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The design of Concrete Cylinder Pipe conforms to AWWA Standard C303, Appendix A.
The Average circumferential stress in the steel cylinder and rod reinforcement
of the pipe at design pressure is limited to 50 percent of the
specified minimum yield strength of the steel used in the cylinder.
The total cross-sectional area of the circumferential steel reinforcement (steel
cylinder plus rod reinforcement) is;
As = Ay + Ar
= PdDy
--------
2fs
where:
As = total
cross-sectional area of circumferential steel, mm2/m of pipe wall
Ay = cross-sectional area
of circumferential steel in the cylinder, mm2/m of pipe wall
Ar = cross-sectional area
of circumferential steel in the rod reinforcement, mm2/m of pipe wall
Pd = design pressure, kPa
Dy = inside diameter of
steel cylinder, mm
fs = circumferential stress in the
steel cylinder at design pressure, MPa
The required circumferential steel area for a given diameter and pressure class
of pipe can be provided by several combinations of steel cylinder thicknesses
and rod diameters and spacing. Any combination which satisfies the following
criteria may be selected.
z Minimum steel cylinder
thickness shall be as follows:
| Pipe Diameter Range (mm) |
Minimum Cylinder Thickness (mm) |
| 300-400 |
1.5 |
| 450-500 |
1.6 |
| 600-800 |
1.9 |
| 900 |
2.3 |
| 1000-1200 |
2.7 |
| 1300-1500 |
3.4 |
z Minimum diameter of rod
reinforcement shall be 5.6 mm.
z Minimum area of rod reinforcement shall
be 493 mm2/m of pipe wall or numerically equal to 83.3 percent of the pipe
diameter in mm.
z Maximum center-to-center spacing of rod
reinforcement shall not exceed 50 mm.
z Design clear space between rods shall
not be less than 1.3 diameters of the rod used.
Steel cylinder thicknesses and rod diameters commonly used in the manufacture of
Concrete Cylinder Pipe are:
|
Cylinder Thickness |
| mm |
mm |
mm |
mm |
| 1.5 |
2.7 |
5.0 |
8.0 |
| 1.6 |
3.0 |
5.5 |
8.5 |
| 1.9 |
3.4 |
6.0 |
9.0 |
| 2.0 |
3.5 |
6.5 |
9.5 |
| 2.3 |
4.0 |
7.0 |
10.0 |
| 2.5 |
4.5 |
7.5 |
|
|
Rod Diameter |
|
mm |
mm |
| 5.6 |
12.0 |
| 6.0 |
14.0 |
| 8.0 |
16.0 |
| 10.0 |
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External Loads
CCP is classified as a semi-rigid pipe. A semi-rigid pipe resembles a flexible
pipe in that it will deflect slightly from external loads and obtain some
supporting strength from the lateral pressure of the soil at the sides of the
pipe. However, the cement-mortar lining and coating add to the pipe's strength
to withstand external loads.
CCP installed in a trench with normal bedding and backfilling procedures will
safely withstand external loads of up to 3 m or more of earth cover. Special
bedding and backfilling procedures can be employed to accommodate abnormal or
excessive loads.
Recommended bedding and backfilling procedures are included in Ameron's
Installation Guide Specifications. The method of determining permissible earth
cover loads on Concrete Cylinder Pipe is covered by Ameron's Design Manual 303.
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