Geotechnical News • December 2015
57
GEO-INTEREST
The sub-consultant was a small firm of
consulting engineers engaged princi-
pally in the field of structural engi-
neering. From time to time they had
worked with the architect to provide
minimum structural design which the
architect incorporated in his drawings.
The architect arranged with the client
to provide a backhoe to dig two test
pits on the site and called the struc-
tural engineer to send someone out
to inspect the test pits. The structural
firm employed, on a part time basis, a
retired engineer whose expertise was
principally in structural design but
who had some practical experience
with soils though he made no claim to
be a geotechnical engineer.
This employee of the structural firm
met the architect on the site and
inspected the test pits. He correctly
described the soil that was exposed in
the test pits and suggested a bearing
capacity for the soil. He also told the
architect that he felt that deep borings
and a proper geotechnical evaluation
was required. The architect replied
that the client would not be prepared
to pay for such an investigation.
The employee reported his observa-
tions and comments to one of the
principals of the structural firm who
phoned the architect and was again
told that the client would not pay for
deep borings and a proper geotechni-
cal study. The structural engineer then
asked what bearing value he should
use in the design and the architect
responded with a conservative value
which he said that the client had pro-
vided. On this basis the structural firm
proceeded to design beams, columns
and footings for the building.
During the subsequent court proceed-
ings both statements were denied by
the client who said that the architect
had never asked for a deep founda-
tion study and had never been given a
recommended bearing capacity. At the
time however the structural engineer
had no reason to doubt these state-
ments, particularly since the client had
technical expertise on his staff and had
experience with other buildings in the
area.
Shortly before the contract for con-
struction of the building was let, the
client asked the architect for a copy
of the soils report. The structural
engineer with some indignation told
the architect that he should know
there was no such report. The archi-
tect replied that all the client required
was a description of the soils exposed
in the test pit and he confirmed this
request in a letter to the structural
engineer. The employee engineer
of the structural firm wrote a letter
describing the soils exposed in the
test pits and gave an estimate of the
bearing capacity. However, his letter
did not include a recommendation for
deep borings and a proper foundation
study.
At the same time that the soils report
was requested the client asked the
architect to obtain a form letter from
the structural engineer certifying that
the building was designed according
to the requirements of the National
Building Code. The structural engineer
provided the letter as requested.
The building was built according to
plan and shortly after completion
showed serious signs of distress.
Various alternative explanations were
considered and substantial amounts
of money were spent in an effort to
correct the problem. However, it was
clear that the problem stemmed from
an inadequate foundation design.
The client sued for damages against
the architect, structural engineering
firm and the contractor. The litiga-
tion was extended and complex. The
contractual relationship and respon-
sibilities of the various parties were
explored in detail. The case was
appealed to the Provincial Court of
Appeal and finally to the Supreme
Court of Canada.
The contractor was found to have no
liability. The architect and the struc-
tural engineering firm were found
to be jointly and severally liable for
the losses suffered by the client. The
liability was assigned 60% to the
architect and 40% to the structural
engineer. However since the architect
did not carry any professional liabil-
ity insurance the entire burden of the
losses fell on the structural engineer-
ing firm and his insurer.
The architect was found liable because
he failed through negligence to fulfill
the terms of his contract with the cli-
ent.
The court concluded that the engineer
did not have a contract with the client
but he was found liable in tort to the
client. The two actions which the court
regarded as significant in the decision
were:
The soils report which the structural
engineer provided failed to estimate
settlements in deep soil layers or rec-
ommend deep borings.
The form letter stated that the design
met all the requirements of the
National Building Code. The code
requires that for a building of this size
the foundation design must be based
on a subsurface investigation by a
person competent in the field of soil
mechanics, or alternatively, be based
on local practice including succesful
experience with similar buildings and
soils in the adjacent area.
Even with the benefit of hindsight
there are only a few points at which
the structural engineer might have
been expected to act differently so as
to minimize the risk of things going
wrong.
Within the practicalities of the consult-
ing business, it isn’t realistic to sug-
gest that he should have refused the
assignment. He could only do this if
at that time he had such a low opin-
ion of the competence and honesty
of the architect that he preferred to
forego all future opportunity of paying
work with this client.
However, if a letter report on the
inspection of the test pits had been
written to the architect immediately
after the inspection, it would probably
have included a recommendation for
