OpenRoads Designer - Corridor Contours Do not Tie into Existing Contours

RE: OpenRoads Designer - Corridor Contours Do not Tie into Existing Contours

Ray Thwaits — Fri, 08 Oct 2021 21:28:10 GMT

At 736+10 your end condition approaches the existing ground from beneath; I suspect that is the situation prior to this station as well. At 736+15 it approaches from above. When your hinge point emerges from beneath existing ground, the end condition will abruptly catch at the bottom of the slope. No matter how many template drops you have, you'll have the same issue with the contours not tying in.

You could:

Drop a conic slope (Model Detailing tab in 2020R2) at the point where the hinge point emerges. I've never used this so I don't know how effective it will be, but it is conceptually an appropriate method and should provide the most realistic model.
Add an end condition that will tie in the second time it encounters the existing ground. This will change your model upstream of 736+10 but it will tie in to the existing ground continuously.
Live with it. Is the material and construction cost worth the effort to clean up the model in this location?

There are other considerations for this area though. For instance, how does the wall affect construction sequencing? Following from that, will field conditions match your existing ground model at the time the slope is built?

RE: OpenRoads Designer - Corridor Contours Do not Tie into Existing Contours

Mark Lehman — Fri, 08 Oct 2021 17:20:52 GMT

Tip: Use the "Key Station" tool place custom Template Drops at odd locations. Instead of decreasing the interval (which may unnecessarily bog down the corridor), place Key Stations in areas that you want to densify the corridor.

RE: OpenRoads Designer - Corridor Contours Do not Tie into Existing Contours

Mark Lehman — Fri, 08 Oct 2021 17:18:09 GMT

At STA 736+12.5, I am guessing that you are looking at an interpolated section - which means the corridor wasn't processed at that station. I am guessing you manually typed in that station to view the cross section - instead of scrolling through the cross sections with the arrows. When you scroll through with arrows - you only view the processed template drop cross sections

RE: OpenRoads Designer - Corridor Contours Do not Tie into Existing Contours

Mark Lehman — Fri, 08 Oct 2021 17:15:34 GMT

At STA 736+12.5, this is definitally the case. Place a few template drops in that area to see better results. basically there is like 15' difference between calculated end conditions between two adjacent template drops. The area inbetween the 15' difference is interpolated.

RE: OpenRoads Designer - Corridor Contours Do not Tie into Existing Contours

Mark Lehman — Fri, 08 Oct 2021 17:12:45 GMT

I agree that it could be an interval thing. The way I see it, if the model had infinite intervals, then all contours would tie in exactly to the existing ground. But what could be the case: there is likely NOT a template drop thats placed exactly where a proposed major contour meets the existing ground. It is likely that major contours are meeting the existing ground between template drops. The model and contours between template drops are interpolated from the adjacent drops. In other words, the corridor is not being processed where major contours meet the existing ground - which is why it appears disconnected.

RE: OpenRoads Designer - Corridor Contours Do not Tie into Existing Contours

Joe Muni — Fri, 08 Oct 2021 15:02:01 GMT

Hello Aaron,

It looks like you have a couple of things going on that are causing what you are seeing. From what I can tell it appears that at each station shown above your template is solving using the same end condition option, which is why in plan view you have a daylight line connected through each station as shown (no gaps or unconnected daylight lines). However, the way the corridor model in ORD (and InRoads previously) works is it only truly calculates a solution at the modeling interval (and various other enhancements, like Key Stations), and every other station in between that will be an interpolation from the previously modeled station to the next. That's why you see an end condition at STA 736+12.5 hanging out in space.

A possible solution to this would be to tighten up your modeling interval in that area (by adding in a template drop with a smaller interval). Although I don't know that this option will really work in your case. Or you can try to add an End Condition Override where you can use a different End Condition through that area to find a suitable solution. An EC Override allows you to use a specific EC Condition solution at a localized level and not have it as an option on the entire length of the rest of the corridor.

I hope this helps.

RE: OpenRoads Designer - Corridor Contours Do not Tie into Existing Contours

Aaron Henne — Fri, 08 Oct 2021 13:27:33 GMT

Hey Karl!

Thanks for the response. I have tested the end condition using the testing function, and it works fine for all the scenarios I could throw at it. I have also made sure that the only target it seeks is the existing terrain.

Please note that this end condition is only failing to solve in that one 5ft area between where the end condition solves at the top of existing fill slope (Section 736+10, see screenshot) and where it solves at the bottom of the existing fill (STA 736+15, see screenshot)

It's like the end condition is caught in a transition between those two stations and does not solve.

RE: OpenRoads Designer - Corridor Contours Do not Tie into Existing Contours

Karl Dauber — Fri, 08 Oct 2021 12:41:28 GMT

Hello Aaron,
If the end condition is not solving, as appears to be the case, then the problem is not the corridor model settings, such as template drop interval, but rather with the template itself. Use the Testing function of the template editor to identify the situations where the end conditions fail. That will be your starting place to fix the problem. Also, check that you don't have other constraints that would result in your end condition seeking a target other than the existing terrain.