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lrfd vs. lfd temperature load
we are working on a three span deck truss design which has hollow stem piers. these piers were designed using the lrfd design specs. after the design was complete we decided to cross check it with the group v loading of lfd and found that the hollow stem pier would require approx. 25% more reinforcing steel with the lfd design. it appears that the 0.5 multiplier for temperature forces in the lrfd strength checks is the reason why there is such a difference between the two codes. could you provide any insight into the use of the 0.5 multiplier for lrfd as compared with the group v lfd loadings. at present, there is quite a disconnect between the two situations. the disconnect disappears if the 1.2 factor for displacements is used for the lrfd situation. did the aashto committee make a conscious decision to reduce force effects due to temperature changes from the lfd specifications?

2009-09-10, 11:59 AM	#1
huangyhg 超级版主注册日期: 04-03 帖子: 18592 精华: 36 现金: 249466 标准币资产: 1080358888 标准币	lrfd vs. lfd temperature load lrfd vs. lfd temperature load we are working on a three span deck truss design which has hollow stem piers. these piers were designed using the lrfd design specs. after the design was complete we decided to cross check it with the group v loading of lfd and found that the hollow stem pier would require approx. 25% more reinforcing steel with the lfd design. it appears that the 0.5 multiplier for temperature forces in the lrfd strength checks is the reason why there is such a difference between the two codes. could you provide any insight into the use of the 0.5 multiplier for lrfd as compared with the group v lfd loadings. at present, there is quite a disconnect between the two situations. the disconnect disappears if the 1.2 factor for displacements is used for the lrfd situation. did the aashto committee make a conscious decision to reduce force effects due to temperature changes from the lfd specifications? __________________ 借用达朗贝尔的名言：前进吧，你会得到信心! [url="http://www.dimcax.com"]几何尺寸与公差标准[/url]