Purpose: Used to specify impact in ASD or LFD Line Girder Projects. (See IMP-i for Girder System Projects)
--> Given in line girder input
A list of nonzero impact fractions for the tenth points if the user wishes to supply these or vary these within a span. This would be an alternative to having the program compute these for the separate spans according to AASHTO 3.8.2.1. A single value will set all tenth point impact values to that value. For example, 0.20 for impact could increase live loading forces by twenty percent at twentieth points. Values cannot be given as 0. Use the condition IGNORE IMPACT if impact is to be ignored.