2.0

Chapter 4 Working with Cross Sections
352
amount of water present in the area. A bench that slopes inwards pools water
and drains it off to the side. A bench that slopes outward causes water to dribble
down the hill. For more information on benching, see Benching Notes in this
chapter.
The slopes between benches are defined by the simple or depth slope settings:
n
Type: Select the type of bench.
n
Height: Enter an absolute value specifying where to bench (the vertical
distance between benches).
n
Width: Enter the width of the bench.
n
Grade: Enter the grade along the bench. A positive bench indicates the
bench is sloped upwards as the bench moves away from the template. A
negative grade indicates the bench is sloped downwards as the bench moves
away from the template.
4 Specify the Left and Right Bench values.
5 Click OK to return to the Design Control dialog box.
6 Click OK to process the sections to display the Process Sections dialog box.
7 Click OK to exit the command.
Benching Notes
The following are rules applied to benching:
n
Benching parameters are ignored if you are using stepped or surface slopes.
You can only apply benches to simple or depth slopes.
n
If existing ground is crossed in the middle of the bench, the command
matches into the existing ground without benching at that point. Therefore,
the height at that point may be higher than the defined height.
n
If the right-of-way hold is on and the benched typical slope exceeds the
right-of-way, and also if only the benched maximum slope fall behind the
right-of-way then benches are turned off and simple slopes pin into the
right-of-way. In the same case, if benched maximum slope exceeds the right-
of-way, then the benches are applied with maximum slope condition.
n
If the right-of-way hold is off and the benched typical slope exceeds the edge
of existing ground, then benches are turned off and the simple typical slope
is used. If the simple typical slope exceeds the edge of existing ground, then
the slope is pinned into the edge of existing ground. If this happens, you can
resample the alignment from the Cross Sections menu by choosing Existing
Ground
ä
Sample From Surface command and specify a larger swath width.
n
You can use benches in conjunction with simple and depth slope types. If
you are using a depth slope type, the depth determines the slope between
benches. Benches are ignored with the stepped and surface slope types. If a
stepped or surface slope type is indicated and benching is on, then the
benching values are not used. Stepped and surface slopes have their own
benching capabilities.