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Pitching 3

The document provides formulas to calculate the size of stones used for rip rap and reservoirs based on factors like water weight, stone weight, embankment slope, and wave height. It also includes formulas to calculate the diameter, weight, and size of concrete/stone blocks for riprap/apron based on parameters like flow velocity, stone unit weight, surface slope, and uplift force. As an example, for a flow velocity of 0 m/s, stone unit weight of 2.4 tons/cubic meter, slope of 0, and uplift of 1 ton, the calculated diameter is 0.974 meters and weight is 101.09 kilograms.

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110 views4 pages

Pitching 3

The document provides formulas to calculate the size of stones used for rip rap and reservoirs based on factors like water weight, stone weight, embankment slope, and wave height. It also includes formulas to calculate the diameter, weight, and size of concrete/stone blocks for riprap/apron based on parameters like flow velocity, stone unit weight, surface slope, and uplift force. As an example, for a flow velocity of 0 m/s, stone unit weight of 2.4 tons/cubic meter, slope of 0, and uplift of 1 ton, the calculated diameter is 0.974 meters and weight is 101.09 kilograms.

Uploaded by

dsananda
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
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Download as PDF, TXT or read online on Scribd
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The size of the stone to be used for rip rap of reservoirs:

yw 1 s2
d m  2.23C hw
y r  y w ss  2
where,

yw=Unit weight of water= 1.00 t/cum

yr=Unit weight of stones= 1.44 cum

dm =diameter of staone in metre

s= slope of the embankment 2.00 H:1V

hw=wave height (m) 0.60 m

C= factor depending on the type of protection

For hand palced rip rap C= 0.54

For dumped rip rap C= 0.80

Therefore dm= 0.46 m

Average size of stone required=dm/0.85 0.54 m

DESIGN OF CONCRETE/STONE/MASONRY BLOCKS FOR RIPRAP/APRON

(Ref:Civil & Structural Design TVA Technical Report No.24, Vol-1)


INPUT
velocity of wave/flow= 0 m/s

Unit weight of stone/slab 2.4 t/cum

Slope of the surface 0 H:1V

Uplift 1t

Anchor rods if any

Dia 20 mm

Length 1.5 m

Spacing 3m

Bond strength= 6 kg/sq.cm

diameter of stone related to fallowing formula

1 2
d v
YZ 2

Y=coefficient which varies for different slopes 0.6285

slope Y SELECTED Y

1.0 0.86

1.5 0.98

2.0 1.05 0.6285

3.0 1.11
4.0 1.14

12.0 1.20

Z=is a coefficient which varies for different specific weights of stone used

Ds
Z  8.03 1
62.4

Z= 9.49
1 2
d v
YZ 2
= 0.974 m( =3.197ft)

Weight of rip rap of a stones/slabs= pd Ds/6


3

Therefore weight of the stone=101.09 kg(=222lbs)

Add for countering uplift force 1000 kg/cum

net weight= 1101.09 -kg(=2607lbs)

Weight contributed by anchor rods 5655 kg

No. of anchor rods 0

Net weight including anchor rods= 1101 kg

d=equivalent spherical diameter of slab/stone


Ds=weight of stone /cft of stone

Equivalent size of the cube= 0.77 m

With factor of safety 2 size of the stone= 1.54 m


Size of block with anchor rods= 0.77 m

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