Course outline

Available on-demand through July 13

Overview Content outline

Schedule

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

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

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

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

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

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

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

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

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

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.