Derivation of factor loading combinations. 1.4DL + 1.7LL
Derivation of factor loading combinations. 1.4DL + 1.7LL
(OP)
We all know that in allowable stress design we use ultimate load = D + L only..
While using Ultimate Strength Design we are using Ultimate load = 1.4DL + 1.7LL
my question is is there a derivation for thos factors. 1.4 and 1.7 or its just a probability..
i think there should be a derivation accoording to principles. anyone knows?
this is the link where someone tries to derive it. http://www.eng-tips.com/viewthread.cfm?qid=325368
While using Ultimate Strength Design we are using Ultimate load = 1.4DL + 1.7LL
my question is is there a derivation for thos factors. 1.4 and 1.7 or its just a probability..
i think there should be a derivation accoording to principles. anyone knows?
this is the link where someone tries to derive it. http://www.eng-tips.com/viewthread.cfm?qid=325368






RE: Derivation of factor loading combinations. 1.4DL + 1.7LL
He and others over the years have developed statistical procedures to weigh the variabilities of various kinds of loads, the variabilities of construction (phi factors) and the basic, desired probability of failure to come up with these load factors.
The 1.4D and 1.7L were earlier numbers used which were later revised to the 1.2/1.6 factors on dead and live.
There are numerous papers written by him and others like Galambos. The one's I read were in the ASCE Structural Journal but I'm sure they show up elsewhere.
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RE: Derivation of factor loading combinations. 1.4DL + 1.7LL
RE: Derivation of factor loading combinations. 1.4DL + 1.7LL
RE: Derivation of factor loading combinations. 1.4DL + 1.7LL
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RE: Derivation of factor loading combinations. 1.4DL + 1.7LL