B08 Solicitation 140A1621R0015_Attachment 3_SOW_BIADOT Bridge Inspection Handbook (2020).pdf

BRIDGE

INSPECTION

HANDBOOK

A guide to the applicable safety inspection and evaluation of vehicular bridges on BIA & tribal facilities

BUREAU OF INDIAN AFFAIRS

Division of Transportation

BUREAU OF INDIAN AFFAIRS DIVISION OF TRANSPORTATION

BIADOT Bridge Inspection Handbook

BIADOT BRIDGE PROGRAM OFFICE

BIA CENTRAL OFFICE WEST (ABQ)

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Table of Contents

Purpose

Revisions

1 INTRODUCTION

1.1 BACKGROUND

1.2 SCOPE OF HANDBOOK

1.3 POLICY

2 INSPECTION REQUIREMENTS

2.1 BIADOT RESPONSIBILITIES

2.2 BRIDGE INSPECTION TEAM

2.3 TYPES OF INSPECTIONS

2.3.1 Initial Inspection

2.3.2 Routine Inspection

2.3.3 In-Depth Inspection

2.3.4 Damage Inspection

2.3.5 Fracture Critical Member Inspection

2.3.6 Underwater Inspection

2.3.7 Interim Inspection

2.3.8 Special Inspection

2.4 FREQUENCY OF INSPECTIONS

2.4.1 Initial Inspections

2.4.2 Routine Inspections

2.4.3 Fracture Critical Member Inspections

2.4.4 Underwater Inspections

2.4.5 Interim Inspections

2.4.6 In-Depth, Damage, and Special Inspections

3 INSPECTION PROCEDURES

3.1 PREPARATION FOR INSPECTION

3.2 BRIDGE ACCESS

3.3 FIELD DOCUMENTATION TECHNIQUES

3.3.1 Field Notes

3.3.2 Urgent Item Forms

3.3.3 Images

3.4 Fracture Critical Members

3.4.1 General Requirements

3.4.2 Pre-Inspection / Documentation

3.4.3 Inspection Documentation

3.4.4 Inspection Procedures

3.5 In-Depth Dive Inspections

3.6 AGENCY PRE-INSPECTION COORDINATION

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3.7 AGENCY POST-INSPECTION DEBRIEFING

3.8 POST-TRIP DEBRIEFING

4 LOAD RATING

4.1 DATA COLLECTION

4.2 TYPES OF LOAD RATING

4.2.1 Inventory Rating

4.2.2 Operating Rating

4.3 STANDARD DESIGN VEHICLES

4.4 ANALYSIS METHOD

4.5 INITIAL LOAD RATING

4.6 REVIEW AND UPDATE OF LOAD RATINGS

4.7 LOAD RATING CALCULATIONS AND RESULTS

4.8 BRIDGE POSTING

4.9 NBI CODING OF LOAD RATING RESULTS

5 INSPECTION REPORTS

5.1 INTRODUCTION

5.2 TYPES

5.2.1 Full Reports

5.2.2 Check Report

5.2.3 Documentation Report

5.2.4 Underwater and Damage Reports

5.2.5 Scour Reports

5.3 CONTENT

5.3.1 Summary of Findings

5.3.2 Fracture Critical Members (FCM) Findings

5.3.3 Recommendations

5.3.4 Load Rating and Posting

5.3.5 Condition Ratings

5.3.6 Sketches

5.3.6.1 Plan View

5.3.7 Images

5.3.8 Structure Inventory and Appraisal Data

5.3.9 Additional NBI and BIADOT Items

APPENDICES

I. BIADOT BRIDGE PROGRAM FORMS

II. FEDERAL HIGHWAY ADMINISTRATION MEMORANDA

III. BRIDGE CLOSURE GUIDANCE

Barricades

IV. GLOSSARY OF COMMON ENGINEERING AND CONSTRUCTION TERMS

V. NATIONAL BRIDGE INSPECTION STANDARDS

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Forward & Purpose

The Bureau of Indian Affairs (BIA) Division of Transportation Bridge Inspection Handbook (Handbook) has been developed by the BIA Bridge Program Manager to provide specific guidance, offer needed technical details and serve as an information source to both tribal and local agency staff related to and involved with bridge inspections. The intent of this handbook is to serve as an operations manual for the collection, processing and reporting of bridge inspection information.

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Revisions

The Handbook is a dynamic document that is updated periodically to incorporate revisions based on new requirements from the Federal Highway Administration (FHWA), as well as newly adopted practices by either federal or local agencies within the regions. We encourage the user to submit to the Bridge Program Manager any proposed revisions or new material. In the event of conflicting information or requirements between the Handbook and NBIS, the NBIS will govern. Agencies are not relieved of the responsibility of complying with the NBIS even when a conflict exists. If a conflict is discovered, notify the BIA Bridge Program Manager.

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1 INTRODUCTION

1.1 BACKGROUND

The Surface Transportation Assistance Act of 1978 (PL 100-17) and Title 23 USC 144 requires that all structures defined as bridges on public roads shall be inventoried and inspected in accordance with the National Bridge and Inspection Standards (NBIS). Under the standards, each Federal Agency is required to record and maintain structure inventory and appraisal data on each bridge and report the data to the Federal Highway Administration (FHWA) upon request.

