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Jim_Mitchell_Nottingham Centre for Geomechanics_talk.ppt
- 3. To understand wherewe are and to help predict where we are going, it is useful to review where we have been.
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- 6. EVOLUTION Prior to 1940- Karl Terzaghi After World War II: Political and societal demands for: New structures and facilities Protection and enhancement of environment New resources Mitigation of natural disaster risks
- 7. SOIL MECHANICS ANDFOUNDATION ENGINEERING EDUCATION IN 1949 Scope of field limited mainly to: Soil Classification Capillarity and seepage Stress analysis by elasticity Consolidation and settlement analysis Shear strength Slope stability Lateral pressures Bearing capacity Shallow and deep foundations Emphasis largely on saturated clays and sands
- 9. DEVELOPMENTS FROM 1950- 1960 Slope stability Shear strength Soil structure, causes of clay sensitivity Compacted clay properties Pavement design Soil stabilization Transient loading
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- 11. Effect of Disturbance on aQuick Clay
- 12. Undisturbed Quick Clay fromDrammen, Norway Width = 20mm
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- 15. DEVELOPMENTS FROM 1960-1970 Pore pressure, effective stress analysis Physico-chemical phenomena Rock Mechanics Computer applications Finite element analyses Soil-structure interaction Soil dynamics Liquefaction Earth and rockfill dams Offshore, cold region, lunar projects
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- 19. Mobile Caisson forArctic Exploration
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- 22. DEVELOPMENTS FROM 1970-1980 Constitutivemodeling In-situ testing Expansive soils Soil dynamics Centrifuge testing Partly saturated soils Geotechnical earthquake engineering Underground construction
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- 26. Lower San FernandoDam Failure, 1971
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- 29. DEVELOPMENTS FROM 1980-1990 Riskand reliability Groundwater and geohydrology Geoenvironmental engineering Geosynthetics Earth reinforcement Ground improvement
- 30. Groundwater Contamination Industrial wasteshave been disposed in many ways
- 31. Placement of aGeomembrane
- 32. Reinforced Earth Wall,Valdez, Alaska
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- 35. DEVELOPMENTS FROM 1990-2000 Wastecontainment Site remediation Seismic risk mitigation Land reclamation Infrastructure Geophysical applications Geographic information systems
- 36. Rumpke MSW Landfill Failure 12.5ha 36 m headscarp Max. waste depth of 110 m Toe moved 300 m in 5 minutes Pre-failure slope of 2.6:1
- 37. Downstream Treatment at MormonIsland Dam
- 38. I-15 / I-80East / SR-201 Junction (Artist's Rendition) Salt Lake City
- 40. MOST SIGNIFICANT RESEARCHCONTRIBUTIONS FROM 1950 – 2000 IN THE UNITED KINGDOM 1. Critical state soil mechanics 2. Small strain and non-linear stiffness 3. Effective stress triaxial testing 4. Numerical analysis 5. Centrifuge modeling 6. Effects of structure and fabric 7. Residual strength in OC soil 8. Partially saturated soils 9. Effective stress analysis of slopes and retaining structures 10. Field measurements at the BRE
- 42. SITUATION AT THEBEGINNING OF THE NEW MILLENNIUM
- 43. SCOPE OF GEOTECHNOLOGY Geotechnical engineering Geology and engineering geology Geophysics Geochemistry Geohydrology Seismology Civil engineering Mining and mineral engineering Petroleum engineering Information science and technology
- 44. PROJECTS AND PROBLEMS Foundations for structures of all types Transportation infrastructure (roads, airfields, rail, ports and harbors, underground) Land reclamation Seismic safety – mitigation of seismic risk Resource recovery Energy Preservation and restoration of old structures
- 45. TOWER OF PISA IN1957 (Speaker’s green automobile for scale)
- 46. PROJECTS AND PROBLEMS(cont.) Waste disposal and containment Site remediation and environmental enhancement Soil and rock as construction materials Deep Ocean, Cold Regions, Space Natural hazard protection and risk reduction (landslides, tornadoes, hurricanes, tsunamis, expansive soils, floods)
- 47. NEW TECHNOLOGIES ANDMATERIALS Earth reinforcement Deep soil mixing Jet grouting Compaction grouting Geosynthetics
