167627478-Corbel-Design-xls.pdf
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Transcript of 167627478-Corbel-Design-xls.pdf
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PROJECT :
TITLE:
BS8110 : CORBELS DESIGN 1) ULTIMATE LOADS ON THE CORBELUlt Vertical Vu = 2926 kN
Ult Horizontal Tu = 293 kN
Fcu = 40 N/mm2
Fy = 460 N/mm2
Ec = 28 kN/mm2
Es = 200 kN/mm2
2) DETERMINATION OF CORBEL GEOMETRY
Check: Max Bearing Stress
= 0.8 Fcu = 32.0 N/mm2
Width of Bearing Plate, w = 1400 mm
Length of Bearing Plate, l = 700 mm
Vu/(l.w) = 3.0 N/mm2 , < 0.8 Fcu
av = 350 mm
Cover @ Top/End, C = 30 mm
Cover @ Side, Cside = 72 mm
Diameter of Rebar, D = 25 mm
Diameter of Link, Dl = 10 mm
Le = D+5D+Dl+C >= 190 mm Width of Corbel, b = 1800 mm
Length of Corbel, req >= 890 mm Length of Corbel, prov = 700 mm
Check: Max Shear Stress vmax h, prov @ col face = 1600 mm
= min(0.8Fcu^0.5, 5N/mm2) = 5.00 N/mm2 d @ column face = 1557.5 mm
Check: av < d --> CORBEL
Vu/bd = 1.04 N/mm2 < Vmax
hy @ outer face >= 0.5h = 800 mm
hy, prov = 800 mm
3) EVALUATION OF INTERNAL FORCES
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Assume x (1st trial = 0.4d) = 421 mm es = 0.0035(d-x)/x = 0.0094 , > 0.002 ?
z = d - 0.45x = 1368 mm fs1(es>=0.002) = 0.87fy = 400 N/mm2
sin A = 0.9688 fs2(es< 0.002) = Es.es = 1890 N/mm2
cos A = 0.2479 fs = min(fs1, fs2) = 400 N/mm2
Fc = Vu/sin A = 3020241 N Ft = Vu.av/z+Tu = 1041184 N
x = Fc/(0.402Fcu.b.cosA) = 421.0 mm
As = Ft/fs = 2602 mm2
>= (0.5Vu+Tu)/0.87fy = 4387 mm2
As, req = 4387 mm2
As, prov: T 25 491 mm2
No. = 24
Total As = 11775 mm2
Check: Asmin = 0.004bh = 11520 mm2
Check: Asmax = 0.040bh = 115200 mm2
4) CHECK SHEAR
p = 100As,prov/bd = 0.420 Horizontal Links:
Spacing Sh = 200 mm
vc = 0.554 N/mm2 Ash = b.Sh(v-vc')/0.87fy = -3494 mm2
vc' = (2d/av).vc = 4.927 N/mm2 Ashmin = 0.5 Asreq = 2193 mm2
v = Vu/bd = 1.04 N/mm2 Ash, req = 2193 mm2
Ash, prov: T 10 78.5 mm2
No. of legs = 6
No. of sets = 7
Total Ash = 3297 mm2
Ash for Upper 2/3.d = 1038 mm
5) CHECK BEARING STRESS INSIDE BEND
Tensile Force in As, Fbt Tension in Bar at Start of Bend
= (Ft/No. As)(As,req/As,prov) = 16162 N/Bar Fbt' = (L1/Lb).Fbt = -107957 N
Ultimate Anchoage Bond Stress
= fbu = 0.5Fcu^0.5 = 3.16 N/mm2
Int. Radius, r = 4D = 100 mm
Anchorage Bond Length Req.
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= Lb = Fbt/(3.14.D.fbu) = 65 mm ab1 (Ctr-Ctr Bar) = 70.9130435 mm
ab2 (Cside + D) = 97 mm
Straight Length of Bar before Start of Bend ab = min(ab1 , ab2) = 70.9130435 mm
= L1 = 500 mm
Check:
Additional Length after Standard Bend Bearing Stress
= La = Lb - L1-12D + 4D = -635 mm = Fbt/(rD) = -43.18 N/mm2
= D = 25 mm Side = 72 mm < 80mm, OK
Internal = 46 mm , OK
Max. Horz Space = 47000/fs = 781 mm