AASHTO Subcommittee On Design (SCOD) Annual Meeting

July 2008 Michael Fazio, Chair Technical Committee on Hydrology and Hydraulics 1

Objectives

Present TCHH Activities, Especially those Centered on the 2011 AASHTO Drainage Manual and H&H Research. Talk about TCHH Future Opportunities July 2008 2

THIS PRESENTATION

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TCHH – Who we are

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TCHH - Brief History

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TCHH - Charter

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2011 AASHTO Drainage Manual

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Research

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Challenges and Opportunities

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TCHH

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Membership Stats

 Total Number of Members – 23  Longest service period – 17 years  Average service period – 7 years  Number of Hydraulics Engineers - 17 July 2008 5

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Brief History

   1969 AASHO Committee on Design commissioned the Exec. Committee to publish a drainage design manual Ten states from the Committee on Design were selected to complete the assignment, with the representation of the Bureau of Public Road (BPR) State drainage/hydraulics engineers from the selected ten states were delegated to serve in the subcommittee, then re-designated a task force July 2008 8

Brief History

     1970 - The first meeting of the AASHO Subcommittee (later named Task Force) on Hydrology and Hydraulics was held in Dallas, Texas 1973 – AASHO becomes AASHTO Several drainage guides published from 1970 on 1987 – The guides were collected in the “Red” guide (color of the cover), titled “Highway Drainage Guidelines” 1992 – The “Green” guide was published July 2008 9

Brief History

 1991 – The first Model Drainage Manual was published after five years of work – The manual featured double parenthesis to allow states to adapt contents to their needs  2005 – Metric Model Drainage Manual published July 2008 10

1970 Charter and Objectives

To maintain a working group with expertise in hydrology and hydraulics to develop AASHTO guidance and policy on drainage design and related issues July 2008 11

Current Charge Statement

TCHH manages the change and development of national policies and guidelines relating to highway hydraulics… Provides guidance to practitioners in the planning, design, construction and maintenance, and regulatory compliance of all drainage related features of surface transportation facilities. The committee promotes and recommends new research in the field.

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1970 Goals

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Develop and update guidelines and procedures for highway drainage

Make a periodic evaluation of all AASHTO publication and policy related to drainage

Advise the subcommittee on Design regarding proposed drainage related policies Provide liaison with researchers to improve implementation of new ideas and encourage research Maintain and update the model drainage manual Identify training needs and provide guidance on curriculum Identify, coordinate and recommend software Identify technology needs for FHWA Promote Technology Transfer to improve implementation of new ideas

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2005 Model Drainage Manual (MDM) Dual Units

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2005 MDM

 Flexible and Adaptable  Double Parenthesis for Agency’s Name  Includes 20 Chapters  Dual Units  New Glossary  Many new Figures and Graphs July 2008 15

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2005 MDM Problems

 Bulky  Hard to use  Limited sales  Dual units  Redundancy  Some outdated information July 2008 17

MDM Resolution

 Because of poor sales, TCHH revisited the MDM objectives, deciding to publish a new manual that would be more practical, easy to use and updated.

 Results: two-part manual, with part I on Policies and part II on Procedures  Parts of the manual to be sold separately July 2008 18

AASHTO Drainage Manual Revision

Revisions Objectives: 1. Make the Manual Authoritative 2. Expand the usefulness to a broader audience, make the manual more user friendly, reduce the clutter and make it more accessible. July 2008 19

2011 AASHTO Drainage Manual Features

 The Policy Part is rarely revised  The Procedures Part is dynamically updated  Chapters can be bundled and sold separately  Duplication removed  One language throughout the manual  Remove outdated information, practices and methods  New Chapters on Wetlands and Groundwater July 2008 20

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2011 AASHTO Drainage Manual Features

Use of “should”  Single U.S. units  New research to be part of the manual appendices  Other FHWA publication to be part of appendices  No more model manual or two parenthesis July 2008 21

Manual Disclaimer

To manage possible conflicts with existing standards published by other federal or state agencies, the following statement will be placed in the manual:

“This manual has been written to provide recommended minimum desired criteria”

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Plan

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Revision Progress

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Funding

•Funding needed to hire a consultant

to complete changes to the manual

•A pool fund set up to get state

participation and funding

•Solicitation 1186 is being reviewed by

FHWA for approval

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TCHH Sponsored Research

 TCHH prepares and shortlists research problem statements to submit to SCOD and NCHRP  TCHH supports and works closely with FHWA Hydraulics Lab  Currently several TCHH members serve seven NCHRP research projects  Research findings are being implemented as changes to policies and practices July 2008 26

Research

 The NCHRP research project include:  One on hydrology  Four on bridge scour  One on culvert rehabilitation methods and policies  One on stream stabilization using “natural structures” July 2008 27

