1. Rating of Local Bridges for SHVs Using Virtis Software Virtis/Opis User Group Meeting August 3-4, 2010 Moises C. Dimaculangan, P.E. Minnesota Department of Transportation

2. Presentation Overview  Specialized Hauling Vehicles (SHVs)  Bridge Rating for SHVs  Rating Contract  Rating Analysis  Challenges  Future Project

3. Specialized Hauling Vehicles  What is a SHV? Single unit (SU) trucks with closely-spaced multiple axles Maximum load of up to nearly 80,000 lbs Must meet the Federal Bridge Formula B Considered legal and typically allowed unrestricted operation Examples: Gravel Trucks, Redi Mix Trucks, Milk Trucks

4. Specialized Hauling Vehicles SU4 18’ 54 kips 62 kips SU5 22’ 69.5 kips SU6 26’ 77.5 kips SU7 30’

5. Bridge Rating for SHVs  Why is bridge rating important? SHVs are increasingly common on our roadways Effects on short span bridges Fulfill National Bridge Inspection Standards (NBIS) requirements Update local bridge rating database

6. Bridge Rating for SHVs  Why is bridge rating important? (cont.) Create a consistent summary of load carrying capacities of all state bridges Used for bridge posting and for issuing overweight permits Monitor safety of bridges over time Determine when rehabilitation or replacement is needed

7. Bridge Rating for SHVs Type M3 Type M3S2-40 51’ 80 kips Type M3S3 16’ 48 kips  Minnesota legal trucks used to determine load posting 47’ 80 kips

8. Rating Contract  Funding - $800,000 from FHWA and State Aid  14,786 bridges in the local system  Bridge selection process Operating Rating < HS 27 Rating date, 30+ years old Rating Method Bridge type Local agencies input - 2 year replacement 581 bridges selected for rating

9. Rating Contract

10.  $1400 ± /bridge Data gathering, field investigation, inspections, rating analysis  4 bridge rating contracts $200,000/contract – Bonestroo – national firm – HDR – national firm – LHB – local firm – WSN – local firm

11. Rating Contract  Phase I May 2010 – May 2011  Impact of the project is statewide  Heaviest concentration of work located in southern Minnesota

12. Rating Contract  Scope of work Information and Data Gathering – Examine current inventory rating sheets and inspection reports – Examine bridge files and records Field Investigations – Bridge inspections – Field measurements

13. Rating Analysis  Virtis 6.1 Bridge will be rated in Virtis – Provides consistency in rating Bridges not compatible with Virtis will be rated by hand or other design approved software such as MDX Rating analysis based on AASHTO Design Trucks, MnDOT Legal (posting) Vehicles, and SHV’s Ratings must meet AASHTO Manual for Bridge Evaluation, MnDOT LRFD Bridge Design Manual requirements Perform a complete QC of each rating

14. Rating Analysis  Virtis 6.1 (cont.) Rating method – Reinforced and prestressed concrete bridges will be rated for both LFR and LRFR methods – Steel bridges - LFR method – Timber bridges - ASR method

15. Rating Analysis  Virtis 6.1 (cont.) Why use Virtis for local bridges? – Consistent with TH system – Ease of permitting with local bridges – Ease of re-rating bridges when a change in rating codes, bridges condition or truck configuration occurs

16. Challenges  No plans available Timber and steel bridges Prestress concrete bridges – Physical Inspection Rating (PIR)  No Access Bridge No. 88494 Built in 1950 Concrete Slab Span – 12ft in length Operating Rating = HS18, Date: 1973

17. Br. No. 88494

18. Challenges  Deteriorated Substructures Bridge No. L3612 Built in 1958 Timber Slab Span – 26ft in length Operating Rating = HS26, Date: 1974

19. Br. No. L3612  Abutment pile failure from earth pressure

20. Br. No. L3612  Deteriorated abutment pile

21. Challenges  Unique Design Bridge No. 92079 Built in 1958 Steel Beam Span – 16ft in length Operating Rating = HS20, Date: 1973

22. Br. No. 92079

24. Br. No. 90343  Concrete slab span  20ft long  Built in 1923  Operating rating = HS19  Rating Date: 1973  No plans available

25. Br. No. 90343

26. Br. No. 94063  Steel beam span  17ft long  Built in 1941  Operating rating = HS20  Rating Date: 1973

27. Br. No. 94063

29. Future Project  Phase II $500,000 budget, 2011-2012 contract FHWA audit of load ratings and postings – Emphasis on load rating updates Help locals with permitting by giving them procedures and guidelines Accommodate changing truck weights

30. Questions?