Coeur d'Alene evening press. (Coeur d'Alene, Idaho) 1907-1929, 1909-01-06

aAL = simply what Il youId has.
been e big trench had baeu -
across the valley down 20 the stratn,..
q atin clay which underiies ~ dsra
ste and had then been fiIled wlth
slone. The work on the dam "a nat A.
any way interrupted by tbeae sn,a n
settings. Rock win be dumped unt,I
the toe has reached the desired be,ght
o. sixty feet ami each settling wtll
only result In more rock being dunn.
eu There until the solid foundation q
rescued and an equilibrium estab.
lished.
The idea that there is lake under
the site Of Gatun dam probably or,g.
mated from the fact that the borinen
nnade ct close intervals all over the
Dam site revealed water in about Ia
per cent Of the holes sunk. The "a.
suits Of these borings were published
Sept 2, 1908. and nothing has devel.
oped further. The report on these ex.
plorations, which win appear in the
annual report Of the chairman ana
chief engineer to congress. covers the
matter thoroughly from a technical
standpoint. Briefly, IT shows that wa
yer UNDER pressure was found in sew
eFal places under the dam site.
The tact that there was no commu-
nication between the various holes
shows beyond question that the water
under the dam site Is in pockets and
is not q pool or lake, and the fact that
the water was under pressure and rose
In the test holes shows that 1t has no
outlet. In addition to the borings two
test pits were sunk 100 feet below sea
level, and they merely confirmed what
the borings had already shown-that
the dam is being built on very arm
foundation Of imperyious clay.
What is true Of the foundation Of
the dam is also true Of the foundation
Of the locks. There Is no question at
all Of Its satisfactory character. The
locks are being constructed in a series
Of three double locks, making a rise
from sea level to the eighty-nve foot
level Of the Gatun lake. Each lock Ia
1000 feet long, Ito feet broad at the
entrance and Al 1-8 feet deep in fresh
water over the sills.
1.-THE excavation for the south or up
per lock Is practically completed, and
the concrete work viii be begun as
soon as thu power handling and mix
ing plants are delivered on the 18TH
mus and can be put in running order.
The excavation In the second and third
locks involves the removal Of ], 400, 900
cubic yards Of material by steam shov-
els and 100000 cubic yards by suction
dredges. The steam shovel work is al
ready well advanced, and the dredging
Will be begun soon.
1.-THE locks will be built entirely Of
concrete, forming series Of three wa
ter tight boxes, each divided into two
parts. Beneath the level of the floor
Of the upper and second locks a cur
tain wall win be sunk to a sufficient
depth to keep out whatever water is
now finding or is likely to find its out
let beneath the lock site. The excava-
ton on the curtain walls will be begun
in a few weeks. The plans for the
locks have been completed in all but
few details. The stone and sand nee
essary can be delivered at the handling
plant in Gatun as soon as they are re-
quired.
1.-THE slide on the relocated line Of
the Panama railroad at Gatun is SINH
lar to those which occurred at Cuca-
racha and at other points along Guile
bra cut and at Mirahores tunnel. 1t is
caused by the earth, which has become
saturated from the excessive rains and
has been burdened with the weight Of
the I'LL, sliding on the surface Of the
rock, which underlies 1t. This slide
has reached its angle Of repose for the
present, but It is expected that during
the next rainy season, when the ill is
continued to the ninety-five foot grade,
the slide will begin again. More mate
rial win then be dumped into the de-
preston, and the filing will be con-
hnued until the material has reached
It's angle of repose, when no further
trouble "a expected"