you can use harmonic pattern load

Dear Tsegay,

You can apply harmonic load on deck. if you want to apply time history analysis such as earthquake, you should first define time history function. then if you want to do linear or nonlinear analysis, check the load case and define what is you want. In sap 2000 time history load usually apply on the restrains.

Dear Tsegay Tesfay Gebremariam

While performing time history analysis, it is customary to apply the seismic input at the base of the structure (i.e. at the supports). To do the same in SAP 2000, go to define->functions->Time history. You may either upload the load ordinates from your file directory or manually enter the ordinates at each time step.

Dears, Rohan Bhasker , Salar Rasti

thanks for your replay.

all the things you said I already done it.But please can you tell me how can i assign the dynamic harmonic load on a deck of a foot bridge in CSI bridge software?

my question is not on how to define the harmonic or time history load from the pedestrians,the question is, it is already defined on the load case but how to assign it(applying it) on the deck before running the model?@Rohan Bhasker , Salar Rasti

https://www.csiamerica.com/products/csibridge/features

https://wiki.csiamerica.com/display/kb/Bridge+Modeler

https://www.academia.edu/31097529/Fu_F._Advanced_Modelling_Techniques_in_Structural_Design

after defining harmonic load model, you should apply a unit of harmonic load on specific points of deck