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AASHTO Seismic load Combination Question

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KOKONIS36

Structural
Oct 28, 2001
28

According to AASHTO Group VII,bridge components shall be designed for the following loading:
D+EQ 133%
EQ loading includes 2 cases,therefore
Case 1: D + 100%L + 30%T 133%
Case 2: D + 30%L +100%T 133% where
L:Elastic seismic force in the Longitudinal direction
T:Elastic seismic force in the Transverse direction

If vertical acceleration is included (symbol V ),then we have the following 3 load combinations:
Case 1: D + 100%L + 30%T + 30%V 133%
Case 2: D + 30%L + 100%T + 30%V 133%
Case 3: D + 30%L + 30%T + 100%V 133%

For certain situations,e.g long span bridges we may have to use live load in the load combination (usually 50% live load).So the load combination becomes:
Case 1: D + 50%LL + 100%L + 30%T + 30%V
Case 2: D + 50%LL + 30%L + 100%T + 30%V
Case 3: D + 50%LL + 30%L + 30%T + 100%V

My question is:DO WE STILL HAVE 133% OR NOT ?
IF NOT,WHAT IS A REASONABLE % ?
 
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