Page 104 - Bridge and Highway Structure Rehabilitation and Repair

CHAPTER 3 BRIDGE FAILURE STUDIES AND SAFETY ENGINEERING 79

to recognize perishable evidence and its potential value. The decisions made will directly
affect theevidence upon which investigations will depend.
2. For examination by the judicial process, the design engineer will maintain important records
for the bridge such as contract documents including feasibility studies, site selection, selec-
tion of bridge type, and value engineering.
In particular documents must refer to:
• Design criteria used and compliance with AASHTO and state codes
• Design assumptions, calculations, and computer output––Evidence of client approval for
use of computer software
• Contract drawings
• Special provisions of technical specifications which are not covered by state standard

specifi cations
• Approved shop drawings prepared by contractors
• A record of requests for information (RFI) and design change notices (DCN) during
construction
• As-built drawings.

3.2.3 Methodology for Forensic Analysis
Accidents at construction sites can often result in serious injuries or death from defective

or collapsing scaffolds and falls through roofing structures. Other cases include electrocutions,
ladder injuries, defective machinery (cranes, hoists, conveyors, tractors, forklifts, etc.), malfunc-
tioning tools, and injuries or death from collapse of walls or fl oors.
If the failure involves a construction site accident, the investigation will include:
• Workplace safety and liability
• Compliance with OSHA

The first steps after failure: Thefirst steps following a collapse are critical (Figure 3.3). The
structural forensicengineer who is called in following a collapse is responsible for documenting

Figure 3.3 Failure of the I-35W bridge in Minneapolis, Minnesota on August 1, 2007.