Page 385 - Moving the Earth_ The Workbook of Excavation

ROADWAYS

ROADWAYS 8.47

FIGURE 8.35 Roadway subdrainage.

with sand. The drain itself may be any type of pipe, laid at the lowest convenient level, and open-
ing into side drains, a catch basin, or a gutter.
The rock fill directs the water toward the pipe and reduces or eliminates softening of adjacent
areas.

JOB STUDY

Road construction may involve clearing vegetation; stripping and storing of topsoil; excavating
soil and rock to cut natural levels to road grades; hauling the spoil to road fills or waste dumps;
building culverts, bridges, and drainage systems; raising low areas to road grade by fill obtained from
roadway cuts or borrow pits and finishing, topsoiling, and seeding of slopes; and cleaning up the
work area.
Usually, this work must be accomplished within a time limit. It is desirable to get the maximum
number of machines and workers on the job as soon as possible after the start, but it is more impor-
tant to keep them efficiently employed once they are there.

Sequences. When time permits, it is often desirable to perform complete operations in
sequence. If an entire work area is cleared, it will usually be easier to arrange dirt moving
sequences than if the excavators have to be limited to a few small sections. Culvert construction
should be completed before fills are raised high enough to go over them, unless they are to be
installed by ditching the completed subgrade.
Liberal areas of rock should be cleaned before drilling starts. Pioneer bulldozer work should
be well advanced before scrapers operate.
If the schedule is close, delay in one operation will delay others that have to wait for it, which
may be more costly in machine and worker time. These secondary delays are much more serious
when the maximum amount of equipment is crammed into a job than when a few units are doing
it over a longer period.