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Tributary area of C1 column is the same in all floor plans and at 2-3-Roof floor and is equal to 95.83 sq ft as shown in Figure 4.
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Figure 4
Tributary area of C1 column at 1st floor and is equal to 95.83 sq ft as shown in Figure 5.
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Figure 5
Self Weight
Slab dead load at each floor is calculated by simply multiplying the thickness of the slab and tributary area of the slab and unit weight of slab material. Since the tributary areas at each floor is the same, only one floor calculation is shown as an example.
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Superimposed Dead Load is grouped as “SDL” in Load Classes section. So all the load cases which are classified as “Superimposed Dead Load” within the boundaries of tributary area of C1 will be included to calculation. Notice that results are reported cumulatively.
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Figure 56
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Figure 67
The loadings of Roof which are classified as Superimposed DL (LG2, LG3) are shown in Figure 5 6 and Figure 67.
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Figure 78
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Figure 89
The loadings of 3rd Floor which are classified as Superimposed DL (LG2, LG3) are shown in Figure 7 8 and Figure 89.
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Figure 910
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Figure 1011
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Figure 1112
The loadings of 2nd Floor which are classified as Superimposed DL (LG1, LG3,LG4) are shown in Figure 9 10 Figure 10 11 and Figure 1112.
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Figure 1213
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Figure 1314
The loadings of 1st Floor which are classified as Superimposed DL (LG1, LG3) are shown in Figure 12 13 Figure and 1314.
The cumulative tributary forces of Superimposed DL is calculated as follows;
→Roof tributary force = 0.4*11.5+95.83*15/1000 =6.04 kips
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Figure 1415
→ 3rd floor tributary force = 6.04+0.3*11.5+95.83*15/1000=10.93 kips
→ 2nd floor tributary force = 10.93+0.3*11.5+95.83*15/1000+10*(21.055/82.08)=18.38 kips
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Figure 1516
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Figure 1617
→ 1st floor tributary force = 18.38 + 0.3*11.5+95.8377*15/1000=23.27 kips
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General LL
General LL is grouped as “L” in Load Classes section. So all the load cases which are classified as “General LL” within the boundaries of tributary area of C1 will be included to calculation. Notice that results are reported cumulatively.
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Figure 18
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Figure 19
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Figure 20
Only 2nd floor has loadings classified as “General LL” as shown in Figures 18-19-20. But LG6 will not be considered in calculations because loading region has no intersection with the tributary area of C1 as illustrated in Figure 21.
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Figure 21
→ Roof tributary force = 0
→ 3rd floor tributary force = 0
→ 2nd floor tributar force = 72.915*40/1000+23.001*100/1000=5.22 kips
→ 1st floor tributary force = 5.22 + 0 = 5.22 kips
Loadings which are grouped as “L” are permitted to be reduced.
→ Live load factor at roof = 1.0 ( Due to no force)
→ Live load factor at 3rd floor = 1.0 ( Due to no force)
→ Live load factor at 2nd floor = (100 - 0.08*(3*95.83-150))/100=0.89
→ Live load factor at 1st floor = (100 - 0.08*(3*95.83+95.77-150))/100=0.81
Modified tributary forces;
→ Roof =1.0*0=0
→ 3rd floor =1.0*0=0
→ 2nd floor =0.89*5.22=4.65 kips
→ 1st floor = 0.81* 5.22 =4.23 kips