Aashto Culvert and Storm Drain System Inspection Guide

AASHTO CULVERT AND STORM DRAIN SYSTEM INSPECTION GUIDE

Jesse L. Beaver, P.E. Principal, Simpson Gumpertz & Heger Inc. 28 August 2018

• Introduction: speaker bio and company profile • Background • AASHTO Culvert and Storm Drain System Inspection Guide • Section 1 – Introduction • Section 2 – Design and performance characteristics • Section 3 – Inspection procedure • Section 4 – Condition rating system • Section 5 – Asset management • Appendices

• Principal, Engineering Mechanics & Infrastructure Division, Simpson Gumpertz & Heger Inc., Waltham, MA • Buried pipe experience: • Principal Investigator, NCHRP 14-26, Culvert & Storm Drain System Inspection Manual • Buried pipe design and investigation; development of pipe structural design methods, materials/products testing; municipal standards development; construction support • Related activities: • Chair, Transportation Research Board (TRB) AFF70 Culverts & Hydraulic Structures • Chair, ASTM F17.65 Plastic Pipes, Land Drainage; Member: ASTM A05 Metal Pipe and F17 Plastic Pipe • Instructor, Design of Buried Pipes, American Society of Civil Engineers (ASCE) Continuing Education • Registered Professional Engineer: Approximately 20 US States and 4 Canadian Provinces • Education: • MSCE, Structural Engineering, Massachusetts Institute of Technology, Cambridge, MA • BSCE, Civil and Environmental Engineering, University of Washington, Seattle, WA • AA, University of Maryland, Augsburg, Germany

• Simpson Gumpertz & Heger Inc. (SGH) • http://www.sgh.com/ • Founded by three MIT professors in 1956 • Dr. Howard Simpson, Mr. Werner Gumpertz, Dr. Frank Heger • 600+ staff, 9 office locations in 6 states • CA, DC, IL, MA, NY, TX

• Project Completed: March 2016 • Objective: Develop an inspection manual for assessing the condition of in-service culvert and storm drain systems to ensure system safety and performance and the economical use of owner resources • Oversight Panel: DOT, FHWA, Manufacturers, Industry, Engineers, Academia • SGH Team: Jesse Beaver (PI), Matthew Richie (PM), Robert Keene • Final Deliverable: Culvert and Storm Drain System Inspection Manual • Replacement for 1986 FHWA Culvert Inspection Manual • Adopted by AASHTO in June 2018 as a Guide • Publication expected early 2019 • http://apps.trb.org/cmsfeed/TRBNetProjectDisplay.asp?ProjectID=3172

• Culverts • Buried structures • Designed to allow passage of water under roadways, railways, or embankments • Can be structurally similar to bridges, with total span less than 20 ft • Storm Drains • Typically low-head or gravity flow • Closed-end conduits with inlet and outlet structures and in-line junction boxes • Convey stormwater from impervious surfaces to collection and discharge points • Highway bridges • “Culverts” with spans ≥ 20 ft, including multi-barrel with spacing less than D/2 • Federally mandated inspection every 2 yrs; state-specific policies vary with some treating 10ft span and up as bridges • Culverts outnumber bridges significantly, with numbers approaching 10 to 1 • No federally mandated (or funded) inspection cycle • Many are not contained in any formal database and go uninspected for years until failure

• Materials: • Precast Reinforced Concrete Pipe (RCP) • Cast-in-place (CIP) Concrete • Corrugated/Structural Plate Steel • Corrugated Aluminum • Stone Masonry • What about plastic?

• Some jurisdictions have developed specifications and hired consultants for culvert inspections - Colorado • Many jurisdictions have developed their own manuals (or used bridge inspection manuals to inspect culverts) - Minnesota, Federal Lands Highways, New York State, Connecticut, New Jersey, Ohio • Some states have developed training and/or certification courses for their culvert inspection programs - Ohio, Minnesota, California

• Inventory Management Systems • Catalog and track infrastructure assets • Identify the infrastructure asset value • Effective systems include: inventory, inspection, management/documentation, planning, budgeting, decision- making

Data from January 2007 questionnaire sent to state bridge engineers.

• Section 1 – Introduction • Section 2 – Design and Performance Characteristics • Appendix A – Structural Shapes, Materials, and System Components • Section 3 – Inspection Procedure • Section 4 – Condition Rating System • Appendix B – Catalog of Distressed Conditions • Section 5 – Asset Management Roadway collapse due to piping along culvert and loss of backfill

Overview: • Introduces culvert and storm drain system inspection • Outlines need for standardized inspection program • Provides the objectives of the guide • Identifies the intended audience • Instructs users on the guide organization and Roadway collapse due to structural failure of culvert use for inspections

Objectives of the Guide: • Quantitative and consistent condition rating criteria based on engineering principles and existing best practices • Enable culvert and storm drain inspectors to: • Identify structural distress for culvert or storm drain system components • Rate the condition of the system components • Document findings of an inspection • Recommend basic corrective actions or notifications where appropriate • Present methods for owners to justify repair funding requests and to prioritize rehabilitation programs • Update the 1986 manual with contemporary information

Goals of the Guide: • Evaluate structural integrity, hydraulic performance, and roadside compatibility • Identify minor issues that can be addressed through maintenance before they become safety hazards • Mitigate repair costs • Reduce risk of unexpected failure • Provide input to prioritize rehabilitation and maintenance • Allow for short- and long-term planning and budgeting for repairs and rehabilitation • Provide a method to meet state and federal requirements to quantify the value of highway infrastructure assets • Provide input to load rating procedures

