Pipe Design, Testing, & Specifications

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1 Pipe Design, Testing, & Specifications Jim Goddard JimGoddard3, LLC. 1

2 Design & Selection What s Important: 1. Hydraulic Capacity 2. Structural Design 3. Durability 4. Installation 5. Quality 2

3 Hydraulic Capacity The anticipated design flows determine the size of pipe or structure required. For culverts or storm sewers, design flows are normally determined from rainfall intensity information available from the USGS, NOAA, or BuRec. For sanitary sewer designs, the number and type/size of connections and length of the collectors. 3

4 Hydraulic Design For most culvert installations, inlet control determines the capacity of the pipe. Manning s n value has no impact. The flow capacity of the pipe seen here is the same regardless of pipe type. 4

5 Hydraulic Capacity Flow capacity of storm sewers, sanitary sewers, and longer, relatively flat culverts is determined by outlet control, and Manning's n determines capacity. Manning's n IS NOT constant for any pipe type, but varies with the velocity and diameter of the pipe. 5

6 Manning's "n" VS. Liner Roughness FPS 10 FPS 15 FPS Linear (3 FPS) Linear (10 FPS) Linear (15 FPS) y = x R 2 = Manning's "n" y = x R 2 = y = 0.008x R 2 = Liner Roughness (inches) 6

7 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 to 0.015! 7

8 Hydraulic Design Available diameters of available pipe types varies: 1. Depending on local capabilities, concrete pipe is 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 from very small diameters (2 ) through 10 or greater depending on pipe type. Available diameters may determine the pipe type or types specified. 8

9 Structural Design AASHTO LRFD Section 12 provides current structural design methodologies for reinforce concrete pipe, corrugated metal pipe, and thermoplastic pipe (both PVC and HDPE). The determination of the loads on these buried pipes comes from LRFD Section 3. Both dead loads and live loads must be considered. 9

10 Live Loads Live Loads 10

11 Cooper E80 Live Loads 11

12 29 Years of Highway Loads 12

13 Dead Loads - Testing 13

14 Pennsylvania Deep Burial Study 23 Years of Data 100 Feet Deep 14

15 Utah DOT Legacy Parkway 15

16 Utah DOT Legacy Parkway 16

17 FEMA P-675 Plastic Pipe in Dams 17

18 Structural Design Every pipe type has different load or structural limits. Site loading conditions; depth of fill, magnitude of live loads; may determine pipe types to be considered. 18

19 Durability Every pipe type has different durability limits. Generally, the environmental conditions effecting pipe durability are: 1. ph 2. Salts 3. Soil chemistry (sulfides, chlorides, etc.) 4. Water chemistry 5. Abrasion 6. Soil resistivity 7. Stray currents 19

20 Supporting Durability Information Information on material selection criteria is available in: AASHTO Highway Drainage Guidelines, Volume 14, Culvert Inspection, Material Selection and Rehabilitation Guideline and/or NCHRP Project 20-5, Topic 25-21, Service Life of Drainage Pipes. 20

21 Quoted Permissible ph Range for Various Pipe Materials CMP RCP 4-10 HDPE ph Levels 21

22 CALTRANS HIGHWAY DESIGN MANUAL Section Year Min. Maintenance-Free Life Pipe Material ph Range Resistivity Range GALV STEEL 6-8 >3000 ALUM. STEEL >1500 ALUMINUM >1500 CONCRETE HDPE No Limits No Limits 22

23 PennDOT I-99 ph<3 23

24 HDPE, PVC and Vitrified Clay unaffected by most chemicals Concrete affected by road salts, low ph, soluble chlorides and sulfates. Deterioration may be accelerated when subjected to freeze/thaw action. Aluminum affected by low and high ph, electrochemical corrosion and abrasion. Corrugated metal pipes affected by low and high ph, electro-chemical corrosion, acids, alkalis and dissolved salts. 24

25 Installation Current AASHTO Construction Standards include installation requirements for the dominant pipe types: Section 27 for corrugated metal pipe; Section 28 for concrete pipe; Section 30 for thermoplastic pipe (PVC & HDPE). 25

26 Installation Post installation inspection of ALL pipe types should be required, with different concerns for 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. 26

27 Installation Time Costs associated with the time to completion of an installation has become more of a factor. Traffic disruption, detours, and inconvenience to the public is not being considered by several DOTs in their bid evaluations. Innovative installation methods can have significant impact. 27

28 Installation Delaware DOT 28

29 Delaware DOT 29

30 AASHTO Pipe Standards In 1972, the only pipe types covered by AASHTO Specifications were reinforced concrete pipe and corrugated steel pipe. Today there are 5 material types, including: Reinforced concrete pipe Corrugated steel pipe Corrugated Aluminum pipe PolyVinyl Chloride pipe High Density Polyethylene pipe 30

31 AASHTO Pipe Standards AASHTO Standard Subcommittee on Materials Subcommittee on Bridges and Structures Design Subcommittee on Bridges and Structures Construction National Transportation Product Evaluation Program Concrete Pipe AASHTO M 86 AASHTO M 170 AASHTO M 175 AASHTO M 176 AASHTO M 206 AASHTO M 207 AASHTO M 242 AASHTO LRFD Bridge Design Specifications Section 12 AASHTO LRFD Bridge Construction Specifications Section 27 Corrugated Metal Pipe AASHTO M 36 AASHTO M 167 AASHTO M 190 AASHTO M 196 AASHTO M 197 AASHTO M 218 AASHTO M 219 AASHTO M 245 AASHTO M 246 AASHTO M 274 AASHTO M 289 AASHTO LRFD Bridge Design Specifications Section 12 AASHTO LRFD Bridge Construction Specifications Section 26 Polyethylene Pipe AASHTO M 252 AASHTO M 294 AASHTO LRFD Bridge Design Specifications Section 12 AASHTO LRFD Bridge Construction Specifications Section 30 None None NTPEP for Thermoplastic Pipe PVC Pipe AASHTO M 278 AASHTO M 304 AASHTO LRFD Bridge Design Specifications Section 12 AASHTO LRFD Bridge Construction Specifications Section 30 Notes: 1. Only one of the four pipe types has in place AASHTO Materials Specifications, AASHTO Design Standards, AASHTO Construction 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 plate standards and coating standards for both steel and aluminum; whereas material standards are within the pipe standards for 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 The AASHTO NTPEP for Thermoplastic Pipe lists over 100 test reports from 11 producing companies (as of 1/2/2010). None

32 Product Quality Independent, 3 rd Party testing should be required for all pipe types. The AASHTO NTPEP might be the best example of such a program. Currently, the HDPE pipe program has been in place for about 8 years. Reinforcing steel is also included in NTPEP. Other pipe types should, and eventually will be included. 32

33 Pipe Type Selection From Wealth of Nations by Adam Smith in 1776: Competition reduces costs and improves quality 33

34 Competition Competition is not only the basis of protection to the consumer, but is the incentive to progress. Herbert Hoover 34

35 Pipe selection There is no one pipe type appropriate for every installation or application. Specifying multiple pipe types, where applicable, reduces costs. 35

36 36

37 Thank You Any Questions? 37

A-2000 PVC Pipe for Storm Sewers and Drainage

ENGINEERED SOLUTIONS A-2000 PVC Pipe for Storm Sewers and Drainage A-2000 Drainage Pipe Drainage systems are required to meet multiple criteria. The choice of a particular material depends upon a number