- 48. NEW TECHNOLOGIES ANDMATERIALS (Cont.) Micro-piles Micro-tunnels Geocomposites Geophysical methods
- 49. INVASIVENESS OF MEASUREMENTS •Satellites, Aircraft • Helicopter • Walk on ground • Disturbance, < 1m • Disturbance, < 100 m • Remote sensing, photo • Remote sensing, electromagnetic magnetic • Magnetics, gravity, GPR, conductivity • Seismic, resistivity, sampling: geochemical, biological, soil • Penetrometers; boreholes and samples, downhole measurements, tomography INCREASING INVASIVENESS
- 50. APPLICATIONS OF NON-INVASIVEMETHODS Characterization of subsurface for: - waste disposal, containment, remediation - infrastructure construction Locating: - voids - resources - underground utilities - buried land mines and unexploded ordnance Monitoring: - ground movements - infrastructure decay Archeological or forensic investigations Search and rescue
- 51. NEW REALITIES OFENGINEERING PRACTICE AND CONSTRUCTION Public participation Regulatory and Legal issues Health and Safety Decision and risk analysis Design-Build replacing Design-Bid-Build Questionable benefit/cost Struggling economies Poorly defined goals
- 53. PREDICTING THE FUTURE “Predictionsare very difficult – especially about the future” (Neils Bohr)
- 54. “Heavier than airflying machines are impossible.” (Lord Kelvin, 1895) “I think there is a world market for maybe five computers” (Thomas Watson, Chairman of IBM, 1943)
- 55. “We don’t liketheir sound, and guitar music is on the way out.” (Decca Records rejection of the Beatles, 1962) “640 K ought to be enough for anybody” (Bill Gates, 1981)
- 56. SOME KNOWLEDGE NEEDS Liquefaction and predicting its consequences Evaluation of improved ground Prediction of deformations Dealing with Difficult Dirt Foundation Capacity Improved site characterization Constitutive models (always!)
- 57. PAPERS IN THE2001 J.G.E.E., A.S.C.E. (What people are working on) Piles and drilled piers 19 Geotech EQ engrg and liquefaction 13 Constitutive behavior, mechanics 7 Ground improvement and stabilization 7 Properties and behavior 6 Micro-mechanics 5 Contaminant transport 5 Stability 5 Geosynthetics 5 Lateral Pressures, excavations 4 Others 13
- 58. NETWORK FOR EARTHQUAKE ENGINEERINGSIMULATION (NEES) (Sponsored by the National Science Foundation) A system of experimental facilities linked by advanced telecommunications that is capable of real-time interactive collaboration across the U.S.
- 59. SOME NEW FRONTIERS Micro-mechanics Nano-technologies Biologicalprocesses “Seeing into the earth” Smart materials Self-monitoring and correcting systems
- 60. KEY QUESTIONS What issoil? How does it respond to different stimuli? Why does it respond this way? How do we relate the answers to these questions to the problem or project at hand?
- 61. Fundamental Mechanical Properties Volumechange Stress-strain Strength Hydraulic conductivity (and their changes with time)
- 62. MOST IMPORTANT UNSOLVEDPROBLEMS Commoditization of services Narrowing the gap between “state-of- practice” and “state-of-knowledge” – rapid transfer of best research results into practice Seismic behavior of earth structures Displacements of earth structures during and after construction
- 63. MOST IMPORTANT UNSOLVEDPROBLEMS (Cont.) Characterizing and designing for materials falling between soil and rock Time effects in disturbed ground Improved site characterization How to generalize and simplify the discipline
- 65. RESEARCH WITH HIGHPAYOFF BY 2010 Faster, less expensive, more reliable in-situ testing Rapid methods of site assessment/characterization/investigation Less expensive, easier to use high level analysis methods New and better ground improvement technologies
- 66. RESEARCH WITH HIGHPAYOFF BY 2010 (Cont.) How to apply GIS and the WWW to maximize value of our collective knowledge base 21st Century implementation of the Observational Method – real time integration of observations, test data, analysis and design during construction
- 67. On this occasionof the launch of the new Nottingham Centre for Geomechanics, the challenges are many, the opportunities to make a difference are great, and I wish you all the best success in your efforts to lead the way during the exciting and unpredictable times that lie ahead.