NSCP 2010 Specification and Equation No.
Prepared by : Date : PRC # : TIN # : Issued On: Issued At:
A.S Structural and Engineering Services Structural Engineers and Project Manager Sheet Content : Design of Tied Column Date : Nov. 27, 27, 2011 2011
Project Title : Location :
Two Storey Resedential House Brgy. Banale, Pagadian City, Zamboanga Del Sur
Client : Address :
Engr. Arnel H. Sinconiegue Dagat-Dagatan, Caloocan City, Metro Manila
Arnel H. Sinconigue, C.E Oct. 13, 2011 116853 406-365-953-000 3/24/2011 Quezon City
Design Refference: NSCP Volume 1, Fourth Edition 2010 ND Design of Reinforce Concrete, 2 Edition by Jack C. McCormac Fundamentals of Reinforced Concrete (Using USD USD Method, NSCP 2001) by Besavilla
I. Design Inputs :
409.4.2.2 409.4.2.3 410.3.7.3
Axial Demand, Pu = Momentt Deman Momen Demand, d, Mu = Shear Demand, Vu = Unsupported Unsup ported Lengt Length, h, lu = Flexure Capacity Reduction Factor, ɸ = Shear Capacity Reduction Factor, ɸ = Compressive Block Deep Factor, β1 =
950.00 90.00 150.00 2.90 0.65 0.75 0.85
KN KN.m KN m
II. Materi Material al Proper Propertie ties s Compressive Concrete Strength, fc' = Steel Yeild Strenght Main Bar, fy = Steel Yeild Strenght Tie Bar, f LT LT = Modulus Elasticity of steel, Es =
20.70 Mpa 415.00 Mp M pa 276. 27 6.00 00 Mp Mpa a 200000.00 Mpa
III. Design Design Assumptio Assumption n
410.10.1 410.13.1.3 411.8.4.3
Column W idth, b = Column Depth, h = Concrete cover, cc = Main Bar diameter, Ø = Lateral Tie diameter , ØLT = Stee ratio, ρact = Effective height factor, k = Modification factor, λ =
450.00 450.00 40.00 28.00 10.0 10 .00 0 0.02 1. 00 1.00
mm mm mm mm mm
IV. Desgin Calculation ( using static eqautions )
Calculation for concrete gross area, Ag Ag = b*h
202500.00 mm
2
Calculation for steel area, A st Ast = ρact*Ag
4050.00 mm
Calculatin for db area, Adb Adb = π*(Ø) /4
615.75 mm
Calculation for No. of db, N N = Ast / Adb
6.58 6.58 pcs pcs
say 8 pcs
Calculation for eccentricity, e e = Mu/Pu
94.74 mm
Small Eccentricity
Calculation for balance yeild strain, ϵy ϵy = fy/Es
0.0021
Calculation for d1 d1 = h - cc - Ø/2
396.00 mm
Calculation for Neutral Axis, c c = (0.003/(0.003+ϵy))*d
410.3.7.2
234.09 mm
Calculation for compressive block depth, a 410.3.7.1
a = β1*c
198.98 mm
V. Check for Slenderness Effect in Compression Members
Calculation for slenderness effect 410.11.1.2 410.11.1
r = 0.3*h
135.00 mm
klu/r =
21.48
Neglect Slendeness
VI. Internal forces and moment Note : drawings are editable and it depends on what calculated above. designers should arrange the reinforcement at his/her instance. calculation done below are also variable it should be incorporated to the drawing. y
0.003
0.85fc' ϵs3
Pu
e
x
f s3
a
C
c d
Pn Mn
ϵs2
f s2
ϵs1
Fs2
f s1
Fs1
b Section
Strain
Nominal Stresses
Calculation of Strains,ϵs Note: This formula was done by similar triangle 410.3.3
ϵs3 = 0.003( c - (cc+Ø/2))/c
