MedianDitchorBerm

This subassembly creates a cross-sectional representation of a depressed median between the attachment point and a marked point or an attachment point and a point defined by width plus elevation parameters. This subassembly will construct slopes with a single ditch point or slopes with a flat bottom ditch.

Side: defines the direction the subassembly offset and width parameter is drawn and constructed in reference to the attachment point.

Median layout width: This is used as the default median width for layout mode and for corridor modeling when targets and or marked points have not been assigned within the corridor.

Target type method: This defines the method to be used to create the connect point opposite of the attachment point. The two methods are Elevation & width or Marked point.

Elevation & width method requires at least a horizontal target be assigned during the corridor creation process. A vertical target may also be assigned. If a horizontal target is not set the width of the median will default to the value set in the Median layout width.

Marked point method requires that both horizontal and vertical targets be assigned during the corridor creation process. If a marked point is not found or assigned then the width of the median defaults to the Median layout width.

Marked point name: User string input to define the name of the marked point used in the assembly.

Slope from right: This defines the left side link slope regardless of which side is used as the attachment point. This parameter can be negative or positive. (See Figure 1)

Slope from left: This defines the right side link slope regardless of which side is used as the attachment point. (See Figure 1)

Ditch bottom width: This parameter defines whether a v-ditch or a flat bottom ditch is constructed. A value of 0 (zero) will create a v-ditch while any number greater than zero will create a flat bottom ditch. This parameter can be assigned a profile control to consume any station point value along the profile as a width. These values can be used to define the ditch width and transitions to and from a v-ditch.

Ditch width (from attachment point): This value sets the ditch width of the ditch point from the attachment side if target is not defined. This value can be used when the Slope constraint is set to Use Left slope or Use Right slope but will not be used if it is set to Use Both slopes.

 

Slope constraint method

Once the connect point location is determined through selecting the Target type and the appropriate targets have been defined in the process of building the corridor, links are extended inward between the attachment point and the connect point locations at a slope determined by which Slope constraint method has been selected. There are three options that can be used to calculate the median slopes. All of these constraint methods work the same, on the same side regardless of which side the subassembly is attached.

Use Both slopes

This will use both slopes defined in the Slope from Left and Slope from right parameters to calculate the slopes and the location of the ditch bottom, whether a V-ditch is defined or a flat bottom ditch is to be constructed. The slope values can be set equal or non-equal, and can be positive or negative. Both slope values must be positive for a berm to be constructed, otherwise only one slope value needs to be negative for the median to be constructed as a ditch. This parameter cannot use the Ditch offset from attachment point parameter or any targets because both slopes are used to calculate the intersection of both links.

Use Right slope

This method uses the Slope from right value to constrain the median geometry. The slope is defined inward towards the ditch. The offset is defined by the Ditch width parameter or the Ditch width target parameter The elevation of the ditch point is calculate by extending the right link inward at the defined slope until it meets the defined width.

• A v-ditch scenario - When the Ditch bottom width value is zero and the Ditch width from profile target parameter is not assigned, or is set to zero. With the right link slope defined, the left link then connects from the left connect point to the right link at the ditch width point.
• A flat bottom ditch scenario - When the Ditch bottom width value is greater than zero or the Ditch width from profile target parameter is assigned and greater than zero. With the right link slope defined, a ditch bottom link is attached and extends at a zero percent slope toward the left at the ditch width value defined. The left link is connected from the left connect point to the left end of the ditch bottom link.
• When Ditch width is set to zero and no width target is set - When the Side is set to Right, the right link will continue toward the attachment point at the slope define for the width of the median. The left link will connect from the end of the right link at an almost vertical slope to the attachment point. When the Side is set to Left, the right link will connect directly to the connect point and there will not be a second link. Once a target or value greater than zero is set, the links and ditch will behave as described for those situations.

Use Left slope

This method uses the Slope from left value to constrain the median geometry. The slope is defined inward towards the ditch. The offset is defined by the Ditch offset from attachment point parameter or the Ditch offset target parameter The elevation of the ditch point is calculate by extending the left link inward at the defined slope until it meets the offset.

• A v-ditch scenario - When the Ditch width value is zero and the Ditch width from profile target parameter is not assigned, or is set to zero. With the left link slope defined, the right link then connects from the right connect point to the left link at the ditch width point.
• A flat bottom ditch scenario - When the Ditch width value is greater than zero or the Ditch width from profile target parameter is assigned and greater than zero. With the left link slope defined, a ditch bottom link is attached and extends at a zero percent slope toward the right at the width value defined. The right link is connected from the right connect point to the right end of the ditch bottom link.

