RM Bridge Loads can be specified with Factors and this could be assigned to Variables that might be associated with either Expressions or Table values. This is very useful for easily create several dynamic loads as only one. Load Sets can then also be assigned with the same Variable Factors inside the Load Case. The total factor will be the sum of the Constant Factor with the Variable Factor, therefore in some cases it is common to set the Const-Fac to 0.
First thing to be done is to create the Variables to be used in the (DEFAULT) Group and insert the data there. Select the data from any file type and just Copy and Paste into the Table list, as shown below. Then, use this references inside the Load Case definition with the Load or the Load Set, as in the screenshot below. Note that the expressions could use also some predetermined internal variables, this list is available at Internal variables button, as shown below. For example t is the time for the Time History Analysis, WT is the Wind Tunnel Load as a Force result in terms of time extracted from a Wind Tunnel study of a the bridge experimental model; so, this is used as the Expression for a new Variable that returns the values of WT in respect to the time for the Time History Analysis:
f = WT ( t )
The Loads definitions should also allow for considering these variations, as shown in the link below:
communities.bentley.com/.../variable-loads
There are reference Verification Examples with this useful technique, in the list at the link below, with the titles of Dynamic Analysis and Time History Calculation.