AEC

All Aboard!?! (Productivity Corner MicroStation Tutorial)

1 May, 2007 By: Michael Gilham

Bentley's PowerCivil automates subdivisional roadway systems.


The roadway network tools available in Bentley PowerCivil are specifically designed to automatically complete the entire design of a subdivisional roadway system. You must input a complex graphical element that defines the road centerline and graphical elements that represent the edges of pavement into the software.

Optionally, you can draw the ROW (right-of-way) and/or sidewalk and include them for vertical definition if they are required for your project.

All of these elements can be in 2D and 3D. You don't have to assign the elevations to the graphics. The tools scan for the graphics and assign elevations based on some preset preferences.

After adding the roads to the Network Tool list, save the list to a file (File/Save) because you may want to recall the list later. Then click Process Network.

figure
Roadway Network tool list of proposed roads prior to processing.

The tool takes the graphical alignment elements that you selected as the centerlines for the roads, stores them as COGO Chains (horizontal alignments), creates proposed vertical alignments (based on the preferences), finds the edge of pavement and assigns elevations to it and adds curb and gutter (or ditches) and assigns elevations to ROW, sidewalk or whatever you need.

It also creates and grades the curb returns and cul-de-sacs (as applicable).

But that's only the beginning.

figure
The program automatically models your roadway network design Objects.

Say, for example, you don't like the profiles created and want to modify them. What do you do?

Part of the Roadway toolset is a Create/Edit tool that lets you create a single road or modify an existing road that has previously been created using the Network Tool or the Create/Edit tool.

Modify a Roadway Object
Let's take a look at the steps required to modify the vertical alignment and apply that modification to the Roadway Object.

Open the Roadway New/Edit tool and load the preference file that you initially used to create the roadway you now want to edit.

Click the Select Element button and select the alignment element (in plan view). This extracts the information stored with the alignment element to populate the appropriate settings and orientate the view windows (Plan, Profile and XS) awaiting your next move.

Click Next.

figure
Modify an existing roadway Object using the Roadway New/Edit tool.

A pop-up dialog appears asking if you want to update or modify the cross sections (XSs). Here, you have the opportunity to widen, add and remove XS locations or add additional surfaces to the automatically generated XSs (these were automatically created from the Roadway Network tool process). You also can delete all the XSs and recreate them, if you'd like.

For this exercise, let's assume that the XSs are in the correct locations and don't require any intervention at this time. Click No to the pop-up and choose the Editing dialog box.

figure
The Edit/Redesign options within the Roadway New/Edit tool.

The Editing dialog box provides a number of options for modifying your roadway.

The Composite Section can be changed. This is similar to applying a different template in template-driven software, except that the Composite Section is intelligent.

You can add elements to the Profile, for example, the top back of curb can be shown in profile.

And, you can create a new roadway!

We want to modify the vertical alignment -- so click the Vertical Design Tools button.

The view windows rearrange themselves to bring the profile view into the main screen (View 1) while providing synchronized Plan and XS views in view windows 2 and 3. Everything you need to make intelligent design decisions is in front of you.

You can even activate the curvilinear coordinates dialog box from the Active Chain Control tool and view curvilinear coordinates (such as stations, elevations and offsets depending on view window you happen to have the cursor) to provide even more accurate information from any view (Plan/Profile/XS) while modifying the Profile.

You can then modify the Profile -- remove, add and change VPIs, lengthen, shorten and reset VCs, re-grade, add and remove Profile lines and more. Close the Editing dialog and click Yes to save the modified profile.

Now that you are back in the Editing dialog box, click Update Design.

The modified profile is now applied back to the Roadway Object. The Composite Section (intelligent template) is rerun, the XSs are deleted and redrawn, and the Profile (plans production profile) is redrawn.

The curb returns are recalculated if you want them to be and, if the roadway has a cul-de-sac, it is rebuilt based on the new vertical geometry.

And, as simple as that, the roadway is remerged back into the finished surface model.

You can immediate evaluate the volumes for the roadway (Cut/Fill), the Profile, the new XS's the finished surface Model and, if desired or required, modify the profile again and update the Object. It's that easy!

This same procedure can be applied to any of the roadways created using the Roadway tools with one caveat. While the roadway curb returns that intersect the modified roadway automatically update, the profiles of the intersecting roads do not (we are working on this).

The New/Edit tool is basically editing a single roadway and its intersections -- not the adjacent roads.

To take care of this, you simply go back to the Roadway Network Tool, disable the roadways that you manually modified and click Apply.

figure
Reconfigured Roadway Network list - shows that Road 1 has been disabled. All other roads will be rebuilt automatically.

Every road that is still enabled is rebuilt (including the creation of the XSs and Profiles for plans production). This redesigns the currently enabled roads based around the manual modifications that you made to the disabled roads in the list. All of the intersections are recreated and any cul-de-sacs are redesigned -- all at the click of one button!

That's it! You are ready to create Plan/Profile and XS sheets and send the project to the plotter -- or to machine control -- but that's another article.


About the Author: Michael Gilham


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