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7k views
1 replies
Dimensioning of glulam, HEA beam and columns
I am going to build a winter garden extending from the house. About 7-degree roof pitch and 5 m span for the roof beams. According to Moelven's beam program (http://www.moelven.com/se/Produkter-och-tjanster/Limtra/lagerbalksprogram/), a 66x315 glulam results in a deflection of about 16 mm (snow zone 2, 1200 spacing between roof beams, metal roof, 4700 width). Should work okay.
My questions concern the load-bearing beam and columns. Since I plan to have a beveled corner, I can't find a typical case at Moelven that works. Tried with three columns (L1=3600, L2=1100) and then, for example, a 90x225 for the load-bearing beam is suggested, which would result in about 10 mm deflection and about 40 kN column load. However, this doesn't work entirely because the load-bearing beam won't span the entire construction at the front; the beveled corner means the beam stops at L1=3600. If I input a structure with two columns and a 3600 width instead, a 90x270 beam is suggested, which gives an 11 mm deflection and about 19 kN column load.
I don't understand the large reduction in column load. Now there are only two columns (even if there’s slightly less roof area to consider)??!? Also, a thicker beam dimension with more deflection... (although I somewhat understand the latter).
Probably, the calculation with two columns is more accurate for the beam calculation, but I don't understand the column load at all and don't know if 19 kN or 40 kN is closer.
Now there is another problem... I have limited space, and a 225 or 270 high beam won’t fit. Therefore, I'm considering an HEA steel beam instead. Free span of 3350. Isn't it true that a 90x270 L40 can be replaced by HEA 120? If I go up to HEA 160, it should be completely fine, right??
40 kN column load - do two screwed-together 45x145 handle that (3 m high column)? They will be part of a wall that ends against a window, so I can support them against buckling on one side, at least.
Sorry for the long description. To summarize the questions:
1) Column load calculation and beam at Moelven, if I go with the worst-case scenario, i.e., beam 90x270 and column load 40 kN, the calculation as above should be safe, right?
2) HEA 120 should work instead of LT 90x270, but HEA 160 with margin? Maybe I should go for HEA 140...
3) 3m high column 2x45x145 for 40 kN, does that work?
Best regards /Peter
My questions concern the load-bearing beam and columns. Since I plan to have a beveled corner, I can't find a typical case at Moelven that works. Tried with three columns (L1=3600, L2=1100) and then, for example, a 90x225 for the load-bearing beam is suggested, which would result in about 10 mm deflection and about 40 kN column load. However, this doesn't work entirely because the load-bearing beam won't span the entire construction at the front; the beveled corner means the beam stops at L1=3600. If I input a structure with two columns and a 3600 width instead, a 90x270 beam is suggested, which gives an 11 mm deflection and about 19 kN column load.
I don't understand the large reduction in column load. Now there are only two columns (even if there’s slightly less roof area to consider)??!? Also, a thicker beam dimension with more deflection... (although I somewhat understand the latter).
Probably, the calculation with two columns is more accurate for the beam calculation, but I don't understand the column load at all and don't know if 19 kN or 40 kN is closer.
Now there is another problem... I have limited space, and a 225 or 270 high beam won’t fit. Therefore, I'm considering an HEA steel beam instead. Free span of 3350. Isn't it true that a 90x270 L40 can be replaced by HEA 120? If I go up to HEA 160, it should be completely fine, right??
40 kN column load - do two screwed-together 45x145 handle that (3 m high column)? They will be part of a wall that ends against a window, so I can support them against buckling on one side, at least.
Sorry for the long description. To summarize the questions:
1) Column load calculation and beam at Moelven, if I go with the worst-case scenario, i.e., beam 90x270 and column load 40 kN, the calculation as above should be safe, right?
2) HEA 120 should work instead of LT 90x270, but HEA 160 with margin? Maybe I should go for HEA 140...
3) 3m high column 2x45x145 for 40 kN, does that work?
Best regards /Peter
Well, I will verify everything with a constructor, but I was hoping there would be someone knowledgeable here who could give an indication if I'm on the right track... I'm working on window quotes and need to know approximately how much space is available to play with after all the beams and pillars have taken their place.
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