Page 143 - Bridge and Highway Structure Rehabilitation and Repair

118 SECTION 1 ADMINISTRATIVE ISSUES

Figure 3.16 Factors affecting vulnerability rating.

Underlying principles for avoiding failures dictate that:
1. There will be regular or routine maintenance
There should be no problem with pre-approved budgeting and availability of maintenance
funds by the owner for emergency or routine maintenance.
2. Engineering planning for original construction shall be sound.
3. There will be no design mistakes:
• There is a need to critically examine state-of-the-art, theoretical concepts, current design
methods, and the quality of construction and maintenance.
• Design errors can occur due to a lack of expertise on the part of the engineer. Nonperfor-
mance of independent checks (for design concepts or structural details shown on drawings)
through lack of a quality control program is a recipe for disaster.
• It should be possible to minimize or prevent failures by developing and implementing
checklists for maintenance adequacy and quality design requirements.
• Bridges are subject to displacement, movement, and sway of the substructure due to
fl oods.
• If design and reconstruction criteria are correctly implemented, many of the failures can
be prevented.
4. Collapse can be reduced by using standard details and, flexible and ductile moment resistance

connections.
5. There will be no construction defects: Construction errors generally arise due to a lack of
adequate supervision when meeting tight deadlines.
6. Some failures may occur due to experimentation with new types of materials or new sys-

tems such as undefined and unpredictable material properties in cast in place or precast
construction.