Roadway Designer Manual: 5 - Create Cross Sections
Introduction
There are multiple approaches to creating cross sections from a Roadway Designer produced model. Unlike the old methodology, the new method generates both existing ground cross sections and proposed cross sections simultaneously.
Historically, proposed cross sections were created using criteria after the existing ground sections were cut from a TIN file utilizing the Draw Cross Sections from Surfaces tool. The Corridor Modeling method does not automatically draw the proposed cross sections into a CAD file like the criteria method.
The Draw Cross Sections from Surfaces tool is used to draw both the existing ground surface and proposed cross sections into the CAD file at the same time.
Figure 1
This tool is an enhanced version of the tool included previously in GEOPAK.
A new feature of the tool is support for a DTM created by Roadway Designer. Proposed cross sections created from a Roadway Designer DTM include all template components (pavement layers, shoulders, sidewalk, tie slopes, etc.).
In addition to the new options in the Draw Cross Section application there are also new options for generating Pattern Lines. While using the traditional Draw Pattern Lines application is still a viable option for creating the Pattern Lines, Pattern lines can also be created easily using the Transverse Features option when generating the proposed model.
Figure 2
This options will place elements at all locations where cross sections where designated in the Roadway Designer, even odd stations. The elements can then be used as Pattern Lines in the Draw Cross Section dialog to create all cross sections.
Draw Pattern Lines
Pattern lines are graphical lines and/or line strings in a 2‐D CAD file that define locations at which the cross sections will be cut. The Place Smartline or Place Line commands can be used to draw additional pattern lines at any user‐defined location. In addition, MicroStation commands can be utilized to modify pattern lines drawn via the dialog to lengthen, shorten, delete, copy, move, etc.
Figure 3
Accessing Draw Pattern Lines
The Draw Pattern Lines tool is invoked by selecting Applications > GEOPAK > ROAD > Cross Sections > Draw Patterns by Station Range or by clicking the Draw Patterns by Station Range icon. It can also be invoked from Project Manager by clicking the Draw Pattern button.
Figure 4
Dialog Options
The dialog is divided into two parts; the top contains the project‐specific information, while the bottom contains the location and element symbology of the patterns to be drawn.
The top part contains the Job, Chain, and Profile to be used in creating the pattern lines. This information will be automatically populated in the dialog if the tool is accessed through Project Manager.
Figure 5
The left grouping contains the beginning station, left and right offset, while the right grouping contains the ending station, left and right offset. The stations may be listed with the plus (+) sign, and if the alignment has station equations, regions may also be included.
Figure 6
Methods
Six methods are supported for drawing the pattern lines:
Figure 7
- Increment – Starts at the beginning station, and draws a pattern line at the given increment.
- Even – Draws pattern lines at stations divisible by the given value.
- Once – Draws a pattern line at a given station.
- Critical Points Horizontal – Draws a pattern line at each of the critical points (i.e. POT, PC, PT, etc.) within a chain.
- Critical Points Vertical – Draws a pattern line at each VPC and VPT in addition to the sag or crest station of vertical curves based on the profile defined in the dialog.
- Superelevation Transitions – The current design file is scanned for Superelevation shapes created with the specified chain. A pattern line is drawn at the beginning and end of each Superelevation shape, ignoring the beginning and ending station fields in the dialog. Superelevation shapes cannot be in a reference file.
When Skew Angle is selected, 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. Level Symbology defines the element symbology that will be used to draw the pattern lines. Click Draw Pattern Lines to commence drawing the patterns. If they are not visible, turn on all levels and fit the view.
Figure 8
Draw Cross Sections from Surfaces
Accessing the Dialog
The dialog is invoked via the GEOPAK Road tools or menus as always, but for convenience it can also be invoked by clicking the Draw Cross Sections from Surfaces icon on the Corridor Modeling dialog. The tool works exactly the same no matter where it is accessed from.
Figure 9
Prerequisites
The prerequisites for generating cross‐sections utilizing digital terrain modeling are:
- GEOPAK coordinate geometry database in which the horizontal and vertical alignments are stored
- Binary GEOPAK TIN file or a DTM created with Roadway Designer
Each surface to be drawn must be added to the list box. This is accomplished via the action/edit buttons on the right side of the dialog. Each surface draws a cross section line or line string. When the list box is populated, clicking Draw in the upper right corner commences the processing.
