In wire see annex e 1 elastic deformation 2 xi32 x

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Unformatted text preview: = 49.57 G-4.2 Jnitial Compressive ~,) = 1098.10 N/mm2 G-4.4 Compressive Factory Test Allowable clear spacing (see 8.4.5) Maximum clear spacing of wire= 50 mm Minimum clear spacing of wire= 6 mm Area of spiral considered in = 0.623 N/mmz design- (A,) 1000 Number of turns per — x (4)2 meter length = ‘“623X 0.7854 Centre to centre spacing of spiral wire = 1 116.91N/mm2 Stress in wire at site test@ = 1286.25 – 188.15 G-4 CALCULATION OF PRESTRESS IN CORE IN CIRCUMFERENTIAL DIRECTION G-4.1 Spacing of Circumferential 188.15 = 169.34 N/mm2 Stress in wire at factory test, &) x = 113 168797mm3 ODP G-4.6 Self Weight of Pipe (W,) a) a) Self weight of core (WC) WC=3.1416X (D+ TC)XTCXKC = 3.1416 x (1.200+0.070)x 0.070x 24000 = 6702.92 N/m = 36.63 N/mm2 = 102.90 N/mm2 = 28.62 N/mm2 Deformation due to shrinkage d) 1 ().000 1 xE,=0.0001 x 20 x Id= 20.00 N/mm2 Total losses 36.63 + 102.90+ 28.62+ 20.00= 188.15N/mm2 b) Self weight of coat (WJ Wb=3.1416X (D+2XTC+Tb)XTb X Kb = 3.1416 x (1.200 + 2 x 0.070 + 0.022) x 0.022 x 21 600 = 2033.31 N/m 18 IS 784:2001 c) Self weight of pipe (W,) W,= WC+ W~= 8736.23 N/m, Thrust (2) = 0.207 x 8736,23 = 1808.40 N/m Stress due to moment: G-4.7 Weight of Water (WW) M WW=(3.141 6/4) X D2 x KW = 0.7854 x (1.200)2 x 10 000= 11309.76 N/m G-4.8 Weight Of Earth Fill (W,) (seeFig. 4 of IS 783) T = = Thrust (T) = = Stress due to moment Moment (M) WI= CPXPIIXO where P = Axle load= 61300 N O = Impact factor= 1.0 1 = 1.15 H+20DP+S=3.918 Assuming S = O the value of CP= 0.664 is obtained from Fig. 3 of IS 783, using the values, M T —. 3053.64 = 0.0332 Nlmm2 A 92000 Net tensile stress: = (-0.6267)+ (-0.0332)= -0.6599 N/mm2 Net compressive stress: = (+0.6267)+ (-0.0332)= +0.5935 N/mm2 WI= 10388.80 N/m 3.918 of Stresses G-4.10.3 Stress Due to Weight of Earth Fill Due to External = = Thrust (T) = = Stress due to moment: Moment (M) Circumferential stresses due to external load Olander’s (coefficient for 90° bedding angle). { Moment Self weight +0.121 Water weight + 0.121 Earth fill + 0.125 Live load + 0.125 + Moment causes tension At Bottom — (Mb) Thrust (HJ W,r + 0.207 W, WWr -0.270 WW W,r + 0.326 We Wlr + 0.326 W, inside pipe at bottom. M 0.125 x 29187.77 x 646.0 2356912.40 Nmm 0.326 x 29187.77 9515.21 N/m 2356912.40 ~= 1410667 Stress due to thrust: = 1.6708 N/mm2 T —. 9515.67 = 0.1034 N/mm2 A 92000 Net tensile stress: = (-1.6708)+ (+0.1034)= -1.5674 N/mm2 Net compressive stress: = (+1.6708)+ (+0.1034)= +1.7742 N/mm’ Only stresses-at bottom are calculated as those are more severe. G-4.1 0.1 Stress Due to Self Weight of Pipe Moment (M) = 0.6267 N/mm2 Stress due to thrust: D 1.384 ——. — = 0.692 2H 2x1 0.664x613001 1410667 0.121 x 11 309.76x 646.0 884038.70 Nmm 0.270 x 11309.8 3053.64 N/m 884038.70 ~= 1 = 1.959, and for ratio — = = 2H 2x1 External Load 1808.40 G-4.1O.2 Stress Due to Weight of Water G-4.9 Live Load (Wl) (see 10.1) G-4. 10 Calculations Loads = 0.4841 N/mm2 = 0.0197 N/mm2 ; = 92000 Net tensile stress: = (-0.484 1)+ (+0.01...
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This document was uploaded on 10/01/2013.

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