Roundabout interchange

[jc03112011]

i want to create an interchange where a highway would pass under the current roundabout, i'm doing a project for university and i truly do not have too much expertise using Civil 3d, do not know how to solve this. The roundabout generates the mesh between the approaches and it floats over the highway, i was giving it a try over an almost flat surface for testing porpuses. I haven't figured it out yet how to design the interchange overpass with a roundabout segment or if it is possible. My expectation was to create the model then bring it to 3ds max with PTV VISSIM Traffic simulation and then render it in lumion 3d, if you have suggestions, guides or ideas, the knowledge about if it is possible or not, it would be awesome.

[tcorey]

Are you needing to tunnel under the existing roundabout? That is a process you can complete in Autodesk InfraWorks, not in Civil 3D. You could layout the Alignment and proposed profile in Civil 3D and then translate that to InfraWorks or simply create the alignment and profile in InfraWorks.

InfraWorks has great tools for capturing video and photos of your proposal.

[jc03112011]

Thank you for replying! i attach a quick sketchup of the idea, these are my questions:

- i want to create an underpass like that, not a tunnel, does the tunnel tool can help me for that porpuse too?

- Can i create a bridge gap for those roundabout segments i circle?

- Infraworks would make easier to create the underpass retaining walls or should i model them with subassambly composer in Civil 3D?

[jc03112011]

also the central island is at a lower level than the original roundabout roadway, that's the reason why an underpass with bridge gap under those roundabouts segments would make the job instead of a tunnel, just to clarify the design, the central island goes from the roadway level with a cone slope until it reaches a circle in the center.

Still not sure if it is possible through civil 3d, infraworks, or any other autodesk software.