the material of this PPt according to the RTU syllabus

1. BRIJLATA SHARMA
Assistant Professor
Department of CivilEngineering
JECRC,J AIPUR

2. Cross DrainageWork
• A cross drainage work is a structure carrying the discharge of a natural
stream across a canal intercepting the stream.

3. • C D work in which canal (Aqueduct) is taken over the river (Fig. a)
• C D work in which stream (natural drain) is taken above the canal
(Fig. b)
Fig. a Cross DrainageWork Fig. b C D Work natural drain above the canal

4. Necessity of C/D Work:
• To carry the discharge of a natural drainage viz, stream, nala or river.
• Canal at a C/D work is generally taken over the drainage or below the
drainage.
• The site condition of the crossing point may be such that without any
suitable structure, it is very difficult to divert the water of canal &
drainage.

5. Selection of suitable Type of C D work:
A) The factor which should govern C/D work are:
• The bed level of irrigation & natural drainage.
• Economy of construction.
• Discharge carried by canal & drain.
B) Important consideration:
• If bed level of canal is above HFL of drain, Aqueduct of medium size.
• If FSL of canal is below the drain bed, super passage should be provided.
• Sufficient headway is not available, by changing alignment of canal,
syphon aqueduct preferred.
C) For the purpose:
• A road bridge can easily provided along with canal
• Cost of construction should be less & not expensive.

6. Classification or Types of C D work:
A) Aqueduct: It is a irrigation structure constructed for passing canal
water over the drainage work.
a) Pipe Aqueduct: In this case water is taken through pipe.

7. b) Box culvert: It is similar to ordinary bridges, difference is that the
road is replaced by canal culvert.
c)Masonry Aqueduct: It is constructed with masonry and width of
drainage is very large & drain water passes through it.
d)Syphon culvert: The bed of drainage is depressed, not preferred
when discharge through drainage is more.
e)Irrigation culvert: These are belongs to class of CD work. These
are located at nallaha, stream, torrent.
f)Syphon Aqueduct: When HFL
of the drainage is above or
touches to CBL, but lower
than FSL.

8. B) Super passage: It is a structure constructed at point of crossing
where drainage water is taken over the canal. In this case stream passes
at higher level than FSL of canal.
a) Pipe super passage: pipe is provided for carrying drainage water
over the canal.
b) Syphon super passage: The bed level canal is depressed, so that
FSL should not touch the roof of water way.

9. C)Level Crossing: It is adopted when the bed level of canal and
drainage is same.
D)Inlet and Outlet: Inlet admits the water of stream into canal.
Capacity of inlet and outlet must be same.
Level Crossing Inlet and Outlet

10. Thank You