Impact loads
Impact loads
(OP)
ASCE 7-10 Section 4.6.3 states:
"For the purpose of design, the weight of machinery and moving loads shall be increased as follows to allow for impact: (1) light machinery, shaft- or motor-driven, 20 percent"
I'm confused, is this in ADDITION TO or INSTEAD OF the 1.6 LRFD factor for Live Loads? Also if I calculate an amplification factor using energy methods for impact loading (see page 4 http://www.pdhcenter.org/courses/s164/s164content....) does that mean I need to increase the impact load even more? or can I use this factor as a substitute for one of the above?
To clarify, I have 3 factors:
Factor 1: 1.6 (ASCE 7-10, Eqn 2)
Factor 2: 1.2 (ASCE 7-10, Sec 4.6.3)
Factor 3: 6~7 (page 4 of http://www.pdhcenter.org/courses/s164/s164content....)
Which ones should I use? Using all of them would be excessive, IMO.
"For the purpose of design, the weight of machinery and moving loads shall be increased as follows to allow for impact: (1) light machinery, shaft- or motor-driven, 20 percent"
I'm confused, is this in ADDITION TO or INSTEAD OF the 1.6 LRFD factor for Live Loads? Also if I calculate an amplification factor using energy methods for impact loading (see page 4 http://www.pdhcenter.org/courses/s164/s164content....) does that mean I need to increase the impact load even more? or can I use this factor as a substitute for one of the above?
To clarify, I have 3 factors:
Factor 1: 1.6 (ASCE 7-10, Eqn 2)
Factor 2: 1.2 (ASCE 7-10, Sec 4.6.3)
Factor 3: 6~7 (page 4 of http://www.pdhcenter.org/courses/s164/s164content....)
Which ones should I use? Using all of them would be excessive, IMO.






RE: Impact loads
FWIW, the impact factor for AASHTO bridges, which is used to account for vehicle bouncing as it travels over small imperfections in the road surface, is a 33 percent increase in the live load.