Evening star., 1933-06-03
DAM CONSTRUCTION
:. TESTS VALUABLE.
Behavior of Materials Seen
| in Research Work of En-
gineering Group.

Problems in construction and in the
behavior Of materials are brought
nearer solution by a 1o-year study just
completed by the Engineering Founda-
ton, New York, research organization
of the major engineering societies OF
civil, mining and metallurgical, me-
thanical and electrical engineers.
The findings, 1t is declared, will ad-
vance President Roosevelt's program
of national planning, involving de-
Felopment of natural resources. con-
struction of public works, and shifts OF
population.
The foundations investigation. world
wide in scope centered on problems OF
constructing and designing arch dams,
which for centuries had remained un-
solved by engineering science. IL
points the way to economies In con-
struction, according to an announce
ment by the foundation, and extends
scientific knowledge of dams. with
which power development. irrigation,
water supplies of cities, flood control,
and security of life and property are
bound up.
Conclusions on Dams.
Four of the most important conclu-
kions are that models of arch dams
will react in a manner similar to the
structure itself, making possible ex-
tensive savings; that some types OF
tension cracks will not affect the safety
of the dam; that the chemically gen.
Grated heat of the concrete plays an
intrinsic part in the serviceability of
che structure, and that concrete dams
are not stationary but flow" to slight
degree in response to water pressure
In other words, concrete Is slightly
plastic under high pressures.
Because so little was known OF arch
dams, strong concrete structures with
walls curved upstream, the foundation
IN 1922 appointed the Committee on
Arch Dam Investigation, with Prof. G.
perleth, jr., of the University OF Cali
Sornia as chairman. He was succeeded
et the beginning of 1925 by Prof.
Charles D. Marx of Stanford University,
former chairman of the Engineers
Advisory Board of the Reconstruction
Finance Corporation.
Although many dams Of this type had
been built previously, the basic facts
for use in designing were relatively
few and much was left to assumption
grounded on experience and to theory
without experimental proof.
Much Spent in Study.
Seventy-five organizations contributed
more than Sl25.000 in cash to further
The inquiry under the direction Of the
Engineering Foundation. United States
Government bureaus, engineering soci-
eties, power companies, manufacturers,
constructors, and bankers were among
kaose who aided Contributions Of Serv-
Gees and materials put the total value
above 100000
In a wild gorge of the Sierras on
Stevenson Greek, about sixty miles from
Fresno Calf. an arch dam sixty feet
high was built and tested solely for the
purpose of uncovering valuable expert
mental data. Undergoing extreme tests
over a period of years. and courting
destruction in the interest OF science,
khe dam successfully withstood them
and the torrents of water that were
hurled against it by floods.
The Stevenson Greek dam, containing
hundreds of testing instruments, is
keven and half feet thick at the base,
tspers to two feet in thickness at thirty
Rect. and continues at that figure to
Aixty feet. It is curved in plan with
kadius of 100 feet and is 140 feet long
pn top.
All available information was gath
bred by the committee because OF the
Importance of the hundreds of arch
dams now in use and the need for
knowledge which would eliminate un-
economical construction and promote
safe practices.