Recent changes in highway legislation, Moving Ahead for Progress in the 21st Century Act (MAP-21), PL 112-141, now require that the Secretary of Transportation, in consultation with the States and Federal agencies with jurisdiction over highway bridges and tunnels shall:

a. Inventory all highway bridges on public roads, both on and off federal-aid highways, including tribally and federally owned bridges that are over waterways, other topographical barriers or other highways and railroads.

b. Inventory all tunnels on public roads, both on and off federal-aid highways, including tribally and federally owned tunnels.

Since its inception, the BIADOT Bridge Program (Program) has been an integral part of BIADOT asset management-related activities. The Program is governed by 81 Indian Affairs Manual (81 IAM), which provides policy regarding structures to be inspected, inspection frequency, inspection program personnel, and other Program requirements. Program management and technical oversight is the responsibility of the Division of Transportation - Central Office (ABQ).

1.2 SCOPE OF HANDBOOK

This document, the BIADOT Bridge Inspection Handbook, provides supplemental guidance about specific bridge inspection activities that have evolved over the duration of the Program. The purpose of this handbook is to:

• Ensure the proper safety inspection and evaluation of bridges on BIADOT facilities,

• Standardize reporting procedures, and

• Provide guidance for complying with the requirements of 81 IAM and the National Bridge Inspection

Standards (NBIS).

Both pedestrian and vehicular bridges are found on BIADOT installations. This handbook addresses the requirements for the inventory, inspection, rating, and reporting for vehicular bridges only.

1.3 POLICY

All bridges identified with this guidance specifically refer to structures owned or maintained by the BIA which are to be inspected and inventoried to ensure their safety and structural integrity in accordance with this guide and other applicable federal laws and regulations. All inspections and inventories shall be officially reported in the BIA Bridge Management System (BMS), and provided to the Federal Highway Administration, Office of Infrastructure, Bridge Technology, annually as required by procedures established in the National Bridge Inventory Standards (NBIS).

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a. For the purpose of this guide, public highway-roadway bridges (see 23 CFR 650.305 for definition) with spans greater than 20 feet (6.1 m) shall be inspected and evaluated in compliance with the NBIS.

b. Short Span (less than or equal to 20 feet (6.1 m)), Non-Public and Public Pedestrian bridges shall be inspected and evaluated in accordance with procedures established under separate guidance from the BIA. This guide is specific to those bridges identified in 23 USC §144, and §202.

c. An inventory of all bridges defined herein shall be prepared and maintained in BIADOT’s Bridge Management System (BMS).

d. All existing bridges over tidal and non-tidal waterways with public vehicular traffic should be evaluated for the risk of failure from scour during the occurrence of a flood on the order of magnitude of the 100-year return period. Bridge scour evaluation shall be conducted for each bridge to determine whether it is scour critical in accordance with HEC 18 – Evaluating Scour at Bridges (5th edition) (April 2012).

(https://www.fhwa.dot.gov/engineering/hydraulics/pubs/hif12003.pdf) Scope of scour evaluations for all other bridges shall be determined by the BPM following guidelines after consultation with Hydraulic and Geotechnical engineers.

e. Fracture critical members (FCMs) on all bridges shall be identified and recorded. An inspection plan for FCMs shall be developed and executed separately from this manual.

f. Seismic performance data shall be reported for each bridge. Seismically vulnerable bridges shall be evaluated in accordance with accepted seismic analysis procedures detailed at FHWA’s Seismic Resilience webpage: https://www.fhwa.dot.gov/bridge/seismic/

g. BIA shall submit consolidated Structure Inventory and Appraisal (SI&A) data of BIA Public highway-roadway bridges and tunnels to FHWA for review and concurrence to comply with the NBIS.

2 INSPECTION REQUIREMENTS

The BIADOT Bridge Program Office (Program) conducts bridge inspections to determine the physical and functional condition of a bridge, to form a basis for evaluation and load rating, to provide a continuous record of the structure and to establish priorities for repair or replacement. The success of the inspection is dependent on proper planning, having the right equipment, and the experience and qualifications of the inspection team.

All bridge inspections are to be conducted in accordance with NBIS and BIADOT requirements. BIADOT bridge inspection requirements are in 23 CFR 650, Subpart C - National Bridge Inspection Standards (NBIS).

The Program plans and conducts bridge inspections as necessary to properly evaluate the condition of the structure and to protect people traveling over or under the structure. The inspection plan should:

• Identify unique structural characteristics and special problems or hazards

• Apply current technology and practice

• Ensure the intensity and frequency of the inspection is consistent with the type of structure and details

• Assign inspection personnel in accordance with their qualifications https://www.fhwa.dot.gov/engineering/hydraulics/pubs/hif12003.pdf https://www.fhwa.dot.gov/bridge/seismic/

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2.1 BIADOT RESPONSIBILITIES

The BIADOT Bridge Program (Program) must ensure the safety of vehicular bridges on federally-managed lands.

The responsibilities described in the 81 IAM ensure that the Program inventories, inspects, load rates, and reports to the Federal Highway Administration (FHWA) National Bridge Inventory (NBI) for bridges under BIA ownership.

As the organizational unit responsible for Program Management, the Bureau of Indian Affairs – Division of Transportation (BIADOT) Bridge Program Office has responsibility for maintaining the BIA bridge inventory, for bridge inspection, and for annual NBI reporting. The BIA Bridge Program Manager (BPM) oversees the day-to-day activities of the Bridge Program. The BPM may also have been appointed as the Bureau’s Load Rating Engineer (LRE). The LRE has overall responsibility for load rating of bridges including the final responsibility for establishing procedures and guidance for the load rating process in the agency.

