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Culvert Solutions

CSP has dominated the culvert application market since its emergence in the construction industry more than 100 years ago. Culverts, storm drains and sub drains are vital to the protection of streets, highways and railroads. As the need for cost-effective, durable infrastructure has grown over the years, the corrugated pipe industry has responded. Technological advancements provide more hydraulically efficient profiles and highly durable coatings, such as spiral rib pipe, polymer coatings, aluminized Type 2 steel and 4-ounce galvanized. CSP culverts provide reliable, economical solutions to handle the flow, including debris, with minimum damage to the slope or culvert barrel.

Strength of Steel

CSP culverts maintain the advantage of the strength of steel with a variety of coatings providing long service life. With allowable fill heights over 100 feet and minimum covers as low as 12 feet, CSP can be matched to the strength required. Established long-term materials properties ensure product performance throughout the design life.

AISI-1
Height of Cover Limits for Steel Pipe
H20 or H25 Live Load • 2-2/3 x 1/2 Corrugation
Diameter or Span, in. Min.* Cover, in. Maximum cover (ft) for Specified Thickness (in.)
0.064 0.079 0.109 0.138 0.168
12
15
18
21
24
30
36
42
48
54
60
66
72
78
84
90
96
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
248
198
165
141
124
99
83
71
62
(53)
310
148
206
177
155
124
103
88
77
67
(57)

248
217
173
145
124
108
94
80
68
(57)
(48)
(40)
(32)

186
159
139
122
104
88
75
63
52
43
35

195
171
150
128
109
93
79
66
54
45

Notes:
1. Fill heights in parentheses require standard trench installations; all others my be embankment or trench.

2. In 12 in. through 36 in. diameter, heavier gages may be available – check with the manufacturer.

* Minimum covers are measured from top of pipe to bottom of flexible pavement or top of pipe to top of rigid pavement. Minimum covers must be maintained in unpaved traffic areas.

“Real” Manning N-Values

Spiral Rib CSP .012
Double Wall .012
Concrete-Lined CSP .012
Fully Paved cSP .012
2-2⁄3 x 1/2 Helical
12″ .011
15″ .012
18″ .013
24″ .015
30″ .017
36″ .018
42″ .019
48″ .020
54″ and larger .021

Superior Hydraulics

CSP provides “smooth” alternatives and fabricated fittings for superior hydraulics. Spiral rib pipe and fully lined CSP have the lowest Manning n-values of any storm sewer material. Small diameter helical CSP also has very low roughness coefficients as proven through independent testing. Fabricated fittings provide superior hydraulics by minimizing energy losses at junctions.

Durability of Coatings

These factors, along with a variety of coating systems, mean CSP can meet any service life requirement. Galvanized, aluminized and polymer-coated CSP are just a few of the coating options. Expected service life can be determined using the NCSPA Service Life Guidelines.

Cost and Installation Advantages

CSP provides the lowest installed cost compared to other materials. This is due to the low up-front material costs plus the added advantages of reduced installation costs, especially in large diameters. CSP is one-tenth the weight of reinforced concrete pipe (RCP) and comes in lengths of 20 feet or longer. Add this to fewer joints and easy, positive connections and it equals an installation cost advantage.

Solutions Archives: Culverts

Culvert Solutions

CSP has dominated the culvert application market since its emergence in the construction industry more than 100 years ago. Culverts, storm drains and sub drains are vital to the protection of streets, highways and railroads. As the need for cost-effective, durable infrastructure has grown over the years, the corrugated pipe industry has responded. Technological advancements provide more hydraulically efficient profiles and highly durable coatings, such as spiral rib pipe, polymer coatings, aluminized Type 2 steel and 4-ounce galvanized. CSP culverts provide reliable, economical solutions to handle the flow, including debris, with minimum damage to the slope or culvert barrel.

Strength of Steel

CSP culverts maintain the advantage of the strength of steel with a variety of coatings providing long service life. With allowable fill heights over 100 feet and minimum covers as low as 12 feet, CSP can be matched to the strength required. Established long-term materials properties ensure product performance throughout the design life.

AISI-1
Height of Cover Limits for Steel Pipe
H20 or H25 Live Load • 2-2/3 x 1/2 Corrugation
Diameter or Span, in. Min.* Cover, in. Maximum cover (ft) for Specified Thickness (in.)
0.064 0.079 0.109 0.138 0.168
12
15
18
21
24
30
36
42
48
54
60
66
72
78
84
90
96
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
248
198
165
141
124
99
83
71
62
(53)
310
148
206
177
155
124
103
88
77
67
(57)

248
217
173
145
124
108
94
80
68
(57)
(48)
(40)
(32)

186
159
139
122
104
88
75
63
52
43
35

195
171
150
128
109
93
79
66
54
45

Notes:
1. Fill heights in parentheses require standard trench installations; all others my be embankment or trench.

2. In 12 in. through 36 in. diameter, heavier gages may be available – check with the manufacturer.

* Minimum covers are measured from top of pipe to bottom of flexible pavement or top of pipe to top of rigid pavement. Minimum covers must be maintained in unpaved traffic areas.

“Real” Manning N-Values

Spiral Rib CSP .012
Double Wall .012
Concrete-Lined CSP .012
Fully Paved cSP .012
2-2⁄3 x 1/2 Helical
12″ .011
15″ .012
18″ .013
24″ .015
30″ .017
36″ .018
42″ .019
48″ .020
54″ and larger .021

Superior Hydraulics

CSP provides “smooth” alternatives and fabricated fittings for superior hydraulics. Spiral rib pipe and fully lined CSP have the lowest Manning n-values of any storm sewer material. Small diameter helical CSP also has very low roughness coefficients as proven through independent testing. Fabricated fittings provide superior hydraulics by minimizing energy losses at junctions.

Durability of Coatings

These factors, along with a variety of coating systems, mean CSP can meet any service life requirement. Galvanized, aluminized and polymer-coated CSP are just a few of the coating options. Expected service life can be determined using the NCSPA Service Life Guidelines.

Cost and Installation Advantages

CSP provides the lowest installed cost compared to other materials. This is due to the low up-front material costs plus the added advantages of reduced installation costs, especially in large diameters. CSP is one-tenth the weight of reinforced concrete pipe (RCP) and comes in lengths of 20 feet or longer. Add this to fewer joints and easy, positive connections and it equals an installation cost advantage.

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