DAR GROUP

Project

Job Ref.

Section

Sheet no./rev.

1

Calc. by

MS

Date

07-Oct-08

Chk'd by

IC

Date

App'd by

Date

RC WALL DESIGN (ACI 318-05)

200 mm

Geometry of wall

Depth of wall; h = 250 mm

Clear cover to reinforcement (both sides); cc = 40 mm

Unsupported height of wall; lu = 3500 mm

Effective height factor; k = 1.00

Reinforcement of wall

Numbers of reinforcement layers; Nl = 2

Vertical steel bar diameter number; Dver_num = 4

Spacing of vertical steel; sv = 200 mm

Diameter of vertical steel bar; Dver = 13 mm

Horizontal steel bar diameter number; Dhor_num = 4

Spacing of horizontal steel; sh = 200 mm

Diameter of horizontal bar; Dhor = 13 mm

Specified yield strength of reinforcement; fy = 415 MPa

Specified compressive strength of concrete; f'c = 40 MPa

Modulus of elasticity of bar reinforcement; Es = 200000 MPa

Modulus of elasticity of concrete; Ec = 4700 (f’c 1 MPa) = 29725 MPa

Ultimate design strain; c = 0.003 mm/mm

Check for minimum area of vertical steel of double layer reinforcement wall (ACI 318-05, cl. 14.3)

Gross area of wall per running meter length; Ag = h 1000 mm = 250000 mm2

Numbers of vertical bars per running meter length; Nv = 1000 mm / sv = 5.0

Area of vertical steel per running meter length; Ast_v = 2 Nv (Dver2) / 4 = 1327 mm2

Minimum area of vertical steel required; Ast_v_min = 300 mm2

PASS - vertical steel provided is greater than minimum vertical steel required

Check for minimum area of horizontal steel of double layer reinforcement wall (ACI 318-05, cl. 14.3)

Gross area of wall per running meter length; Ag = h 1000 mm = 250000 mm2

Number of horizontal bar per running meter height; Nh = 1000 mm / sh = 5.000

Area of horizontal steel per running meter height; Ast_h = 2 Nh (Dhor2) / 4 = 1327 mm2

Minimum area of horizontal steel required; Ast_h_min = 500 mm2

PASS - horizontal steel provided is greater than minimum horizontal steel required

Unbraced wall slenderness check (ACI 318-05, cl. 10.12)

Maximum slenderness ratio limit; sr_max = 100

Permissible slenderness ratio; sr_perm = 22

Slenderness check for unbraced wall

Radius of gyration; rmin = 0.3 h = 75 mm

DAR GROUP

Project

Job Ref.

Section

Sheet no./rev.

2

Calc. by

MS

Date

07-Oct-08

Chk'd by

IC

Date

App'd by

Date

Actual slenderness ratio; sr_act = k lu / rmin = 46.67

Wall slenderness limit OK, wall is unbraced slender wall

Design loads and moments for wall subjected to shear, axial load and bending

Ultimate axial force per running meter; Pu_act = 2620.00 kN/m

Ultimate large end moment per running meter; M2_act = 99.00 kNm/m

Ultimate small end moment per running meter; M1_act = 75.00 kNm/m

Ultimate shear force per running meter; Vu_act = 360.00 kN/m

Ratio of DL moment to total moment; d = 0.650

Magnified moment for uniaxially unbraced slender wall (ACI 318-05, cl. 10.13)

Moment of inertia of section; Ig = (1000 mm h3) / 12 = 1302083333 mm4

Euler’s buckling load; Pc = (2 0.4 Ec Ig) / ((1 + d) (k lu2) 1 m) = 7559.73 kN/m

Correction factor for actual to equiv. mmt. diagram; Cm = 1

Moment magnifier; ns1 = Cm / (1 - (Pu_act / (0.75 Pc))) = 1.859

Moment magnifier; ns = ns1 = 1.859

Magnified uniaxial moment; Mc= ns M2_act = 184.05 kNm/m

Axial load capacity of double layer reinforcement wall subjected to bending

c/dt ratio; r = 0.752

Effective cover to reinforcement; d’ = cc + (Dver / 2) = 47 mm

Depth of tension steel; dt = h - d’ = 204 mm

Depth of NA from extreme compression face; c = r dt = 153 mm

Factor of depth of comp. stress block (cl.10.2.7.3); 1 = 0.764

Depth of equivalent rectangular stress block; a = min((1 c), h) = 117 mm

Stress in compression reinforcement; f’s = Es c (1 - (d’ / c)) = 418 MPa

Since abs(f's) > fy, hence f'cs = fy

f’cs = min(abs(f’s), fy) = 415 MPa

Stress in tension reinforcement; fs = Es c ((dt / c) - 1) = 198 MPa

Since abs(fs) < fy, fs = fts

fts = min(abs(fs), fy) = 198 MPa

Capacity of concrete in compression; Cc = 0.85 f’c a 1000 mm /1 m= 3974.53 kN/m

Area of vertical tension steel per running meter; As = Ast_v / 2 = 664 mm2

Area of vertical comp. steel per running meter; A’s = Ast_v / 2 = 664 mm2

Strength of steel in compression; Cs = A’s f’cs / 1 m = 275.42 kN/m

Strength of steel in tension; Ts = As fts / 1 m= 131.60 kN/m

Nominal axial load strength; Pn = Cc + Cs - Ts = 4118.35 kN/m

Strength reduction factor; = 0.65 = 0.650

Ultimate axial load carrying capacity of wall; Pu = Pn = 2676.93 kN/m

PASS - wall is safe in axial loading

Bending capacity of wall

Centroid of wall; y = h 0.5 = 125 mm

Nominal moment strength; Mn = Cc (y - (0.5 a)) + Cs (y - cc) + Ts (dt - y) = 298.25 kNm/m

Ultimate moment strength capacity of wall; Mu = Mn = 193.86 kNm/m

PASS - wall is safe for bending

Eccentricity ratio

Actual eccentricity; ed = Mc / Pu_act = 70 mm

Calculated eccentricity; eall = Mu / Pu = 72 mm

DAR GROUP

Project

Job Ref.

Section

Sheet no./rev.

3

Calc. by

MS

Date

07-Oct-08

Chk'd by

IC

Date

App'd by

Date

Eccentricity ratio; er = ed / eall = 0.970

Compression controlled case

Check for shear capacity of wall subjected to shear, axial load and bending (ACI 318-05, cl. 11.3.1.2)

Effective cover to reinforcement; d’ = cc + (Dver / 2) = 47 mm

Depth of tension steel; dt = h - d’ = 204 mm

Factored moment for axial compression; Mm = M2_act - (Pu_act ((4 h) - dt) / 8) = -161.85 kNm/m

Shear force resisting capacity of wall (eq. 11.5); Vc1 = (0.16(f’c1MPa)dt)+(17Ast_vmin(1,(Vu_actdt/Mm)))(1kN/m3)

Shear force resisting capacity of wall; Vc1 = 205.92 kN/m

Max. shear force resisting capacity of wall(eq.11.7); Vmax = 0.29 (f’c) h (1 MPa + (0.29 Pu_act 1 m / Ag))

Max. shear force resisting capacity of wall; Vmax = 921.54 kN/m

Shear force resisting capacity of wall; Vc = Vmax = 921.54 kN/m;

PASS - shear force resisting capacity of wall is greater than shear force acting on wall

Design summary

Wall is 250 mm thick with 40 MPa concrete and 415 MPa steel

Vertical reinforcenment is 13 mm dia at 200 mm spacing

Horizontal reinforcenment is 13 mm dia at 200 mm spacing

Design status

PASS - wall is safe

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