PI-10)

Comparison of USCS and AASHTO Comparison of USCS and AASHTO Soil Classification SystemSoil Classification SystemggFigure 4Figure 4--66ggFigure 4Figure 4--77


ggAt the end of this session, the participant will At the end of this session, the participant will be able to:be able to:-- Describe Unified Soil Classification System Describe Unified Soil Classification System

(USCS)(USCS)-- Explain soil plasticity chartExplain soil plasticity chart-- Discuss the AASHTO soil classification systemDiscuss the AASHTO soil classification system



SOILSAND

FOUNDATIONS



Lesson 04 Lesson 04 -- Topic 3Topic 3Engineering Characteristics of SoilsEngineering Characteristics of Soils

(Section 4.3, 4.4 and 4.5)(Section 4.3, 4.4 and 4.5)


ggAt the end of this session, the participant will At the end of this session, the participant will be able to:be able to:-- Contrast engineering characterization for Contrast engineering characterization for

coarsecoarse--grained and finegrained and fine--grained soilsgrained soils-- Explain potential problems with organic soilsExplain potential problems with organic soils-- Apply engineering characterization to practiceApply engineering characterization to practice

Sands and GravelsSands and Gravels

ggGenerally very good foundation materialsGenerally very good foundation materialsggGenerally very good embankment materialGenerally very good embankment materialggGenerally the best backfill material for wallsGenerally the best backfill material for wallsggMight settle under vibratory loads or blastsMight settle under vibratory loads or blastsggDewatering may be difficultDewatering may be difficultggGenerally not frostGenerally not frost--susceptiblesusceptible

FineFine--grained Soils (Inorganic Clays)grained Soils (Inorganic Clays)

gg Generally low shear strengthGenerally low shear strengthgg Plastic and compressiblePlastic and compressiblegg Can lose part of shear strength upon wetting and Can lose part of shear strength upon wetting and

disturbancedisturbancegg Can shrink upon drying and expand on wettingCan shrink upon drying and expand on wettinggg Generally very poor material for backfillGenerally very poor material for backfillgg Generally poor material for embankmentsGenerally poor material for embankmentsgg Can be practically imperviousCan be practically imperviousgg Clay slopes are prone to landslidesClay slopes are prone to landslides

FineFine--grained Soils (Inorganic Silts)grained Soils (Inorganic Silts)

ggRelatively low shear strengthsRelatively low shear strengthsggHigh capillarity and frost susceptibilityHigh capillarity and frost susceptibilityggRelatively low permeabilityRelatively low permeabilityggFrost heave susceptibilityFrost heave susceptibilityggDifficult to compactDifficult to compact

Organic SoilsOrganic Soils

ggReduces load carrying capacity of soilsReduces load carrying capacity of soilsgg Increases compressibility considerablyIncreases compressibility considerablyggFrequently contains toxic gases that are Frequently contains toxic gases that are

released during excavation processesreleased during excavation processes

ggNot suitable as construction materialsNot suitable as construction materials

Practical Aspects of CoarsePractical Aspects of Coarse--Grained Grained SoilsSoilsggUse wellUse well--graded soils as backfillgraded soils as backfill

-- Can be compacted to a dense stateCan be compacted to a dense stateggUse uniformly graded soils as drainage Use uniformly graded soils as drainage

materialsmaterialsggAvoid gapAvoid gap--graded soils for drain materialsgraded soils for drain materials

Practical Aspects of FinePractical Aspects of Fine--Grained Grained SoilsSoilsggAre more compressibleAre more compressibleggHave greater potential to shrink upon drying Have greater potential to shrink upon drying

and swell upon wettingand swell upon wettingggAre less permeableAre less permeable


ggAt the end of this session, the participant will At the end of this session, the participant will be able to:be able to:-- Contrast engineering characterization for Contrast engineering characterization for

coarsecoarse--grained and finegrained and fine--grained soilsgrained soils-- Explain potential problems with organic soilsExplain potential problems with organic soils-- Apply engineering characterization to practiceApply engineering characterization to practice



