Mathcad - Assignment 7 - Column design - Solution7_solution.pdf · ^ppfdkjbkq=T=plirqflk=hbv=...
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^ppfdkjbkq T plirqflk hbv Erpb lc bu`bi pebbq clo ob`q^kdri^o `lirjk abpfdkF Select a cross section for a square tied column to support axial loads PD=400kip, PL=485kip, MD=50k', ML=48k'. Try to use about 4% reinforcement with f'c=4ksi and fy=75ksi. Select ties and sketch the cross section with ties. f y 75ksi := f' c 4.ksi := ρ g .04 := ϕ .65 := P DL 400kip := P LL 485kip := P u 1.6P LL 1.2P DL + := P u 1256 kip = M DL 50k' := M LL 48k' := M u 1.6M LL 1.2M DL + := M u 136.8 k' = Processing Data: ecc M u P u := ecc 1.31 in = ΦP n_max P u := ΦP n_max 0.8 ϕ ⋅ .85 f' c ⋅ A g ⋅ ρ g A g ⋅ f y .85 f' c ⋅ − ( ) ⋅ + ⋅ = solve A g , 385.59779939090283918 in 2.0 ⋅ → ACI 318 10.3.5.2 OR A g 25. ΦP n_max ϕ 17. f' c ⋅ 20. ρ g ⋅ f y ⋅ 17. ρ g ⋅ f' c ⋅ − + ( ) ⋅ ⋅ := A g 385.6 in 2 = Solving for square column edge dimension: edge A g := edge 19.6366 in = Override edge 20in := A g edge 2 := A g 400 in 2 = ΦP n_max 0.8 ϕ ⋅ .85 f' c ⋅ A g A st − ( ) ⋅ A st f y ⋅ + ⋅ = solve A st , 14.740008594757198109 in 2.0 ⋅ → A st 14.74in 2 := ρ A st A g := ρ 0.037 = Use 4#11 rebars on corners, and 4 #14 rebars on midpoints - see results below
Transcript of Mathcad - Assignment 7 - Column design - Solution7_solution.pdf · ^ppfdkjbkq=T=plirqflk=hbv=...
^ppfdkjbkq=T=plirqflk=hbv=Erpb=lc=bu`bi=pebbq=clo=ob`q^kdri^o=`lirjk=abpfdkF
Select a cross section for a square tiedcolumn to support axial loads PD=400kip,PL=485kip, MD=50k', ML=48k'. Try touse about 4% reinforcement with f'c=4ksiand fy=75ksi. Select ties and sketch thecross section with ties.
fy 75ksi:= f'c 4.ksi:= ρg .04:= ϕ .65:=
PDL 400kip:= PLL 485kip:=
Pu 1.6PLL 1.2PDL+:= Pu 1256 kip=
MDL 50k':= MLL 48k':=
Mu 1.6MLL 1.2MDL+:= Mu 136.8 k'=
Processing Data:
eccMuPu
:= ecc 1.31 in=
ΦPn_max Pu:=
ΦPn_max 0.8 ϕ⋅ .85 f'c⋅ Ag⋅ ρg Ag⋅ fy .85 f'c⋅−( )⋅+ ⋅= solve Ag, 385.59779939090283918 in2.0⋅→ ACI 318 10.3.5.2
OR
Ag 25.ΦPn_max
ϕ 17. f'c⋅ 20. ρg⋅ fy⋅ 17. ρg⋅ f'c⋅−+( )⋅⋅
:= Ag 385.6 in2=
Solving for square column edge dimension:
edge Ag:= edge 19.6366 in= Override edge 20in:=
Ag edge2:= Ag 400 in2=
ΦPn_max 0.8 ϕ⋅ .85 f'c⋅ Ag Ast−( )⋅ Ast fy⋅+ ⋅= solve Ast, 14.740008594757198109 in2.0⋅→Ast 14.74in2:=
ρAstAg
:=ρ 0.037=
Use 4#11 rebars on corners, and 4 #14 rebars on midpoints - see results below
