PipeEng

Pipe Input Data

Pipe Dimension Standard Iron Pipe Size (IPS) Ductile Iron Pipe Size (DIPS)

Pipe Nominal Size (IPS) 1 1 1/2 2 3 4 6 8 10 12 14 16 18 20 22 24 28 30 32 36 42 48 54 Custom

Dimension Ratio (DR) 9 9.3 11 13.5 17 21 26 32.5

Pipe Nominal Size (DIPS) 3 4 6 8 10 12 14 16 18 20 24 30 Custom

Dimension Ratio (DR) 7 9 11 13.5 17 21 26 32.5

Outer Diameter, OD

inch

Wall Thickness, t

inch

Dimension Ratio (DR)

 

Pipe Material Code PE 2606 PE 2706 PE 2708 PE 3608 PE 3708 PE 4608 PE 3710 PE 4710 Custom

Pipe Code

 

Modulus of Elasticity of Pipe Short Term Long Term

Using the short-term modulus is satisfactory for most applications for PE pressure pipes installed in granular or compacted fills. Other design conditions may use long-term modulus to be conservative.

Modulus of Elasticity of Pipe, E

psi

Load Input Data

Dry Unit Weight of Soil, γ

pcf

Pipe Depth of Cover, C

ft

Pipe Trench Width, B_d

inch

Trench Embedment Soil Type Fine-grained soils with less than 25% sand content Coarse-grained soils with fines (SM, SC) Coarse-grained soils with little or no fines (SP, SW, GP, GW)

Trench Embedment Soil AASHTO Relative Compaction 85% 90% 95% 100%

Native Surrounding Soil Type Very, very, very loose granular / very, very soft cohesive Very very loose granular / very soft cohesive Very loose granular / soft cohesive Loose granular / medium cohesive Slightly compact granular / stiff cohesive Compact granular / very stiff cohesive Dense granular /hard cohesive Very dense granular / very hard cohesive Rock

Wheel Load (Max. Point Load), W_w

lb

Wheel Contact Area, A

ft²

Pipe to Wheel Horizontal Distance, X

ft

Number of Distrubuted Wheel loads on Pipe, n

 

Impact Factor, I_f

 

Design Parameters

Bedding Factor, K

 

Typically, bedding factor is 0.1

Time-lag Factor

 

Typically, the time-lag factor ranges from 1.25 to 1.5. For design purposes, a time-lag factor of 1.5 is generally conservative for flexible pipes including PE pipe.

Output Data

Surcharge Load, P_ES

psi

Surcharge may be other distributed loads to create pressure in the soil beneath the loaded area, such as footings, foundations, or other stationary loads. It is assumed to be 0 unless otherwise specified.

Maximum Allowable Pipe Deflection

%

Deflection limit selected for pressure pipe. For non-pressure applications, deflection limit is 7.5%.