So I have been thinking about this for a while now and wanted to get others input an opinions on the best way to model a very wide bridge in OBM. I have a very simplified model of the bridge which I created with ORD but would like to migrate the model in ORD, if it possible to accurately model the geometry. The bridge I am working on is a 3-span continuous steel plate girder bridge that is 360' long and 608' wide. Given the extreme width of the bridge, I currently need to use 5 different alignments (all of which are parallel) with different profiles to set the deck geometry. To add another level of complexity, our Abutment 1 support follows the alignment of an on-ramp below which picks up a horizonal curve part way along its length.
For my model in ORD, I am not actually modeling the substructures, and for the girders, I am basically using a rectangle around the girder extents. To handle the horizontal curve at Abutment 1, I extend the corridor beyond the end limit and then use a clip boundary to trim the corridor back along the curve. For the deck geometry, I use 2 primary alignments, one at the left edge of the deck and one at the right edge of the deck. These two alignments corresponds to the two roadway alignments that cross the bridge. In between these I have 3 working alignments with profiles which I target with point controls when running the corridor.
I am having trouble figuring out how I can model this bridge in OBM accurately. I think I can handle the deck geometry the same way I am handling it currently in ORD by using point controls on the key deck points. My bigger question is how to handle the Abutment 1 support that has a horizontal curve partway along its length. I am not sure this is something OBM can handle, at least not yet. I am not sure if anyone else has run into similar situations or has an idea as to how I can model this? Thank you!
Carl ...you can model the abutment by creating it using the solids modeling tools and save it as a cell in the PierCellLib.cel file. You can then place the abutment with the Place Custom Abutment tool.
Steve, won't the abutment still need to follow the support line? I still will have the issue of modeling the horizontal curve along the abutment 1 centerline of bearings and getting the end of deck and girders to follow the curvature.
Carl:
When OBM places the abutment. the cell origin will be used to determine the location of the abutment transversally, longitudinally and vertically.
As for the girders, each can have a different Support Line offset, so you are good there. Using v10.08.02, the deck can be modified to have the curvature needed. The only shortcoming then becomes the girder line. I believe in the current version each bearing can have its own properties. If not, maybe those could also be built into the abutment cell.
OK, so you are saying to not use the OBM interface to model the abutment, and instead extrude it along the bearing CL that will follow the curvature. I know that you can specify different support line offers for the girders but I figured that would mess up the bearing locations. I do believe you can specify specific bearing properties per girder but I have not looked into what those actually control. I just assumed that the bearings would have to be placed along the support line. Its been a little bit since I have used OBM so I'm sure there are ways around this stuff that I just haven't thought of know about. How would you go about contoling the curvature at the end of the deck, again, I assumed this would need to follow the support line. I know you can control deck geometry with point control, but those work parallel to the template, whereas the end of deck would be perpendicular.
Thank you for the input/advise!
Carl ... first step is to use solids modeling tools and create a 3D cell of the exact abutment you want to place in your model. Then, make that solids model a cell in our PierCellLib.cel file. Lastly, use the Place Custom abutment tool to place your abutment from the PierCellLib.cel file.Make sure the origin of the cell when you create it is where the abutment cap intersects your alignment and vertically located at or near the top if the cap. The tool allows horizontal, vertical and supportline offsets so if you need to adjust it after placement you are covered in all 3 directions.