RC Pier LL manual input when Impact is not considered.

Certain DOTs do not require impact to be included in the design of elements below the bearings. in this case, is it still necessary to break down the manual LL input into lane and truck if the impact is set to 0% ?

  • If I select live load and click on generate button and in that window if I select Design truck + Lane load and generate the loads then
    The program will generate 2 sets of bearing loads one for design truck and one for lane and eventually in the analysis tab it multiplies the design truck with its respective impact factors.
    With the manual input and if I tried to input the lane loads (Bearing ) manually (just copied the lane loads which were generated before automatically ) and try to run the analysis then the program does not understand if the loads are lane loads or truck loads and multiplies all the loads by Truck Impact factors .

    The workaround solution for this issue is to go to Analysis TAB --> A/D parameters --> Impact and Reduction TAB --> Change the impact factor to 1 for Cap and column.

  • Change the impact factor for Cap/Column to 1 or to 0? if I change to 1 wont it apply an impact equal to the live load?
    Also, does the program separates Lane and Truck only for the purpose of applying the correct impact factor? if so, whenever impact is not considered (that is , 0%) then the Lane / Truck separation does not matter correct?
  • Yes that's right whenever impact is not considered (that is , 0%) then the Lane / Truck separation does not matter.