Page 107 - Trenchless Technology Piping Installation and Inspection

Existing Pipeline Renewal and Replacement Methods 73

Pipe Material ‘n’
Liner pipe a 0.009–0.012
Vitrified clay b 0.013–0.017
Concrete 0.013–0.017
Corrugated metal 0.019–0.030
Brick 0.015–0.017

a Selection of the liner pipe ‘n’ is based on the condition of the underlying pipe.
For example: If a low range ‘n’ is selected for the existing pipe, select a low range
liner pipe ‘n’.
b The values shown are for pipes in fair to poor condition from “Applied Hydrau-
lics for Technology” by J.D. Kanen.
TABLE 2.13 Manning Coefficient, ‘n’, for Typical Pipeline Materials

Existing Pipe Insitupipe Dimension Ration (D/t)
Roughness Coefficient, ‘n’
30 40 50 60
0.014 117% 122% 126% 128%
0.015 125% 131% 135% 137%

0.016 133% 140% 144% 146%
0.017 141% 148% 153% 155%

a Assumes liner pipe ‘n’ = 0.010
Existing pipe flow = 100 %
TABLE 2.14 Gravity Pipe Flow Comparison Percent Existing Full Flow
Capacity after Liner Installation a

Fully Deteriorated Pipe DR
Parameters: Groundwater 50 percent of soil cover
120 lb/ft —soil density
3
1000 psi soil modulus
50 percent flexural modulus reduction
H20 traffic loading