Regionally, the Regional Engineer appoints a Regional Bridge Coordinator who assists the Bridge Program Manager with coordination of inspections within the Region, reviews findings and recommendations included in bridge inspection reports, and distributes bridge inspection reports to field stations and others within the Region.

a. Region. The Regional Director’s function is responsible for ensuring a safe bridge inventory through proper inspection and reporting. The Regional Director’s element shall be responsible for the following activities:

1. Providing the BPM with an accurate accounting of all bridges within the Region through the BMS. Assist the BPM in determining scope and frequency of future inspections and providing independent technical review.

2. Preparing, maintaining and updating an accurate Regional Bridge Inventory through the BMS and RIFDS.

3. Provide representation from the region to participate in each inspection.

4. Coordinate with Tribal Governments on the annual operation and maintenance budget process for funding existing bridge, repairs, improvements, or rehabilitation related to bridge safety.

5. Coordinate with Tribal Governments on upcoming bridge inspections and evaluations.

6. Tracking of recommendations and remedial actions.

b. Bureau of Indian Affairs - Central Office. Central Office shall be responsible for the following activities:

1. Designating a Bridge Program Manager (BPM) for the Bridge Program.

2. Identifying qualified Regional Technical Experts to conduct technical quality assurance reviews of Regional bridge inspections and evaluations and other Bridge Safety related products and ensuring reviews are conducted as required.

3. Conducting Quality Assurance (QA) of Regional programs, reviewing and monitoring the data collection, processing, evaluation, and inspection activity, maintaining a schedule of inspections and status of

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4. Conducting Quality Control (QC) of inspection reports. Review and approval of bridge inspection reports should be within 90 days after completion of the field inspection. This period should include satisfactory resolution of all review comments.

5. Coordinate with the Region Roads Programs on inspection schedules for inspections, evaluations, repairs, improvements, or rehabilitation related to bridge safety.

6. Review each Regions Bridge Inventory submittals and approve by August 15 of each year.

7. Review and approve each Region’s Bridge Transportation Improvement Plan (TIP) for repairs, rehabilitation or replacement.

8. Finalize the Bridge Management System (BMS) by March 01 of each calendar year. Finalizing the BMS includes review of inspection reports and ensuring each Region has finalized their data.

9. Developing policy and procedures for implementing a Bridge Safety Program covering public use of bridges and other BIA Bridges.

10. Providing policy advice to BIA elements on any new legislation related to the safety of BIA bridges.

11. Providing policy compliance review of all decision documents related to bridge safety deficiencies.

12. Acting as proponent for training needs of BIA bridge staff and coordinating the training effort with courses offered by FHWA and American Association of State Highway and Transportation Officials

(AASHTO).

2.2 BRIDGE INSPECTION TEAM

Each bridge inspection team must be comprised of at least two bridge inspectors. The bridge inspection team must be under the full-time, on-site supervision of a team leader. Some inspections will require more than two team members for safety reasons or to include needed expertise.

A bridge inspection team leader must have, at a minimum, the following qualifications:

• Registration as a Professional Engineer;

• 5 years of bridge inspection experience;

• Certification of completion of an FHWA-approved comprehensive bridge inspection training course.

The BIA Bridge PM may waive the Professional Engineering registration requirement on a case-by-case basis if the following conditions are met:

• The proposed team leader meets the NBIS requirements of 23 CFR 650.309 (b) , and (2)

• It is in the best interest of BIA to waive the requirement.

Team leaders must complete an FHWA-approved bridge inspection refresher course every 5 years.

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If a team leader will be engaged in a fracture critical member inspection, they must have successfully completed an FHWA-approved fracture critical member inspection course.

Underwater inspection personnel must:

• Have successfully completed an FHWA-approved underwater bridge inspection course, or

• Provide suitable documentation that they have received training throughout their career that covers the topics covered in an FHWA-approved underwater bridge inspection course.

Commercial diver certification is not, in itself, sufficient to meet underwater bridge inspection training requirements.

All inspectors conducting non-destructive tests must be trained in the specific technology employed and must have appropriate certification, as required, in accordance with the American Society for Nondestructive Testing

(ASNT).

The BPM recommends that other members of the inspection team complete an FHWA-approved comprehensive bridge inspection training course. All inspectors shall complete the BIADOT Bridge Program Inspection Team Qualification Form (BPQA 2016) in Appendix I and submit to the BPM annually.

2.3 TYPES OF INSPECTIONS

The type of inspection team personnel perform may vary over the useful life of a bridge to reflect the level of effort needed to document its condition. The following sections describe these types of inspections:

• Initial inspection

• Routine inspection

• In-depth inspection

• Damage inspection

• Fracture critical member inspection

• Underwater inspection

• Interim inspection

• Special inspection

2.3.1 Initial Inspection

An initial inspection is the first inspection of a bridge as it becomes part of the BIA’s bridge inventory. The initial inspection is a fully documented investigation performed by qualified personnel. It must also include an analytical determination of the load carrying capacity (load rating).

