Washington standard. [volume] (Olympia, Wash. Territory) 1860-1921, 1899-06-30
MAMMOTH BUILDINGS.
VAST FOUNDATIONS OF CHlCA-
COS POST OFFICE.
One of the Greatest Superstruetures in this
Countrywide Structure viii Weigh 10000
Tons.

Tons.
Times Herald.
If all the materials in the recently
completed foundation for Chicago,
magnificent government building wort
to be loaded on wagons, ton to eacl
load, and 25 feet allowed for eacl
wagon and team, the procession o.
teams and wagons would reach 73l
miles, or as far as from Chicago to
Rochester. Gen. William Sooy-Smith
engineer in charge of the foundation
recently read paper OIL the sub-struc'
ture at a meeting Of the Western So
ciety of Engineers, in which he gave
many interesting data regarding the
work that has been done the past year
These are some of the facts:
The soil on which Chicago rests is
loose and sandy, in general, for about
II feet. Then comes II stratum OF
hard, brittle clay about three feet
thick. Below this, for so to 60 feet,
there is very soft, blue plastic clay
with spots of stitler clay here and
there and traces of gravel, but no
where is the clay firm enough to sus-
tain any considerable weight. At a
depth of from 69a to 71A feet below
the surface hardpan is struck, and this
is almost impossible to penetrate. On
account OF this peculiar nature of the
soil it was decided that the most feast.
BILE, safest and also least expensive
foundation would be one of piles, rest
ing upon the hardpan limestone.
Piles of Norway pine, 5,OS7 in num-
ber, and none less than Is inches in
diameter at the butt and more than
ten inches at the small end,
were driven by the powerful drivers,
and each pile driven until it required
from six to eight blows of the hammer
to drive the pile one inch. The piles
were driven with lower ends squared,
not sharpened, and were cut off 26s
feet below street level and 12t feet
lower than low water level of the lake.
1t was nice job to cut off these tops
OF piles at the required depth below,
for the trenches kept filling up with
water that oozed all too freely through
the clay. The work, in fact, had to
'e done under water. The piles and
oak platforms bolted to their tops are
thus perpetually immersed, insuring
everlasting durability. Fifty-nine of
the piles are driven under the place
where the subtreasury is to be.
AS the building is to weigh not less
than 10000 tons, each pile will have
its share to perform in sustaining this
great weight. But the building will
be safe, for each pile is required to
uphold but 80 tons, whereas the ex-
treme load it will sustain is 1865
tons. There are piles under London
bridges over the Thames, and also in
bridges over the Seine, which sustain
weights OF from 60 to 100 tons each.
When the new Chicago public library
was being built SO tons of pig iron
were loaded upon the top Of one of the
piles, and the weight stood for weeks
without settlement.
Upon the tops of the groups of piles
white oak timber platforms are secure
ly bOlted, and upon these platforms
are beds of flint-like concrete three
feet thick which have undergone
thorough, searching tests. The ma
sonry for retaining walls is of Joliet
and Lemont limestone. This was laid
by eight derricks, laying from 1000 to
1900 cubic feet OF stone per day. In
the excavations for the basement in
the center of the lot 22,267 cubic yards
Of earth were taken out, and in the
digging of the outer trenches "a ,294
cubic yards more were removed. Con-
crete to the extent of 5,122 cubic
yards, 796,352 board measure of tim
ber Gaping, 2S4,144 cubic yards ol
stone and 81 1927 cubic yards OF rubble
masonry have been used.
The whole constitutes a typical pile
foundation, one in which engineers
and architects everywhere are inter.
ested, and one which builders of edi
fees in Chicago would do we'll to copy
There is no danger that the new gov
ernment building will settle and crack
Another significant fact, and one
which reflects great credit upon the
architects and contractors, is that moi
one Of the surrounding big building:
l-Monadnock, Great Northern, Mar
quette or Grand Pacifc-has beer
moved one inch from its place, not
withstanding the heavy pile driving
that has been going on for many
months. The depression of part o
Jackson boulevard, on account of th'
pile driving, was because the tempo
rary plank wall that had been driver
in the outer side of the trench was no
strong enough to prevent the spongy
watery clay from coming in to fill uI
the depression caused within the fenc'
by the pile-driving.
A DISCUSSION as to the exact Ian
guage OF Scriptural quotation re
Gently developed the fact that there