CEE 437 Lecture 1

April 1, 2008Thomas Doe

Bill Dershowitz

Outline

Course IntroductionGeology and EngineersBrief History of GeologyGlobal StructurePlate TectonicsThe Rock Cycle and Material Differentiation

Instructors

Thomas Doe, Golder AssociatesMS, PhD, Geology, Mining Engineering, WisconsinFractures, Fracture fluid flow, geo-characterization, in situ stressTunnels, hydroelectric projects, petroleum reservoirs, mine inflow

William Dershowitz, Golder AssociatesMS, PhD MITFractures, fluid flow and rock mass stabilityProbabilistic simulation, fracture network modelingRadioactive waste R&D, Petroleum reservoirs, mining applications (block caving)

Class Overview

Basic Treatment of Physical GeologyEmphasis on Material PropertiesEmphasis on Pacific Northwest

Geo-CharacterizationSite CharacterizationGeophysics

Rock EngineeringGeohydrology

Preliminary SyllabusCEE 437 Syllabus, Rev. 2008-04-03

Week Day Date Student Presentation Lecturer Quiz Project LectureTextbook -Waltham

1 Tue 1-Apr Doe Overview: Earth as an Engineering Material Ch. 1

1 Thu 3-Apr DoePlate tectonics, rock cycle, mineral introduction Ch. 9,10

2 Tue 8-Apr Dershowitz Origin and Classification of Soils Ch. 13,26,36

2 Thu 10-Apr Dershowitz Landslides and slope stability Ch. 33, 34,35

3 Tue 15-AprGeologic History of Puget Sound

DoeWeathering, Sediments and Clay Minerals

3 Thu 17-AprCoal Mines of Newcastle, Washington

Doe Glacial Sediments and Subsidence

4 Tue 22-AprGeologic History of Olympic Peninsula

Dershowitz Q1 (to 4/17)Structural Geology, Rock Deformation Ch. 6,7,8

4 Thu 24-AprGeological Issue Effecting Construction of I-5 through Seattle Dershowitz P1 Rock Fractures Handouts

5 Tue 29-AprThe Seattle Fault

West Geologic Aspects of Seismic EventsCh. 10, Handouts

5 Thu 1-May Foundations on Peat DoeRock-forming minerals; mineral deformation

6 Tue 6-May Rock Slope Stability Problems in I-90 Doe P2 Igneous and Metamorphic Rocks6 Thu 8-May Sylwester Q2 (to 5/6) Engineering Geophysics7 Tue 13-May Fracture Image Logging Technologies Doe7 Thu 15-May Doe

8 Tue 20-May Dershowitz Rock Mass ClassificationCh. 24-25, Appendix

8 Thu 22-May Dershowitz Q3 (to 5/20) P3 Slopes and Foundations in Rock Ch. 32,35,36

9 Tue 27-May Tunneling for Sound Transit Dershowitz Tunnels and Underground Openings Ch. 38-39

9 Thu 29-May Seattle Watershed Geology Dershowitz Ch. 1810 Tue 3-Jun Rock Tunnel Failures in the Alps Dershowitz Handouts10 Thu 5-Jun Dershowitz Q4 (to 6/3) P4 Leftovers Ch. 27,37,40

Ch. 3-4, 13-17, (28-30)

Site Characterization Techniques Ch. 19-23

Ch. 2-5

Groundwater and Geologic Settings

What We Can and Can’t Do

Cannot doProvide enough to pass the state engineering geology testProvide a comprehensive engineering geology curriculum

Can doProvide an appreciation of the importance of geology in engineeringProvide a good overview of issues of Pacific Northwest significance

Course Grading

Quizzes (4 drop 1) 25%Projects 30%Field Trip 20%Presentation 10%Class Participation 10%Engineer as Artist Notes 5%

Geology SubdivisionsAcademic – earth history and fundamental processes

Mineralogy, Petrology – Rocks, mineral and originsStratigraphy – classification and definition of beds (sedimentary)Structure/Tectonics – earth structure and originsGeochemistryGeophysicsGeomorphology

Applied – applications to specific industries, engineering and environment

Petroleum Geology/GeophysicsEconomic Geology (Minerals)Environmental Geology (geophysics, geochemistry)HydrogeologyEngineering Geology (geophysics, geochemistry)

Geo-engineeringGeotechnical Engineering – Soil MechanicsRock Mechanics – as it saysGeological Engineering

Three Uses of Geology in Engineering

Evaluate and predict the distribution of materials with specific engineering properties

Subsurface evaluation – uncertainty and propertiesAvailability of materials

Evaluate the actions of geologic processes on engineering structures

SeismicFloodSlopes

Evaluate the impact on engineering development on human and natural environments

What is Engineering Geology?Critical Question: How do geomaterials perform? How do they move?Granular materials

River sedimentsGlacial sedimentsSoilsWeathered Materials

Hard RockRock properties usually secondary (except deep mining and excavation concerns)Fractures and discontinuities

Rock as and Engineering Material

HeterogeneousHighly variable

Treat probabilistically, probability density functionsTreat with geologic insight

AnisotropicDirectional

Strength, elastic constants vary with directionTreat using tensor properties

Scale DependentMineral/Crystalline scaleRock Sample ScaleRock Mass Scale

Heterogeneity

Rock properties vary from location to location (sometimes very drastically)Reduce by explorationTreat mathematically by probabilistic methodsReduce through geologic insight

Anisotropy

Depends on scaleMineral propertiesRock fabric/textureRock fracturing

Properties affectedPermeabilityStrengthElastic properties

Represent properties as tensors

Scale Effects

Behavior depends on the scale of critical processBehavior depends on what aspect of geology controls critical behaviors

Differentiation

Geologic processes work by differentiationCrustal-scale processesMagmatic differentiationSedimentary differentiation

Case Study – Snoqualmie Rock Slope Failures

Rock slide on I-90, September 11500 cubic yardsThree fatalitiesInterstate closure for over 12 hours

Why Did it Fail Now?

Why was it stable?Fracture roughnessFracture persistence

Why did it fail?Water inflow/pore pressureWeathering degradationBad luck?