Schedule
Week 1 — Introduction and background
Learning outcomes
- Identify key properties and defining characteristics of tornadoes
- Explain the current state of practice with regard to design for tornadoes
- Estimate tornado speeds required to cause specific levels of damage to typical buildings
Lectures (7)
- Course introduction – overview; syllabus, learning objectives, logistics
- Tornado characteristics – what is a tornado; tornado hazards; how do they form; path length and width
- Tornadic winds – rating tornadoes from damage using the EF Scale; measured tornado speeds from radar
- Tornado climatology ‐ when and where do tornadoes occur; occurrence rates; population bias
- Tornado impacts – tornado damage and common damage mechanisms; tornado losses to life and property
- Current practice for tornado design – existing codes and standards; storm shelters; nuclear facilities
- Overview of ASCE 7‐22 tornado requirements – scope of tornado provisions in Ch. 1, 2, 26, 32, and appendix G
Week 2 — Tornado load procedures and tornado hazard maps
Learning outcomes
- Summarize the scope and limitations of ASCE 7‐22 tornado load requirements
- Identify tornado load symbols and notations
- Explain the process for development of the tornado hazard maps
- Determine tornado speed for any geographic location, building/facility size, shape, and risk category
- Determine if design for tornado loads is required or not
Lectures (6)
- Tornado load framework – tornado‐related provisions of Ch. 1, 2, and 26; Ch. 32 coverage and organization
- Tornado load procedures – section 32.1: scope, limitations, methods, performance‐based design
- General tornado load provisions – sections 32.2‐32.4, definitions, nomenclature, sign conventions
- Tornado hazard maps – integration of tornado climatology, wind fields, damage, and uncertainty modeling to create tornado hazard curves and the probabilistic tornado hazard maps in section 32.5 and appendix G
- Effective plan area – determination of smallest convex polygon; application to essential facilities
- Tornado speed – determination of tornado speed using hazard maps and online hazards tool; interpolation
Week 3 — Tornado load coefficients and equations
Learning outcomes
- Explain the differences between wind load and tornado load coefficients and equations
- Choose appropriate values for the different tornado load coefficients
- Calculate tornado velocity pressures and design pressures for various elements of a building or other structure
Lectures (7)
- Tornado velocity pressure – sections 32.7‐32.10; exposure, topographic effects, ground elevation factor, velocity profile
- Tornado directionality and gust effect factors – sections 32.6 and 32.11; directionality effects; gust effects
- Tornado internal pressure coefficient – sections 32.12‐32.13; enclosure classification; atmospheric pressure change; impact protection requirements; internal pressures
- Tornado external pressure coefficients – section 32.14; aerodynamic effects of vertical wind component; adjustment factor for vertical winds
- Main wind force resisting system load equations – sections 32.15‐32.16; buildings; appurtenances; other structures
- Component and cladding load – section 32.17; buildings; appurtenances; other structures
- Wind tunnel method – section 32.18; procedures; limitations
Week 4 — Tornado load calculations and load combinations
Learning outcomes
- Describe the rationale for how wind and tornado loads are treated differently in load combinations
- Evaluate tornado loads for a building and for another structure
- Determine controlling loads on buildings and other structures using strength and ASD load combinations
Lectures (6)
- Tornado load example part I – evaluate MWFRS tornado loads on a hospital building
- Tornado load example part II – continuation of example for C&C loads on the hospital building
- Tornado load example part III – evaluate tornado loads on a vessel at a petrochemical plant
- Load combinations – sections 2.3 and 2.4; combining tornado loads with wind loads; strength design; allowable stress design
- Tornado load example part IV– continuation of example parts I‐III to determine controlling load combinations
- Wind loads vs. tornado loads – geographic comparisons of wind loads and tornado loads; where are tornado loads most likely to control at least some part of wind load design
- Practice/evaluation
- Determine design loads using both strength and ASD load combinations
Week 5 — Tornado shelters and safe rooms
Learning outcomes
- Identify options for higher levels of tornado protection beyond ASCE 7‐22 minimums
- Explain the differences between performance objectives for ASCE 7‐22 minimum tornado requirements, tornado shelters, and tornado safe rooms
- Summarize key differences in tornado load procedures between ASCE 7‐22 and ICC 500
Lectures (5)
- Tornado design beyond ASCE 7‐22 minimum requirements – current state requirements, codes, standards, and other guidance
- Performance‐based tornado design – section 32.1.3 and appendix G; adaptations of performance‐based wind design
- Tornado shelters – ICC 500 Storm Shelter Standard; tornado loads; debris impact loads; other loads and load combinations; architectural and other design considerations
- Tornado safe rooms – FEMA P‐361 and FEMA P‐320; differences from ICC 500; grant funding for safe room construction
- Course review – summary of key concepts, ASCE 7‐22 tornado load requirements, other code and standard tornado requirements
Exam — over whole course, although main focus is ASCE 7‐22 tornado loads (material from weeks 2‐4)
This course outline is subject to change.