Various OBM issues and questions

Question

Hello all, 
 
 I have a few questions and concerns regarding OpenBridge Designer (version 10.10.00.26) that I hope someone is able to answer. Please find my questions below: 
 1. I have a situation where multiple bridges share the same substructure (abutment & piers). Is there a way to define multiple bridges but link them to the same support lines? 
 2. Do any of the included OBD programs analyze and/or design post-tensioned reinforced concrete piers? 
 3. I have experienced issues where the OBM was sent to LBC only to find that certain items that were modeled did not transfer properly. For instance, items like bearing pad and seat geometry, abutment backwall heights (when told to meet the top of slab), beam end offsets from the backwall, and a few other items did not transfer to LBC appropriately. I then sent the LBC model back to OBM (standalone option) only to find that my model was updated with wrong information, which had to be corrected. I have tried to pick and choose the items I want to transfer back to OBM, but there is not enough independence in the selection options. Though, the additional independence would not be needed if the transferring worked as intended. Is this a common issue and what are the solutions? 
 4. I have also had an issue where the LBC models were updated and saved but when I attempted to open the model the next day, the information had not been saved. An image below shows that OBD stated the LBC model was updated at 6:13PM, but the linked file in the folder indicated the last update was at 1:58PM.

5. The saving issue has caused me to not only &ldquo;Save&rdquo; but &ldquo;Save As&rdquo; the LBC models after updating. When I find that LBC did not save correctly, is it appropriate to delete the previous LBC file and relink the &ldquo;Save As&rdquo; file to OBD? Will there be any issues with this process? 
 6. I do not understand why the haunch estimation in OBM needs to be so complex. Initially, a haunch is estimated in OBM for the beam placement. Then the model is sent to LBC (Conspan) to be designed. The camber tab in OBM allows the user to import the CONSPAN camber and DL deflection values. However, these values are not automatically sent to the beam definition, where the program updates the haunch. Instead, the user has to manually enter the required start/end haunch or camber for each beam while also verifying adequate beam to slab clearance. However, the haunch process has all the tools necessary to be automated. Another concern is with the option to specify Min. Clearance and Camber. This method does not account for the beam DL deflection at mid-span, which affects the haunch at the center of girder. This is of particular concern since some DOT's have specific ways of calculating haunch at mid-span. 
 7. If I decide to use the BIM Workflow option, do I need to re-enter all of the loads in RCPier each time I update the model in OBM? Using the standalone option, changes in the OBM (i.e., horizontal alignment) have to be re-sent to LBC. This results in me losing all of my previous analysis and designs. There must be a better way? 
 
 Thank you!

Vlad Grigoras · Accepted Answer

Hi William, 
 I will try to respond to your questions based on the information that you provided. 
 1. Short answer, no. When you place a bridge element, that element is tied to the bridge unit. This means that if a change occurs all elements under that bridge unit will update accordingly. Only one element can adapt to changes from 2 bridge units, and that is a pier (transition pier) that supports girders from 2 adjacent bridge units, in the longitudinal direction. 
 2. RM Bridge can be used. 
 3. There are known limitations in the transfer process (as stated in the Transfer Report GUI that appears when you send a model to LEAP/RM) but also there are limitations in the LEAP programs. In OpenBridge Modeler you can model the physical model with a high level of detail but LEAP software has its own limitations when it is creating the analytical model. Can you model in LBC the abutment back wall that you have modeled in OBM? If not, then assumptions are made during the transfer. 
 4. The LEAP files are by default saved in the obd database and not on external files. If you have exported a LEAP file to a local folder, that model is absolute and it is disconnected from the obd database. More info regarding this you can find in the links below. 
 Standalone Workflow for Analysis and Design - LARS | LEAP | OpenBridge | RM Wiki - LARS | LEAP | OpenBridge | RM - Bentley Communities 
 BIM Workflow - LARS | LEAP | OpenBridge | RM Wiki - LARS | LEAP | OpenBridge | RM - Bentley Communities 
 OpenBridge Designer - New File Format (.obdx) in v10.08.01 - LARS | LEAP | OpenBridge | RM Wiki - LARS | LEAP | OpenBridge | RM - Bentley Communities 
 5. Se number 4 answer. 
 6. The girders are created in OBM always straight, thus those haunch values coming from LBC can't be used. The haunch values coming from LBC are used in the reports only. 
 7. See number 4 answer. The BIM workflow makes a continuous connection between the physical model and the analytical model. If the change in OBM is major, like you are adding an extra column in your pier template, when you open LBC the software will inform you that a major change has been detected and the design results will be reset, but it will try to preserve the loads coming from the superstructure. If your change is minor, say you decrease the distance between girders, in LBC we will inform you that we detected minor changes and we will update the results accordingly, including rebar design if that was done previously. 
 Hope this will help you!

Vlad Grigoras · Answer

3. Please file a service request and we will take a look at your files. You should not encounter any problems on this matter. 
 4. Please read carefully the links that I have provided. Those files that are created in the Temp folder are only temporary files that are run when the file is opened. The last good file is always saved in the database. When you reopen the LBC file on the second day, we will create a fresh new file in the Temp folder that will be used only for that instance of OBD. When you close LBC, we will again store a new version of the file in the OBD database. 
 The only "external" file is the dgn, everything else is saved in the OBD file itself. An exception from this rule is only the RM project folder created under the Setting 2 option. 
 6. Please have a look at these links 
 Beam Definition dialog (bentley.com) 
 Assumptions and Limitations When Exporting to LEAP Bridge Concrete (bentley.com) 
 To generate a camber and deflections report (bentley.com)

Various OBM issues and questions

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