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Office of Maintenance

Office of Maintenance / Structure Operations / Bridge Load Rating

Bridge Load Rating

Picture of a Temporary Bridge

CONTACTS

District Name Email Phone
Central Office Andrew DeVault CO-LoadRating@dot.state.fl.us 850-410-5531
District 1 Steve Womble D1-LoadRating@dot.state.fl.us 813-612-3362
District 2 Ross Hammock D2-LoadRating@dot.state.fl.us 386-961-7007
District 3 Tim Barnard D3-LoadRating@dot.state.fl.us 850-330-1601
District 4 Hector Kinda D4-LoadRating@dot.state.fl.us 954-777-4481
District 5 Sandusky McCartney D5-LoadRating@dot.state.fl.us 386-740-3455
District 6 Giuseppe Noto D6-LoadRating@dot.state.fl.us 305-470-5438
District 7 Steve Womble D7-LoadRating@dot.state.fl.us 813-612-3362
District 8 Aran LessardD8-LoadRating@dot.state.fl.us 954-934-1234

DOCUMENTS

Name Attributes
2018 Load Rating Manual Adobe PDF - 1.77 MB - Rev. Date 12-22-17
2018 Load Rating Summary Form with Emergency Vehicles Excel XLSX - 535 KB - Rev. Date 10-08-18
2018 Load Rating Summary Form Excel XLSX - 548 KB - Rev. Date 12-22-17
Bridge Management System (BMS) Coding Guide Document is located on the Bridge Inspection page
Hinged-End Culvert Example Zip File - 2.2 MB - Rev. Date 04-12-16
Structure Number Request Form Excel XLSM - 35 KB, Rev. Date 09-22-17

DOCUMENTS ARCHIVE

Name Attributes
2017 Load Rating Manual Adobe PDF - 2 MB - Rev. Date 02-20-17
2016 Load Rating Summary Form Excel XLSX - 540 KB - Rev. Date 09-26-16
2016 Load Rating Manual Adobe PDF - 750 KB - Rev. Date 09-26-16
2015 Load Rating Manual Adobe PDF - 1.3 MB - Rev. Date 07-13-15
2015 Load Rating Summary Form Excel XLSX - 538 KB, Rev. Date 07-13-15
2014 Load Rating Manual Adobe PDF - 891 KB - Rev. Date 01-01-14
2014 Load Rating Summary Form - LRFR Excel XLSX - 32 KB - Rev. Date 01-01-14
2014 Load Rating Summary Form - LFR Excel XLSX - 32 KB, Rev. Date 01-01-14
2012 Load Rating Manual Adobe PDF - 1.4 MB, Rev. Date 08-01-12
2011 Load Rating Memorandum Redacts FL120 Service III Adobe PDF - 141 KB, Rev. Date 09-01-11
2011 Load Rating Manual Adobe PDF - 933 KB, Rev. Date 01-01-11
2010 Load Rating Memo, Striped Lanes - Segmentals Adobe PDF - 271 KB, Rev. Date 04-06-10
2009 Load Rating Memo, Double-Leaf Bascules Adobe PDF - 119 KB, Rev. Date 08-19-09
2006 Load Rating Manual Adobe PDF - 171 KB, Rev. Date 10-19-06
1995 Load Rating Manual Adobe PDF - 2.4 MB, Rev. Date 03-16-95
1982 Load Rating Manual Adobe PDF - 24.3 MB, Rev. Date 09-01-82
Florida SU Load Posting Signs for AASHTO SHV-SU Trucks Zip File - 1.4 MB - Rev. Date 11-14-17

REFERENCES

AASHTO Bookstore - Specifications and Design Manuals
FDOT Bridge and Other Structures Inspection and Reporting Manual
FDOT Bridge Information
FDOT Bridge Inspection
FDOT Construction Project Administration Manual (CPAM)
FDOT Load Rating Detail Table, CAD
FDOT Manual of Uniform Minimum Standards for Design (GREENBOOK)
FDOT Plans Preparation Manual (PPM)
FDOT Standard Specifications for Road and Bridge Construction
FDOT Structures Design Guidelines (SDG)

QUESTION & ANSWER, GENERAL

The Bridge Load Rating Manual (BLRM) "Quick Check" description is rather vague and "quick" is relative. Does this confirmation only seek to show that the operating truck, placed at the ordinates shown in the table, meets shear and moment criteria in the underlying beams? If more is expected, please clarify.


