I have several questions and need clarification on several aspects of the load generation in LEAP Bridge for substructure design.
1. For WS, is the "barrier height" in the Geometry tab used for any other purpose besides determining WS? I want to use a larger barrier height to account for a fence or barrier-mounted wall, but I want to verify that this dimension isn't being used by LEAP for other purposes.
2. The 8th ed. of AASHTO requires different wind velocities for each load combination of STR/SVC. I do not see a way to set the Load Combination in LEAP when manually inputting WS. How is this done?
3. For DW loading from future wearing surface, does LEAP run an additional DW=0 load case to account for the lack of FWS or does this need to be configured by the user?
4. Both BR and WL do not provide inputs for tributary length when auto-generating the loads in the LL and WS tabs. It appears LEAP just assumes a length of 1/2 span 1 + 1/2 span 2 by default, which is incorrect in my case. How do you specify the tributary length for these loads?
5. Is there still a limit of 6 lanes for LL auto-generation? I read on another post on these forums that there was a 6 lane limit on LL and BR auto-generated loads. I have a bridge with a clear roadway width of 85.25', so I can fit in 7 lanes @ 12' wide. The LEAP output report for "Superstructure Info" indicates my model has 7 lanes. However, the model itself and all load cases only show up to 6 lanes being loaded. And lastly, the output report for "Live Loading" indicates I only have 5 lanes being loaded. I'm very confused by what LEAP is doing with LL lanes. Can you clarify? Is there a bug in the computation?
1) Based on the height of the barrier provided in the super structure parameter the program calculates the bearing load for WS load case. you can use the larger barrier height and the program will account for the height in the calculation of bearing load.
I shall try to answer other questions as well.
2 ) Please let me know if this is the information you are looking for. If not please provide me additional information .
3. Leap does not run an additional DW =0 load case to account for the lack of fws and the user has to create a new load case considering the above mentioned case
4) user can add the contributing length manually. Please let me know if you are looking any other information.
The user can manually input the bearing loads directly for these 2 load cases .
5) Max 6 trucks side by side will be moved across the bridge The load effect of 7th truck on the 1st bearing /Girder is not significant so most of the critical cases are controlled when truck is directly above that girder and the number of lanes under super structure parameter option are used differently basically for multiple presence factors calculation .
In future versions the user should be able to generate LL for all the lanes loaded.