The Big Stone Gap post. [volume] (Big Stone Gap, Wise County, Va.) 1892-1928, 1894-10-04
LAYING IH= FOUNDATION.

How Architects H;tvn overcome oAc OF
Chicayo's Natural Ohstuclcs.
Foundations for large Chicago build
ings are constructed in Il peculiar man
ner owing to the nature Of the material
underlying the city. The site was
originally a wild rice swamp. which
has been gradually flied III until the
streets are now ut al average elevation
OF about Is feet above Che water level
.oY the lako. All lA~so cities have sn
artificial top stras1m. bat Chicago IS
unfortunate in having below the arti-
fetal filing and tho thin natural top
layer of earth jelly-lille mass Of clay
of very varia bic depth. The sustaining
power of this clay is only from 1900 to
1000 pounds a square foot and on this
account it has been customary until re-
Gently for the architects of high build
ings to support them By spreading
floors OF concrete and steel beams under
each wall anil column. Even VITA
such web-footed foundations. build
ings sometimes settled urevenly, pro-
ducing cracks and endangering the
lives of their occupants, the great
Board of Trade building being perhaps
the most noteworthy instance of this.
Recently some Of the largest buildings
have been provided with deep pile
foundations. reaching entirely through
the Jelly stratum into the firm, hard
clay below The Stock Exchange
building now going up is an
example. II is Ito feet. inches
wide and 1SO feet, 8 inches long,
measured on the building line, al
though the foundations are extended
beyond these limits in order to support
the walls. The piles used were 80 feet
long and driven III clusters about feet
apart. A steam hammer was employed
to drive them. which weighed $500
pounds and was provided with 400
pound tup, or striking part, having 4
stroke of 315 feet With this hammer
72s piles were driven in one month.
each pile being so spaced as to support
a weight of at least thirty tons. Fin
beers IL inches square were laid across
the foundation on top of the piles and
covered with grillage of similar Sim-
bers running at right angles to the
first set. On these concrete and steel
beam base was made for each column
or wall, the total amount OF steel re-
quired being about 125 tons. On one
side the foundations Joined those of the
..Herald" building, and as piles could
not be driven here there walls carried
bv wells from to q feet inches in
diameter. filed with concrete. These
were excavated doyl to to. har,l clay
substratum By means Of c.rcula:.
sheathing oe oak stav he d in place
bv steel rings When tie concrete
hardened these wills o.clms cquiva
lent to piers such IS 'appo:5 brieg IS.
the only d ference b,in.; the r mailer
diameter d proportion to the l,.g5h-
The cost of sue.l foundations Is ststs.i
10 be about tn. same as that OF tn.
wide-soreading concrete and steel type
which has been SO long in use, while
tkey take up but very little room above
the aoey level of the basement, in
which respeas they differ again from
The spread founeation. Their use is
gradually increasing sra among the
eecent buildings built on the1s are the
new Illinois Central station, ths Art
Institute, al the Medina Temple.
Nh :ou<rn Raeorl1