Target audience: • Highway departments • State highway agencies (DOTs) • County Highway Divisions • Local agencies • Personnel • Culvert and storm drain system inspectors and bridge inspectors • Consultants to highway agencies responsible for culvert and storm drain system inspection • Personnel responsible for performing scheduled maintenance on culvert and storm drain systems

Overview: • Introduces factors that affect structural and functional performance • Describes design characteristics • Provides structure shapes, materials, and coatings • Describes culvert and storm drain components

Contents: • Design Characteristics • Hydraulic Requirements • Structural Behavior – Flexible vs. Rigid • Loads on Culverts and Storm Drains • Construction and Installation Requirements • Performance Characteristics • Durability • Culvert and Storm Drain Shapes and System Components • Refer to Appendix A for additional details

Design Characteristics: Hydraulic Requirements • Design is based on size, shape, alignment, end treatments, elevations • Storm drain system considerations - detention, retention, infiltration • Consider debris control, sedimentation, inlet/outlet protection

Example drainage area Factors affecting hydraulic capacity Outlet protection (estimate runoff) (hydraulic design) 21 28 August 2018 © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz & Heger Inc. Section 2 – Design and Performance Characteristics

Design Characteristics: Structural Behavior • Behavior of flexible culvert barrels • Deflect to carry load, typically 3% - 8%, depending on material/type, load, and installation details; surrounding embedment soil supports pipe

Deflection of flexible culverts Schematic load in flexible culverts

Design Characteristics: Structural Behavior • Behavior of rigid culvert barrels • No significant deflection, load is carried by wall compression and resistance to bending

Zones of tension and compression in rigid pipes developed to resist vertical load Three edge bearing test (TEB)

Design Characteristics: Loads on Culverts & Storm Drains • Live Load - AASHTO HL-93, Design Truck (HS-20), Tandem, Lane Load

DESIGN TRUCK AXLES

DESIGN TRUCK AND LANE LOAD

DESIGN TANDEM AND LANE LOAD Live load distribution through fill AASHTO HL-93 live load (pipe orientation may vary for storm drains) 24 28 August 2018 © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz & Heger Inc. Section 2 – Design and Performance Characteristics

Design Characteristics: Loads on Culverts & Storm Drains • Live Load – AREMA Cooper E-80

AREMA Cooper E80 Railway Loading Corrugated metal culvert below RR

Design Characteristics: Construction and Installation Requirements • Embankment has final grade above native grade

Embankment installation for buried culvert or storm drain

Design Characteristics: Construction and Installation Requirements • Trench installation is excavated below native grade

Design Characteristics: Construction and Installation Requirements • Compaction and Side Support • Trench Width • Foundations and Bedding • Minimum Depth of Fill • Camber • High Groundwater (flotation)

Camber in pipe to allow for settlement under high fill

Performance Characteristics: Durability • Corrosion of Metals • Corrosion mechanisms, aggressive soils • Degradation of Concrete • Acid attack • Alkali-Aggregate Reaction • Sulfate attack • Hydrogen Sulfide Attack Severe corrosion of • Freeze-Thaw corrugated steel pipe (CSP) • Impact Damage • Corrosion of Reinforcing • Degradation of Plastics • Oxidation Degradation • Environmental Stress Cracking • Photo-Induced (UV) Degradation • Thermal Degradation • Chlorine-Induced Degradation • Abrasion Corrosion of reinforcing steel in Degradation and cracking reinforced concrete pipe (CSP) of plastic pipe (HDPE) 29 28 August 2018 © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz & Heger Inc. AASHTO Culvert and Storm Drain System Inspection Guide Appendix A – Structural Shapes, Materials, and System Components

Contents: • Shapes • Materials • Culvert Systems and Components • Storm Drain Systems and Components • Pipe Coatings and Linings

• Shapes • Circular • Pipe Arch • Box Culvert • Arch • Three-Sided • Multi-Barrel/Multicell

• Shapes

Circular Pipe Arch Box

Arch Three-Sided Multi-Cell / Multi-Barrel

• Materials (common) • Corrugated Steel and Aluminum • Factory-Made Pipe Metal pipe corrugation nomenclature • Structural Plate Steel • Corrugated Box Culvert • Long-Span Corrugated Structures • Plastic • Thermoplastic vs. Thermoset Resins • HDPE, PVC, PP • FRP • SRPE • Concrete • Precast Shapes • Cast-In-Place • Fiber Reinforced Concrete Pipe Long-span corrugated steel structure

• Other Materials • Solid Wall Steel Casing • Cast and Ductile Iron • Masonry • Timber

Stone masonry barrel Timber barrel

• Culvert Systems and Components • Approach Roadway and Embankment • End Treatments • Headwall, Spandrel, Wingwall • Energy Dissipators Reinforced concrete • Foundations spread footing

Headwall (arrow 1) and wingwall Reinforced concrete (arrow 2) on concrete box mat foundation 36 28 August 2018 © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz & Heger Inc. Appendix A – Culvert and Storm Drain Shapes and System Components

