Pattern lines determine cross section locations. Existing ground cross sections are generated using pattern lines and proposed cross section are drawn upon existing ground cross sections. Pattern lines are the foundation of all cross sections.
Best practices for Western Federal Lands is to use pattern lines, Although cross sections can be generated by station, the station method would be cumbersome to handle specific station location with automation. A general rule is, if there is not a cross section at a location then there is no design data for that location. This does not represent the intention to generate a large quantity of pattern liens, but the the idea of having the right amount of and location of cross sections. Give forethought into the right amount of sampling to represent the design intent.
To create pattern lines, open the pattern base dgn file, XX####_Patt.dgn, and open the project manager. A best practice is to have the horizontal alignment (HA) file and planametric survey file (PLM) referenced to coordinate pattern lien placement and to facilitate individual pattern line placement.
Go to Directory>Current Working Directory, next Select Project, Select OK, and then Select User [name] from Project Users menu.
Select Draw Pattern on the Project Manager menu. Note the active Project name, User name, Job # and Working Alignment.
The Select Run menu will appear. All select run menus are loaded with a default "Untitled" run. Do not use, delete or rename the "Untitled" run
Create a new run. Go to Run>New.
Enter a run name and description.
Select created run and then OK
If the Working Alignment definitions are up to date in the Project Manager, much of the design data will be filled in automatically, such as chain and stations. Note the placement symbology has been filled in with data that used in the define working alignment menu.
Complete all fields according to design parameters then select Draw Pattern Lines. The increment method is used for most of the project limits.
Use level symbology to segregate possible pattern lien placement, i.e. culvert pattern lines place on P_GPK_Pattern_02 level and color 2.
It is recommended not to use "by level" symbology for pattern lines. Use the following Levels for Patter levels;
P_GPK_Pattern_01 thru P_GPK_Pattern _10
Once method is widely used for individual pattern line placement and useful for specific location such at existing and proposed transition points. Use the begin station button to data point (snap) on the drawing for pattern file station locations.
Other methods for pattern line placement are shown below. As a design progresses use of other design data will be required for pattern line placement.
Increment (best practice)
Patterns are drawn at the specified interval when added to the beginning station.
Patterns are placed at even stations based on value in the key in field, but are not based on the beginning station. For example, when Even 25 is utilized, patterns are drawn at the beginning and ending station values plus +00, +25, +50, and +75.
Once (best practice)
One pattern is drawn based on the station in the beginning station field and utilizing the offset in the beginning group box. Note the ending station group box is ghosted for this option.
Control Points – Horizontal (best practice)
Patterns are drawn at each horizontal critical point, i.e., P.C., P.T., P.I., S.C, etc. Note no manual entries (Even, increment, etc.) are required for this option.
Control Points – Vertical (best practice)
Patterns are drawn at the beginning (VPC) and ending station (VPT) for each vertical curve. In addition, a pattern is drawn at the high or low point on each vertical curve. If there is no low or high point on a curve, only the VPC and VPT lines are drawn. Note that the profile must be specified in the upper right corner of the dialog for this option. No manual entries (Even, increment, etc.) are required for this option.
Superelevation Transitions (best practice)
The current design file and reference files are scanned for superelevation shapes created with the specified chain, therefore the superelevation dgn file (SHP) needs to referenced or can be a nested reference. A pattern line is drawn at the beginning and end of each superelevation shape, including the beginning and ending station fields in the dialog. No manual entries (Even, increment, etc.) are required for this option. Note: Pattern lines are not drawn that are coincident with horizontal control points. Therefore, the user need not be concerned about double patterns when using both the horizontal control points and superelevation transition options.
When activated, the pattern line(s) are skewed by the specified angle from the standard pattern line (perpendicular to the baseline). A positive skew angle rotates clockwise, while a negative value rotates counter-clockwise. Use for culvert locations is recommended. Skewed sections should be kept in a separate cross section file and not used for earthwork calculations.