The purpose of an initial inspection is twofold. BIA uses it to gather the FHWA NBI Structure Inventory and Appraisal (SI&A) data and any other data that the BIA Bridge Program requires. The BPM also uses it to determine the baseline structural conditions and identify any existing deficiencies or potential deficiencies. As part of the planning for an initial inspection, inspectors shall review all available information about the bridge, including as-built plans. This review, in conjunction with the inspection, should identify any fracture critical elements that may warrant special attention. Refer to Section 2.3.5 for more information on fracture critical member inspection.

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As a part of the initial inspection, inspectors must complete a structural analysis to determine the safe load carrying capacity (load rating). If there is not enough existing information available in the bridge history file to determine the load rating, the inspectors must collect more detailed information in the field. Refer to Section 2.3.3, In-Depth Inspection, for more information. During the initial inspection for bridges over a waterway, inspectors must take soundings of the channel bottom around each of the substructure units, across the channel along the upstream and downstream fascia and along lines parallel to the upstream and downstream fascia at specified distances from the bridge.

2.3.2 Routine Inspection

BIADOT regularly schedules routine inspections consisting of observations and-or measurements needed to determine the physical and functional condition of the bridge and to identify changes from the previous inspection. The results of a routine inspection should fully document the condition of the bridge and must include text, images and drawings.

Routine inspections consist of an arm’s length visual inspection of all portions of the structure with the use of simple tools, measuring devices, and recording methods. Inspectors must use climbing techniques, ladders, and access equipment to reach all portions of the bridge structure. As part of a routine inspection, inspectors must estimate and document losses of bridge member cross sections due to deterioration and damage.

The routine inspection will include rating all components and component elements in accordance with the 1995 (2000 edit) FHWA Recording and Coding Guide for the Structure Inventory and Appraisal of the Nation’s Bridges (Coding Guide), and reporting the results of the inspection in accordance with the Bureau’s reporting requirements, as described in Chapter 5.

During the routine inspection, the inspection team must verify all data, correct inconsistencies, and update the Structure Inventory and Appraisal (SI&A) data.

Routine inspections of bridges over water must include a visual inspection for indications of scour and an examination of the condition of the channel embankments. During the routine inspection for bridges over a waterway, inspectors should take soundings of the channel bottom around each of the substructure units and across the channel along the upstream and downstream fascias of the bridge.

2.3.3 In-Depth Inspection

An in-depth inspection is a close-up, hands-on inspection of one or more bridge members above or below water to identify and assess any deficiencies not readily detectable using routine inspection procedures. Inspectors may need special equipment, such as under-bridge inspection equipment, staging, and workboats to obtain access. Non-destructive field tests and-or material tests may be required to fully ascertain the existence or extent of deficiencies. The BPM may need to conduct in-depth inspections to gather detailed information about the remaining cross section of structural members for load rating (see Chapter 4).

The level of effort necessary to collect the needed information is determined to some extent by the availability of design and as-built drawings. For well-documented structures, the BPM may limit the field inspection to a routine inspection, plus verification of key dimensions, visual estimation of remaining thickness, and limited measurements. When there are limited or no construction drawings available, it will be necessary to get detailed measurements of structural members and the general configuration of the structure.

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2.3.4 Damage Inspection

A damage inspection is an unanticipated inspection that is undertaken to assess the structural damage caused by environmental or human actions. Typically, personnel at the regional level will initiate these inspections to determine if emergency load restrictions or closure of the bridge to traffic is necessary and to determine what repairs are necessary. The effort needed for this type of inspection may vary significantly depending on the extent of damage. Inspectors must evaluate the affected members, determine the extent of section loss, measure misaligned members and check for any loss of foundation support. The inspection team must be capable of making on-site assessments to determine if emergency load restrictions are necessary.

2.3.4.1 Flood Monitoring Inspection

Flood events can compromise the safety of bridges susceptible to scour. Scour caused by these events can remove large amounts of foundation material from under the footings of the structure and cause it to become unstable. Bridge owners are required by the National Bridge Inspection Standards (NBIS) to monitor scour critical bridges during flooding events. BIADOT’s Monitoring Category is based on the most recent scour analysis.

With regard to scour criticality, three categories exist for frequency of monitoring:

MONITORING CATEGORY NBI ITEM 113 MONITORING FREQUENCY

A ≤ 3 Once every 4 hours B 4 Once every 12 hours C 5, 6, 7 Once every 24 hours

Monitoring requires a minimum of 2 visits to verify whether the water level is rising or receding. Use a log to record these levels and also use the log to record visible distress to the structure to identify if the conditions for closure exist at each structure. For further instructions, refer to BIADOT’s Bridge Flood Monitoring Log (Form BPFM 2020 located in Appendix I).

The monitoring process occurs in distinct stages of a flood event described as BEFORE, DURING, CLOSING and

AFTER.

BEFORE a Flood Event:

• Identify individuals who will monitor bridges.

• Individuals responsible to monitor bridges need to be familiar with monitoring procedures.

• Identify bridges within the municipality or county which are scour critical and require monitoring.

• Determine bridge closure methods.

• Pre-plan bridge monitoring assignments and create a plan to communicate bridge closures that may occur during flooding events.

DURING a flood event:

• SAFETY FIRST

• Do not endanger yourself or others while monitoring bridges.

• Do not enter flood waters.

• Flood waters include both standing and flowing water.

• When stream waters rise, begin monitoring visits for Category A bridge(s).