• Culvert Systems and Components • Aquatic Organism Passage (AOP) • Stream Fragmentation • Barriers to passage • Excessive velocity • Outlet configuration • Insufficient depth • Turbulence • Excessive length/daylighting • Sedimentation and structural damage • Characteristics for Design for AOP • Brief discussion on AOP for Inventory Management

• Storm Drain System Components • Stormwater Collection • Channels and Ditches • Curbs and Gutter • Inlets and Inlet Structures • Stormwater Conveyance • Storm drains • Manholes and Access • Junction boxes/Chambers Storm drain system components • Inverted Siphons • Pumps stations • Best Management Practices

• Pipe Coatings and Linings – Tables and Text • Nonstructural Pipe Coatings and Linings • Cement Mortar, Bituminous, Epoxy, Galvanized, Polymer, Invert Paving, Internal Joint Bands • Structural Pipe Linings • Sliplining, Multi-Plate or Structural Plate, Fold-and-Form PVC, Cured-in-Place Pipe (CIPP), Spray-Applied, Spiral Wound, Swagelining and Rolldown, Pipe Bursting and Splitting

Contents: • General • Purpose and Scope of Inspections • Inspection Frequency • Preparation and Planning • Types of Inspections • Types of Entry • Inspection Team Role and Qualifications • Inspection Equipment (separate slides after overview) • Recording the Inspection • Safety • Inspection Quality Control and Quality Assurance

Purpose: • Assess the condition of the entire culvert or storm drain system • Structural issues • Materials issues • Service performance • Make accurate ratings that are repeatable by other inspectors • Collect data to be included in an agency’s asset management system • Used for maintenance, repair, rehabilitation decisions/budgets, and load rating • Collect data that assess roadway safety for the traveling public

• Scope of Inspections: • All culverts and storm drains in an agency’s inventory • All systems should be inventoried upon installation, when creating an asset management system, during maintenance, or during minor roadway work • Many culverts may not require routine inspection such as small diameter pipes or low traffic areas • Each agency should define its inspection program in terms of: • Inspection frequency • Characteristics of culverts to be inventoried and inspected (importance) • The information to be collected

Inspection Frequency: • Defined by agency, each state should weigh their risks in developing a state-specific inspection frequency. • Culverts with spans > 20 ft are bridges are inspected every 2 yrs under NBIS • New installations should be inspected within 30 days of completion • Example frequency by barrel span:

Barrel Size (S) Inspection Frequency S < 4 ft Inspect during roadway maintenance. Every 10 years or prior to routine roadway maintenance 4 ft ≤ S ≤ 10 ft activities, whichever is less. Every 5 years or prior to routine roadway maintenance activities, S > 10 ft whichever is less.

Preparation and Planning: • Organize and schedule inspections while considering: • Inspection type and frequency for each structure • Review of prior condition and reports • Selection of proper equipment and inspection forms • Evaluation of site access, safety, and availability of emergency response • Seasonal conditions • Other planned maintenance (routine cleaning, roadway work, etc.) • Environmental conditions, permits, notification of land owners • Ensure inspections are completed during planning for any roadway maintenance or construction activities

Preparation and Planning: • Review of Inventory and Data from Previous Inspections • Review inspection reports, plans • Review AOP or other site-specific special designs • Consider job hazards and mitigation of hazards in selection of personal protective equipment (PPE), inspection methodology, access, and coordination with other entities • Check the weather and topography • Consult aerial photos/ street views for steep terrain, thick vegetation, etc.

Preparation and Planning: • Develop an Inspection Sequence • General observations of the approach roadway and structure • Select one end and inspect embankment, waterway (e.g., channel alignment, high water marks), end treatments, culvert barrel • Then move to the other end • Use a Checklist or Developed Procedure • Defines the minimum steps for the inspection • Reduces error, improves quality • Provides a record of what can (and cannot) be inspected

Types of Inspections: • Initial (Inventory) Inspection • Detailed first inspection establishes agency inventory record • Baseline for future comparison • Provide data required for agency asset management decisions • Routine Inspection • On defined frequency, visual and non-destructive measurements to assess condition and assign ratings • Note changes to inventory baseline • Track how components are functioning and aging • Special Inspection • Triggered by critical or failed rating in a routine inspection • Research to monitor new materials, special detailing, etc.

• Damage Inspection Special Inspection triggered by flooding event, • Emergency inspection - flooding, fires, roadway sinkholes, traffic accidents severe damage to roadway and embankment • Determine if emergency restrictions/critical repairs are required 48 28 August 2018 © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz & Heger Inc. Section 3 – Inspection Procedures

Types of Entry: • Person-Entry Internal Inspection (preferred) • Component ratings require close-up inspection • Follow OSHA and local confined space entry procedures • Non-Entry Internal Inspection • Visually examine structure from both ends (less thorough) Person-entry inspection • Identifies significant problems in barrel, etc. • Outlet observations may be representative of worst-case abrasion, etc. • Remote-Entry Internal Inspection • When internal inspection is necessary but person-entry is not practical - small diameter, deep sedimentation, deep water, closed-end conduits • Preferred to have video plus other specialized measurement equipment Non-entry inspection 49 28 August 2018 © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz & Heger Inc. Section 3 – Inspection Procedures

