Power Civil: One Alignment for 2 objects

Hi neil,

its a known limitation that you cannot have more than one combination of Chain/Profile + Comp Section in the same Object.

There is a work-around... maybe 2 work-arounds.

1) Place your first Chain/Profile/Comp Section combination into Object 1.

2) Create Object #2 and place the appropriate Chain/Profile/Comp Section combination into Object 2. At this time, the alignment will be deleted from Object 1.

3) You can now go to Element>New/Edit and put the alignmnet back into Object 1. It won't have the Comp Section as an associated dependancy, but it will form the Object correctly.

The other thing you could try is this (and this may be a better solution for keeping associations alive).

Go into COGO and copy the chain with a zero offset. COGO>Element>Chain>Store>Offset Chain

You can then go into Modeler and create one Comp Section using Chain 1 and the other Comp Section using Chain 2.

One word of warning here... after creating the first Comp Section; close the Comp Section dialog. Then re-open the dialog to create the second Comp Section (using Chain 2).

We must not be clearing memory or something... I need to investigate further - but if you don't close the dialog the alignment element from the first comp section will be removed when you create the second comp section.

HTHs.

 

I understand your solutions Michael. I don't want to duplicate alignments so option 1 is my preferred approach. What I would probably do is create the element from the chain first and then apply the comp section to the element. Would that work? If I edit the chain horizontally, will the centerline element used in the road object move when I update it? Also, if I apply a comp section to the centerline element, what would I do if I wanted to extend or shorten the centerline element? Would I have to recreate it using the new station range and the re-apply the comp section? I am wanting to evaluate design scenarios so I need to have things dynamic for rapid assessments.

I understand your solutions Michael. I don't want to duplicate alignments so option 1 is my preferred approach. What I would probably do is create the element from the chain first and then apply the comp section to the element. Would that work? If I edit the chain horizontally, will the centerline element used in the road object move when I update it? Also, if I apply a comp section to the centerline element, what would I do if I wanted to extend or shorten the centerline element? Would I have to recreate it using the new station range and the re-apply the comp section? I am wanting to evaluate design scenarios so I need to have things dynamic for rapid assessments.

Hi Neil,

 

let me try and address all these questions one at a time.

1) I dont know if that will work - try it. I've never tried that before. If it works... you should be OK with regards to "dynamics". If it doesn't, my original Option 2 may be a better bet.

2a) The Alignment Elements aren't really designed for Horizontal updates (take a look at the Element>Info for an alignment element and note that only the profile can be swapped). There was some logic behind this decision (believe it or not) in that based on the way Comp Section is intended to scan for already drawn plan elements, the expectation was that a change of Hz alignment would typically require a follow on manual redraw of plan elements. This would require an Object>Delete to allow for the CAD element modifications. Thus, the expectation was that an Object Delete, Object New, and a modified Comp Section would be a safer alternative. Looking at the example in your attached image it would appear that the centerline location is locked in with the ROW being established and not readily movable - which was our expected design scenario.

2b) You can assign a Comp Section to a smartline that is a Site Element. The Comp Section can have plan elements defined by copy parallel and sections. A plan view modification to the smartline will recreate the plan elements and/or sections that does provide for a dynamic horizontal update... but this is typially not practical for road designs (given start/stop/join/intersection requirements) and typically is appropriate to open channels and simple/evaluation scenarios.

3) You can certainly extend/shorten the Alignment element. Element>Info. Select the Comp Section button and go to the Alignment Element and reset the start/end stations. Close the Alignment Element dialog and click Apply to the Comp Section.

 

HTHs.

 

I decided that duplicating the chain was the better approach for my needs after all as it makes for much easier alternate evaluations.

 I understand your reasoning behind the horizontal editing limitations and it makes sense in most scenarios. One of the strengths of Comp Section is the ability to change out the alignment and profile. When the section graphics are defined as parallel elements it can easily handle multiple horizontal scenarios, but as you say, if it is looking for element symbology then it is not so well suited, although I've thought of some ways to trick it..

 Along a similar thread on this topic, is there any way to shift a profile along an alignment? For example if I have to extend an alignment in the negative direction, say 500 feet, I don't want my design profile to move with it since it is intended to fit the terrain in a certain location. Is there a way to shift the profile stationing by plus 500 feet to make up for the shift in the alignment? I don't want to use an equation.