LARS | LEAP | OpenBridge | OpenTunnel | RM - Apply 3D by Slope to Target

The Apply 3D by Slope to Target from the 3D Geometry Tab in the Civil Ribbon Tab is very useful to adjust Terrain models near the bridge abutments. Users can rearrange the terrain slope to match a reference and create models adjusted to reality. Basically what we want to achieve is an accurate proposed terrain; so, it must adjust to the abutment without interfering with the girders' bearings and wing walls limits. This can be created by following the steps below, and the final result is a clean, exact terrain model, as shown in the second screenshot below.

AbVsTer

Though, Apply 3D by Slope to Target is a general civil tool created to modify a tridimensional element from a line to a surface and, it was originally created for expanding the Alignment to create the Corridor modeling surface. Despite it might be a very simple and straightforward task for those used with these road features, for bridge engineers just starting to expand their activities to the 3D Terrain modeling it might get tricky to learn it without more detailed explanations. Therefore, this Wiki article is intended to guide users into the best practices to allow them to start learning the Apply 3D by Slope to Target tool by experimenting just doing it.

To model an abutment slope to a terrain model in OpenBridge Modeler users could follow the steps below:

1. Isolate the necessary elements for your visual reference, preferably in a 3D View. Use the Explorer Window to turn off all bridge elements, but not the abutments. Also, turn on the terrain model, by selecting it and modifying the Properties.

2. Create an additional reference line from where the 3D slope will target the Terrain: In View, Select Wireframe, then in the Workflow the Drawing option, as shown below. Assign it to the Model and the Level Terrain_Design. At the Ribbon: in the Home Tab at Placement select a Place a SmartLine to draw the line from where the new terrain slope will intersect the abutments. Consider this line as the starting point or the limit until where the Terrain will be modified. As you don't want to change the Terrain of the Corridor just behind the abutment you might want to include the wing walls in the line. In most cases, it is easier to draw the line at the wing walls and the abutment, and then as a second step, just move this line slightly back to the other abutment face, as shown below.

OBM1 DrSmL

3. Use Apply 3D by Slope to Target icon from the Civil Tab Ribbon, at the 3D Geometry Tab, using a Plan View and a Profile Model. Set the Parameters by texting or clicking:

Slope Option: To Terrain Model
Cut Fill Option: Cut And Fill
Start/End Cut/Fill Slope: The slope percentage from the line entered as a unit value: for example, 0.5 = 50%
Corner Option: Rounded
Transition Type: Constant. Only used if the Start and End values are different.
Slope Location: Consider the Smartline creation, the line Start, direction, and End.
1. Side: Consider the Smartline direction to set the Right and Left sides as in the picture below.
2. Start/End: Either Lock to Start and End or enter this when with values or data points. The reference is the actual length of the Smartline, as it would be stationing inside the reference element.
Feature Definition: Terrain Interior. Set the Feature Definition to a Terrain feature to get the correct symbology, annotation, etc.

Prompt sequence: Datapoint, SmartLine, Reference Terrain, Datapoints until it accepts. Note that for the available valid set of data it will start drawing the start and end perpendicular line as a dashed line perpendicular to the reference line, and then the new terrain borderlines in blue, as shown below.

OBMSl OBMDr

4. Additionally, if needed, users can then create the terrain and apply it to the proposed terrain mesh: Turn off Terrain Reference for easier visualization, and at the Civil Ribbon Tab, at the Terrain Model Tab, use Import Terrain and choose to Create from Elements, select the Feature Type Contour, and click the two Boundaries. Then, still at the Civil Ribbon Tab, at the Terrain Model Tab, and at the Import Terrain use now the Create Complex Terrain Model to Merge the new component into the existing terrain and have a Proposed Terrain Model.

PRO TIP: Creating more than one separated SmartLine will allow for a constant definition of the slope in front of the abutment and a gradient slope in the additional lines for the abutments wing walls. Creating separated lines and additional terrains for the transition from inside abutment walls structures to the outside will guarantee the corridor is maintained.