Inspector Role and Training: • Role of Inspector • Inspectors perform the routine inspections, including assignment of component condition ratings using the tables in Section 4 • Training by the guide and on-the-job experience • Basic familiarity and understanding of culvert and storm drain system function, including hydraulic performance, structural behavior • Understanding of failure modes, critical inspection points, and the condition rating system described in this guide • Ability to read and interpret plans, construction documents, and inspection reports • Working knowledge of inspection tools, their use, application, and limitations • Appropriately trained to agency safety requirements for site access and culvert entry • Physical Ability • Be prepared to work in demanding conditions including cramped spaces, rugged terrain, steep embankments, in and around water • Able to carry tools and equipment 50 28 August 2018 © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz & Heger Inc. Section 3 – Inspection Procedures

Recording the Inspection: • Inventory Record • Design and installation records • Assigned structure identification number • Location, type, span, etc. • Road and stream/feature crossed by the structure • If no inventory data is available on existing culverts, establish guidelines to prioritize collection methods for maintenance, paving, and construction staff

Recording the Inspection: • Inspection Record • Standardization is important • Agencies should have standard forms to suit their asset management needs • Forms should include space for: • Relevant data from previous inspections (identify components that may need particular attention) • Fields for different features • Sketches and narrative description • Photo references • Condition ratings/comments

Safety: • Safety of the inspection team and the public is important when planning and conducting inspections • Establish appropriate safety practices which comply with all federal, state, local municipality, and agency regulations • Topics include: • Confined space entry (permit and non-permit) • Traffic hazards • Drowning hazards • Rugged terrain • Animals and insects • Poisonous plants • Equipment safety Hazardous conditions in embankment above culvert • Other hazards (fire, floods, chemical spills, etc.)

Inspection Tools and Equipment: • Tools and Equipment for Access • Tools for Cleaning • Tools for Inspection and Measurement • Tools for Visual Aid • Tools for Documentation of Condition • Miscellaneous Tools and Equipment

Tools and Equipment: Access • Inspection Vehicle • GPS • Locate outlet end • Devices with geotagging capabilities also useful (e.g., smartphone) • Ladders or lifts • Initial access • Access crown or other high areas such as headwalls, shoulders • Harness and tripod if access through vertical manhole Tools and equipment for access • Ropes and carabiners to lower tools • Rubber boots, waders, small boat • Probe to check for voids beneath water surface • Manhole lid hook 55 28 August 2018 © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz & Heger Inc. Section 3 – Inspection Procedures

Tools and Equipment: Cleaning • Whisk broom/rags to remove debris • Wire brush to remove loose paint and corrosion • Scrapers (5-in-1 tool) to remove corrosion/growth from surfaces • Flathead screwdriver for general cleaning of surfaces and probing • Shovel to remove soil and debris • Machete or other cutting tool to clear overgrowth Tools for cleaning

56 28 August 2018 © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz & Heger Inc. Section 3 – Inspection Procedures Tools and Equipment: Inspection and Measurement • Chipping hammer/pry bar • Loosen dirt and rust scale • Sound concrete • Check for sheared/loose fasteners • Probe (screw driver/other) • Check for scour holes, voids behind joints, etc. • Pocket or utility knife • Ice pick • Timber surface examination Tools for inspection and measurement • Concrete deterioration depth • Steel corrosion extent • Timber boring tools • Plumb bob • Measure vertical alignment or barrel lateral racking

Tools and Equipment: Inspection and Measurement • 25 and 100 ft tape measures, measuring wheel • Calipers, micrometer, crack width comparator, pit depth gage • Paint film gage • Carpenter’s level with digital inclinometer • Electronic distance meter • Line level and stringline • Utility knife for marking/ scoring Crack width comparator

Tools and Equipment: Visual Aid • Binoculars • Preview areas prior to inspection • Observe members/features at a distance • High powered flashlight and head lamp • Lighted magnifying glass • Close examination of cracks • Inspection mirrors • Observe inaccessible areas Tools for visual aid • Reflect sunlight into dark areas for non-entry inspection (e.g., from ends of culverts into barrel)

Tools and Equipment: Documentation of Condition • Inspection forms, clipboard, tablet computer • Digital camera with optical zoom, flash, macro capability • Field books with waterproof paper • Straight edge • Sketching • Depth measurements from surface • Chalk, lumber crayon (keel), paint sticks/markers, Sharpie • Center punch • Reference marks to metal members for repeatable Tools for documentation of condition measurements

Inspection Tools and Equipment: Miscellaneous • Hard hat, glasses, dust masks, respirators, proper footwear, coveralls, gloves (PPE) • Traffic safety equipment • First aid kit, insect repellant, wasp/hornet spray • pH test meter or kit • Soil resistivity meter • Surveying equipment (not typically necessary) Personal protective equipment

Nondestructive inspection (NDI): • Evaluate conditions or characterize a material without damage, typically using electronic devices • Nondestructive testing (NDT) and nondestructive evaluation (NDE), often used interchangeably • Usually not necessary for routine inspections • Advanced distress or special features may require a closer look • Conduct limited physical measurements to validate NDI methods, then, if validated, proceed with NDI for remainder of measurements • For example, measure diameter with tape measure to establish comparison data point, then continue with laser profilometer

Nondestructive inspection equipment: • Laser Profilometer • Scans interior surface of the barrel • Can include projection and image capture by camera (trailing behind laser) • Can include direct measurement by laser (e.g., rotating head to develop point cloud) • Results can be used to measure and see barrel alignment, joint alignment, barrel deflection, local curvature, and surface distress (sometimes crack dimensions)

