Advances and Research Trends in GeoEnvironmental Engineering and GeoHazards Mitigation Juan M Pestana University of California, Berkeley. National Science Foundation US- South America Workshop on Mechanics and Advanced Materials Research & Education. Rio de Janeiro, Brazil. August 5, 2004
General Hazards. • Natural Hazards. • Man-made Hazards –GeoEnvironmental Problems –Terrorism.
Motivation Natural Hazards - Exposure Annual exposure of worldwide population � 1. Cyclones, Hurricanes and Tornados – 119 m 2. Floods – 196 m 3. Earthquakes – 130 m 4. Drought – 220 m (source: UNDP- Reducing Disaster Risk – 2004)
Natural Hazards - Losses � For the US – based on best data available 1. Tornados and Hurricanes - $3.5b/yr – Population in hurricane prone coastal areas is increasing 2. Floods - $5b/yr – Development in flood plains and increase in heavy rains 3. Earthquakes - $4-5b/yr – 39 states and 75m people are exposed to earthquake hazard 4. Drought - $6-8 b/yr – 35 % of the country exposed. Population shift to drier regions and land and water use effects.
Advances and Research Trends • GeoEnvironmental Engineering – Multidisciplinary approach to model, simulate and evaluate material response for remediation applications. • GeoHazards Mitigation – Multilevel processes and integrated systems. Large Scale Simulations. – New technologies for modification of “natural” and “built” environment. Smart Materials.
Advances and Research Trends • For both: Realization that you must deal with existing “materials” soils with complex behavior. – Rapid developments of non-intrusive techniques for site investigation/ characterization and monitoring. – Soil can be highly heterogeneous, so the introduction of uncertainty and stochastic simulation of both material properties and behavior.
Advances and Research Trends • Introduction of Uncertainty at all levels and use stochastic simulations, rather than deterministic approaches. • Improved Simulation Methods (multiprocesses and multiscale) • Multi-scale Monitoring Systems to evaluate performance- Need for “smart”- networked sensors. • Consistent evaluation of risk.
Advances and Research Trends Example: GeoEnvironmental Engineering • Conception/construction of “smart” barriers for contaminant migration. – Need to incorporate complex mechanisms and interactions: chemical, biological and mechanical response. – Iron, zeolites soil mixes for degradation, absorption and reduction of seepage velocity for organic compounds. – Monitoring? Embedded or remote sensors
Advances and Research Trends Example: GeoHazard Drought-Flood • Use of Multi-scale monitoring (sensors) systems to integrate vastly different data types (precipitation, soil moisture, temperature). Remote sensing for determining health of vegetative cover. • Use of sophisticated “global” or large scale stochastic models to simulate and predict catastropic events as drought and floods.
Advances and Research Trends Example: Earthquake Hazards • Prevention of poor performance of loose soils during earthquake loading : liquefaction. – Use of biological methods to alter material response – Chemical/ Mechanical – Complex Biochemical mechanical Nanoprocesses
Foundation Failure Structural- adequate System Performance= Unacceptable
B B 0.4 0.4 Example:Enhanced 0.2 0.2 C C SSR strike SSR strike Understanding of 0.0 0.0 A A Material Response -0.2 -0.2 bubble diameter= σ ' v / σ ' c D -0.4 -0.4 D Deformation -0.4 -0.2 0.0 0.2 0.4 -0.4 -0.2 0.0 0.2 0.4 SSR dip Potential for SSR dip Liquefaction Prone 15 Soils under 10 B D c ) B Multidirectional 0.4 5 SSR ( τ/σ ' C γ strike 0 Excitation – after A 0.2 -5 Kammerer, Pestana -10 D A C & Seed (2004) 0.0 -15 10 15 20 25 30 0.0 0.4 0.8 γ dip Norm. Eff. Vert. Stress ( σ ' v / σ ' c )
Multi-disciplinary Approach Seismic event Seismic Hazard Earth Sciences Transmission of Seismic waves Site Response Soil-Foundation-Structure Interaction Performance Engineering Simulation System Response Performance Modeling Consequences Impact Social Sciences (Losses/Decisions) Assessment
Multidisciplinary Approach Example: Earthquake Hazards � Seismology � Tsunamis � Geotechnical engineering � Built environment - Buildings & Lifelines � Risk assessment – Decision sciences � Public policy
Advances and Research Trends Earthquake Hazards • Use of Large scale testing for both individual components (beams, columns) and multicomponent arrays (structural and non-structural elements). • Analysis and Simulation of large scale systems. • Use of smart-networked sensors to monitor health and identified adverse performance.
Network for Earthquake Engineering Simulation (NEES) � Goal � Improve understanding of effect of earthquakes on building and infrastructural systems through collaborative research � 16 Universities are funded for enhanced capabilities in earthquake engineering research � Research � $9 million annual commitment (FY 2004)
NEES Resources Rem ote Users NEES Resources ( Faculty, Instrum ented Students, Structures Practitioners) Sim ulation and Sites Tools Repository High- Laboratory Perform ance Equipm ent Netw ork(s) Field Equipm ent Curated Data Repository Leading Edge G lobal Com putation Connections (FY 2005 – FY 2014) Rem ote Users: Laboratory Equipm ent ( K-12 Faculty and Students) V. M ujum da r George E. B row n, Jr. N etw ork for Earthquake Engineering Sim ulation
NEES Capabilities � Integrates resources for research and education to serve the earthquake engineering community � Shared use facilities, � Data repository, � Simulation tools, � Collaborative/communication tools, � Numerical and model-based simulation, � Partnering, training, …
Illustration Super-material (UCSD) • Fiber-reinforced polymeric composite with embedded microchips with on board data processors and copper wires • Sensors provide information on damage and ambient conditions to assess the condition of the structure • Copper wire allow wireless communication • Embedded sensors allow tunable electromagnetic properties to heal the material
Summary. • Soil as a complex material: non-intrusive site investigation and material parameter determination. Incorporation of uncertainty • Infrastructure as complex systems requiring multi- scale and networked sensors and the associated processing capability. • Modification of material response for both natural and constructed systems. Smart materials • Multidisciplinary approach and incorporation of multiple mechanisms and processes to describe complex material response
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