410.3.3
ϵs2 = 0.003*(c-h/2)/c ϵs1 = ϵy
0.0023 0.000116 0.0021
Calculation of Nominal Stresses 410.3.4
f s3 = ϵs3*Es
461.59 Mpa
410.3.4
f s2 = ϵs2*Es
23.30 Mpa
410.3.4
f s1 = ϵs1*Es
415.00 Mpa
Calculation of Internal Forces N3 = N2 = N1 =
Fs3 C
3.00 pcs 2.00 pcs 3.00 pcs
Forces & Moment
1847.26 mm
2
1231.50 mm
2
1847.26 mm
As2 = (π*(Ø) /4)*(N 2) As1 = (π*(Ø) /4)*(N 1) Fs3 = As3*f s3 Fs2 = As2*f s2 Fs1 = As1*f s1 410.3.7
2
2
As3 = (π*(Ø) /4)*(N 3)
C = 0.85fc'*a*b
2 2
852.68 KN 28.69 KN 766.61 KN 1575.44 KN
VII. Check for Axial & Flexural Capacity/Demand ratio,C/D
Calculation for Axial Capacity, Pn ΣFv = 0 Pn = Fs3 + Fs2 + C - Fs1
1690.19 KN
Calculation for Ultimate Axial Capacity, Pu Pu = ɸ*Pn
1098.62 KN
Calculation for Flexure Capacity, Mn ΣM@ bottom steel = 0 Mn = Fs3(0.32) + Fs2(0.16) + C(0.273) - Pu(0.256)
274.85 KN.m
Calculation for Ultimate Flexure Capacity, Mu Mu = ɸ*Mn
178.65 KN.m
Calculation for the Capacity/Demand Ratio, C/D Calculation for Axial = C/D Calculation for Flexure = C/D
1.16 1.99
Complaint Compliant
VIII. Design Vertical Tie Spacing,S
Ultimate Design Factored Shear Force, Vu =
150.00 KN
Calculation for Nominal Shear Strength provided by concrete, Vc 411.4.1.2
Vc = 0.17 ( 1 + Nu/14*Ag )*λ*sqrt(fc')*b*d/1000
184.02 KN
Check if Lateral Ties is needed, Vu > 0.5 ФVc 411.6.6.1
0.5*Ф*Vc =
69.01 KN
Shear Reinforcement Needed
Calculation for Nominal Shear Force, Vn 411.2.1
Vn = Vu/Ф
200.00 KN
Calculation for shear strength provided by lateral ties, Vs 411.2.1
Vs = Vn - Vc
15.98 KN
Check if shear strength provided by lateral ties, Vs exceeds 0.33*sqrt(fc')*b*d/1000 0.33*sqrt(fc')*b*d/1000 =
267.55 KN
max. spacing d/2
Calculation for maximum spacing, Smax 411.6.5.1
Smax=d/2
198.00 mm
Check if shear strength provided by lateral ties, Vs exceeds 0.66*sqrt(fc')*b*d/1000 411.6.7.9
0.66*sqrt(fc')*b*d/1000 =
535.10 KN
Section is Appropriate
Calculation for area for lateral t ie reinforcement, Av 411.6.7.3
2
Av = 2*π*(ØLT) /4
157.08 mm
2
Calculation for theoretical spacing, S 411.6.7.2
S= Av*f LT*d/Vs
1074.06 mm
1074 mm
275.26 mm
275 mm
Calculation for maximum spacing to provide minimum area of shear reinforcement, S 411.7.5.2
S = Av*f LT/(0.35*b) Vertical spacing shall not exceed the following :
407.11.5.1 407.11.5.1 407.11.5.1
16*Ø = 48*ØLT = least dimension =
448.00 mm 480.00 mm 450.00 mm
smallest value =
448.00 mm
Adopt actual spacing, S act =
198.00 mm
Note: these should be used over one-fourth of the column length of each end.
IX. Design of lap splices, ld
412.17.1
ld = 0.071*fy*db
412.17.1
actual length of splice,ld
825.02 mm 1074.00 mm
X. Design Summary
The column is 450 x 450 mm @ 8pcs - Ø28mm main bar and ties spaced @ 198mm O.C with lap splice length @ 1074 mm and having a Concrete Compressive Strenght of 20.7 Mpa and Steel Yeild Strenght of 415 Mpa for Vertical Reinforcement , 276 Mpa for the Lateral Ties.