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• A Flood Warning issued by the National Weather Service should trigger bridge monitoring (Flood Warnings are often preceded by Flood Advisories or Flood Watches).

• As flood conditions worsen, or continue over a long period of time, then begin monitoring Category B and Category C bridges.

• Monitor Category A, B, and C bridges for signs of distress and record observations on scour critical bridge flood monitoring log during each visit.

• Continue to make monitoring visits while water level is rising.

• Monitor bridges a minimum of two times. This is necessary to determine if the water level is receding.

• Once it is confirmed that the water level is receding, monitoring may be discontinued.

CLOSING a Bridge (when necessary)

• Close the bridge when necessary to ensure public safety. Follow the directions on the scour critical bridge flood monitoring log to determine if conditions at the bridge make this step necessary (Refer to Appendix III. Bridge Closure Guidance):

- Bridge

• Pressure flow

• Water overtopping the bridge

• Misalignment, settlement or tilt damage

- Approach Roadway

• Settlement damage

• Embankment erosion damage

- Waterway Channel

• Significant debris build-up

• In order to re-route emergency response vehicles after a bridge has been closed, immediately notify appropriate law enforcement, local emergency responders, and county emergency communications center using a non-emergency phone number or pre-established alternate communications.

• Avoid directly calling 911 unless there is an actual emergency.

AFTER the flood event:

• Completed monitoring logs for each bridge that was monitored are to be placed in the bridge file maintained by the owner.

• These records may be subject to audit at a later date as required by BIADOT or FHWA.

• Bridges that have been closed undergo a post-flood damage inspection performed by a certified bridge safety inspector.

• All closed Category A bridges must be inspected PRIOR to re-opening.

• All flood-damaged bridges (including settlement, tilt, misalignment, erosion or bridge washout) must remain closed until inspected.

• Depending on the severity of the storm, some or all Category A, B, or C bridges may require a post-flood damage inspection after water recedes to normal levels; this may include bridges that were not closed during monitoring.

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• Post-flood inspections are conducted by a certified bridge safety inspector.

• This determination will be made by BIADOT. The BIADOT Bridge Program Manager will coordinate and designate team leaders with efforts surrounding in-service bridge inspections and determining post-flood structure statuses.

2.3.5 Fracture Critical Member Inspection

The BIA BPM regularly schedules fracture critical member (FCM) inspections to examine the fracture critical members or member components of a bridge. Bridges require a fracture critical member inspection if they have steel tension members or steel tension components along a non-redundant load path, whose failure would likely result in partial or full collapse of the bridge. Inspectors should have identified the FCMs during the initial inspection of the bridge. Below are some typical examples of FCMs:

• One or two girder systems, including single boxes with welds

• Suspension systems with two eyebar components

• Steel pier caps and cross girders

• Suspended spans with two girders

• Welded tied arches

• Pin and hanger connections on two or three girder systems

• Steel trusses or gusset-plate connection systems

2.3.6 Underwater Inspection

An underwater inspection is the examination and assessment of bridge elements located below the waterline.

2.3.6.1 Routine Wading Inspection

If the water is shallow enough (below approximately 3 feet), the inspector can cautiously wade through the water to do the inspection. While wading, the inspector should be able to touch or access all portions of the bridge elements below water.

2.3.6.2 In-Depth Diving Inspection

If the water is too deep, the current too swift, or other conditions are present such that the inspector cannot safely conduct the inspection or achieve certainty as to the underwater conditions, an underwater diving inspection is required.

Underwater diving inspections must be accomplished in accordance with the requirements for Level I, II, and III inspections, as described in the current editions of the AASHTO Manual for Bridge Evaluation and FHWA-NHI-10- 027 Underwater Bridge Inspection Manual. Generally, these are the underwater inspection levels:

• Level I inspection of 100% of underwater elements: This level is essentially a “swim-by” overview, which does not involve cleaning any structural elements. It should confirm as-built plans and detect obvious defects.

• Level II inspection of 10% of underwater elements: This level of effort is directed toward detecting and identifying damaged/deteriorated areas which may be hidden. It requires cleaning the structural elements in 1-foot-high bands at the mudline, waterline, and half way between.

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• Level III inspection of 5% of underwater elements: This level of effort often requires the use of non-destructive testing techniques, but may also require use of partially destructive techniques, such as sample coring, material sampling, or in-situ surface hardness testing.

If the percentage of element inspection does not allow the inspector to be certain about the structural condition of the underwater elements, then he/she should increase the level of inspection and use whatever techniques necessary to achieve certainty.

2.3.6.3 Soundings

At a minimum, the inspector should take soundings (elevation measurements) of the channel bottom around each of the substructure units, across the channel along the upstream and downstream fascias of the structure, and along additional lines parallel to the upstream and downstream fascias of the bridge as specified in the scope of work or as deemed necessary.

2.3.7 Interim Inspection

The BIA Bridge Program uses interim inspections to monitor a particular known or suspected deficiency, such as foundation settlement, scour (undermining), or member conditions that may have an impact on the structural integrity of the bridge.

The team leader for an interim inspection, with input from the Regional Engineer, Regional Coordinator and the BIA BPM must:

• Have a clear understanding of the known or suspected deficiency

• Incorporate the appropriate guidelines and procedures from this handbook regarding what to observe or measure

• Develop an appropriate reporting method based on mitigation urgency

Interim inspections are usually not comprehensive enough to meet NBIS requirements for biennial inspections.

