I'm trying to model/test a three span bridge, have a few questions:
1. once support lines are defined for two abutments and two piers, beam layout and beams are defined accordingly, I try to generate beam report and noticed this: if beam ends at support line at abutments (see attached), beam reports in spans 1 & 3 can be generated, however, if I want to have beam projection over the support lines (supposed to), no beam reports will be generated. However, there is no problem for span 2 where beam projection are defined at both piers.
2. Bearing seats at abutments - WP for both abutments are defined at front face of backwall, in order to place abutments properly, I define longitudinal offset of -1' and 1' for abut 1 and abut 2 respectively (as seen). For left abutment, I assume bearings have beam seat, and bearing and seats are properly defined; for right abutment, I assume bearing seats are stepped, however, the stepped seat are outside of abutment.
Please add your file to the thread or send it directly to me to have a look at your model. Add all your referenced files, if any.
vlad.grigoras@bentley.com
Bridge Wizard.dgn
Vlad,
I'm attaching the .dgn file for your review. the problem is at support line 1, where centerline of bearings is set at supportline, beam end is 9" offset back station from centerline of bearing/support line, abutment is 12" offset back station from centerline of bearing/supportline. Thanks.
You have entered a 0.00 value for bearing line ahead offset and this was causing the bearing seat to go outside. I have placed a 0.75 value, as per the end value and everything looks good. Please let me know if this has solved your problem.
Vlad, thank you for the response. Normally I would like to think support line is centerline of bearings, and span length is defined as the distance between centerline of bearings, we can then define end of beam and location of abutment by utilizing offsets, it appears this is not the case. In Open Bridge, can we assume the support lines for piers are centerline of the pier cap, and we can define centerline of bearing by using ahead and back offset, what about abutments, where do we define support line? WP of abutment, centerline of bearings or beam end? Thanks and have a great weekend.
On question #1 from above, was it answered? I have the same issue on question #1 for OpenBridge Modeler not able to generate beam reports for spans 1 & 3 with bridge setup similar to original post mentioned bridge setup. My bridge has prestressed beam ends offset a distance from the centerline of Abutments and piers. The OBM was only able to generate beam and camber reports for span 2 of 3 and I was wondering if the program produces these report only for continuous beams or so.
Thanks.
Hi,
Please be aware of the following:
- the pier centerline is aligned with the support line at placement time
- the abutment centerline can be set in 3 positions in relation to the receiving support line, as shown in the image below.
- the bearings are placed in relation to the support line and not in relation to the abutment centerline
- the camber report will be generated only if you insert the required data (camber, self deflection, additional deflection) in the input dialog; also, you can import this information from LBC if you have designed the bridge there
- the girders in OBM are always drawn straight i.e. no camber is modeled, so the report will be computed based on your input
Thank you for the timely reply. I have checked my placement of the Abutment centerline to to align with supportline centerline no issues there. Also, I toggle the 'Read from LBC' option in the beam camber dialogue to populate the camber, deflection, and add'l deflection values for all three spans, then generate. The program still gives values for the middle span and not spans 1 & 3! Perhaps there is more to setup or workaround to this issue as my bridge is not symmetric, i.e. outer spans have different lengths. Is it possible to send a file, or perhaps a brief MS Teams' meeting?!
Please send me your working file ( and any referenced files) to vlad.grigoras@bentley.com and I will try to have a look at it in a timely manner.