SOILSAND

FOUNDATIONS



Lesson 04 Lesson 04 -- Topic 4Topic 4Engineering Description of Rock and Rock Engineering Description of Rock and Rock

Mass ClassificationMass Classification(Section 4.6)(Section 4.6)


ggAt the end of this session, the participant will At the end of this session, the participant will be able to:be able to:-- Identify rock characterization componentsIdentify rock characterization components-- Contrast intact rock and rock mass performanceContrast intact rock and rock mass performance-- Describe rock mass classificationDescribe rock mass classification

Description of RockDescription of RockInternational Society of Rock Mechanics (ISRM)International Society of Rock Mechanics (ISRM)

ggRock typeRock typeggColorColorggGrain size and shapeGrain size and shapeggTexture (stratification / foliation)Texture (stratification / foliation)ggMineral compositionMineral compositionggWeathering and AlterationWeathering and AlterationggStrengthStrengthggOther relevant factorsOther relevant factors

Rock TypeRock TypeTable 4Table 4--1616gg IgneousIgneous

-- Intrusive (coarse grained)Intrusive (coarse grained)-- Extrusive (fine grained)Extrusive (fine grained)-- PyroclasticPyroclastic

gg SedimentarySedimentary-- ClasticClastic (sediment)(sediment)-- Chemically formedChemically formed-- Organic remainsOrganic remains

gg MetamorphicMetamorphic-- FoliatedFoliated-- NonNon--foliatedfoliated

Color and Grain SizeColor and Grain Size

ggSame as soilsSame as soils

ggTable 4Table 4--1717ggTable 4Table 4--1818

Texture (Stratification/Foliation)Texture (Stratification/Foliation)Table 4Table 4--1919

ggDescribe stratum thicknessDescribe stratum thickness-- Very thickly beddedVery thickly bedded > 1m> 1m-- Thickly beddedThickly bedded 0.5m to 1m0.5m to 1m-- Thinly beddedThinly bedded 50 mm to 500 mm50 mm to 500 mm-- Very thinly beddedVery thinly bedded 10 mm to 50 mm10 mm to 50 mm-- LaminatedLaminated 2.5 mm to 10 mm2.5 mm to 10 mm-- Thinly laminatedThinly laminated < 2.5 mm< 2.5 mm

Weathering and AlterationWeathering and AlterationTable 4Table 4--20 20 ggGrade I Grade I FreshFreshggGrade II Grade II Slightly weathered/alteredSlightly weathered/alteredggGrade III Grade III Moderately weathered/alteredModerately weathered/alteredggGrade IV Grade IV Highly weathered/alteredHighly weathered/alteredggGrade V Grade V Completely weathered/alteredCompletely weathered/alteredggGrade VI Grade VI Residual SoilResidual Soil

Rock StrengthRock StrengthTable 4Table 4--21 21 ggR0R0 Extremely weak rockExtremely weak rockggR1 R1 Very weak rockVery weak rockggR2R2 Weak rockWeak rockggR3R3 Medium strong rockMedium strong rockggR4R4 Strong rockStrong rockggR5R5 Very strong rockVery strong rockggR6R6 Extremely strong rockExtremely strong rock

Rock HardnessRock HardnessTable 4Table 4--22 22 ggS S SoftSoftggF F FriableFriableggLHLH Low hardnessLow hardnessggMHMH Moderately hardModerately hardggHH HardHardggVHVH Very hardVery hard

Rock DiscontinuityRock DiscontinuityTable 4Table 4--23, Table 423, Table 4--24 24 ggDiscontinuity typeDiscontinuity typeggType of infillingType of infillingggAmount of infillingAmount of infillingggDiscontinuity spacingDiscontinuity spacingggDiscontinuity widthDiscontinuity widthggSurface shape of jointSurface shape of jointggRoughness of surfaceRoughness of surfaceggAperture sizeAperture size

