Structures / Bridge Load Rating

  DOCUMENTS

2023 Load Rating ManualAdobe PDF - 1.14 MB - Rev. Date 01-03-23
2022 Load Rating Summary FormExcel XLSX - 453 KB - Rev. Date 01-26-22
Bridge Management System (BMS) Coding GuideDocument on the Bridge Inspection page
BrR FDOT CustomizationZip File - 28.5 KB - Rev. Date 03-05-24
Example, Hinged-End CulvertZip File - 8.5 MB - Rev. Date 01-26-22
Example, SegmentalZip File - 15.3 MB - Rev. Date 05-01-24
Structure Number Request FormExcel XLSM - 35 KB, Rev. Date 09-17-19

 

  DOCUMENTS ARCHIVE

1982 Load Rating ManualAdobe PDF - 24.3 MB, Rev. Date 09-01-82
1995 Load Rating ManualAdobe PDF - 2.4 MB, Rev. Date 03-16-95
2006 Load Rating ManualAdobe PDF - 171 KB, Rev. Date 10-19-06
2009 Load Rating Memo, Double-Leaf BasculesAdobe PDF - 119 KB, Rev. Date 08-19-09
2010 Load Rating Memo, Striped Lanes - SegmentalsAdobe PDF - 271 KB, Rev. Date 04-06-10
2011 Load Rating ManualAdobe PDF - 933 KB, Rev. Date 01-01-11
2011 Load Rating Memo, Redacts FL120 Service IIIAdobe PDF - 141 KB, Rev. Date 09-01-11
2012 Load Rating ManualAdobe PDF - 1.4 MB, Rev. Date 08-01-12
2014 Load Rating ManualAdobe PDF - 891 KB - Rev. Date 01-01-14
2014 Load Rating Summary Form - LFRExcel XLSX - 32 KB, Rev. Date 01-01-14
2014 Load Rating Summary Form - LRFRExcel XLSX - 32 KB - Rev. Date 01-01-14
2015 Load Rating ManualAdobe PDF - 1.3 MB - Rev. Date 07-13-15
2015 Load Rating Summary FormExcel XLSX - 538 KB, Rev. Date 07-13-15
2016 Load Rating ManualAdobe PDF - 750 KB - Rev. Date 09-26-16
2016 Load Rating Summary FormExcel XLSX - 540 KB - Rev. Date 09-26-16
2017 Load Rating ManualAdobe PDF - 2 MB - Rev. Date 02-20-17
2018 Load Rating ManualAdobe PDF - 1.77 MB - Rev. Date 12-22-17
2018 Load Rating Summary FormExcel XLSX - 548 KB - Rev. Date 12-22-17
2018 Load Rating Summary Form with Emergency VehiclesExcel XLSX - 535 KB - Rev. Date 10-08-18
2019 Load Rating ManualAdobe PDF - 1.79 MB - Rev. Date 10-11-19
2019 Load Rating Summary FormExcel XLSX - 532 KB - Rev. Date 10-11-19
2020 Load Rating ManualAdobe PDF - 1.83 MB - Rev. Date 12-19-19
2020 Load Rating Summary FormExcel XLSX - 535 KB - Rev. Date 10-23-20
2021 Load Rating ManualAdobe PDF - 1.62 MB - Rev. Date 12-30-20
2021 Load Rating Summary FormExcel XLSX - 453 KB - Rev. Date 04-15-21
2022 Load Rating ManualAdobe PDF - 1.11 MB - Rev. Date 01-28-22
Florida SU Load Posting Signs for AASHTO SHV-SU TrucksZip File - 1.4 MB - Rev. Date 11-14-17
Florida Bridge Classification for Emergency VehiclesAdobe PDF - 1.22 MB - Rev. Date 07-03-18

 

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 HS20 or HL93 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)

Do new bridges require EV assessments?
No. LRFD design strength criteria is sufficient. Furthermore, a widening need not assess EVs either, if the rating methodology is LRFR and the results meet minimum strength criteria outlined within SDG Chapter 7.

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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