Column Shear Design

NSCP 2010 Specification and Equation No.

Angel Lazaro & Associates International Consulting Engineers and Architects 160 Panay Ave., cor EDSA, Diliman, Quezon City, 1103 Phil Tel # : 924-1911 924-1879 Fax #: 924-1865 924-1931 (632) 924-1887

Project Title : Location :

Design of Rockery Slope Protection Palali, Sta. Lucia, Ilocos Sur, Region 1

Client : Address :

Department of Public Work and Highways (DPWH)

Cal'c by : Date : Checked by: Date : Rev : Date :

A.H.Sinconiegue Feb. 4 , 2013 B.S.Buenconsejo

Design Refference: NSCP Volume 1, Fourth Edition 2010 Design of Reinforce Concrete, 2ND Edition by Jack C. McCormac Reinforced Concrete Mechanics and Design ( 4th Edition SI Units) by James McGregor I. Design Inputs :

409.4.2.3

Axial Demand, Nu = Shear Demand, Vu = Shear Capacity Reduction Factor, ɸ =

127.13 KN 137.53 KN 0.75

II. Material Properties Compressive Concrete Strength, fc' = Steel Yeild Strenght Main Bar, fy = Steel Yeild Strenght Tie Bar, fLT = Modulus Elasticity of steel, Es =

21.00 413.00 276.00 200000.00

Mpa Mpa Mpa Mpa

650.00 650.00 602.00 40.00 16.00 12.00 1.00

mm mm mm mm mm mm

III. Design Assumption

411.8.4.3

Column Width, b = Column Depth, h = Effective depth, d = Concrete cover, cc = Main Bar diameter, Ø = Lateral Tie diameter , ØLT = Modification factor, λ = IV. Design Vertical Tie Spacing,S Ultimate Design Factored Shear Force, Vu =

137.53 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

311.39 KN

Check if Lateral Ties is needed, Vu > 0.5ФVc 411.6.6.1

0.5*Ф*Vc =

116.77 KN

Shear Reinforcement Needed

Note: If shear reinf. Not needed adopt spacing from Section.407.11.5.1. Calcualtion below N/A. Calculation for Nominal Shear Force, Vn 411.2.1

Vn = Vu/Ф

183.37 KN

Calculation for shear strength provided by lateral ties, Vs 411.2.1

Vs = Vn - Vc

-128.02 KN

Check if shear strength provided by lateral ties, Vs exceeds 0.33*sqrt(fc')*b*d/1000 411.6.5.3

0.33*sqrt(fc')*b*d/1000 =

591.74 KN

max. spacing d/2

Calculation for maximum spacing, Smax 411.6.5.1

Smax=d/2

301.00 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 =

1183.49 KN

Section is Appropriate

Calculation for area for lateral tie reinforcement, Av 411.6.7.3

Av = 2*π*(ØLT)2/4

2 226.19 mm

Calculation for theoretical spacing, S 411.6.7.2

S= Av*fLT*d/Vs

-293.58 mm

250 mm

274.42 mm

250 mm

Calculation for maximum spacing to provide minimum area of shear reinforcement, S 411.7.5.2

S = Av*fLT/(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 =

256.00 mm 576.00 mm 650.00 mm

smallest value =

256.00 mm

Adopt actual spacing, Sact =

250.00 mm

Note: these should be used over one-fourth of the column length of each end. V. Design Summary Therefore since lat. Ties is not needed adopt spacing, Sact = Provide : Ø12mm lat tie, spaced 1 @ 50mm rest @ 200mm O.C.

250.00 mm

say

200

mm