Page 319 - Moving the Earth_ The Workbook of Excavation

LANDSCAPING AND AGRICULTURAL GRADING

LANDSCAPING AND AGRICULTURAL GRADING 7.13

FIGURE 7.7 Tree trunk protection in fill.

The fill should be pervious enough that water will not stand in it and in the holes. Tile may be
laid to drain the tree wells, but a saturated fill is liable to kill the roots anyhow.
Root protection is more complex, and the results are less certain. Land tile is laid on the old surface
of the ground or slightly below it, with lines 3 to 6 feet apart. A 4- to 6-inch blanket of crushed stone is
laid over the area and covered with hay. Pipe openings at each end of the fill or into wells should allow
enough air circulation to preserve favorable conditions long enough to enable the tree to adjust to the
changing conditions. Wire mesh must be placed across openings to keep animals out.
If it is not economically feasible to take these precautions, the fill should be made of clean
bank gravel or coarse sand. Trees may survive heavy additions of such open textured material.
Removal. Landscaping work may involve removal of trees. If they are to be destroyed, the job
resembles the land clearing described in Chap. 1, except that interference from buildings, wires,
valuable trees, and other obstacles is much more common.
If the ground is to be filled, trees may be cut as nearly flush with the ground as possible. This
may also be done if the grade is not to be changed and the presence of the stump is considered less
objectionable than the cost of removing it. If the grade is to be cut, stumps must be uprooted.

DRIVEWAYS

Most home landscaping involves the planning of a driveway. It may be a straight connection to a
street a few feet away, or a long roadway involving considerable problems.
Short, straight drives can be as narrow as 8 feet for use by passenger cars only, but 12 feet is
more comfortable. A long drive, one in a slot between walls, or any drive to be used by trucks,
should be at least 12 feet wide.
Curves should be 1 to 3 feet wider than straightaways, the sharper turns requiring the greater width.
The entrance from the street should be 30 feet wide at the curb, in order to permit turning into it
from the near side of the street. An effort should be made to avoid entering the road through a deep cut,
between large trees, or in or very near to a curve, as any of these features add to the danger of accident.