Page 170 - Forensic Structural Engineering Handbook

CHAPTER 5

THE FIRST STEPS

AFTER A FAILURE

David B. Peraza, P.E.

INTRODUCTION 5.3
SAFETY 5.4
PRESERVATION OF PERISHABLE EVIDENCE 5.7
Collapse Configuration 5.7
Steel Fracture Surfaces 5.11
Curing Concrete Test Cylinders 5.12
Snow and Ice Accumulation 5.13
RESERVING SAMPLES 5.14
Failed Components 5.14
Unfailed Components 5.14
DOCUMENTATION OF CONDITIONS 5.14
Field Notes 5.15
Photographs 5.16
Video 5.17
New Technology 5.17
3D Laser Scanning 5.17
3D Photography 5.19
INTERVIEWS 5.22
Information Sought 5.23
Who Should be Interviewed 5.24
INTERACTION WITH OTHER ENGINEERS 5.24
INITIAL DOCUMENT GATHERING 5.26
PRELIMINARY EVALUATION 5.29
CLOSURE 5.30
REFERENCES 5.30

INTRODUCTION

The first steps following a structural collapse are critical. They will blaze the trail for sub-
sequent investigations, and they may prevent further damage or loss of life.
The activities immediately following a collapse profoundly influence the success of
subsequent technical investigations. So much of the evidence associated with a collapse is
of a perishable nature—and some of it highly perishable—that swift action is needed to pre-
serve as much as possible. Snow will melt, fracture surfaces will corrode, the debris will be
removed, and memories will fade.
The forensic engineer who is called in following a collapse plays a crucial role in deter-
mining what those first steps should be. He or she is often the most qualified to recognize

5.3