X k 045 x 40 180 0503 8 05935 17742 9773

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Unformatted text preview: lx fsi} AC = AC 28X 12.57x 1286.25 Initial precompression (fil) = 3.146x(D + ~) 279288.24 . 1.6209 N/mm* N Concrete strength required at detensioning longitudinal ~Pl) (see 8.3.2) of 2 x ~i, or 15 N/mm’, whichever is greater that is 2 x 1.6209 = 3.24 or 15 N/mm2, whichever is greater. considered in Adopt ~P, = 15 N/mm’ G-6.3 Loss of Stress in Longitudinal Annex F) Initial stress in longitudinal wire ~,1) a) = 1286.25 N/mm’ 21 1 0.45 ‘fik = 0.45 x 40 =18.0 + ve is compressive 3.1416 x 1270 x 70 Longitudinal G-6.2 Initial Longitudinal Precompression in Core (see 8.4.2) 1715.0 x 0.75 18.0 Area of core concrete (AC) IN LONGI- —3.1416 X(1 200+ 70) , that is 142.49 mm 28 I < (+12.644 6)+ (+0.63 1 5) =+13.276 1 +13.276 1 –1.54 - ve is tensile, longitudinal wires 142.49 mm <150 mm Hence, number of Iongitudinals design is correct. +11.037 8 (0.503 8 + 0.5935 + 1.7742 + 9.731) = +12.644 6 150 mm =28 Number of longitudinal considered in design 0.45 x ~k = 0.45 x 40 = 18.0 (0.503 8 + 0.5935 + 9.940 5) =+11.0378 0.13 ~ck)””c’ o.13 x (40)0”67 =–1.54 -1.54 Centreline spacing between longitudinal wires shall not exceed twice the core thickness or 150 mm whichever is greater, that is 2 X 700r 150mm \ Permissible Actual 0.00 < 25 N/mm’), Spacing / 0.00 (+1.337 o)+ (-0.557 9) = +0.779 1 +0.779 1 OF STRESS G-6 CALCULATION TUDINAL DIRECTION G-6. 1 Centreline Wires (see 8.3) < Compressive A Wires (see Relaxation of wire 0.08 X&i,= 0.08 x 1286.25 = 102.9 N/mmz IS 784:2001 b) Deformation due to creep = 2.50 X~il = 2.50 x 1.6209= 4.05 N/mm* c) Deformation due to shrinkage = 0.0001 x E, = 0.0001 x 20.0 x 104 = 20.00 N/mmz d) Yield due to mould shortening (Wire stretch due to filling, vibration during spinning, etc) G-6.6 Stress Due to Beam Action w, = 8736.23 N/m Self weight of pipe Weight of water Ww = 11309.76 N/m Earth load to be considered (see Note 2 under 7.4.1) 1384 = 2“2 x *PD = 3.0448 2xE, = 2“2 x 1000 N/m KN/m=3044.80 Total load, W= 8 736.23+ 11 309.76+3 044.80 =23 090.79 N/m = Effective length of pipe + 80 mm Bending moment (BM) 2X2OX1O J7-~2 = 78.74 N/mm* = 5000+80 8 Total losses = 102.9+ 4.05 + 20.0+ 78.74 Modulus of circular section of pipe = 205.69 N/mm2 G-6.4 Precompression in Core in Longitudinal At the stage of winding Loss of prestress in longitudinal wire at winding Stress in longitudinal wire at winding ~,lW) = 1286.25 –185.12 = 1101.13 N/mm2 Precompression at winding (&,) 28x12.57x1 G6.7 = Total 10SSx 0.9 = 205.69 x 0.9 = 185.12 N/mm* Stress Due to Self Weight of Core 1000 6702.92x5x5x— 101.13 2798288.24 = 1.3876 N/mm* = 1286.25 – 205.69 = 1080.56 N/mm* G-6.8 Summary Direction Stresses Due To = 20946625 of Stresses Nmm in Longitudinal Tensile N/mm2 Maximum local longitudinal — tensile stress due to bending during winding Beam action + 0.6376 Self weight of core + 0.2485 Initial precompression + 1.6209 Precompression at winding + 1.3876 Final precompression + 1.3617 2798288.24 = 1.3617 N/mm* Stre...
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This document was uploaded on 10/01/2013.

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