Question

The floor system shown has a dead load that includes: Floor tile and bedding 17 psf 2VLI20 (2" deep metal deck with 42" of concrete on top) Mechanical ducts = 4 psf Electrical 1 psf Gypsum board ceiling 3 psf Beam self-weight is given by its name (ie. W16x26 is 26 plf) Girder self-weight is given by its name (ie. W30x90 is 90 plf) The floor live load is 150 psf. 45 psf 1. Determine the end reactions for Beams B1, B2, B3, and B4. [Note, no credit will be given if you do not show your work. The reaction values given in the plan do not match my idealized numbers in every case.] 2. Determine the end reactions from girder G1 if the framing from FG is mirrored on the other side of grid G (ie. doubled). [Note, no credit will be given if you do not show your work. The reaction values given in the plan do not match my idealized numbers in every case. G 30'-0 (oru o W16x26 (30) 22k 22k 22k A 3 B1 wW16x26 (30) 22k 22k 1/54.04 B2 w16x31 (28) 24 24k 24 3.3 B3 W16x31 (28) 3.4 26k B4 W16x31 (28) 28k 28k 5% EOS W24x68 (39) 50k 5tk 4 19-4 8-8" 32" EOS W18x35 (27) 32 W18x35 (18) T - 7-2 7'-2" 0-L 9-9 W30x90 (52)

Answer 1

1)Total dead load from floor=17+45+4+1+3=70 psf

Live load=150 psf

Factored load from floor=1.2*70+1.6*150=324 psf

B1

Tributtary width=(6'4"/2)+(6'6"/2)=6'5"

Factored load on B1 from floor=324*(6+5/12)/1000=2.079 kip/ft

Factored load from self weight=1.2*26/1000=0.0312 kip/ft

Total load on B1=2.079+0.0312=2.11 kip/ft

Beam span=30 ft

End reaction=2.11*30/2=31.65 kips

Similarly

End reaction of B2=33.77 kips

End reaction of B3=34.98 kips

End reaction of B4=34.98 kips

2)

Span of G1=8'8"+7'2"+7'0"+7'2"=30 '0"

Reaction of grider G1 at each support due to its own weight=1.2*0.09*30/2=1.62 kips

Reaction from G1 at grid 4 suppport=

2*(31.65*2'2"+33.77*8''8"+34.98*15'10"+34.98*22'10")/30'0"=

114.25 kips

Reaction from.G1 at grid 3 suppport=

2*(31.65+33.77+34.98+34.98)-114.25=156.6 kips

Total reaction at grid 3 suppport=156.6+1.62=158.1 kips

Reaction from G1 at grid 4 suppport=114.25+1.62=115.9 kips