Conditions and events warranting interim inspection include:

• Summary condition rating of 3.0 or less

• Load Rating of less than 3 tons

• Excessive deformation of any load bearing element

• Cracks in the tension zone of a Fracture Critical Member

• Scour that threatens the stability of a substructure unit

• Any other condition or event that the BIA Bridge PM deems sufficient, such as:

o Natural disasters in the vicinity of the bridge including wildfire, flooding, or earthquake o Damage caused by humans, animals or any other outside agency

2.3.8 Special Inspection

The BIA Bridge PM may schedule special inspections, which the PM typically uses to verify and document the closure or removal of a bridge. The BIA Bridge PM will specify the condition to be documented and the appropriate reporting method in the bridge inspection task order Statement of Work (SOW).

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2.4 FREQUENCY OF INSPECTIONS

In general, BIADOT bridges are inspected at regular, 24-month intervals in accordance with the NBIS. Certain bridges may require inspection at less than 24-month intervals, while the Bridge Program Office can inspect others at greater than 24-month intervals. The BIA Bridge PM, based on the NBIS, BIADOT policy, the recommendation of the inspection team leader, regional input, and these guidelines, will determine the level and frequency of inspection for each bridge in the Bureau’s inventory.

2.4.1 Initial Inspections

The Bridge Program conducts initial inspections once when a new bridge is added to the BIADOT inventory, typically during the next biennial inspection cycle encompassing the bridge’s geographic area.

2.4.2 Routine Inspections

Routine inspections are required for all bridges on the Federal Highway Administration’s National Bridge Inventory (NBI) at 24-month intervals. The inspection of non-NBI bridges (typically bridges under 20 feet long or bridges not open to the public) are conducted at 24-month intervals unless they meet all of the following criteria:

• Structural condition ratings are seven or higher,

• Scour condition ratings are seven or higher,

• The bridge does not have fracture critical members, and

• The bridge’s estimated remaining life is greater than 10 years.

If a non-NBI bridge meets these criteria, then an inspection cycle of 48-month intervals may be determined and assigned by the BIA Bridge PM.

2.4.3 Fracture Critical Member Inspections

All FCM elements of a bridge require fracture critical member inspection during initial and routine inspections and shall be conducted every 12 months unless the BPM specifies a different inspection frequency.

2.4.4 Underwater Inspections

All submerged elements of a bridge require underwater inspection during initial and routine inspections. The team leader and BIA Bridge PM should assess the need for in-depth diving inspection for any portion of a bridge exposed to water deeper than 3 feet. The assessment should consider such factors as:

• Structure type

• Foundation type

• Footing location relative to channel bottom

• Known or suspected problems

• Waterway characteristics

• Superstructure and substructure redundancy

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Any portion of a bridge submerged more than 6 feet during periods of normal low water must undergo an in-depth diving inspection conducted at an interval not to exceed 60 months.

2.4.5 Interim Inspections

The BIA Bridge PM determines when to schedule interim inspections. Typically, the PM will schedule interim inspections to take place midway between the regularly scheduled routine inspections and will continue until the deficiency requiring monitoring has been eliminated.

2.4.6 In-Depth, Damage, and Special Inspections

The BIA Bridge PM, with input provided by the Regional Engineer and Regional Coordinator, will determine how often to conduct in-depth, damage and special inspections.

3 INSPECTION PROCEDURES

3.1 PREPARATION FOR INSPECTION

Prior to beginning the inspection, the inspection team should obtain the original design drawings, as- built drawings, repair drawings, maintenance history, and previous inspection reports for the bridge. The BIA Bridge PM, Regional Engineering Office or facility Point of Contact (POC) can assist in locating or supplying the original design drawings, records, previous inspection reports, etc.

The inspection team should review available records prior to going into the field. Inspection planning activities should include a determination of the necessary inspection equipment, required forms, and any special access requirements such as rigging, snooper or bucket trucks, underwater inspection equipment, and-or personnel. A copy of the previous inspection report, if available, should be used as a reference during the current inspection.

FCM inspection requires additional preparation. The most important activities are:

• Identify and provide BPM with technical drawing(s) of all possible FCMs.

• Create a separate FCM inspection plan and procedure templates for a two-girder bridge system and a truss bridge system

• Note the particular members in the structure that may require special field attention, such as built-up tension members composed of few individual pieces.

• Pre-plan necessary access to the members, including special equipment needs such as ladders, bucket truck, or climbing gear.

• Identify and make available any necessary special tools and equipment that may be required in addition to the normal inspection gear.

3.2 BRIDGE ACCESS

Many BIA bridges are located in remote locations or in other areas that are not accessible to the general public.

It is not unusual to encounter locked gates or other access controls due to wildlife migration and breeding, or because of natural hazards such as wildfire and flooding. Other bridge sites may be home to unexploded ordnance or wildlife that may not be amenable to human interaction. Some locations can only be accessed by boat, All Terrain Vehicle (ATV) or other means of conveyance. It’s important to closely coordinate with the

Page | 22 agency POC to make arrangements for special access, lodging, keys, escort (armed or otherwise), or site-specific training in the months, weeks and days preceding field inspection.

