Page 162 - Forensic Structural Engineering Handbook

STANDARD OF CARE 4.11

reinforced-earth type retaining structure. The structural engineer had never designed such
a wall before. The retaining wall system vendor provided sample calculations to the struc-
tural engineer as an example of how to design the wall, but the vendor’s method included
errors. The structural engineer used the calculation method provided. After the wall was
completed, during heavy rains a portion of the wall failed.
During the meetings and depositions that ensued, an experienced expert forensic engi-
neer who had designed and analyzed “thousands of these walls,” and who had developed
his own calculation method, described the structural engineer as negligent.
The use of “canned” calculations and design approaches without understanding their
application and limitations can be beneath the standard of care and can be an instance of
professional negligence. However, the practice of the experienced expert, far exceeding
that of a normally competent engineer, is not the standard of care. The question was not,
“How did the defendant engineer’s performance compare with the expert’s?” It was more
appropriately, “Did the defendant engineer utilize reasonable diligence and his or her best
judgment given the fact that he had not designed such a retaining wall before?”
The answer to that second question, in this author’s opinion, was no. Reasonable dili-
gence would have resulted in the error in the canned calculations becoming apparent to the
structural engineer. The structural engineer’s best judgment would have resulted in his or
her reverting to first principles, as described in readily accessible soils engineering texts on
retaining wall design. The failure may or may not have happened anyway, given the inten-
sity and duration of the rain; but the actions of the design engineer would have been defen-
sible under a standard-of-care defense.

Foundation Design
A large condominium project was built in six phases, spread out over several years. For
phases 1 through 3 the soils engineer recommended the foundation be a drilled pier type,
and that the piers be 4 ft deep. When construction of phase 4 started, the soils engineer
issued revised and updated recommendations for phase 4, requiring 6 ft deep piers. Later,
during construction of phases 5 and 6, the structural engineer’s design went back to 4 ft
piers of the original soils report. All the buildings in all six phases were of the same design,
and the soils were similar in all phases. Was the structural engineer negligent in not carry-
ing forward the soils engineer’s phase 4 recommendations to phases 5 and 6?
Management and control of information is part of diligent engineering practice. It was
argued that the structural engineer’s failure to carry forward the revised soils engineering
parameters represented an error inconsistent with the standard of care.

Unreinforced Masonry Wall Collapse
Engineering design drawings and specifications for the seismic strengthening of a circa
1888 unreinforced brick masonry building included the requirement for the general con-
tractor to produce shoring and bracing plans and submit them to the structural engineer of
record (SER) for review. Construction started without the knowledge of the SER, and work
was done without those plans. The SER was excluded from the construction process, includ-
ing the review of shoring and bracing plans, by the owner and the contractor. No shoring and
bracing plans were ever produced by the contractor, and no shoring and bracing was
installed on the project. Due to the absence of shoring and bracing, a brick wall collapsed
during construction, killing the contractor’s foreman. The SER was sued for professional
negligence and wrongful death. Two years after the “accident” and after a 6-week trial, the
jury found the SER not negligent and not liable. The jury found against the owner and the