Engineering involvement with property losses demands an open technical mind that can look at the bigger picture, sometimes beyond the scope of work initially requested by the adjuster or insurance company. Engineering law requires the professional engineer to protect "public health, safety, and welfare. "Sometimes specific technical requests are made to a forensic engineering firm that lead to much broader technical involvement in order to ensure compliance with engineering law and the protection of the public. Is it a benefit for an engineer to look at a broader picture when investigating a loss event, even if the scope of work has been specified? Let's examine two examples.
Following a large hurricane, a request was made to determine the cause of brick veneer damage on a large church structure. Inspection of the building revealed that the structure was an irregularly-shaped building, which is not uncommon for large church facilities. The hurricane event had produced strong, sustained winds for a short period of time, resulting in leeward suction wind loads on the high brick veneer face of the building. At first glance, there appeared to have been lateral forces on the wall that pulled the brick away from the wall, resulting in limited failure of the brick ties. Closer examination of the brick wall revealed a bulge in the brick at a mezzanine level and not the entire height of the wall. Subtle buckling of the roof and wall surfaces indicated that the shear walls that resist lateral loads had not responded properly to the wind loads applied to the building during the storm event. Inspection of construction drawings revealed that the building framing was changed from a steel-framed structure to a wood-framed structure to resist the applied wind loads. This was a significant structural modification and required different design and construction methods. Further investigation of the building and a structural analysis review determined that the building was under-designed to handle the code-required design wind conditions. The structure had twisted, resulting in compromise to wood connections throughout the structure. Even though the structure had rebounded back to a visually stable condition, suggesting minor cosmetic damage, the structural performance during the wind event led to condemnation of the structure for public occupancy. Clearly, relatively minor cosmetic symptoms can sometimes suggest major problems.
A request was also recently made to investigate the extent of damage to an industrial concrete warehouse structure built in 1954. A forklift driver ran his forklift into a concrete column and sheared the column at the base. The heavy concrete roof sagged under the weight and shifted the load to an adjacent column, resulting in load failure to the adjacent column. Fortunately, the structure appeared to stabilize and did not totally collapse. A contractor was called in by the owner to shore up the roof structure in the damaged area. Pipe columns were designed and installed under the beam that was supported by the failed concrete columns.
Several weeks after the accident and temporary repairs, a further inspection of the structure was required to determine extent of damage. At the time of the initial inspection, the structure appeared to be stable, and the owner insisted that the installed columns were designed by a professional engineer. Several days after the initial site inspection, the adjuster requested an investigation of the concrete that had fallen from the ceiling. A more detailed investigation of the "temporary repair" revealed that what was originally assumed "stable" was under-designed and inadequate for supporting the heavy concrete roof deck. The concrete deck continued to move, resulting in further crack distress to the roof deck and other concrete columns. he owner, of course, wanted the structure repaired and concrete columns installed under the roof deck so that much-needed operation space could quickly be restored. However, the structural conditions demanded more area to be cordoned off for occupant safety.
Emergency shoring and wood cribbing was designed and installed to support a much larger area of roof deck. The crack patterns in the structure indicated extensive deformation of the roof deck and severe damage to column joints and deck sections. In the absence of material specifications and structural drawings, material testing revealed that the structure was also deficient in the required concrete strength. Repair to the observed distress alone would not bring the structure into compliance with structural code requirements. Ultimately, it was determined that replacement of a large section of the concrete roof deck would be required.
Assumptions of adequate "temporary repair" or structural strength can result in a false sense of security. Thus, an understanding and review of all conditions when engaged on a site investigation should be made by the investigating engineer and the scope of work for this effort relayed to the client.
In summary, careful consideration of the technical qualification of the engineer or engineering firm for a small or large property loss investigation is essential. A good forensic engineer should not only perform a proper technical investigation, but also have the ability to think "globally" on a loss, in order to protect the public, minimize client and owner risks, and identify conditions beyond the obvious.
EFI Global is a full-service Engineering, Fire Investigation, Environmental, Health and Safety, and specialty consulting firm. Over the last four decades, they have grown from a boutique firm to become a recognized leader in engineering failure analysis, origin and cause investigations, and environmental consulting. This expertise coupled with the extensive coverage of our 27 national offices, more than 400 professionals, and global work abroad capability allows EFI Global to deliver timely responses that consistently meets their clients' expectations.
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