3.3 FIELD DOCUMENTATION TECHNIQUES

Inspectors must document existing conditions found during the inspection with detailed field notes and digital color images. The inspection team must prepare inspection notes and sketches in enough detail to accurately locate deficiencies, describe the limits of the deficiencies in enough detail to estimate the quantities for proposed repairs and restoration work, and evaluate the effect of the deficiencies on the load carrying capacity of the structure. Images should support and supplement the field notes.

3.3.1 Field Notes

Thoroughly examine all physical features of a bridge that affect its structural integrity during the inspection. The inspection team must accurately determine and record the location, severity, and extent of all damaged and deteriorated sections. Direct measurements of the surface area, depth, and location of defects are preferred to visual estimates of percentage loss.

Inspectors make field measurements to provide baseline data on the existing structure components and to track changes, such as crack width and length. Deficiencies such as cracks, spalls, and delamination can change over time, so it’s important to acquire the initial measurements in a manner that can be replicated during future inspections.

Measurements may be required on structures for which no plans are available or to verify data shown on plans.

Your measurements should be precise enough to serve the purpose for which they are intended.

When plans are available for a structure that is to be load rated, the inspector will typically take dimensions, member types, and member sizes from the plans. However, many plans are not as-built plans and may not reflect all changes made to a bridge during construction or subsequent repairs. Check and compare the plans during the field inspection to ensure that they truly represent the structure before you use them in structural calculations. Give special attention to changes in dead load, such as alterations in deck geometry, additional overlays, and-or new utilities. Increased dead load will be documented because it may affect the load rating for the structure.

Make and record enough measurements to track changes in joint opening, crack size, or bearing position.

Members of the inspection team may also have to take measurements to monitor suspected or observed substructure tilting or movement. In these cases, it is necessary to permanently mark on the structure and record in the field notes the measurements to serve as a datum for future readings. Include a log of the readings in the inspection report and update it with the new readings after each inspection cycle.

3.3.2 Urgent Item Forms

Inspectors must bring critical findings to the attention of the Bride Program Manager as soon as practicable using the Urgent Item form (BPUW 2020). A critical finding is an existing bridge or bridge-related condition that presents an imminent safety hazard to BIADOT staff or to the general public. A completed Urgent Item form should contain the following (Refer to Form BPUW 2020 located in Appendix I):

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• The location of the hazard o Region o Agency o Bridge name and number

• A description of the hazard

• Feasible action or actions that will address the hazard

• The date that the hazard was first brought to the attention of station personnel (may be the current reporting date)

• The name and affiliation of the team leader reporting the hazard

• The name and title of the regional representative to whom the critical finding is reported

• The date that the report is acknowledged by the regional representative

Urgent Item forms must be prepared by the team leader and provided to a station representative within 24 hours of identification of the critical finding.

Stations should resolve all items identified on the Urgent Item form as soon as possible, but in no case should a critical finding remain unresolved after 12 months.

A blank Urgent Item form (BPUW 2020) is included in Appendix I.

3.3.3 Images

Take images with a minimum resolution of 240 dpi to document typical and significant structure conditions.

Your images should be well composed, without extraneous vehicles, people, or debris. Images should be properly lighted using a flash if necessary. When composing images of details or localized deficiencies, place a scale or inspection tool (e.g., hammer, pencil, etc.) on the area you are recording in order to provide a frame of reference for the subject. Add digital annotations, such as arrows, when you prepare the report to draw attention to the deficiency or detail.

As a minimum, record the following images in the field:

• An elevation view of each side of the bridge

• A view of each approach roadway, looking toward the bridge

• A view of each approach roadway, looking away from the bridge

• A view looking upstream and a view looking downstream from the bridge

• Typical view of any deficiency rated “5” or less

• Typical view of superstructure

• Typical view of substructure units

3.4 Fracture Critical Members

3.4.1 General Requirements

Inspection of fracture critical members requires hands-on inspection, i.e. close up within arm’s length to properly identify, measure, and determine the extent of deficiencies. When required by the condition of the member or where required by procedures established for the bridge, visual inspection must be supplemented by applicable non-destructive testing (NDT).

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Inspections of fracture critical members are done at the same time as the routine inspection, and will be inspected on a frequency not to exceed 24 months. If a significant defect is found in a fracture critical member, inspection frequency will generally be 12 months or less until the defect can be repaired.

3.4.2 Pre-Inspection / Documentation

Bridges with fracture critical members are identified by the structure folder and any special inspection procedures must be in the folder. The outside of the folder must be labeled “Fracture Critical.”

Fracture critical members are called out on the sketches with the symbol: FCM Beneath the symbol is the member description (e.g. Bottom Chord, Floor Beams, etc.)

3.4.3 Inspection Documentation

Inspection types may be initial or routine. Formats for report types may be full or check.

NBI Item 92A will be coded as “Y _ _” where the second and third characters contain the inspection frequency in months (not to exceed 24).

NBI Item 93A must be coded with the last date a fracture critical inspection was done.

The “Additional Comments” field of the “Additional Information and Comments” section of the full report or the “Comments” section of the check report must contain a summary statement of the findings of the inspection of fracture critical members.

Recommendations for repair work or other action, such as load restriction or bridge closure due to significant inspection findings, must be included in the “Recommended Work” section of the report and marked as urgent.