Nondestructive inspection equipment: • Ultrasonic Thickness (UT) Gage • Measure thickness of solid metal and plastic materials • Can be used to measure localized section loss due to corrosion in steel pipe and delamination depth in FRP pipe • Works by measuring the time it takes for a sound pulse to travel through a test piece of known material • Sound waves are reflected from the material boundary, timing of the echo from the far side is used to determine thickness • Requires material calibration (e.g., block of similar material at known thickness or at cut edge and measured with calipers) • Allows for thickness measurement with single-side access after calibration

Nondestructive inspection equipment: • Borescope/Videoscope • Small video camera attached to a flexible tube • < 0.5 in. diameter • Up to ~50 ft long • Integral light • Handheld display with controls to articulate camera (on some models) • Allows for inspection of inaccessible areas • Behind a pipe wall into a void • Inside smaller diameter pipes • Inside a joint, etc. • Requires an access point/hole

65 28 August 2018 © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz & Heger Inc. Section 3 – Inspection Procedures Nondestructive inspection equipment: • Ground Penetrating Radar (GPR) • Short pulse of high frequency electromagnetic waves into a material • Records the amplitude and phase shift of the reflected response • Reflections are produced when the pulse passes between materials of different dielectric constants • Large changes in dielectric constants are easiest to locate (e.g., steel and concrete; air and concrete) • Can be used to determine thickness, reinforcement location, voids, condition, buried structure location • Sensitive to moisture • Different moisture conditions may require recalibration even at same location • Experience is necessary

Nondestructive inspection equipment: • Cover Meter • Used on concrete structures to determine rebar location, bar size, thickness of concrete cover • Creates electromagnetic fields with coils, detects changes in coil current when metal objects are near • Good accuracy and lower cost when compared to GPR • Underlying layers are hidden, works with ferrous metals only

67 28 August 2018 © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz & Heger Inc. Section 3 – Inspection Procedures Nondestructive inspection equipment: • Infrared (Thermographic) Imaging • Camera that measures the thermal energy emitted by an object and converts it to an image in the visible light spectrum • Maximize usefulness through proper timing (or provide external heat source) • Field operation and data analysis require some experience • Can be used to locate leaks in buried pipe walls, geometric distress in concrete members, and delaminations in FRP

Delamination

Nondestructive inspection equipment: • Impact-Echo Testing • Impact applied to a surface and reflected stress waves are measured • Requires a relatively smooth surface, 2 to 18 in. thick • Field operation and data analysis require some experience • Can be used on concrete members to measure thickness, locate internal flaws/distress • Honeycombing, voids, cracks, delaminations, etc. • In some cases, can locate voids behind walls

Nondestructive inspection equipment: • Drones (Unmanned Aerial Vehicles - UAVs) • UAVs, typically with cameras, operated by a pilot on the ground using a remote control • Real-time video monitoring and recording capabilities • Becoming common in bridge inspections for difficult access areas • Can be used for culvert inspections for close-up inspection of soffits in large-span culverts, areas over active stream flow, areas in confined spaces, and others • Models include protective cages to move through smaller spaces

Nondestructive inspection equipment: • Remote Entry Equipment • For use where person-entry cannot be feasibly accomplished • Storm drains (i.e., permit required confined spaces) • Small diameter culverts • Common tools include: • Remote-controlled vehicles with closed circuit television (CCTV) • Laser profilometers • Inclinometers • Sonar for underwater areas • Intelligent pigging Remote inspection with camera (top) and screenshot from CCTV (bottom) 71 28 August 2018 © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz & Heger Inc. Section 3 – Inspection Procedures

Nondestructive inspection equipment: Remote entry equipment • Remote Vehicles with CCTV • Real-time, high-definition video record for later viewing and analysis with 360° rotation • Distance should be measured and recorded on screen • Software should have ability to provide operator comments of observations associated with video and/or still photos • Optical Scanning • Similar to CCTV, but high resolution cameras provide an “unfolded” image of pipe interior • Inclinometer • Measures slope usually of the invert along the length of the structure • May be coupled with remote vehicle/CCTV • Sonar • Submersible equipment that sends out sound waves to evaluate shape, identify and measure wall distress (pits, voids, cracks), and identify debris buildup • Can be coupled with camera and laser profilometer above the waterline, and sonar below 72 28 August 2018 © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz & Heger Inc. AASHTO Culvert and Storm Drain System Inspection Guide Section 4 – Condition Rating System

Contents: • Use of the Condition Rating System • Approach Roadway • Embankment • Channel • End Treatments and Appurtenances • Concrete Footing and Invert Slab • Barrel Alignment • Plastic, Concrete, Corrugated Metal, (Masonry, and Timber) Barrels • Joints and Seams • Storm Drain System Components • Manholes, Catch Basins, Buried Junctions • Aquatic Organism Passage

Use of the Condition Rating System: • Rating Scale of 1 to 4 • 1 (Good) is like new, little or no deterioration, structurally sound, functionally adequate with no action required • 4 (Severe) indicates possible imminent failure with urgent corrective action required • Ratings based on comparison of the existing condition with the as-designed condition and are assigned before leaving the site • Each component gets a rating; no overall structure rating • The poorest characteristic rating (highest number) determines the component rating • Where quantified criteria are provided, measurements may be required • If the provided table criteria are not adequate, judgement and experience may be used to assign a rating • NR rating for inaccessible component to indicate “Not Rated” (provide description) • Appendix B Catalog of Distressed Conditions shows photographs of varying levels of distress severity to allow assignment of consistent ratings between inspectors and over time

