The Farmington times. (Farmington, St. Francois County, Mo.) 1905-1926, 1916-04-28

That the rocks in which all the pres
ent sliding in the Panama Canal is
taking place cannot be weakened to
any notable degree by heavy rains,
and other facts instructive for the
civil engineering profession, are re-
suits that have been derived from
Investigations made to ascertain what
value, if any, there was in the innum-
cradle suggestions for controlling the
canal slides that have been mailed to
General Goethals from all parts of
the world.
That there was nothing practical in
all the schemes that contemplated
draining the area that has been giving
all the trouble, by means of tunnels or
wells as has been suggested from
many quarters, has been conclusively
proved by series Of experiments
made under conditions that will make
the results convincing and of interest
to all civil engineers and biologists.
Told Water Was the Trouble
at is the water in those banks that
makes them slide," General Cocktails
has been advised in all languages.
eff you had drained off that water by
means of small tunnels and wells
these slides would not have occurred, =
and, "by means of wells and tunnels
future slides from this rock would
be avoided" are two other opinions
that have been mistakenly sent to him
for a long time and especially of late.
What the General thought he did not
say but a cable was sent for every
thing that was needed to conduct a
series Of Investigations that would be
the last and most scientific answer to
all these suggestions. Donald f. Nc
Donald, the Canal geologist for the
last four or five years, was retained
and ordered to conduct the most ex-
haustive experiments along the lines
of the lates geologic knowledge and
the suggestions of the Committee of
eminent Scientists that lately came TO
the Canal. Professor j. II. Meade, a
Gelolgist from the University of Wis
consin, who has made speciality of
just such experiments as were sug-
gested, was engaged to come to the
Canal and assist Mr.. Mcdonald with
his very special knowledge Of his de-
velopment of geological work.
What Experiments Prove
The experiments Messrs. McDon-
aid and Meade have been making
prove that the rocks that have been
sliding contain about thirty per cent,
by volume, of water, very large
amount. The rocks that are moving
toward the Canal channel are so
broken up that they have had every
opportunity to drain and to lose wa
ter by evaporation. Notwithstanding
these conditions these rocks as these
experiments prove, have only about
one-half of one per cent less water
than the rocks of the same class that
were examined after they had been
submerged in the Canal for months,
a period long enough to have thor
oughly saturated them with water.
With this result as basis, Messrs.
Mcdonald and Meade continued their
experiments until they proved con-
clusively that while the rocks that
have been sliding contain the high
percentage of water mentioned, this
water is largely in capillary form and
cannot be effectively drained except
to the extent of possibly four or five
per cent, by any system that could
be devised. No more convincing ar
gument can be advanced to prove that
not deep drainage of the weak rocks
but vigorous digging away by the
dredges of the material now sliding,
is the. remedy for the slides under
present conditions.
An Absurd Theory
A theory once held tenaciously dur
ing the dry excavation construction
period among the engineers directly
connected with the Culebra Cut was
that the high ground above the Canal
channel should be allowed to slide so
as to reduce the amount of blasting.
This was one of the many ideas Gem
eral Goethals had to overrule during
the building of the Canal. These ex-
periments prove that he was abso-
lutely correct from scientific geo.
logical point of view in overruling
this theory and in digging away with
steam shovels as much earth as pos
sible Of the banks that might slide.
Geologist Mcdonald from the first
ItidtHIdlIiCu tLtAt WAhI Is AuUWH d6
initial movement or the first break
ing up of the higher banks should be
prevented. He told the engineers
that thes breaking up of the ground
weakened it and that digging away
with steam shovels of the most Of the
ground at the tops of the banks, would
so relieve the tendency to break up,
that this digging away should be Wig
orously carried on. Before the grounds
became weakened by any movement
slopes might be maintained at an an
gle Of something like one on three,
or sleeper; but after movement had
once started, the sheared or broken
rock could contain enough water to
bring them almost to the consistency
of mud. They would therefore stand
only at very flat angle, perhaps one
on ten.
The experiments just concluded
prove that this is what actually has
been happening. They prove that the
rock in the Canal banks that has Civ
en- the recent trouble is not weakened
or affected to any special degree by
heavy rains except after it has moved
and thus been weakened.
Geologists yindicated.