Instructors Praveen K. Malhotra, Ph.D., P.E., M.ASCE, Dr. Malhotra is a Senior Research Specialist with FM Global in Norwood, MA. He has published extensively on seismic response of tanks. He is the current chair of the ACI 376 task group for seismic design of LNG tanks. He has actively participated in updating the tank design provisions in NEHRP, Eurocode and Indian Standard. Dr. Malhotra received his Ph.D. in structural/geotechnical earthquake engineering from Rice University. He is a member of the American Concrete Institute (ACI), Earthquake Engineering Research Institute (EERI), Seismological Society of America (SSA), and the Indian Society of Earthquake Technology (ISET). He is a registered Civil Engineer in California.

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Course Description Under gravity loads, upright cylindrical tanks are highly efficient structural systems for storing liquids such as drinking water, sprinkler water, crude oil, LNG, wines and juices. Under earthquake loads, a complicated pattern of stresses is generated in the tanks. Poorly designed tanks have leaked, buckled or even collapsed during earthquakes. Common modes of failure are wall buckling, sloshing damage to roof, inlet/outlet pipe breaks and implosion due to rapid loss of contents. In recent years, significant advances have occurred in linear and nonlinear dynamic analyses of tank-liquid-foundation system. Significant advances have also occurred in site-specific estimates of ground motion parameters. Modern seismic analyses are based on probabilistic response spectrum rather than deterministic peak ground acceleration. This seminar will present a step-by-step discussion of advances in ground motion estimates and dynamic response analyses.

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Seminar Benefits

• Gain an understanding of the dynamic response of tanks
• Learn to obtain site-specific response spectra for tanks
• Learn rules to avoid common modes of failure in tanks
• Learn about the shortcomings of current design provisions
• Learn changes to the seismic design provisions in AWWA
  D 100, API 650 and ACI 376
• Learn about nonlinear analysis of tanks
  
• Learn about base isolation and energy dissipation techniques to improve seismic performance of tanks

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Who Should Attend

Structural and geotechnical engineers, planners, risk managers and manufacturers interested in design and performance assessment of tanks for various applications.

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Summary Outline 8:00 AM to 9:45 AM 8:00 AM to 9:45 AM Introduction Model of tank-liquid system Impulsive, convective and ‘breathing’ modes of vibration Ground-supported and elevated tanks 10:00 AM to 12:00 Noon Design Response Spectrum Definition of response spectrum Response spectrum from ASCE 7-02 Spectrum from site-specific analysis Displacement-sensitive region of response spectrum Spectrum of vertical motion Damping adjustment of response spectrum 1 PM to 2:45 PM Seismic Response of Tanks Moments, base shear, axial and hoop stresses in tank wall Sloshing at free-surface Freeboard requirement Roof loads in tanks with insufficient freeboard 3 PM to 5 PM Special Topics Soil-structure interaction analysis Nonlinear static (pushover) analysis of tanks Base isolation Seismic energy dissipation

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