09-OFFTAKE SLUICES



OFF-TAKE SLUICES

I.SITE SURVEY:

a.Site survey to be furnished as per check slip Check slip enclosed a Report accompanying the site survey 

b Site plan along with flow direction of canal, location & alignment of O.T.

c Bore hole data / T.P.s upto hard strata or for  a min depth of 2 m.

2.DESIGN: 

Note on Principles of Design the assumptions made &a the general features of the structure

HYDRAULIC DESIGN :

a) HPs of parent canal and Distributory: Ayacut,Discharge and Heighest Field Level to be irrigated  be furnished.

b )Discharge: Method of calculation of Discharge By modified penman method

c) Distributory section:of Fixation of distributory section adopting b/d ratio and satisfying critical velocity ratio(Technical Report no.7 C.B.I.P, C.W.C Recomendations,  & IS:7112-1973.)

d) Sill level of OT Sluice: i ) Sill level  be fixed based on 3/4 F.S.L.condition at head reach manual and half F.S.L condition at the tail reach where the Q of parent by , canal is less than 20 % with a min. driving head of 0.15 m above heighest field level. Tii ) Sill level shall be invariably 300 mm above the Parent canal Bed Level. (Text book of IrrigationW.M. Ellis Civil Engg Hand Book by Association of Engineers )

e) Ventway of sluice: i) Ventway calculations using orifice formula and vent may be proposed by Pipe / R.C.C.Box Q = Cd A 2gh ii)The minimum size of pipe / box shall be 300 mm dia / 1200 mm ( to be restricted with suitable diaphram ) 

f )Scour depth calculations:( IS:7784(Part I):1993)

h Proposal sketch indicating the ventway proposed and other components:

g U/S and D/S Transitions. (IS:7784(Part2 / Sec I))

STRUCTURAL DESIGN:

a Design of Head walls,wings and returns (u/s and d/s)  adopting TVA / Coulomb's / Rankine's Theory with  minimum top width of 500 mm(TVA Handbook )

b Protection works on D/S. , c Miscellaneous Details:(Text book of Irrigation manual by W.M. Ellis)

1 ) PIPE  :- 

i Calculation of required class of Hume pipe. (IS:783-1985)

ii Pipe, collar and related dimensions. (IS:458-1988)

2 ) RCC BOX  :

RCC box under Earth bank and Head wall. (IS:7784 part I - 1993)

MECHANICAL PARTS :

i Shutters / Gates, embedded metal parts etc  ii Hoist / working platform arrangements Separate (Guidelines issued by C.D.O. IV)

DRAWINGS :

a General Layout on net level plan duly showing contours.

b General Plan, Sectional elevation and End View (Scale 1:200 or 1:100)

c Sections and RCC details. (i) Scale 1:50 or 1:100  for sections ii) Scale 1:25 or 1:20 or 1:10 for RCC details d)

Bar bending schedule, stress table etc. 

The Drawings shall contain assumptions made, TPs,Specifications, HPs of parent canal& distributory,

*****