Use of the Condition Rating System: • Assign general thresholds for each inspection criterion to determine its rating and therefore any corrective action • Base the thresholds on: • Engineering principles related to design • What can be easily measured and quantified in the field • Other than for observed failures, ratings do not lead to an immediate call for remediation or replacement • Poor ratings typically lead to further engineering evaluation • Criteria is based on rapid assessment of condition

Use of the Condition Rating System: • Documentation Convention • Distress Severity • Document severity, extent, and location of significant and typical distress • Include photos and sketches as necessary • Adequate for follow-up inspections • Distress Location • Identify outlet end GPS coordinates • Use offsets (stationing) along pipe length from outlet end • Use clock positions looking upstream from outlet or offsets from corners of box culvert, etc. • Joint Distress • Identify offset/stationing rather than counting joint numbers to allow for location identification after lining, barrel extensions, etc.

78 28 August 2018 © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz & Heger Inc. Section 4 – Condition Rating System Use of the Condition Rating System: • Component Condition Rating Tables: • Approach Roadway • Embankment • Channel Alignment and Protection • End Treatments and Appurtenant Structures • Concrete Footings and Invert Slab • Barrel Alignment • Plastic Barrel • Concrete Barrel • Corrugated Metal Barrel • Masonry Barrel • Timber Barrel • Joints • Seams

Approach Roadway: • Approach roadway is the length of roadway, shoulder, and guardrail above the buried culvert or storm drain system that is influenced directly by the performance of the buried system • Purpose: • Identify roadway distress indicators for problems with the culvert or storm drain below and often to locate the buried structure • Not intended for pavement condition Approach roadway inspection length inspection

Definition of Distress Type Approach Roadway: • What to Look For: • Pavement distress Quantitative Measure of Distress Type • Flexible vs rigid pavement • Settlement (sags, humps, rutting) • Pavement maintenance history (repeated patching) • Infiltration, loss of backfill support Example of Distress Type

Left: high severity transverse pavement cracks Right: high severity longitudinal pavement cracks 81 28 August 2018 © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz & Heger Inc. Section 4 – Condition Rating System

Approach Roadway:

Pavement failure due to inadequate embedment soil compaction or low-quality embedment soil adjacent to flexible pipe

Pavement failure due to inadequate soil compaction or low-quality fill soil adjacent to rigid pipe 82 28 August 2018 © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz & Heger Inc. Section 4 – Condition Rating System

Approach Roadway: • Surface distress indicators

(A) Backfill Loss Beneath Pavement Causing Sag in the Approach Roadway (A.1) (B) Large Void Beneath Pavement Due to Backfill Loss, Discovered by Probing Small Hole (B.1) (A.2 and B.2) Resulting backfill infiltration inside barrel 83 28 August 2018 © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz & Heger Inc. Section 4 – Condition Rating System

Evaluate need Corrective

Section 4 – Condition Rating System Appendix Appendix B

Embankment: • Inspection focuses on immediate slope area that provides burial for the culvert, 20 ft either side of culvert • Purpose: • Identify conditions that may be distress indicators for the structure • Must be paired with findings from other components

Embankment sloughing

Definition of Distress Type Embankment: • What to Look For: • Slope stability Quantitative • Sloughing, tension cracks Measure of • Embankment Erosion Distress Type • Sheet Erosion, gullying/rill erosion, piping Example of Distress Type

Moderate sheet erosion on steep embankment

Channel: • The channel consists of the stream, streambed, and adjacent banks. • Purpose: • Identify channel-related problems that may affect the performance or structural integrity or stability of the culvert. Change in stream alignment causing flow to be directed into wingwall

Channel: • What to Look For: • Channel Alignment • Horizontal alignment, vertical alignment • Bank erosion and scour • Protection • Waterway adequacy (non-AOP) • High water marks Sedimentation: fair (left), poor (middle), severe (right) • Drainage area • Sedimentation and debris

End Treatments and Appurtenances: • Purpose: • Identify conditions that may relate to their structural stability, hydraulic performance, and traffic safety characteristics • What to Look for: • Projecting ends • Changes to prefabricated end treatments Left: wingwall severe condition (cracking, movement) • Issues with headwalls/spandrel Right: wingwall has progressed from severe to failed after rain event walls/wingwalls • Issues with aprons and flumes, debris accumulations • Issues with weep holes, etc.

