1 FHWA Update 2020 020 AASHTO Rating and Design Bridge (RADBUG) User Group Meeting August 3, 2020 Thom omas S as Saad ad, P P.E. Seni nior S r Struc ructura ral E Engi gineer r FHWA Resource C e Center thomas.saad@dot.gov
Presentation Outline 2 Key FHWA Program Initiatives FHWA Bridge Load Rating Initiatives FHWA Resources, Tools and Training for Bridge Design and Analysis Engineers
FHWA Program Initiatives 3 • National Bridge Inspection Standards (NBIS) Rulemaking • Specifications for the National Bridge Inventory (SNBI) • Critical Findings Database
NBIS - Overview of Proposed Changes 4 • Required by MAP-21 • Changes and lessons learned since last update (2004) o Update methodology, training, and qualifications for inspectors o Element level data o Update frequency of inspection, o Load rating vehicles including a risk-based approach o Clarifications o Establish procedures for reporting o Fill gaps and monitoring of critical findings o Address other questions and o Establish national certification of requests for change bridge inspectors o Ensure uniformity of the inspections and evaluations (NBIS and National Tunnel Inspection Standards)
Proposed 650.311 Inspection Interval 5 Method 1: Method 2: Simplified Risk Rigorous Risk • Routine Interval • Routine Interval 24 months ≤ 12, 24, 48 or ≤ 72* months ≤ 12 months (3 criteria) *>48, Service Insp. at 24 months > 24 and ≤ 48 months (9 criteria) Min. 5 criteria, min. 4 damage mode types • Underwater Interval • Underwater Interval 60 months ≤ 36, 60 or ≤ 72 months ≤ 36 months (2 criteria) 72 months (4 criteria) Min. 5 criteria, min. 4 damage mode types • NSTM Interval • NSTM Interval 24 months ≤ 12 months (3 criteria) ≤ 12, 24 or ≤ 48 months > 24 and ≤ 48 months (4 criteria) Min. 5 criteria, min. 4 damage mode types
Proposed 650.311 Inspection Interval 6 Method 1: Method 2: Simplified Risk Rigorous Risk • Routine Interval • Routine Interval 24 months ≤ 12, 24, 48 or ≤ 72* months ≤ 12 months (3 criteria) *>48, Service Insp. at 24 months > 24 and ≤ 48 months (9 criteria) Min. 5 criteria, min. 4 damage mode types • Underwater Interval • Underwater Interval 60 months ≤ 36, 60 or ≤ 72 months ≤ 36 months (2 criteria) 72 months (4 criteria) Min. 5 criteria, min. 4 damage mode types • NSTM Interval • NSTM Interval 24 months ≤ 12 months (3 criteria) ≤ 12, 24 or ≤ 48 months > 24 and ≤ 48 months (4 criteria) Min. 5 criteria, min. 4 damage mode types
Summary of Process 7 • NPRM Process Started in 2012 • NPRM Published November 12, 2019 • NPRM Closed March 13, 2020 • 265 sets of Comments submitted 190 Comments were submitted w/o attachments 75 Comments had one or more attachments Attachments ranged in length from 1 to 30 pages • 19 Internal FHWA commenters (237 total comments)
Categorizing Comments 8 • 90 day load rating requirement • 30 day load posting requirement • Inspection of private bridges • Reporting of critical findings • Agreements for delegating functions • Inspection intervals • Cost of implementation • Supplemental NPRM
SNBI Comment Counts 9 • 1,450 comments from docket 1,290 from 39 States 160 from: 4 Federal Agencies (34) Counties & County Associations (15) AASHTO (7) Michael Baker (19) Other Industry (7) Professional Associations (2) NTSB, MTA, NSBA (3) Individuals (73)
Transition Plan 10 • NextGen • Tools Crosswalk Converter • Transition period Publish SNBI Collect transitioned dataset on a specific date Collect new data items by a specific date New historical items going forward only
Critical Finding Database (CFD) Effort Overview 11 • Develop a CFD framework – identify data & collection tool • Draft CFD Specifications & create collection tool (SharePoint) • Conduct two pilots – Bridge CFs and Tunnel CFs Revise the specification and collection tool based on the results of the pilots and comments/suggestions received from DBEs and BSEs. • Assist with the implementation of the CFD
CFD Effort Overview 12 • There are 2 SharePoint lists One for Bridges One for Tunnels • 20 Items in each list • Lists are created in SharePoint 365
