Geotechnical News • June 2017
39
GEOTECHNICAL INSTRUMENTATION NEWS
Kiel Canal between the North and
Baltic seas. In 1913, the situation in
Panama, as well as continuing dam
failures and building settlements, led
the American Society of Civil Engi-
neers to appoint a committee to look
into these matters. The committee
stressed “the importance of expressing
the properties of soils by numerical
values.” Similar realizations came in
Europe.
Seldom has one man dominated a
discipline as did Karl (Charles) Ter-
zaghi (1883-1963) in the field of soil
mechanics. An Austrian, he studied
mechanical engineering and geology,
receiving a mechanical engineering
degree in 1904, and later a doctor of
technical sciences, from the Techni-
cal University of Graz. For six years
preceding World War I, he worked on
a variety of engineering and construc-
tion projects in the Alps, in Croatia,
and in northern Russia, where he was
able to absorb the practical side of
civil engineering. In particular, prob-
lems which arose in constructing the
foundations of a large building in St.
Petersburg, where he had opportunity
to observe “the incompetence of the
engineering profession in the field of
earthwork engineering,” piqued his
interest and set Terzaghi on his life
mission to find a rational basis for
predicting the performance of soils in
earthwork and foundation engineering.
At this time, the United States Rec-
lamation Service was doing pioneer-
ing work on a large number of dams
and irrigation works in the Western
States under a wide range of geologic
conditions. With the agreement of the
director, Terzaghi spent two years in
America studying case histories of
these projects. But he returned home at
the end of 1913 disillusioned, because
he had failed to find the “missing
link,” the correlation between the
performance of a foundation and the
geologic characteristics of its site.
At the beginning of World War I,
Terzaghi enlisted in the air force of the
Austrian army. However, in 1916 he
was posted by the Ministry of Foreign
Affairs to Constantinople, Turkey, to
lecture on foundations at the Imperial
School of Engineers the present Tech-
nical University of Istanbul (The Otto-
man Empire sided with the Central
Powers and the institution was under
German influence). There Terzaghi
began a study of all German, French,
and English literature on the subject.
At the end of the war, the victorious
Allied Powers occupied Constanti-
nople and the teaching staff, including
Terzaghi, were summarily dismissed.
At this nethermost point in his career,
Terzaghi felt humiliated, depressed,
and without any means of support.
He had “no urge whatsoever to teach”
inasmuch as he was “too deeply preoc-
cupied with [his] own ignorance.”
Soon enough though, he was offered
an appointment at Robert College-
now Bogazici University in Istanbul,
an English-speaking school founded
by American missionaries. In a flash
of inspiration, Terzaghi visualized
what was needed to obtain a rational
approach to the problems involved in
earthwork and foundation engineering.
Progress depended on the develop-
ment of testing equipment which could
provide a quantitative measure of the
properties of the soils involved. On
two sheets of paper he listed a number
of possible ways to test soils, made
sketches of the equipment needed, and
suggested how the results could be
interpreted. Terzaghi had finally made
his fundamental discovery: “Engineer-
ing geology cannot become a reli-
able tool in the hands of earthwork
engineers unless and until we acquire
the capacity to assign to each material
of the earth numerical values.”
Within a few weeks of beginning work
at Robert College, Terzaghi had set up
a small laboratory in the engineering
building. During the week the lab’s
lights were to be seen burning well
into the night. Weekends were spent
on expeditionary field trips along the
Bosporus and the Marmara Sea. Hav-
ing scant funds, Terzaghi had begun
seven years of “strenuous experimen-
tation” with soils, using borrowed
measuring devices and apparatus built
with odds and ends scrounged from
the college dump. His first earth-pres-
sure apparatus was made from empty
cigar boxes, and his loading devices
consisted of empty oil cans filled with
Sand. In Terzaghi’s first aAmerican
article, “Old Earth-Pressure Theories
and New Test Results,” published in
1920 in Engineering News-Record
in which he discarded the theories of
Coulumb and Rankine, he described
the small-scale experiments that
established the relationships between
earth pressure and the lateral defor-
mation or yielding of mass of soil.
Earth pressure against retaining walls,
braced cuts, and anchored bulkheads,
as well as arching over tunnels and
around shafts, are dependent on
this relationship. In 1925, with the
publication of Terzaghi’s first book,
Erdbaumechanik, the science of soil
mechanics emerged from is academic
womb.
From the fall of 1925 until October of
1929, Karl Terzaghi spent his sec-
ond period in the United States, this
time at the Massachusetts Institute
of Technology, where numerous new
buildings were undergoing large and
continuous settlements. While at MIT
he codified the equipment needed
for soil testing. There he made the
acquaintance of Dr. Arthur Casagrande
(1902-1981), who was to become his
principal associate throughout the
second half of Terzaghi’s career. Like
Terzaghi, Casagrande was a native
Austrian. He had graduated from the
Technical University in Vienna before
coming to the United States in 1926
with no real prospect of work. He
gained n interview at MIT< met Terza-
ghi and immediately began to work for
him. In 1934 Casagrande moved on to
Harvard University becoming Profes-
sor of Soil Mechanics and Foundation
Engineering.
COMMEMORATIVE DITION
