Page 167 - Moving the Earth_ The Workbook of Excavation
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BASEMENTS
BASEMENTS 4.7
FIGURE 4.7 Finishing excavation.
amount of dirt removed for ramps can be slightly reduced by narrowing them as they go up, as in
(B). The ramps can be partly filled by the last loads pushed, as in (C), except where space is left
for supply trucks.
As the bottom of the hole approaches final grade, it should be checked. A 4-foot stick, or a
rule, may be used to measure down from the edges, if they are well enough preserved, or from a
string stretched diagonally between two corner stakes. The mason contractor generally expects to
do some hand leveling and trimming, but will be pleased to find it unnecessary.
It is not practical to dig narrow footwall trenches below the pit level with a dozer.
Results. The procedure outlined above should produce an excavation such as shown in Fig.
4.7(C) with two straight walls correctly spaced. Ramping out of the short sides reduces the
amount of extra digging that is one of the drawbacks of dozer work. The whole front is left free
for access and for piling building material.
However, the spoil may not be properly placed for backfill and grading. In such a location, a
house would usually have the fill spread all around it, with particular attention to building up the
front. Here, fill for the front yard would have to be obtained from the sides, which, in turn, might
need to be partly replenished from the back. This involves extra pushing, and the presence of a
few trees might make distributing it a major problem.
Time. This basement involves about 220 yards of excavation. It might take an 80-horsepower
bulldozer (a good size for the job) from 1 to 3 hours to strip the topsoil, and 2 to 6 hours to do the
digging.
Rock (even if not removed), water, irregularities, or obstacles will increase the cost of the
work.
OTHER DOZER WORK
Four-Pile Method. Another pattern for digging this same basement is shown in Fig. 4.8. The
soil is pushed in four directions. The east and west ends, for a distance of perhaps 8 feet from the