• When Ditch width is set to zero and no width target is set - When the Side is set to Left, the left link will connect directly to the connect point and there will not be a second link. When the Side is set to Right, the left link will continue toward the attachment point at the slope define for the width of the median. The right link will connect from the end of the left link at an almost vertical slope to the attachment point. Once a target or value greater than zero is set, the links and ditch will behave as described for those situations.

Constructing a berm

A berm can be created two ways; by assigning a target profile where the elevation is greater than both the attachment point and connect point, or by setting both the Slope from right and Slope from left parameters positive. A ditch will always be created unless both parameters are positive.

The attachment point is at the outside edge of either the left or right median ditch, usually located at the subgrade shoulder point.

In the layout mode we cannot get the horizontal and vertical target or a marked point, so the subassembly width is derived from the Median layout width and is drawn in the direction defined by the Side parameter.

 

In layout mode, the Median layout width parameter defines the full median width. This subassembly displays two or three links depending on whether a value greater than zero has been set for the Ditch width parameter. The first link starts at the attachment point and is drawn for half the distance of the Median layout width using the slope defined for that side. The second link begins at the end of the first and is drawn for half the distance of the Median layout width using the slope defined for that side.

Info: All dimensions are in feet unless otherwise noted. All slopes are in run-over-rise form (for example 4:1) unless indicated as a percent slope with a "%" sign.

Parameter	Description	Type	Default
Side	Specifies which side to place the subassembly.	String, Combo List of options: Left Right	Right
Median layout width	Defines the default median width for layout mode and if the connect point target is not assigned.	Numeric, positive	25
Target type	Defines the method for defining the location of the connect point, by defining the target type to be used; a marked point, or elevation and/or width target.	String Combo List of Options Elevation & width Marked point	Elevation & width
Marked Point Name	Name of a previously defined marked point. Marked point must be found in the direction of the insertion side.	String	RT
Slope From Left	Slope of the link extending inward from the left-most insertion point, which is either the attachment point or a marked point.	Slope	6:1
Slope From Right	Slope of the link extending inward from the right-most insertion point, which is either the attachment point or a marked point.	Slope	6:1
Ditch bottom width	Width of the bottom of the median ditch (zero for a V-ditch).	Numeric, positive	0.0
Ditch width (from attachment point)	Defines the width of the ditch bottom from the attachment point.	Numeric, positive	0.0
Slope constraint	Determines whether the slope from the left side, slope from the right side or a computation for both slopes should be used to define the slope of the two links inserted.	String Combo List of Options: Use Both slope Use Left slope Use Right slope	Use Both slopes

This section lists the parameters in this subassembly that can be mapped to a target object such as a surface, alignment, or profile object in a drawing. For more information, see Setting and Editing Targets in the AutoCAD Civil 3D User's Guide Help.

Parameter	Description	Status
Connect point elevation	Object that defines the elevation of the median connect point, opposite from the attachment point. The following object types can be used as targets for specifying this elevation: profiles, 3D polylines, feature lines, or survey figures.	Optional
Connect point width	Object that defines the horizontal location of the median connect point, opposite from the attachment point. It defines the median width. When a ditch width is defined, this location is at the center of the flat bottom ditch; in a V-ditch situation, this defines the location of the valley point. The following object types can be used as targets for specifying the width: alignments, polylines, feature lines, or survey figures.	Optional
Ditch elevation	Object that defines the elevation of the ditch bottom. The following object types can be used as targets for specifying this elevation: profiles, 3D polylines, feature lines, or survey figures.	Optional
Ditch width	Object that defines the horizontal location of the ditch point. The following object types can be used as targets for specifying the width: alignments, polylines, feature lines, or survey figures.	Optional
Right slope from profile	A profile that defines the left link slope. A slope control profile that has the PVI elevations defined as the invert slope is required.	Optional
Left slope from profile	A profile that defines the right link slope. A slope control profile that has the PVI elevations defined as the invert slope is required.	Optional
Ditch bottom width from profile	A profile that defines the ditch bottom width. A slope control profile that has the PVI elevations defined as a ditch width is required.	Optional

None

Point/Link/Shape	Codes	Description
P1	Median-Attach	Insertion or attachment point.
P2	MedDitch1	Edge of the median ditch closest to the attachment point, or center of a V-ditch.
P3	Median-Connect	Connect point on the opposite side of the median from the attachment point.
P4	MedDitch2	Edge of the median ditch furthest from the attachment point on a flat bottom ditch.
L1	Top,LABELSLP,Fslp,TOPDATUM	Link extending at a slope from the attachment point toward the connect point.
L2	Top,LABELSLP,Bslp,TOPDATUM	Link extending at a slope from the connect point toward the attachment point.
L3	Top,DtchBot,TOPDATUM	Link defining the flat bottom ditch.