DAR GROUP

Project

The PearlJob Ref.

Q09079

Section

PASheet no./rev.

1

Calc. by

Eng.MSDate

09-July-06Chk'd by

Eng.AEDate App'd by Date

RC SINGLE CORBEL DESIGN TO ACI 318-05

Vu

Nuca

d h

Framingbars

Maintensionbars

Horizontalbars

Steel angle

min

d /

2

Shd23

Sh

Sh

Corbel geometry

W idth of corbel; b = 300 mm

Total thickness of corbel; h = 500 mm

Depth to main reinforcement; d = 450 mm

Material properties

Yield strength of reinforcement; fy = 415 MPa

Compressive strength of concrete; f’c = 35 MPa

Type of concrete; Normal weight

Unit weight of concrete; = 1.00

Corbel construction; Monolithic

Coefficient of friction; = 1.4 = 1.40

Design load data

Factored vertical load; Vu = 370.00 kN

Distance of vertical load from face of column; a = 100 mm

Horizontal force acting on corbel; Nuc = 75.00 kN

Strength reduction factor; = 0.750

Vertical load capacity check

Nominal vertical load; Vn = Vu / = 493.33 kN

Nominal vertical load capacity; Vn_cap = min(0.2 f’c b d, 5.5 MPa b d) = 742.50 kN

PASS - Nominal vertical load is less than the nominal vertical load capacity

Find shear friction reinforcement

Minimum horizontal force acting on corbel; Nuc_min = 0.2 Vu = 74.00 kN

Horizontal force acting on corbel; Nuc_act = max(Nuc, Nuc_min) = 75.00 kN

For balanced condition; j = 0.85

Area for shear friction reinforcement; Avf = Vn / (fy ) = 849 mm2

Af = [(Vu a) + (Nuc_act (h –d))] / ( fy j d) = 342 mm2

Nominal area required; An = Nuc_act / ( fy) = 241 mm2

DAR GROUP

Project

The PearlJob Ref.

Q09079

Section

PASheet no./rev.

2

Calc. by

Eng.MSDate

09-July-06Chk'd by

Eng.AEDate App'd by Date

Main tension reinforcement check

Minimum area of tension reinforcement; Asc_min = 0.04 f’c b d / fy = 455 mm2

Area of tension reinforcement required; Asc = max([(2 Avf) / 3] + An, Af + An) = 807 mm2

Asc_req = max(Asc, Asc_min) = 807 mm2

Main tension reinforcement; 3 No.6 bars

Diameter of tension bars; Dtension = 19 mm

Number of tension bars; Ntension = 3

Area of tension reinforcement provided; Asc_prov = Ntension Dtension2 / 4 = 851 mm2

PASS - Tension reinforcement is adequate

Horizontal reinforcement check

Minimum area of horizontal reinforcement; Ah_min = 0.5 (Asc_req - An) = 283 mm2

Area of horizontal reinforcement required; Ah = max(Avf / 3, Af / 2) = 283 mm2

Ah_req = max(Ah, Ah_min) = 283 mm2

Horizontal reinforcement; 3 No.3 bars

Diameter of horizontal bars; Dhorizontal = 9 mm

Number of horizontal bars; Nhorizontal = 3

Area of horizontal reinforcement provided; Ah_prov = 2 Nhorizontal Dhorizontal2 / 4 = 382 mm2

PASS - Horizontal reinforcement is adequate

Maximum spacing of horizontal bars; Sh_max = 2 d / (3 Nhorizontal) = 100 mm

Actual spacing of horizontal bars; Sh = 100 mm

PASS - Horizontal bar spacing is adequate

Design Summary

Single corbel 300 mm wide by 500 mm deep with 35 MPa concrete and 415 MPa steel

Provide main tension reinforcement as 3 No. 6 bars

Provide horizontal reinforcement as 3 No. 3 link bars at maximum 100 mm centres