Specifications for CFD 13 • Scope and purpose • Definition of a CF • Address CF vs. Resolve CF • Examples of CFs to be included in this database • Examples of CFs NOT to be included in this database • Reporting tool • Access your State’s CFD: https://usdot.sharepoint.com/teams/fhwa -hibs- CriticalFundingDB/ Select your email address to sign in Select Bridge_CFD or Tunnel_CFD to report CFs Select your State folder
Bridge CF and Tunnel CF Piloting Programs 14 • Bridge CF pilot – Completed in June 2019 Four (4) piloting FHWA Divisions : Minnesota, Pennsylvania, Washington State, and West Virginia Report Critical Findings occur during 1 st and 2 nd quarters of FY19 • Tunnel CF pilot – From January to February 2020 Six (6) piloting FHWA Divisions: California, District of Columbia, Idaho, Indiana, Michigan, and Virginia Report Critical Findings occur during 1 st and 2 nd quarters of FY20
Bridge Pilot - Data Summary 15
Tunnel Pilot - Data Summary 16 NTEs with High Number of CFs Occurred 12 10 8 6 4 2 0 10200 Ventilation System 10650 Fire Detection 10700 Fire Protection 10750 Emergency System System Communication System
Next Step - Implementation 17 • Plan to initiate effort Fall 2020 • Prepared a roll out plan • Will conduct webinars to inform Division Bridge Engineers • Start collecting data
FHWA Bridge Load Rating Initiatives 18 Load rating of bridges continues to be a big challenge for the industry It is critical to assuring safety of traveling public and providing mobility The FHWA has ongoing efforts to provide policy and guidance to assist State DOTs 18
Changing Truck Weights 19 Special Hauling Vehicles Emergency Vehicles Heavy Duty Tow and Recovery Vehicles Image Source: FHWA
Changing Truck Weights 20 Table le 3 3-8. . Tru rucks a and Tru ruck Mi Mile les b by y Avera rage W Weight: 1987, , 1992, 992, 1 199 997, 7, and 2002 2002 1 Percent Change, 1987 1992 1997 2002 1987 to 2002 Average weight (pounds) VMT Number VMT Number VMT Number VMT Number Number VMT (millions) (thousands) (millions) (thousands) (millions) (thousands) (millions) (thousands) Total 3,624 89,972 4,008 104,987 4,701 147,876 5,415 145,624 49.4 61.9 Light-heavy 1,030 10,768 1,259 14,012 1,436 19,815 1,914 26,256 85.9 143.8 10,001 to 14,000 525 5,440 694 8,000 819 11,502 1,142 15,186 117.6 179.2 14,001 to 16,000 242 2,738 282 2,977 316 3,951 396 5,908 63.6 115.8 16,001 to 19,500 263 2,590 282 3,035 301 4,362 376 5,161 43.2 99.3 Medium-heavy 766 7,581 732 8,143 729 10,129 910 11,766 18.8 55.2 19,501 to 26,000 766 7,581 732 8,143 729 10,129 910 11,766 18.8 55.2 Heavy-heavy 1,829 71,623 2,017 82,832 2,536 117,931 2,591 107,602 41.7 50.2 26,001 to 33,000 377 5,411 387 5,694 428 7,093 437 5,845 15.9 8.0 33,001 to 40,000 209 4,113 233 5,285 257 6,594 229 3,770 9.7 -8.4 40,001 to 50,000 292 7,625 339 9,622 400 13,078 318 6,698 9.0 -12.2 50,001 to 60,000 188 7,157 227 8,699 311 12,653 327 8,950 73.8 25.1 60,001 to 80,000 723 45,439 781 51,044 1,070 74,724 1,179 77,489 63.1 70.5 80,001 to 100,000 28 1,254 33 1,529 46 2,427 69 2,950 144.3 135.2 100,001 to 130,000 8 440 12 734 18 1,051 26 1,571 238.5 257.2 130,001 or more 4 185 5 227 6 312 6 329 43.2 77.9 Source: https://ops.fhwa.dot.gov/freight/freight_analysis/nat_freight_stats/docs/13factsfigures/table3_08.htm
Truck Platooning Image Source: USDOT Office of Infrastructure 21
Objective 22 Period of Performance: 08/13/2018 to 12/12/2020 “The objective of this task order is to produce a comprehensive report for FHWA that covers the technical aspects of truck platooning impacts on bridges with a focus on structural safety.” The report shall include a brief discussion of: The truck platooning technology Identify most common, probable truck platooning scenarios Document the research methodology and findings Recommend load models for bridge evaluation Propose design specification modifications Recommendations for further research
Shear Load Rating for Concrete Bridges John Holt, Uriel Garcia, et al. (2018), Concrete Bridge Shear Load Rating, Synthesis Report, FHWA-HIF-18-061, Federal Highway Administration, November 2018. https://www.fhwa.dot.gov/bridge/loadrating/pubs/hif18061.pdf Office of Infrastructure 23
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