Rock Mass ClassificationRock Mass ClassificationTable 4Table 4--25, 425, 4--2626ggAssign a relative rating to 5 measurable Assign a relative rating to 5 measurable

parameters (Table 4parameters (Table 4--25)25)-- StrengthStrength-- RQDRQD-- Spacing of jointsSpacing of joints-- Condition of jointsCondition of joints-- Groundwater conditionsGroundwater conditions

ggRock Mass Rating (RMR) is the sum of all the Rock Mass Rating (RMR) is the sum of all the relative ratingsrelative ratings

Rock Mass ClassificationRock Mass ClassificationTable 4Table 4--2727ggUsing RMR, classify rock mass using Table Using RMR, classify rock mass using Table

44--2727-- Class IClass I Very good rockVery good rock-- Class IIClass II Good rockGood rock-- Class IIIClass III Fair rockFair rock-- Class IVClass IV Poor rockPoor rock-- Class VClass V Very poor rockVery poor rock

ggRMR is used to develop engineering RMR is used to develop engineering properties of rock, e.g., elastic modulusproperties of rock, e.g., elastic modulus


ggAt the end of this session, the participant will At the end of this session, the participant will be able to:be able to:-- Identify rock characterization componentsIdentify rock characterization components-- Contrast intact rock and rock mass performanceContrast intact rock and rock mass performance-- Describe rock mass classificationDescribe rock mass classification



SOILSAND

FOUNDATIONS



Lesson 04 Lesson 04 -- Topic 5Topic 5Subsurface Profile DevelopmentSubsurface Profile Development

(Section 4.7)(Section 4.7)


ggAt the end of this session, the participant will At the end of this session, the participant will be able to:be able to:-- Review components of soil profileReview components of soil profile-- Construct subsurface soil profileConstruct subsurface soil profile-- Interpret subsurface soil profileInterpret subsurface soil profile

Subsurface Profile DevelopmentSubsurface Profile Development

gg Interpret the engineering dataInterpret the engineering datagg Identify average soil and rock propertiesIdentify average soil and rock propertiesggLocate groundwater levelLocate groundwater levelggNotations for special items such as boulder, Notations for special items such as boulder,

artesian pressure, etc.artesian pressure, etc.

Subsurface Profile DevelopmentSubsurface Profile Development

Use of Historical Data in Use of Historical Data in Development of Subsurface ProfilesDevelopment of Subsurface ProfilesggHistorical data can be very usefulHistorical data can be very usefulggBe careful and verify the intent, exact Be careful and verify the intent, exact

location and accuracy of the development of location and accuracy of the development of historical datahistorical data

gg If the historical boring cannot be located If the historical boring cannot be located properly then perhaps it should not be properly then perhaps it should not be included in the subsurface profileincluded in the subsurface profile


ggAt the end of this session, the participant will At the end of this session, the participant will be able to:be able to:-- Review components of soil profileReview components of soil profile-- Construct subsurface soil profileConstruct subsurface soil profile-- Interpret subsurface soil profileInterpret subsurface soil profile


Road to the Laboratory

SOILS AND FOUNDATIONSSOILS AND FOUNDATIONS

Testing

Experience

Theory

Lesson 05Lesson 05Chapter 5 Chapter 5 –– Laboratory Testing Laboratory Testing

for Geotechnical Design and Constructionfor Geotechnical Design and Construction

TopicsTopics

ggTopic 1 (Visit the laboratory)Topic 1 (Visit the laboratory)-- Laboratory sessionLaboratory session

ggTopic 2 (All sections in Chapter 5)Topic 2 (All sections in Chapter 5)-- Classroom sessionClassroom session

