pipe design, testing, & specifications

8/9/2019 Pipe Design, Testing, & Specifications

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Pipe Design, Testing,

&Specifications

Jim GoddardJimGoddard3, LLC.

[email protected]


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Design & SelectionWhats Important:1. Hydraulic Capacity2. Structural Design

3. Durability4. Installation

5. Quality


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Hydraulic CapacityThe anticipated design flows determine the

size of pipe or structure required. Forculverts or storm sewers, design flows arenormally determined from rainfall intensity

information available from the USGS,NOAA, or BuRec.For sanitary sewer designs, the numberand type/size of connections and length ofthe collectors.


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Hydraulic DesignFor most culvert

installations, inletcontrol determinesthe capacity of the

pipe. Mannings nvalue has no impact.

The flow capacity of the

pipe seen here is thesame regardless ofpipe type.


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Hydraulic CapacityFlow capacity of storm sewers, sanitary

sewers, and longer, relatively flat culvertsis determined by outlet control, andManning's n determines capacity.

Manning's n IS NOT constant for any pipetype, but varies with the velocity and

diameter of the pipe.


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Manning 's "n" VS. Liner Roughness

y = 0.0145x + 0.01R2 = 0.7016

y = 0.0108x + 0.0087R2 = 0.7796

y = 0.008x + 0.0088R2 = 0.8766

0.008

0.009

0.01

0.011

0.012

0.013

0.014

0.015

0 0.05 0.1 0.15 0.2 0.25 0.3

Liner Roughnes s (inches)

M a n n

i n g

' s " n

"

3 FPS

10 FPS

15 FPS

Linear (3 FPS)

Linear (10 FPS)

Linear (15 FPS)


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Hydraulic Design All pipe industry tests are done in the lab

with near perfect alignment, tight joints,clean water, and new, clean pipe.

In the real world, none of this is true.Have you ever seen a 2 year old pipe that

did not have some debris or build-up in it?Thus, for smooth interior pipe the design

n should be a minimum of 0.013 to0.015!


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Hydraulic Design Available diameters of available pipe types varies:

1. Depending on local capabilities, concrete pipeis available up to 10 diameter or more.

2. Corrugated steel pipe is generally available

from 6 up to small bridges (40 or more)3. Thermoplastic pipe is generally available fromvery small diameters (2) through 10 orgreater depending on pipe type.

Available diameters may determine the pipe typeor types specified.


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Structural Design AASHTO LRFD Section 12 provides current

structural design methodologies forreinforce concrete pipe, corrugated metalpipe, and thermoplastic pipe (both PVC

and HDPE). The determination of theloads on these buried pipes comes fromLRFD Section 3.

Both dead loads and live loads must beconsidered.


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Live LoadsLive Loads


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Cooper E80 Live Loads


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29 Years of Highway Loads


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Dead Loads - Testing


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Pennsylvania Deep Burial Study 23 Years of Data 100 Feet Deep


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Utah DOT Legacy Parkway


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Utah DOT Legacy Parkway


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FEMA P-675 Plastic Pipe in Dams


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Structural DesignEvery pipe type has different load

or structural limits.Site loading conditions; depth of fill,

magnitude of live loads; maydetermine pipe types to beconsidered.


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DurabilityEvery pipe type has different durability limits.

Generally, the environmental conditionseffecting pipe durability are:

1. pH2. Salts3. Soil chemistry (sulfides, chlorides, etc.)4. Water chemistry5. Abrasion

6. Soil resistivity7. Stray currents


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Supporting Durability InformationInformation on material selection criteria is

available in:AASHTO Highway Drainage Guidelines,

Volume 14, Culvert Inspection, MaterialSelection and Rehabilitation Guideline

and/or

NCHRP Project 20-5, Topic 25-21, ServiceLife of Drainage Pipes.


