How to Edit Alignments in BricsCAD

Quick answer: ALIGNMENTEDIT covers continuing a horizontal or vertical alignment, adding or deleting PI/PVI points, deleting elements, adding or removing station equations, and changing the referenced TIN surface. Whichever edit you make, the 3D alignment updates automatically.

Continuing a Horizontal Alignment

1. Draw a horizontal alignment using the PI method covered on the alignment creation page.
2. Run ALIGNMENTEDIT.
3. Select the alignment you want to edit.
4. Choose Continue by Pi.
5. Pick new PI points to extend the existing alignment.
6. Use Undo to step back if needed.
7. Press Enter when finished. The horizontal alignment extends accordingly, and the 3D alignment updates automatically.

Adding and Removing PI Points

To add a PI point:

1. Run ALIGNMENTEDIT.
2. Select the horizontal alignment.
3. Choose Add Pi.
4. Pick the point where you want the new PI.

To remove a PI point:

1. Run ALIGNMENTEDIT.
2. Select the horizontal alignment.
3. Choose Remove Pi.
4. Pick a point near the PI you want removed.

Adding an Additional TIN Surface to a Vertical Alignment View

1. Open a drawing containing a TIN surface, alignments, a vertical alignment view, and a grading.
2. Launch ALIGNMENTEDIT.
3. Choose the change Tin surface option.
4. Select the TIN surface to add.

An additional light blue line now appears in the vertical alignment view, representing the grading object.

Editing Alignments Through the Properties Panel

Vertical Alignment: select it, and the Properties panel shows its list of PVIs. Click the PVI field to highlight the currently selected PVI in the drawing, then switch between PVIs and edit their parameters directly, the vertical alignment updates in the drawing automatically.

Horizontal Alignment: select it, and the Properties panel shows its list of elements. Click the Element field to highlight the currently selected element in the drawing, then switch between elements and edit their parameters, the horizontal alignment updates automatically too.

3D Alignment: select it, and you can edit both its Horizontal and Vertical alignment parameters from the same panel, switching between elements and PVIs exactly as above. The 3D alignment updates automatically to match.

Working with Station Equations

Adding one to an existing horizontal alignment:

1. Run ALIGNMENTEDIT.
2. Select the horizontal alignment.
3. Choose Add Station equation.
4. Pick the point where you want the new station equation.

Removing one:

1. Run ALIGNMENTEDIT.
2. Select the horizontal alignment.
3. Specify the index number of the station equation you want to remove.

Editing station equation parameters in the Properties panel: select the horizontal alignment, click the Station equation field to switch between existing equations (the selected one highlights in the drawing), then adjust:

• Raw station back: relative to the alignment’s start point and the specified point for this station equation. The alignment’s start station may not be zero, since you can specify it yourself. If only one station equation exists on the alignment, Raw station back matches Station back. Editing this value moves the station equation’s point along the alignment.
• Station back: for every station equation except the first, this is relative to the station equation value and Station ahead value of whichever equation comes directly before it. With only one station equation defined, Station back matches Raw station back.
• Station Ahead: sets the new station value that starts right after this station equation’s point on the alignment.
• Type: sets whether stations increase or decrease after this station equation’s location.

Frequently Asked Questions

Does the 3D alignment need to be updated manually after editing the horizontal or vertical alignment? No, it updates automatically regardless of which type of edit you make.

What shows up in a vertical alignment view after adding a TIN surface that has a grading applied? An additional light blue line representing the grading object, alongside the original terrain line.

What’s the difference between Raw station back and Station back for a station equation? Raw station back is always relative to the alignment’s own start point. Station back is relative to the previous station equation instead, except for the very first one, where the two values match.

Can I edit an alignment element’s parameters without redrawing it? Yes, select the alignment, then in the Properties panel switch to the relevant element or PVI and edit its parameters directly; the alignment updates in the drawing automatically.