Design of intake structure :
As per cl.5.3.9 of IS 9761-1995 ("Hydro power Intakes -'-Criteria for Hydraulic Design") ,
the trash rack pier shall be designed for a differential head of 3 to 6mts .
depending upon the efficiency of the cleaning of Trash rack
Considering the Max differential head of 6 m for the design of Trash rack piers,
Total Horizontal force H = 706.05 Kn
=(6*10 +0)*3.9225*6/2
Length of the Pier = 10500 mm
Avg. width of pier = 2000.00 mm
Bed Level of the trash rack pier = 41.417 m
Top level of the trash rack pier = 73.000 m
Ht.of the Trash rack pier =73-41.417 = 31.583 m
C/C of D/T = 17.00 m
Avg.Spacing of the trash rack pier = 3.92 m
Design of middle pier :
Vertical loads on the pier :
Ht of the pier = 31.58 m
Area of c/s of the pier = 21 Sq.m
Wt. of the pier =31.583*21*25 = 16581.075 Kn
Loads from the Deck slab :
Avg. Thickness of Top slab = 0.5 m
Length of the slab along the flow direction = 10.5 m
Avg. width of pier = b = 2000.00 mm
Wt. of slab on pier =0.5*10.5*3.9225*25/2 = 257.41406 Kn
Live Load on the slab =10.5*3.9225*10 = 411.8625 Kn
Total Load on Pier = = 17250.352 Kn
say 21200 Kn
Moments middle pier
Max differential water head = 6m
Horizontal load on trash rack pier =6*10*3.9225*6/2 706.05
C.G of the horizontal force from bottom 26.733
Max.BM in Trash rack pier = 18874.83 Kn-m
F.B.M = = 28312.252 Kn-m
DESIGN OF middle pier as column -
DESCRIPTION
P IN Kn. 21200.00 Kn
Mx IN Kn-M (Moments about xx) 18874.83 Kn-m
My IN Kn-M (Moments about yy) 424.00 Kn-m
Pu 31800.00 Kn
Mux 28312.25 Kn-m
Muy 636.00 Kn-m
COLUMN SIZE. (B) 2000.00 mm
COLUMN SIZE. (D) 10500.00 mm
ASSUMED STEEL IN SQ.MM 126000.00 Sq.mm
% OF STEEL p 0.60 %
Grade of concrete(Fck) 25.00
p/Fck. 0.02
Pu/Fck*B*D 0.06
Puz 274050.00
Pu/Puz 0.12
n 1.00
Mux1' =0.05*2000*10500*10500*25/1000000275625.00
Muy1' =0.04*2000*2000*10500*25/1000000 42000.00
(Mux/Mux1)n +( Muy/Muy1)n 0.12
safe
Provide T32 @ 150 c/c (avg spacing)
Design of Gate Pier:
Pier size of the pier = 2000 x 12500 mm
Bed Level of the D.T pier = 41.417 m
Top level of the D.T pier = 73.00 m
Ht.of the D/T pier bellow 79.0m to E.L 41.417 31.58 m
Avg, spacing of c/c of supports = 8.50 m
Max. water level in fore bay 67.161
pump floor level 51.30
Max. water head on piers 15.86
Total Horizontal load 10691.78 Kn
Max moment at pump floor level 56527.447 Kn-m
Vertical loads on the Gate pier :
Area of c/s of the pier = 25000000 Sq.mm
= 25 Sq.m
Ht.of the D/T pier = 31.58 m
Area of c/s of the pier = 25000000 Sq.mm
= 25 Sq.m
Wt. of the pier =25*31.583*25 = 19739.375 Kn
Loads from the hoist platform slab at E.L73 :
a) Slab Load , =(12500/1000*(17/2)*0.4*25)= 1062.5 Kn
b) Beam Load =(2*(17/2)*0.5*1*25) = 212.50 Kn
c) L.L on Slab =(12500/1000*(17/2)*10) = 1062.5 Kn
d) Wt. of gate & hoist 500 kn
Total Load = 22911.51 Kn
say 27000 Kn
DESIGN OF D/T PIER :-
P IN Kn. 27000.00 Kn
Mx IN Kn-M 56527.45 Kn-m
My IN Kn-M Min. eccentricity 540.00 Kn-m
moment
Pu 40500.00 Kn
Mux 84791.17 Kn-m
Muy 810.00 Kn-m
PIER SIZE. (B) 2000.00 mm
PIER SIZE. (D) 12500.00 mm
ASSUMED STEEL IN SQ.MM 150000.00 Sq.mm
% OF STEEL p 0.60 %
Grade of concrete 25.00
p/Fck. 0.02
Pu/Fck*B*D 0.06
Puz 326250.00
Pu/Puz 0.12
n 1.00
Mux1' =0.05*2000*12500*12500*25/1000000390625.00
Muy1' =0.04*2000*2000*12500*25/1000000 50000.00
(Mux/Mux1)n +( Muy/Muy1)n 0.23
safe
Provide T32 @ 130 c/c (avg spacing)
Design of Beam - B1 at Hoist plotform level at EL73 m
( Beam in between the D.T piers in vent)
B D
Beam size = 500 x 1000 mm
Eff. Depth of beam 950 mm
Load on the slab =0.3*25+10 17.5 kn/m
Span of the Beam = l 7.16 m
Slab Panel Size = = 7.16 x 6.25
U.D.L on The Beam = =(12500/4/1000)*(17.5) 54.6875 kn
Self-wt. =500*1000*25/1000^2 12.5 kn
Wt. of railing 2 kn/m
Total Load coming on the beam = w 69.2 kn
Point load due to gate wt. 250 kn
Max BM = w*l^2/10 =69.1875*7.155^2/10 354.19866 kn-m
Moment due to point load = 223.59375
Total moment = 577.79241
F.B.M = =577.79241046875*1.5 866.68862 kn-m
Mu/b*d*d =866.688615703125*10^6/(500*950^2) 1.92
pt = 0.498 %
Ast =0.498*500*1150/100 2863.5 mm^2
Provide T 32 - 4 No.s straight and 2 No.s extra at Top at supports
Provide T 32 - 4No.s straight and 2 No.s extra at Bottom at mid span
Check for SHEAR
Shear Force = 372.51828 kn
Max.shear force =*250/2+354.19866046875/2 177.09933 kn
pt = 0.498 %
Load taken by Concrete =0.36*500*950/1000 171 kn
Load taken up by stirrups =S.F = =177.099330234375-171 6.0993302 kn
S.F / d =6.09933023437506/950*10 0.06 Kn/cm
Provide T 12 - 2 Legged Stirrups @125 mm c/c at the ends
Provide T 12 - 2 Legged Stirrups @200mm c/c at Mid-span