Research

 Some projects the FHWA Hydraulics Lab (Sterling Jones) is working on are:  Improving stream shear stress calculations  Improving deck profile for submergence flow  Fish passage  Scour measurement instrumentations July 2008 28

Challenges and Opportunities

       NPDES II Decaying drainage infrastructure Plan of Action for Scour Critical Bridges Adding capacity to the highways EPA Permits Flooding risks DOT Organizational Changes July 2008 29

Conclusions

 TCHH is a group of dedicated professionals  TCHH goals: manual/guides, policies, research, training  2011 AASHTO Drainage Manual to be more user friendly and authoritative  TCHH supports national research on hydrology and hydraulics July 2008 30

 “The Task Force provided a forum where members could discuss their problems with others who had similar technical and creditability problems…This process of sharing information and learning through the experience of other members continues to be an important benefit of serving on the Task Force.” Mainard Wacker, P.E., History of the AASHTO Task Force on Hydrology and Hydraulics, October 1993 July 2008 31

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Research

NCHRP 15-36, Estimating Joint Probabilities of Design Coincident Flows at Stream Confluences (estimated completion is Spring 2009) NCHRP 24-15(2), Bridge Scour in Cohesive Materials – (estimated completion is 06/2008).

NCHRP 24-27, Recommendations for the Adoption of Bridge Scour Research by State Highway Agencies –Panel decided to break project in three parts: abutments, piers and geomorphology. NCHRP 24-29, Scour at Bridge Foundations on Rock. (estimated completion: June 2010) NCHRP 24-32, Scour at Wide Piers and Long Skewed Piers.

NCHRP 24-33, Development of Design Methods for In-Stream Control Structures (estimated completion Spring 2011).

NCHRP 14-19, Culvert Rehabilitation to Maximize Service Life While Minimizing Direct Costs and Traffic Destruction (estimated completion Fall 2010) July 2008 34

NCHRP 24-15(2)

 A benefit of the cohesive soils scour would be a  realistic analysis in soils where there is some resistance to scour. see this a means to reduce scour for sites where the frequency and  duration of flows are less and the soil is quite resistant. For long  durations and less resistant soils, there may not be as much benefit.

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NCHRP 15-24 – Culvert Coefficients Update

 Final Stages  Provides information on additional culvert features which were not addressed in the original Bureau of Standards testing in the 1950's. (multiple culverts evaluation)  Some of the results will be incorporated in the updated HY-8. July 2008 36

NCHRP 15-36, Estimating Joint Probabilities of Design Coincident Flows at Stream Confluences

 Currently designer use USACE table for coincident flow  Table may not be very reliable across USA  This project will provide guidance for properly designing a drainage structure near or at a stream confluence July 2008 37

NCHRP 24-32, Scour at Wide and Long Skewed Piers

  The objective of this research is to develop methods and procedures for predicting time-dependent local scour at wide piers and at long skewed piers in non-cohesive soils and steady flow. Improvements to scour estimates could save money by reducing over prediction of scour for large or skewed pier situations.

This project improves scour prediction at wide bridge piers. Current national equations grossly over-predict scour at wide piers, resulting in wasteful bridge substructure designs.

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NCHRP 24-33, Development of Design Methods for In-Stream Flow Control Structures

 Evaluate the potential of in-stream structures for protecting bridges and embankments  Develop design methods for properly placing in-stream structures July 2008 39

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NCHRP 24-27, Evaluation of all Scour Research for Design and Policy Implementation

Significant improvement in scour prediction practice adopted from this research will safely reduce bridge substructure costs.

 Project 14-19, Culvert Rehabilitation to Maximize Service Life: this project will produce a handbook to address pipe repair decisions, including assessing the conditions of existing pipe and factors affecting the choice of repair methodology. The project will also develop a training course and repair specifications. Repair methodologies and issues such as grouts, pipe voids, joint seals, etc. will be addressed. States currently lack guidance in these areas.

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NCHRP, 24-29, Scour of Degradable Rock

 This project will improve scour prediction in rock, allowing significant savings through more reasonable scour predictions.

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NCHRP 14-19, Culvert Rehabilitation to Maximize Service Life

 States currently lack guidance in these areas.

 Produce a handbook to address pipe repair decisions, including assessing the conditions of existing pipe and factors affecting the choice of repair methodology.  Develop a training course and repair specifications. Repair methodologies and issues such as grouts, pipe voids, joint seals, etc. will be addressed. July 2008 42

20-07 Project on Pipe Material Selection (upcoming)

 Examine national research on pipe materials selection, providing preliminary guidance and identifying areas of needed research. Currently, little national guidance is available in this area.

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