Concrete Footing and Invert Slab: • Purpose • Identify distress and distress indicators that result in foundation problems for three-sided and other structures. Differential footing settlement • What to Look for: • Differential settlement • Scour and stability • Concrete deterioration

Barrel Alignment: • Purpose • Identify distress indicators that result in misalignment of pipe segments and may reduce hydraulic performance Severe visible sag in vertical alignment causing ponding • What to Look for: • Misalignment • Vertical and horizontal

Severe vertical misalignment resulting in joint offset

Barrel: • Purpose: • Identify distress in the barrel that may affect structural stability or functional performance • Focus on structural, functional, and durability issues (alignment and joints covered separately) • Rate each barrel based on its level of distress (if any) and tie the rating to specific actions • Materials covered • Plastic Barrel • Concrete Barrel • Corrugated Metal Barrel (not covered) • Masonry Barrel (not covered) • Timber Barrel (not covered) 99 28 August 2018 © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz & Heger Inc. Section 4 – Condition Rating System

Plastic Barrel (HDPE, PVC, PP, FRP): • What to Look For: • Shape • Deflection, deformation • Surface Damage • Wear/Abrasion Minor photodegradation of end section • UV Degradation • Wall Distress • Local Buckling • Splitting • Cracking

Plastic Barrel: • Basis for Rating Limits

• Recall the relationship between vertical deflection (ΔA) and flexural wall strain (εf) from thermoplastic pipe design (see AASHTO LRFD Bridge Design Specifications):

• Allowable vertical deflection, ΔA, is typically set at 5% in design and construction specifications

• The deflection from circumferential shortening, εscD, must be accounted when converting ΔA, which can be measured in the field, to Δf, which is the reduction in vertical diameter from flexure • If εscD is constant, as ΔA increases, the flexural strain, εf, increases linearly • Flexural strain is combined with axial (hoop) strain, εuc, and compared to the design strain limit • If deflection increases, strains increase and can approach or exceed the design strain limit

Plastic Barrel: • Basis for Rating Limits

• Thermoplastic pipes are typically designed for a range of cover heights (e.g., 2 to 20 ft) • Most installations are not at the limiting cover height • In-service loads are typically less than the design loads • Engineering evaluation may show an in-service pipe with greater than 5% deflection to still have the full safety factor • If deflection increases enough to cause strains beyond the strain limit, the safety factor will be reduced 103 28 August 2018 © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz & Heger Inc. Section 4 – Condition Rating System

Plastic Barrel: • Basis for Rating Limits

• Surface damage cannot cause a failed rating • Some level of surface damage will not cause structural or functional distress • Key to the surface damage plastic barrel rating criterion is tracking with time • If, in subsequent inspections, wear or abrasion causes increased section loss, or UV degradation progresses, limits are established to track the rating progression and provide a trigger point for engineering evaluation or required corrective action

Plastic Barrel: • Basis for Rating Limits

• Thermoplastic pipes will show some local buckling (accounted for in design) • Widespread local buckling may indicate loads greater than anticipated • Vertical loads are directly related to axial strain • Similar to flexural strain, there may be reserve capacity based on the installation not being at a critical cover height • An increase in axial strain beyond the design limit will reduce the design safety factor 105 28 August 2018 © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz & Heger Inc.

Section 4 – Condition Rating System Appendix Appendix B

Concrete Barrel: • What to look for: • Cracking • Longitudinal, circumferential, vertical, offsets Results of poor and good side support in rigid pipe • Spalling • Delamination • Slabbing • Deterioration • Abrasion, chemical attack, freeze-thaw • Clogged weep holes

Cracks with radial offset

Concrete Barrel: • Spalling • Fair – spalls are not greater than 1/2 in. in depth and less than 6 in. in diameter or longest dimension; no exposed rebar • Poor – spalls are not greater than 3/4 in. in depth and larger than 6 in. in diameter or longest dimension; no exposed rebar • Severe – spalls are greater than 3/4 in. in depth with exposed rebar Left: small spall along crack Right: large spall with exposed/corroded rebar

Concrete Barrel: • Delamination is separation along a plane parallel to a surface; slabbing is a radial failure of concrete due to action of rebar in tension with inadequate competent concrete cover

• Freeze-thaw distress is due to the action of Severe freeze-thaw deterioration expanding/contracting water that has been absorbed by the concrete; de-icing chemicals can work with freeze-thaw to cause surface scaling

Slabbing in concrete pipe

Concrete Barrel:

Moderate deterioration (possible chemical attack) Severe deterioration (possible chemical with exposed aggregate and loss of surface mortar attack) with complete loss of invert

Concrete Barrel: • Basis for rating: • Recall from rigid pipe behavior: • Concrete culvert and storm drain barrels do not bend or deflect appreciably under load before cracking or fracturing • Adequate stability of surrounding soil, particularly below a pipe or box, is necessary to prevent excessive stresses that would lead to cracks • Measurements of crack widths are an indication of the structural condition of the concrete structure • Wide cracks allow water and oxygen to penetrate the wall and access the rebar, which can initiate corrosion • Corrosion is expansive and can eventually lead to spalling and structural distress

Crack Width AASHTO Construction Specs Culvert & Storm Drain Barrel Rating (in.) (intended for new structures) ≤ 0.01 Note in report 1- Good, no action 0.01 to 0.05 Measure in detail, measure diameters 2- Fair, no immediate action 0.05 to 0.1 Measure in detail, measure diameters 3- Poor, evaluate need for corrective action > 0.1 Consider repair 4- Severe, corrective action required Offset Cracks Repair or replace 4- Severe, corrective action required 116 28 August 2018 © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz & Heger Inc. Section 4 – Condition Rating System Concrete Barrel: • Basis for rating:

• For the spalling, slabbing, delamination, and patches rating criterion, the key is to generally not expose or affect rebar • Trigger for poor rating and corrective action • 6 in. or larger in diameter spall/delamination greater than 3/4 in. deep (likely still within concrete cover) or patches that are delaminated or deteriorating • Trigger for severe rating and corrective action • Widespread spalling greater than 3/4 in. deep (concrete cover is gone), delamination with exposed rebar, or slabbing 117 28 August 2018 © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz & Heger Inc. Section 4 – Condition Rating System