LABORATORY TESTING FOR LABORATORY TESTING FOR GEOTECHNICAL DESIGN AND GEOTECHNICAL DESIGN AND

CONSTRUCTION CONSTRUCTION Lesson 05 Lesson 05 -- Topic 1Topic 1Laboratory SessionLaboratory Session

Visit the laboratoryVisit the laboratory


ggAt the end of this session, the participant will At the end of this session, the participant will be able to:be able to:-- Identify tests conducted by the State AgencyIdentify tests conducted by the State Agency-- Recall the typical soils of the StateRecall the typical soils of the State

Back to the ClassroomBack to the Classroom

BACK TO THECLASSROOM

SESSION


ggAt the end of this session, the participant will At the end of this session, the participant will be able to:be able to:-- Identify tests conducted by the State AgencyIdentify tests conducted by the State Agency-- Recall the typical soils of the StateRecall the typical soils of the State

Interstate 0 Interstate 0 –– Apple FreewayApple FreewayNote: Scale shown in Station FormNote: Scale shown in Station Form

Baseline Stationing

Baseline Stationing

S.B. Apple Frwy

N.B. Apple Frwy

Proposed Toe of SlopeProposed Toe of Slope

Existing Ground SurfaceExisting Ground Surface

12

Proposed Final GradeProposed Final GradeProposed AbutmentProposed Abutment

Interstate 0Interstate 0

9090 9191 9292 9393

Apple Freeway Apple Freeway ExerciseExerciseggAppendix AAppendix A

-- Section A.3Section A.3

Subsurface explorations

Terrain reconnaissance Site inspection Subsurface borings

Basic soil properties

Visual description Classification tests Soil profile

Laboratory testing po diagram Test request Consolidation results Strength results

Slope Stability

Design soil profile Circular arc analysis Sliding block analysis Lateral squeeze analysis

Approach roadway settlement

Design soil profile Magnitude of settlement Rate of settlement Surcharge Vertical drains

Spread footing design Design soil profile

Pier bearing capacity Pier settlement Abutment settlement Surcharge Vertical drains

Driven pile design Design soil profile

Static analysis – pier Pipe pile H – pile Static analysis – abutment Pipe pile H – pile Driving resistance Lateral movement - abutment

Construction monitoring

Wave equation Hammer approval Embankment instrumentation

Develop a Preliminary Idealized Soil Develop a Preliminary Idealized Soil Profile for Analysis and DesignProfile for Analysis and DesignggStep 1Step 1

-- Locate the borings in planLocate the borings in planggStep 2Step 2

-- Show elevation view of borings, soundings and Show elevation view of borings, soundings and auger holesauger holes

ggStep 3Step 3-- Develop preliminary idealized soil by Develop preliminary idealized soil by

interpolating between borings to identify zones interpolating between borings to identify zones where soils may have similar characteristicswhere soils may have similar characteristics

Designer’s Interpretation of Designer’s Interpretation of Preliminary Idealized ProfilePreliminary Idealized Profile

Summary of Soil CharacteristicsSummary of Soil Characteristics

gg Based on field descriptionBased on field description-- Predominant soil types are sand, Predominant soil types are sand, siltysilty clay and sandy clay and sandy

gravelgravelgg Based on laboratory classificationBased on laboratory classification

-- Sand (SW), Sand (SW), SiltySilty Clay (CL), and Sandy Gravel (GW) as per Clay (CL), and Sandy Gravel (GW) as per USCSUSCS

gg Moisture contentMoisture content-- Shown next to NShown next to N--values on the profilevalues on the profile

gg Subsurface profileSubsurface profile-- Use CPT in conjunction with SPT based profileUse CPT in conjunction with SPT based profile-- CPT indicates that CPT indicates that siltysilty clay layer may contain distinct clay layer may contain distinct

seams of silt which can reduce consolidation timeseams of silt which can reduce consolidation time



SOILSAND

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SOILS AND FOUNDATIONS Lesson 04 667 Geotech Design... · SOILS AND FOUNDATIONS Testing Experience...

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