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Quoted Permissible pH Range for Various Pipe Materials

pH Levels 2 4 6 8 10 12 14

CMP 6 - 9.5

RCP 4 - 10

HDPE 1.5 - 14


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CALTRANSHIGHWAY DESIGN MANUALSection 850

50 Year Min. Maintenance-Free Life

GALV STEEL 6-8 >3000 ALUM. STEEL 5.5-8 >1500

ALUMINUM 5.5-8.5 >1500CONCRETE 5.5-9 -HDPE No Limits No Limits

Pipe Material pH Range Resistivity Range


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PennDOT I-99 pH


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HDPE, PVC and Vitrified Clayunaffected by most chemicals

Concrete affected by road salts, low pH, solublechlorides and sulfates. Deterioration may beaccelerated when subjected to freeze/thaw action.

Aluminum affected by low and high pH, electro-chemical corrosion and abrasion. Corrugated metal pipes affected by low and high

pH, electro-chemical corrosion, acids, alkalis anddissolved salts.


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InstallationCurrent AASHTO Construction Standards

include installation requirements for thedominant pipe types:

Section 27 for corrugated metal pipe;Section 28 for concrete pipe;Section 30 for thermoplastic pipe (PVC &

HDPE).


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InstallationPost installation inspection of ALL pipe types

should be required, with different concernsfor different pipe types:

Rigid pipe should be inspected for cracking, joint tightness and integrity, alignment;

Flexible pipe should be inspected for

deflection, joint tightness and integrity,alignment.


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Installation TimeCosts associated with the time to completion

of an installation has become more of afactor. Traffic disruption, detours, andinconvenience to the public is not beingconsidered by several DOTs in their bidevaluations.

Innovative installation methods can havesignificant impact.


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Installation Delaware DOT


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AASHTO Pipe StandardsIn 1972, the only pipe types covered by AASHTO

Specifications were reinforced concrete pipe andcorrugated steel pipe. Today there are 5material types, including:

Reinforced concrete pipeCorrugated steel pipe

Corrugated Aluminum pipe

PolyVinyl Chloride pipeHigh Density Polyethylene pipe


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AASHTO Pipe Standards

AASHTO StandardConcrete Pipe Corrugated Metal

PipePolyethylene Pipe PVC Pipe

Subcommittee onMaterials AASHTO M 86AASHTO M 170AASHTO M 175AASHTO M 176AASHTO M 206AASHTO M 207AASHTO M 242

AASHTO M 36AASHTO M 167AASHTO M 190AASHTO M 196AASHTO M 197AASHTO M 218AASHTO M 219AASHTO M 245AASHTO M 246AASHTO M 274AASHTO M 289

AASHTO M 252AASHTO M 294 AASHTO M 278AASHTO M 304

Subcommittee onBridges and Structures

Design

AASHTO LRFDBridge Design

Specifications Section12







Subcommittee onBridges and Structures

Construction

AASHTO LRFDBridge Construction

SpecificationsSection 27







National TransportationProduct Evaluation

Program

None None NTPEP forThermoplastic Pipe

None

Notes: 1. Only one of the four pipe types has in place AASHTO Materials Specifications, AASHTO Design Standards, AASHTOConstruction and Inspection Standards, and an AASHTO NTPEP for quality assurance; HDPE pipe.

1.The corrugated metal pipe AASHTO Materials Specifications include both fabricated pipe and metal sheet or platestandards and coating standards for both steel and aluminum; whereas material standards are within the pipe standardsfor concrete pipe, HDPE pipe, and PVC pipe.

1.Design standards for all four listed pipe types are contained in the AASHTO LRFD Bridge Design Specifications,

Section 12.4. The AASHTO NTPEP for Thermoplastic Pipe lists over 100 test reports from 11 producing companies (as of 1/2/2010).


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Product QualityIndependent, 3 rd Party testing should be

required for all pipe types.The AASHTO NTPEP might be the best

example of such a program. Currently, theHDPE pipe program has been in place forabout 8 years. Reinforcing steel is also

included in NTPEP. Other pipe typesshould, and eventually will be included.


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CompetitionCompetition is not only the

basis of protection to theconsumer, but is the incentive

to progress.Herbert Hoover


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Pipe selectionThere is no one pipe type appropriate for

every installation or application.

Specifying multiple pipe types, whereapplicable, reduces costs.


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Thank You Any Questions?

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