At "Definition, Complete Load Rating" the BLRM defines a "Quick Check" as follows:

At a minimum, confirmation of the governing Design Operating Rating; show the factored components of the rating factor equation. A more comprehensive check is recommended, especially when results significantly differ from the original Design Load increased to the Operating Level.

The “governing Design Operating Rating” is the minimum rating that controls or governs the Design Vehicle overall at the Operating Level. The governing rating may be moment, shear, or occasionally service – but only one rating governs the Design Vehicle overall. The “factored components of the rating factor equation” are just that – factored capacity, factored dead load, and factored live load. It is helpful to show the internal components as well, the factors and such, but only the fully factored components are required. The intent is to (1) provide a starting point for review, and (2) show that the analyst can readily identify the critical components, that the work is more than “button pushing.”

QUESTION & ANSWER, EMERGENCY VEHICLES (EVs)

The 2019 Bridge Load Rating Manual will incorporate new Emergency Vehicles (EVs) for bridges carrying interstate highway traffic, and state-owned bridges within 1 mile reasonable access to interstate interchanges. Prior to implementation of the EVs, a 2018 parametric study identified 78 bridges for EV analysis. These questions and answers pertain to those 78 bridges analyses.

For the 78 bridges identified for EV analysis, only load rate the EVs?
No. For the selected bridges, assess all vehicles. For LFR, rate the HS20, 7 Florida Legal Loads, and the 2 EVs. For LRFR, rate the HL93, the FL120, 7 Florida Legal Loads, and the 2 EVs. There are exceptions. For example, a complex bridge like the Skyway Bridge in Tampa might only assess EVs. However for most all the selected bridges, perform a fresh new all-in-one load rating. This will keep things together in one report. Also, since the EV bridge list identifies the weakest structures on or near the interstate, many will benefit from a second look.

Can you make available to us a successfully completed load rating done including EV vehicles in the State of Florida?
An example will be published by January 1, 2019.

Does the 30 day posting requirement timeline apply to EVs?
Yes, but the requirement will not apply to EVs until January 1, 2020.

How will segmental bridges be assessed?
On a case-by-case basis. EV analysis for segmental bridges may be based upon the existing load rating, and amended to include EV ratings.

Should EV analysis begin by considering unmixed EV-only traffic, where the EV is in one or more lane?
Yes. Only consider mixed traffic (EV and the governing legal load) as a posting avoidance technique.

When load rating the EV vehicles, are we to simultaneously consider other vehicles (such as other Legal Loads) in other lanes on the bridge? Yes.
At first, with the associated multiple presence factors, take the worst of:
  • EV in one lane
  • EV in two lanes
  • EV in three lanes
If the EV rating factor is greater than 1.00, stop there. However if the EV rating factor is less than 1.00, try posting avoidance techniques. If other posting avoidance techniques are unsuccessful, then try the most difficult posting avoidance technique – mixed traffic. With the associated multiple presence factors, take the worst of:
  • EV in one lane
  • EV in one lane, and the Florida legal truck that governs moment in the adjacent lane
  • EV in one lane, and the Florida legal truck that governs moment in the two adjacent lanes
The “Florida legal truck that governs moment” is:
  • SU3 for span lengths less than 12 feet
  • SU4 for span lengths between 12 and 100 feet
  • C5 for span lengths over 100 feet
Posting avoidance typically progresses from easy to hard, from say rounding or impact adjustments to refined analysis and mixed traffic, and the recommendations above follow such a progression. However load ratings need not apply posting avoidance in a rigidly prescribed order. That is, it is not necessary to doggedly exhaust a maze of regulations before concluding with a path that was known at the outset.

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