Be sure to select ‘Line’ when select the Type option in the Details portion of the Draw Cross Section dialog. Selecting Line as the Type is crucial in order for the earthwork input file to work correctly.
Figure 10
The generation of cross sections must be invoked from within the CAD file or model wherein the sections are to be drawn. GEOPAK does not create this CAD file.
Cross Section Symbology
Existing ground symbology is controlled from “By Level Symbology” or “By Feature”.
Proposed cross section symbology is controlled by Roadway Designer. The same symbology that is used in Roadway Designer to display the design template will also be used to draw the proposed cross sections. Symbology must be set in the Draw Cross Sections from Surfaces dialog, but that setting will be ignored when the cross sections are processed.
Cross Section point symbology is controlled by the active MicroStation settings when the cross sections are processed. Set the active symbology and text attributes before generating cross sections.
The increment for creating cross sections needs to match, or be evenly divisible by, the increment that is set for the Template Drops in Roadway Designer. If these settings do not match, then the cross sections will be an interpolation and could affect the earthwork.
Three action/edit icons are located on the right side of the dialog.
Figure 11
- Add Surface – Adds a Surface to the list box.
- Modify Surface Settings – Modifies a highlighted line in the list box.
- Remove Surface – Removes a highlighted line in the list box.
Cross Section Cell
The Cross Section Cell is the location of the cross section data for each pattern to be drawn into the CAD file. The cross section cells are created when cross sections are processed. The cross section cell provides the following reference information about a given cross section:
- Baseline
- Station and region (if applicable)
- Coordinates of the intersection between the baseline and the cross section pattern (if pattern by design was used)
- Elevation reference
- Plan View coordinates at both ends of the cross sections. (NE only, XY coordinates are not available)
- Coordinates of each vertex of the pattern defined in terms of a line string element type
All labeling, sheet layout and other cross section‐related software references these cross section cells. Additional cross sections drawn into the same design file will be placed in the far right column above the last cross section previously drawn. If the cross sections are out of numerical sequence, they will be "sorted" into order when sheet layout is utilized.
Other than to avoid deleting or "dropping" the cell, the cross section cell can be essentially ignored by the user. The cells can be locked, to avoid being deleted or dropped. They should not be copied to a different location within the same design file, as unpredictable cross section data placement can occur. However, the cell and its accompanying data can be moved to another location, if desired.
The cross section cells are drawn into the user‐defined CAD file. The cells are drawn from bottom to top in columns containing approximately twenty cells per column. By default, GEOPAK spaces cross section cells every 500 master units vertically and every 1000 master units horizontally.
Viewing Cross Sections
Cross Section Navigator
Since GEOPAK Cross Sections are created in a column format on cross section cells, a special viewing tool is needed. This tool is known as the Cross Section Navigator. The Cross Section Navigator provides a quick and simple method of scanning through cross sections or locating specific sections.
Figure 12
Accessing the Cross Section Navigator
To access the Cross Section Navigator, select Applications > GEOPAK > ROAD > Cross Sections > Navigator or click the Cross Section Navigator icon.
Figure 13
The Cross Section Navigator also provides several tools that can be used to draw cross section lines and set active angles. These tools will not be discussed. For more information on these and other tools, see the online HELP.
Viewing Options
The preferred methods for viewing cross sections are the Scrolling Buttons and the Available Stations List.
Scrolling Buttons
The Scrolling Buttons enable the user to quickly scan both forwards and backwards within the cross section range. The single arrows move forward (>) or backward (<) one section each time the button is pressed. The double arrows move to the first section (<<) or last section (>>). The navigation maintains the same relative positioning and window size. The Reset Navigator (center button on the dialog) returns the user to the first section, and the entire section is placed on the screen. Therefore, the relative window is not maintained.
Available Sections List
The Available Stations List is utilized to view cross sections at specific stations or scroll through a series of cross sections.
Figure 14
Conclusion
Advantages:
- Cross sections created from the Roadway Designer model are an exact representation of the design.
- The process is simplified by creating existing ground sections and proposed sections simultaneously.
Disadvantages:
- The necessity to import base files for use with Roadway Designer.
Uses:
- To provide cross sections in order to generate end area volumes
Workflow:
To access this workflow, follow this link: Create Cross Section Workflow
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