Page 280 - Moving the Earth_ The Workbook of Excavation

PONDS AND EARTH DAMS

6.16 THE WORK

FIGURE 6.11 Controlled inflow.

The dragline or a backhoe are the preferred tools for spreading such piles. A bulldozer can be used
if the piles are dry, and is frequently used for finishing after the dragline has knocked them down.
A dragline spreads piles by a combination of dragging down with lifting and swinging. First
the machine approaches the pile closely and digs off the top. Each time the bucket is filled, it is
pulled closer to the shovel than necessary, sliding several times its capacity ahead of it. It is then
lifted, swung, and dumped in a low spot, and the process repeated until the dirt piles against the
tracks.
The shovel is then backed a few feet, and the digging and dragging are continued, cutting to
somewhere near final grade. The shovel continues to back and dig until the pile is exhausted,
when it pulls down the lip in front of it, and walks up on the freshly graded area to work on the
portion of the pile that was originally beyond its reach.
In Fig. 6.12 the pile is shown to be on the edge of the pond excavation. The dragline digs this
shore to its final slope, widening the pond in the process. It is good procedure to cut banks back
to a slope which will be stable under water, as it reduces the accumulation of soft mud at the edge
of the bottom from parts of the bank sliding and falling in.
If the spoil is in windrows, the shovel may be walked parallel to the pile, digging and pulling it
down until it starts to fall against the tracks, then moving on to wreck another section, continuing
until the end is reached. It then comes back, parallel with the windrow but farther back, digging
and dragging in the same manner. The ridge pulled against the tracks can be dug and spread
behind the shovel. If the windrow is small, one trip may be sufficient.