With the holiday season upon us and 2023 coming to a close, we at Nelson Forensics are reflecting on the past year.
With the nature of our forensic investigation work, we often observe interesting conditions. Some of these involve obvious failures, while others are interesting because they are unique or rare. We thought we would share some of the interesting things that our investigators encountered in 2023.
Figures 1 and 2 show collapses that occurred in the middle of the night. Both were sudden and without warning. Figure 1 shows a second-floor walkway slab that collapsed suddenly. Figure 2 shows a concrete panel near a loading dock of a warehouse building which suffered a support failure, resulting in sudden collapse. While such collapses can be very dangerous to building occupants due to the lack of warning, nobody was injured during these collapses.
Figure 3 also shows a collapse. This occurred at a church that was over 50 years old. In this case, some sagging had been noticed at the roof and some cracks had formed on the interior that were a concern to members of the congregation. It was very fortunate that the collapse occurred on a Tuesday, two days after Sunday celebrations. Nobody was injured.
Figure 4 shows an unreinforced brick masonry chimney chase that displaced and rotated above the roof level when a strong wind blew off a portion of the adjacent roofing that was tied into the masonry. While the brick did not collapse, the nature of the rotation and displacement are a helpful reminder of the potential damage from the transfer of forces from one element to another during a significant failure event.
Figure 5 shows a condition that is quite rare. Hail impact has of course been known to cause dents in metal panel roofing, but it is not common to see the panels actually fractured as a result of impact. This photo of a fractured metal panel is from a hail impact during a storm event near Waco, Texas in April. The site had large hail and this hailstone hit the panel at just the right spot to cause a rupture, close to the supporting purlin framing.
The deterioration of exterior stone is something that we observe frequently, but advanced deterioration typically takes a long period of time to occur. Interestingly, the deterioration shown in Figure 6 occurred within the first 5 years of installation.
Every year, we investigate at least a few structures that have been impacted by a moving vehicle. However, it is unique for a vehicle impact to affect a building’s roof. While flying cars are still a thing of the future, we investigated a project where a vehicle was reportedly moving at high speed and apparently caught some serious air when it jumped a curb. Figure 7 shows some auto glass remnants that we found on the roof.
At Nelson Forensics, we are thankful for our work, our clients, and of course, our people. We thank you for your continued faith in our team, and hope that you enjoy the start of a safe and wonderful holiday season.