3.4.4 Inspection Procedures

FCM inspections are done no further than arm’s length away. This may entail walking along the lower chord of trusses or conducting close inspections by other means. The inspection of FCMs may require an under bridge access vehicle, a ladder, a bucket truck, or a boat to get close enough to the members and connections to clean and measure corrosion and-or cracks. The inspector needs to follow safety protocol by using fall arrest or other applicable safety equipment. The inspector may need to remove dirt and debris to sufficiently observe and measure the remaining section on the lower chord, gusset plates, and ends of floor beams. Tension areas of FCMs will be the main focal points. The inspector needs to observe the coped sections of floor beams and their connections to the truss.

Inspectors must follow any special inspection procedures outlined in the bridge folders. For most bridges special inspection procedures are not needed, for example the detection of fatigue cracks in most steel girders is adequately addressed in the FHWA manual for the Safety Inspection of In-Service Bridges and the FHWA Bridge Inspector’s Reference Manual (BIRM).

If fatigue cracks are suspected, the bridge inspector must clean the area, remove any applied coating, if necessary, and perform grinding and-or dye penetrant testing as necessary to determine if there is cracking and the extent. If these methods are inadequate or impractical for the particular situation, the BIADOT Bridge PM

Page | 25 must be consulted and additional personnel must be employed to complete the fracture critical inspection using ultrasonic or other applicable NDT methods. The locations, date, and type of test must be documented in the inspection report.

Significant defects, such as fatigue cracking, tearing, impact damage, significant corrosion, etc. will be brought to the attention of the BIADOT Bridge PM and the facility POC. The defects and repair or other action, such as load restriction or bridge closure, will be relayed to the facility POC before leaving the agency using the Urgent Bridge Work Recommendation Items form (BPUW 2020). The BIA Bridge PM or consultant’s Senior Bridge Inspection Engineer must reduce the inspection frequency to 12 months or less until the defect can be repaired. The structure may be load restricted or closed until the deficiency is repaired. The BIA Bridge PM will determine the course of action.

3.5 In-Depth Dive Inspections

Each bridge with elements requiring in-depth dive inspection must have written bridge-specific inspection procedures which address items unique to the bridge. The written inspection procedures must address those items that the dive team leader should know to insure a successful inspection. In- depth dive inspections must be performed according to these written inspection procedures. Proper development of good inspection procedures and concerted attention to following those procedures will mitigate most risks. The prior inspection report is a valuable resource for reviewing previous inspection findings, but it does not serve the same purpose as the bridge-specific in-depth dive inspection procedures.

In addition to following the bridge-specific in-depth dive inspection procedures, planning and preparation for in-depth dive inspections must incorporate:

• Identified underwater elements

• Physical scour countermeasures

• Access

• Inspection equipment

• Structural details

• Hydraulic features and characteristics

• Risk factors (as detailed below)

• Ιinspection methods and frequencies

• Required qualifications of inspecting personnel

• Scheduling considerations (lake draw-down, canal dry time, etc.)

Specific risk factors include waterway features that may promote scour and undermining of substructure elements, such as:

• Rapid stream flows

• Significant debris accumulation

• Constricted waterway openings

• Soft or unstable streambeds

• Meandering channels

Water conditions that may affect the inspection such as black water or rapid stream flows should also be identified and accounted for in the inspection methods. Water environment and structural systems or materials

Page | 26 that may combine for accelerated deterioration of the bridge elements should be identified, such as highly corrosive water, unprotected steel members, timber piling in the presence of marine borers, etc. By identifying these conditions or risk factors, and providing the BIA BPM with this list of risk factors, the underwater inspectors can appropriately prepare for and perform a thorough inspection.

3.6 AGENCY PRE-INSPECTION COORDINATION

Prior to arrival at an agency, the inspection team must notify the agency POC of the team’s pending arrival. In the best circumstances, this should occur twice:

• Once prior to the start of the inspection trip to confirm the tentative inspection date, and

• Once anywhere from 3 to 24 hours before the anticipated arrival time at the station.

After arrival at the agency but prior to starting the actual field work, the inspection team must conduct an in-brief meeting with agency personnel. The purpose of this meeting is to:

• Review the scope of work

• Ensure all available information is collected

• Ensure facility personnel are aware of the scope and schedule

• Exchange emergency contact numbers

• Determine any special requirements, such as:

o Work hour restrictions o Locked gates o Special access (boat, ATV, horse) o Special vehicles (required for load rating)

The agenda should include:

• Introductions

• Scope of work

• Maps of facilities

• Bridge plans

• Average Daily Traffic (ADT) counts

• Property record numbers

• Special bridge concerns/scheduling issues

During the meeting, the inspection team leader must ensure all interested parties understand the nature of the work and determine if they have any special requirements.

3.7 AGENCY POST-INSPECTION DEBRIEFING

At the end of the field inspection, the inspection team must hold a debriefing in conjunction with the on-site station representative. The purpose of the debriefing is to notify station personnel of conditions found during the inspection, any operational restrictions, and any possible repair recommendations. The inspection team leader must summarize the inspection findings for each bridge inspected. Items to present include:

• General condition of each bridge

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• Critical findings

• Other findings

• General recommendations for repairs or maintenance

Although the information presented is typically general in nature, it should be thorough and well- presented.

3.8 POST-TRIP DEBRIEFING

At the end of the field inspection trip, the inspection team shall conduct a post-trip debriefing with the BIADOT Bridge PM and Regional Bridge Coordinator. This debriefing should include:

• Lead…