Alpha1 and Alpha2 are use to calculated the nominal creep. They are used in Eq. B.3a and B.3b.
Edit: Obviously only used in B.3b, but in that set of equations :)
I've read it as 100% can be transferred via direct bearing, but the splice should still have capacity to transfer 25% of the design load.
You can find some information and calculation examples on page 172 and onward in SCI P358
https://www.steelconstruction.info/images/a/a9/SCI_P358.pdf...
Direct bearing splices are doable. I know Eurocode requires you to be able to transfer at least 25% of the compression force in the splice (not by direct bearing, but through plates and bolts). Also keep 2nd order effects in mind.
See EC1993-1-8 6.2.7.1 (14) and (15)
There has been some good discussion regarding this.
https://www.eng-tips.com/viewthread.cfm?qid=477967
https://www.eng-tips.com/viewthread.cfm?qid=408814
Agent666: I agree with you. I read the question as asking for partial factors, since like you mention, the final factor of safety is dependent on many factors and will vary.
human909: Considering that 1992-4 is relativity new (I'm not even sure it is listed on JRC) I made an exception...
I dont know much about BS, but if they are similar to Eurocodes, you will have to be more specific. There are a bunch of partial factors depending in material/load-situation/failure-mode. See for example EC for fasteners in concrete.
I'm going out on a limb and guessing this is about a failure in Kiruna, Sweden. There's a preliminary report on the failure by a university. unfortunately just in Swedish...
LittleInch: Seems resonable. Here's another picture from the launching side.
The articale mentions a "king pin" coming loose. Not sure what that refers to (not a bridge guy).
So this just happened a few hours ago in Umeå, Sweden. A bridge has failed during the launching. Only one person received minor injuries and could walk off-site by himself. Some videos can be found in the local news-paper.
https://www.svt.se/nyheter/lokalt/vasterbotten/se-broolyckan-fran-ovan...
