I have a large warehouse type building that has a heavy bridge crane in it. The bridge itself runs along two stationary rails at each end of the bridge. The crane moves along the length of the bridge.
I add the load as a transportation load to account for it being in multiple places along the rails and the bridge. But I have one problem. On any given day, it will be "parked" at various locations. In such a situation, it would be considered a dead load that will contribute to seismic.
QUESTION: It seems that transportation loads cannot be included in seismic loads as a repeat or reference load. Can we have this functionality available in future versions?
Hello Will,
I guess you have created the transportation load through vehicle load generation option. If that is the case there is no option to include it in seismic load.
But I would like to highlight that when you are doing seismic analysis the load due to crane is considered as stationary as it is parked. I understand the vehicle can be parked anywhere. So, it is difficult to take that effect in seismic loading. In STAAD only one seismic mass matrix is formed for seismic analysis. So, in this case I can suggest you to find out 3-4 cases for which the effect will be maximum - like the vehicle is parked in middle of a span, parked at an intermediate support, parked where the maximum bending moment occurs etc. For all these cases you will have the position of the load and create separate STAAD files for each of the load case. This load will be within mass reference load case which will only be used for seiismic calculation.