Page 354 - Moving the Earth_ The Workbook of Excavation

ROADWAYS

8.16 THE WORK

Lignum sulfonate, a by-product of paper manufacture, is used for the same purpose. It is sold
in 50 percent solution form in drums, diluted to 10 percent, and spread by watering trucks.
Gravel road maintenance is discussed in Chap. 19. For haul use the surface should be kept free
of loose stone and coarse gravel pieces, as these may cut tire mileage by as much as 50 percent.
Quantities of gravel needed for various areas and depths are given in the Appendix.

SIDEHILL CUTS

In hilly or mountainous country, roads are largely notched into slopes so that the land rises from
one side of the road and dips away on the other. Such a road may be constructed by digging on
the high side and using the spoil to build up the low side, as in Fig. 8.10(A); by cutting only, as in
(B); or, less commonly, by building a shelf of fill as in (C).
Difficulties of design, excavation, draining, and stabilizing increase rapidly as hill slopes
become steeper.

Stripping. Removal of topsoil, stumps, and logs may or may not be required. This matter will
be decided by the job specifications, or by the judgment of the engineer or contractor.
In general, stripping of topsoil becomes both more difficult and less important as the slope
increases, as deep cuts in steep hills increase the proportion of subsoil in the dirt moved.
When stripping is required, the topsoil can most economically be pushed straight downhill by
dozers to form the toe of the fill, as in Fig. 8.11(A), or a windrow below it, as in (B). Such a
windrow may be moved by scrapers to a stockpile, or left to be pushed or pulled back up the slope
to cover the completed fill.
If the hill is too steep to back up, the dozer may be equipped with a towing winch, and the line
anchored above the work so that it can pull itself up the slope. It may also be helped by winch or
direct pull from a tractor above it, or by a line around a pulley anchored above it to a tractor on
its own level or on a lower one.
Loose stumps can be used in pioneer road fills but are unsuitable for highways. Their use in
intermediate classes of roads will depend on job conditions, the estimated useful life of the road,
and the rate of decay of the stumps.

FIGURE 8.10 Sidehill cut-and-fill cross sections.