prior to the demonstration. Water, approxi-
mately 1020 cm (48 in.) deep, was flow-
ing across the trail. By use of a D7 bull-
dozer, the fascine was moved into place,
placed on top of a geotextile, and covered
with chunkwood.
The second location was another area
where water was flowing across the trail.
The HEMTT was used to transport the
fascine to this test section. The fascine was
unrolled so it was only one pipe thick
(Fig. 6), and covered with tire mats.
Overall comments on all mats
Test site construction could have been
more efficient if the delivery truck had
a. Fascine.
unloaded the mats at the test site. This
would have enabled the construction crew
to work continuously. As an alternative,
the mats could have been brought to the
staging area on a lowboy and then trans-
ferred to the construction site using a cargo
HEMTT with a crane.
Fill materials
Three types of fill material were used:
chunkwood mixed with sand, tire chips,
and gravel. Similar construction methods
were used to place all three. The material
was loaded into dump trucks, delivered
to the site, and then spread with a D7
bulldozer (Fig. 7). Hauling distance fig-
ured significantly in overall construction
time.
b. Covered with chunkwood.
Chunkwood
Figure 6. PVC fascine.
The chunkwood was produced by
shredding whole trees with a USFS proto-
type wood chunking machine. The result-
ing wood chunks were approximately 3.8
cm (1.5 in.) thick and were well graded,
ranging from 1 to 20 cm (0.5 to 8 in.) in
diameter. The chunkwood was mixed with
sand in the approximate ratio of three parts
chunkwood to one part sand. The density
of the chunkwood/sand mix was approxi-
mately 796 kg/m3 (50 lb/ft3). The bulking
factor appeared to be low. Although test-
ing by the USFS has shown a sheepsfoot
or padfoot roller improves compaction,
the chunkwood compacted easily with
construction vehicle traffic. The compacted
surface was relatively smooth and pro-
Figure 7. Spreading fill material with D7 bulldozer.
vided a good wear surface (Fig. 8).
13
Previous Page
