Reference Criteria for Consulting Services
for Infrastructure Projects

Appendix 2: Check List for Designing to Counteract Earthquakes, Hurricanes and Torrential Rains

Executive Summary | Introduction | Part 1: Guidelines for Owners | Part II: Guidelines for Maintenance | Part III: Notes for the Consulting Engineer | Appendix I | Appendix II

Check lists are invaluable in the design process. All the items may not be relevant for any particular project, but excluding items from a comprehensive list is always easier than adding relevant items to a short list.

Check List Items Taken into account Not taken into account
1 Seismic, Hurricane and Rain Hazards    
  1. History
    
  • Earthquake
  • Hurricane
  • Torrential Rain
    
b) Geology    
c) Tectonics    
d) Design characteristics    
  • Earthquake design characteristics
  • Hurricane design Characteristics
  • Design characteristics for torrential rains
    
2 Site Conditions    
a) Soils    
  • Liquefaction
  • Seismic characteristics
    
b) Topography    
  • Land slide
  • Building on slopes
  • Topographic effect on wind speeds
  • Ridges
  • Valleys
  • Flood prone areas
  • Torrential rains
  • Storm surge
  • Tsunami
    
c) Other factors    
  • Corrosive environments
  • Coastal areas
  • Industrial and other pollutants
    
3 The Client’s Brief    
a) Function    
b) Cost    
c) Reliability    
  • Serviceability for different components of the facility
  • Safety for different components of the facility
    
4 Design Philosophy    
a) Performance in moderate and frequent hazardous events    
  • Protection of property
  • Cost of repairs should be minor
    
b) Performance in strong, rare, hazardous events    
  • Saving lives
  • Repairable damage (very critical facilities in earthquake events)
  • Protection of all property in hurricanes and torrential rains
    
c) Critical areas or components of the facilities    
d) Post-yield behaviour of structural elements    
  • Ductility
  • Energy absorption
  • Deformations
    
e) Building Envelope for Hurricanes    
  • Windows, external doors and roof cladding
    
5 Choice of Form or Configuration    
a) Failure modes    
  • Redundancy
  • Accidental strength
  • Column capacities (and those of other vertical load-carrying elements)
  • Designing for failure
  • Avoid failure in vertical, shear and compression elements
  • Avoid brittle failure
  • Avoid buckling failure
  • For hurricane forces design for repeated loads without degradation
    
b) Geometric Issues    
  • Simplicity and symmetry
  • Long buildings to be structurally broken
  • Elevation shape
  • Sudden steps and setbacks to be avoided
  • Distribution of structural strength
  • Openings in principal members to be avoided
  • Continuity
  • Columns and walls from roof to foundation (without offsets)
  • Beams free of offsets
  • Coaxial columns and beams
  • Similar widths for columns and beams
  • Monolithic construction
  • Stiffness and slenderness (h>4b)
  • Stiffness vs flexibility
  • Maintaining the functioning of equipment
  • Protecting structure, cladding, partitions, services
  • Resonance
  • Diagrams of favourable and unfavourable shapes
  • Square
  • Round and regular polygons
  • Rectangular
  • T and U shaped buildings
  • Aspect ratios
  • Deep re-entrant angles
  • Ideal to establish structural breaks (Create rectangular plan forms)
  • H and Y shaped buildings
  • Aspect ratios
  • Deep re-entrant angles
  • Ideal to establish structural breaks (create rectangular plan forms)
  • External access stairs
  • False symmetry – regular perimeter masking irregular positioning of internal elements
  • Soft storey
  • Cantilevers to be designed conservatively
  • Desirable roof shapes for hurricane resistance
  • Steep pitched roofs (20 – 40 degrees)
  • Hipped roofs are preferable
  • Gable roofs are an acceptable compromise
  • Mono-pitched roofs are undesirable
  • Boxed eaves recommended for overhangs exceeding 450 mm
  • Parapets reduce wind uplift
  • Ridge ventilators reduce internal pressure
    
c) Distribution of horizontal load-carrying functions in proportion to vertical load-carrying (avoid the overturning problem)    
d) Structural system to be agreed by design team    
  • Moment-resisting frames
  • Framed tubes
  • Shear walls and braced frames
  • Mixed systems
    
6 Choice of Materials    
a) Local availability    
b) Local construction skills    
c) Costs    
d) Politics    
e) Ideal properties    
  • High ductility
  • High strength-to-weight ratio
  • Homogeneous
  • Ease of making connections
  • Durable
    
f) Order of preference for low-rise buildings    
  • In-situ reinforced concrete
  • Steel
  • Reinforced masonry
  • Timber
  • Prestressed concrete
  • Precast concrete
  • Unreinforced masonry not recommended
    
g) Light-weight roof cladding of pitched roofs    
  • Method of fixing critical to roof performance
    
7 Construction Considerations    
a) Supervision    
b) Workmanship    
c) Ease of construction    
8 Components    
a) Base isolators and energy-absorbing devices (to be given consideration)    
b) Foundations    
  • Continuous
  • Isolated (to be avoided)
  • Piled
    
c) Movement joints    
d) Diaphragms    
e) Precast concrete    
f) Welded beam-column joints for moment- resisting steel frames (to be avoided)    
g) Shear walls and cross bracing    
h) Hurricane straps, wall plates and connection    
9 Elements    
a) Structure    
b) Architecture    
c) Equipment    
  • Electrical feed to be kept clear of roof structure
  • Electrical feed to be routed underground within the property
    
10 Cost Considerations    
a) Capital costs ignoring natural hazards (hypothetical, academic)    
b) Capital costs including natural hazards    
c) Maintenance costs    
11 Analysis    
a) Understanding the structural model    
b) Torsional effects    
c) Geometric changes    
The P-delta effect    
d) 3-D analysis (required only for irregular structures)    
e) Dynamic analysis (required only for complex structures)    
f) Stress concentrations    
  • Complexity of earthquake effects and inadequacies of sophisticated analytical Methods
   
h) Effects of non-structural elements    
  • Change in the natural period of the overall structure
  • Redistribution of lateral stiffness and, therefore, forces and stresses. [This could lead to premature shear or pounding failures of the main structures and also to excessive damage to the said non-structural elements due to shear or pounding.]
    
i) Soil-structure interaction    
  • Critical but usually ignored or played down
    
12 Detailing    
a) Compression members    
b) Beam-column joints    
  • Reinforced concrete
  • Structural steel – all-welded construction
    
c) Reinforced-concrete frames    
d) Non-structural walls and partitions    
e) Shelving    
f) Mechanical and electrical plant and equipment    
  • Securely fastened to the structure
  • Pipework
    
13 Construction Quality    
14 Maintenance    

Executive Summary | Introduction | Part 1: Guidelines for Owners | Part II: Guidelines for Maintenance | Part III: Notes for the Consulting Engineer | Appendix I | Appendix II

CDMP home page: http://www.oas.org/en/cdmp/ Project Contacts Page Last Updated: 20 April 2001