Agriculture Reference
In-Depth Information
with shallower slopes to conform to less steep terrain and steeper slopes
for steep terrain. The designer varies the slope to minimize earthwork,
and in this case so that the walk fits with the existing terrain.
Step Two: A is the main slope of the walkway, B1 represents the
cross slope, and C is spot elevation 103.5, slightly higher by 1 percent
than spot elevation F.
104
A
A
B
2
B
2
Contour 104
showing cross slope
103
1%
1%
103 with
cross slope
C
C
B
1
B
1
1%
1%
F
=103.4
F
=103.4
103.5
103.5
Figure 13.4-B
Step Two providing information to make
slope and spot elevation calculations
Figure 13.4-C
Step Three showing the grading solution
with contours and spot elevations
Step Three: The locations of contours
103 and 104 are shown to help the viewer
visualize how they might appear in the land-
scape. The spacing of the contours would be
33.3 feet apart to achieve a 3 percent slope.
The slopes of the switchback ramp
system shown in Figure 13.5 were designed
to accommodate wheelchair access and
meet ADA design criteria for the recently
completed Grand Park, located in down-
town Los Angeles. Eight percent is the
maximum slope allowed for walkways
designed for wheelchair access. The length
of the ramp cannot exceed 20 feet. In
H = 15'
H = 20'
8%
8%
8%
2 4
1%
Figure 13.5
A switchback wheelchair access ramp, Grand
Park, City of Los Angeles, CA
