80 Fy (ksi)= 50 2 nd Floor = 61. Length (ft) Plan View. Penthouse

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1 SUBJECT: CORNER SHEET 62 of 131 Design Columns for the lightest W10's and W12's section. Columns are to be sized for two options: Option I Continuous, Option II with Splices. Then prices are to be compared to select most economical option. Both explicit calculations or Column Design Tables may be used. COLUMN A-1 LOAD TAKEOFF Dead load (psf) Live load (psf) Roof = KLL (corner)= 3 rd Floor = Fy (ksi)= 50 2 nd Floor = Bold Numbers are Roof Live Loads Tributary Areas Width (ft) At 1 = Length (ft) At 1 : DL = 61 psf At 1 15 LL = 80 psf 18 Plan View Penthouse Note: Live load reduction can be applied in accordance with ASCE 7-02 section (see ASCE 7-02 Eq. 4-1) L = L o *( /AI^0.5) ASCE 7-02 Eq. 4-1 AI (1) = <400 ft^2 L = reduced design live load value in psf L o = unreduced live load in psf if AI > 400 ft^2 live load reduction is allowed A I = Tributary area *KLL L > 0.5*Lo L > 0.4*Lo (columns supporting one floor) (columns supporting two or more floors) L (2nd floor) = psf > 32 psf, thus use = L (3rd floor) = psf > 32 psf, thus use = Note: Live roof loads are NOT allowed to be Reduced

2 SUBJECT: CORNER SHEET 63 of 131 METHOD 1 - EXPLICIT CALCULATIONS METHOD 2 - USE TABLES CONTINUOUS - L =13 FEET Notation: φpn - design compressive strength, Fcr - critical design force λc - width-thickness ratio Ag - gross area of member, in 2 Fy - specified yield strength, ksi E - modulus of elasticity, ksi K - effective length factor l - Laterally unbraced length of member, in r - governing radius of gyration about the axis of buckling, in Begin Load Takeoff from roof and proceed downward: From Ground floor to 2nd floor: Roof 3 rd Floor 2 nd Floor dead loads (psf) live loads (psf) P u = [1.2*dead load + 1.6*live load] P u = [1.2*dead load + 1.6* roof live load] Pu (Roof) = Pu (3rd Floor) = Pu (2nd Floor) = psf * A1 = psf * A1 = psf * A1 = sum = PU = Note: Use column A1 for ALL Corner Columns.

3 SUBJECT: CORNER SHEET 64 of 131 From Ground floor to 2nd floor: Note: For small axial loads the smallest section from the column design Tables (Table 4-2 LRFD) may not be the lightest. If this is the case, do explicit calculations and then try a section from the Table 1-25 LRFD. Use W8x24 as the smallest size (do not use W10 s or W12 s with a nominal weight less than 24 lb/ft). If the column tables are used you only need to write down the section selected and its capacity. φpn = 0.85 * Ag * Fcr Fcr = (.658 λc^2 ) * Fy when λc < 1.5 Fcr = (0.877 / λc 2 ) * Fy when λc > 1.5 λc = (K * L/π r) * (Fy / E) 0.5 (Equation E2-1 LRFD p ) (Equation E2-2 LRFD p ) (Equation E2-3 LRFD p ) (Equation E2-4 LRFD p ) Fy = 50 ksi K = Pu = L = ft E = ksi Assume KL/r = 60 to start λc = Fcr = ksi Ag = in 2 LRFD p.4-25 Check W 12: LRFD p.4-26 Check W 10:

4 SUBJECT: CORNER SHEET 65 of 131 METHOD 1 - EXPLICIT CALCULATIONS METHOD 2 - USE TABLES CONTINUOUS - L =13 FEET Notation: φpn - design compressive strength, Fcr - critical design force λc - width-thickness ratio Ag - gross area of member, in 2 Fy - specified yield strength, ksi E - modulus of elasticity, ksi K - effective length factor l - Laterally unbraced length of member, in r - governing radius of gyration about the axis of buckling, in From Ground 2nd floor to 3rd floor: dead loads (psf) live loads (psf) Roof 3 rd Floor 2 nd Floor - - P u = [1.2*dead load + 1.6*live load] P u = [1.2*dead load + 1.6* roof live load] Pu (Roof) = Pu (3rd Floor) = psf * A1 = psf * A1 = sum = PU =