Concrete Barrel: • Basis for rating:

• For the deterioration rating criterion, the key is to generally not expose or affect rebar • Trigger for poor rating and corrective action • Exposed aggregate, deep and widespread abrasion, or impact damage with exposed rebar • Trigger for severe rating and corrective action • Extensive surface damage, loose or missing aggregate, exposed/corroded rebar, or loss of invert 118 28 August 2018 © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz & Heger Inc. Section 4 – Condition Rating System

Manholes, Catch Basins, and Buried Junctions: • What to Look For: • Material degradation • Settlement, joint with pipe • Ladder condition • Sedimentation and debris • Use materials ratings from barrel evaluation tables, e.g., concrete pipe barrel

Manhole and access ladder Catch basin diagram

Aquatic Organism Passage: • Not explicitly covered; refer to specific AOP plan if applicable • AOP not historically considered in design or inspection • Culverts can result in barriers and stream fragmentation • Common barriers include: • Excessive velocity • Outlet configuration (drops) • Turbulence • Insufficient depth • Excessive lengths (darkness) • Debris and sediment • Culvert damage (can prevent fish from passing)

Contents: • General • Transportation Asset Management • Best Practices for Developing an Asset Management Plan

General: • Gather information, prioritize and schedule maintenance and repair • Well established for bridges and pavement • Not well established for culvert and storm drain systems • Older culverts and storm drains may not be cataloged or even show up on plans • Agencies have traditionally relied on maintenance personnel to observe, report, and address problems in a reactionary manner rather than proactively • Proactive management can extend lifespans and better utilize resources

Transportation Asset Management: • Makes an account of inventory and maintenance to prolong the service life of highway assets • Weigh costs and benefits of maintenance with importance of structure and performance goals to prioritize and optimize actions • Goals can be over an extended time horizon and draw from both economics and engineering principles • Allows for accountability and transparency in public funding

Transportation Asset Management: • GASB 34 (1999) • Government Accounting Standards Board established new financial reporting requirements for state and local governments • States must capitalize infrastructure assets on financial statements • Report the value • Provide maintenance and replacement costs • Include depreciated cost based on useful life of structure • Assets do not have to be depreciated if they are being preserved at or above minimum established conditions • Only possible through regular inspection and documentation

Transportation Asset Management: • MAP 21 (2012) • Moving Ahead for Progress in the 21st Century Act signed into law • Reforms transportation asset management • Reduce federal budget deficit through better utilization of funds • Only required for bridges (including culvert systems with total span ≥ 20 ft) and pavements, but encouraged for other assets • Requires states to develop a risk-based transportation asset management plan (TAMP) • Weighs • Engineering • Life-cycle costs • Risk analysis

Guidance for Developing an Asset Management Plan:

AASHTO Guide for Inspection of Culvert and Storm Drain Systems

Expected publication: February 2019

Mr. Jesse L. Beaver, PE, P.Eng, NCHRP 14-26 PI 41 Seyon Street, Building 1, Suite 500 Waltham, MA 02453 781-907-9272 (office) [email protected] 128 28 August 2018 © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz & Heger Inc. AASHTO Culvert and Storm Drain System Inspection Guide Useful Figures

• Inventory and inspection forms (Section 3) • Inspection and condition rating flowchart (Section 3) • Condition rating tables (Section 4)

• Culvert and Storm Drain Inventory Form • Culvert Inspection Form 1 of 3 • Culvert Inspection Form 2 of 3 • Culvert Inspection Form 3 of 3 • Storm Drain Inspection Form 1 of 2 • Storm Drain Inspection Form 2 of 2

131 28 August 2018 © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz & Heger Inc. © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz 28 August 2018 & Heger Inc. © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz 28 August 2018 & Heger Inc. © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz 28 August 2018 & Heger Inc. © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz 28 August 2018 & Heger Inc. © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz 28 August 2018 & Heger Inc. © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz 28 August 2018 & Heger Inc. Section 4 - Condition Rating Tables

• Approach Roadway • Embankment • Channel Alignment and Protection • End Treatments and Appurtenance Structures • Concrete Footings and Invert Slab • Barrel Alignment • Plastic Barrel • Concrete Barrel • Corrugated Metal Barrel • Masonry Barrel • Timber Barrel • Joints • Seams of Corrugated Metal Plate • Manholes, Catch Basins, and Buried Junctions

138 28 August 2018 © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz & Heger Inc. © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz 28 August 2018 & Heger Inc. © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz 28 August 2018 & Heger Inc. © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz 28 August 2018 & Heger Inc. © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz 28 August 2018 & Heger Inc. © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz 28 August 2018 & Heger Inc. © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz 28 August 2018 & Heger Inc. © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz 28 August 2018 & Heger Inc. © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz 28 August 2018 & Heger Inc. © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz 28 August 2018 & Heger Inc. © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz 28 August 2018 & Heger Inc. © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz 28 August 2018 & Heger Inc. © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz 28 August 2018 & Heger Inc. © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz 28 August 2018 & Heger Inc. © 2018 Jesse L. Beaver, All Rights Reserved Simpson Gumpertz 28 August 2018 & Heger Inc.