Burlington weekly free press. [volume] (Burlington, Vt.) 1866-1928, 1914-01-15
MAKING THE FILL
j, w. y OULLI ' TN
BURLINGTON. VT.

First in starting the fll, coup'e
Of 20 to Soft. trestes were run out s''no
30 IT, inside the upstream and downstream
toe lines Of the dam, and material iloi''
the Dit was dumped off these, workins
out from both ends Of the dam lnese
four toe fills were thus pushed out unti'
the water was reached when the gap IN
the upped dixie was flied In When TINS
was done, the water rose until the elti''
flow was through tho conduit The pool
between the two bikes could then We
drained through the gap in the lower
dixie and the remaining work OF stripping
the site completed.
When the work was IN this stage
pumping plant was built just above the
dam, taking water from the reservoir lor
Gin. supply lines laid along both trestles'
There were in this pant three "-hp'
| locolnotive-type boilers, two compound
duplex pumps rated for 80 gal. per min
at 20o-lb. pressure, and one smaller pump
| as a spare unit Only $50 ID. pressure
was held on the pipe lines however. Ihe
| lines were fitted every so IT. with Lit
| tings and valves for connecting on lengths
of Sin. rubber alulcinF hose fitted with
! 1N-in. taper nozalcs mounted on port
able wood stands as monitors.
The material dumped from the trestles
| was undercut with streams from these
nozzcs and washed down into position.
Obviously a pool was created between the
two bikes and the finer material settled
| in the center At times alum was used
| in the sluicing water to increase the pre-
cpitation of claycy material. but this was
! finally abandoned as unnecessary. An IL
in. concrete pipe was carried mp from n
| hole in the outlet conduit; through this
| the excess water was drained and the
depth in the pool regulated, being allowed
to vary between 10 and 20 IT. The out
side faces Of the two bikes We're filled
with coarscr material and boulders from
the pits and this, ON being washed down
into place. gave a satisfactory rock face
| without riprapping.
When the washed III reached the level
inward. Five heights of trestlcs were
run in during the work on the dam; the
old timbers We're not pulled
TESTING THE DAM BODY.
Samples were taken at each five feet
along the length of the dam to see if suf
hcicnt fine material was being deposited
to build up a satisfactory imperviou'
core. In sounding the center pool tho
bottom at each stage was always fount
quite hard. and examination Of the &C
cumuatcd samples shows that the fine
material has considerable bonding prop
erty. The two years occupied in con
struction has given opportunity for muci
Of the expected settlement. which l.
small with such a washed fill, but tn
dam has been carried to an excess hcigh
OF about # to care for any gradua
settlement and any natural change o
. future years.
During the past season the concrct
spillway has been completed and drillin;
for the spilway channel started through
, rock on the west side Of the dam. Thi
work will be completed during the mex
few weeks. The upper material was re
moved by steam shovel after shootin
wcldrll holes at grade. Remaining wor
has been handled by derrlcks with steai
drills where material was not sufficient
broken up a first.