5 SUBJECT: CORNER SHEET 66 of 131 From Ground 2nd floor to 3rd floor: Note: For small axial loads the smallest section from the column design Tables (Table 4-2 LRFD) may not be the lightest. If this is the case, do explicit calculations and then try a section from the Table 1-25 LRFD. Use W8x24 as the smallest size (do not use W10 s or W12 s with a nominal weight less than 24 lb/ft). If the column tables are used you only need to write down the section selected and its capacity. φpn = 0.85 * Ag * Fcr Fcr = (.658 λc^2 ) * Fy when λc < 1.5 Fcr = (0.877 / λc 2 ) * Fy when λc > 1.5 λc = (K * L/π r) * (Fy / E) 0.5 (Equation E2-1 LRFD p ) (Equation E2-2 LRFD p ) (Equation E2-3 LRFD p ) (Equation E2-4 LRFD p ) Fy = 50 ksi K = Pu = L = ft E = ksi Assume KL/r = 60 to start λc = Fcr = ksi Ag = in 2 LRFD p.4-25 Check W 12: LRFD p.4-26 Check W 10:

6 SUBJECT: CORNER SHEET 67 of 131 METHOD 1 - EXPLICIT CALCULATIONS METHOD 2 - USE TABLES CONTINUOUS - L =13 FEET Notation: φpn - design compressive strength, Fcr - critical design force λc - width-thickness ratio Ag - gross area of member, in 2 Fy - specified yield strength, ksi E - modulus of elasticity, ksi K - effective length factor l - Laterally unbraced length of member, in r - governing radius of gyration about the axis of buckling, in From 3rd floor to roof level: dead loads (psf) live loads (psf) Roof 3 rd Floor 2 nd Floor - - P u = [1.2*dead load + 1.6*live load] P u = [1.2*dead load + 1.6* roof live load] Pu (Roof) = psf * A1 = sum = PU =

7 SUBJECT: CORNER SHEET 68 of 131 From 3rd floor to roof level: Note: For small axial loads the smallest section from the column design Tables (Table 4-2 LRFD) may not be the lightest. If this is the case, do explicit calculations and then try a section from the Table 1-25 LRFD. Use W8x24 as the smallest size (do not use W10 s or W12 s with a nominal weight less than 24 lb/ft). If the column tables are used you only need to write down the section selected and its capacity. φpn = 0.85 * Ag * Fcr Fcr = (.658 λc^2 ) * Fy when λc < 1.5 Fcr = (0.877 / λc 2 ) * Fy when λc > 1.5 λc = (K * L/π r) * (Fy / E) 0.5 (Equation E2-1 LRFD p ) (Equation E2-2 LRFD p ) (Equation E2-3 LRFD p ) (Equation E2-4 LRFD p ) Fy = 50 ksi K = Pu = L = ft E = ksi Assume KL/r = 60 to start λc = Fcr = ksi Ag = in 2 LRFD p.4-25 Check W 12: LRFD p.4-26 Check W 10: Lab Note: When beams and girders are framed to columns with simple shear connections, the columns are usually designed as concentrically loaded members.

8 SUBJECT: CORNER SHEET 69 of 131 SPLICED vs CONTINOUS Steel Prices per ton = $1,600 Wt of additional splice (lb) b = 500 W10's Continous: Member Length (ft) Weight (tons) Cost W10x30 All columns spliced: Member Length (ft) Weight (tons) Cost W10x30 W8x24 W8x24 splice = TOTAL COST = Answer: Use: b - indicates general value according to Modern Steel Construction, April 2000

9 SUBJECT: CORNER SHEET 70 of 131 SPLICED vs CONTINOUS W12's Continous: Member Length (ft) Weight (tons) Cost W12x26 Steel Prices per ton = $1,600 Wt of additional splice (lb) b = 500 All columns spliced: Member Length (ft) Weight (tons) Cost W12x26 W8x24 W8x24 splice = TOTAL COST = Answer: Use: b - indicates general value according to Modern Steel Construction, April 2000