Agriculture Reference
In-Depth Information
Notice that contours are not shown or used in the grading plan for
the hardscape area shown in Figure 10.23. Contours could have been
included in the original grading plan to provide coordination of this
gathering area with the grading of the surrounding campus landscape
areas and adjacent access walks.
hoW a contractor uSeS Spot eLevationS
ShoWn on a GradinG pLan
The four photographs in Figures 10.24-A through 10.24-D were taken at
several construction sites and were selected to show how a contractor
uses spot elevations from a site-grading plan to construct concrete work.
Figure 10.24-A shows the wood forms a contractor constructs in prepa-
ration for pouring concrete for an entry drive. A surveyor marks each
corner stake with the elevation shown on the grading plan. The contrac-
tor fastens (usually with nails) the form boards, first lining up the boards
with the surveyor's elevation mark. Figure 10.24-B shows the concrete
pad with the wood form boards still in place soon after the concrete
was poured and the concrete surface was finished. The contractor will
remove the forms, usually within a day after the concrete has set up or
begun the hardening process.
Figure 10.24-C shows the manner in which the contractor makes
sure the wood concrete forms are square and are set at the elevation
specified in the grading plan. In this case, carpenter's string is used to
guide the squaring of the wood form. Note that one end of the string is
tied to a nail. The nail was set by the surveyor at the prescribed eleva-
tion shown on the grading plans. Figure 10.24-D provides a bird's-eye
view of the forming layout for a circular driveway and drop-off. After all
the forms are in place and secured, a concrete pour will be scheduled,
followed by a finishing crew to complete the finishing of the surfaces per
the technical specifications.
