Draft

2.3LateralLoads 33

Floor Roof 10 9 8 7 6 5 4 3 2 Total

Cumulative R (%) 8.48 16.96 25.44 33.92 42.4 51.32 59.8 60 60 60

Cumulative LL 20 80 80 80 80 80 80 80 80 80 740

Cumulative RLL 18.3 66.4 59.6 52.9 46.08 38.9 32.2 32 32 32 410

Theresultingdesignlive loadforthebottomcolumnhasbeenreducedfrom 740 Kipsto

410 Kips.

5. ThetotaldeadloadisDL= (10)(60)= 600Kips,thusthetotalreductionin loadis

740 410

740+

100=25%.

2.2.3 Snow

19 Roof snow loadvarygreatlydependingongeographic location andelevation. They

rangefrom 20 to 45 psf,Fig.2.2.

Figure2.2:Snow Mapof theUnitedStates,ubc

20 Snow loadsarealways givenontheprojectedlengthor areaona slope, Fig.2.3.

21 Thesteeper theroof,thelower thesnow retention.For snow loadsgreaterthan 20 psfand

roof pitches morethan 20



thesnow loadpmay be reducedby

R= ( 20)



p

40

0 : 5



(psf) (2.2)

22 Otherexamplesof loadsactingoninclinedsurfacesareshownin Fig. 2.4.

2.3 LateralLoads

2.3.1 Wind

23 Windloaddependon:velocity of thewind,shape of thebuilding,height, geograph-

icallocation,textureof thebuildingsurfaceandstinessof thestructure.