Overview of Bridge Inspections in Missouri David Koenig Bridge Management Engineer Missouri...
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Transcript of Overview of Bridge Inspections in Missouri David Koenig Bridge Management Engineer Missouri...
Overview ofBridge Inspections
in Missouri
David KoenigBridge Management Engineer
Missouri Department of Transportation
Missouri Bridge ConferenceApril 9, 2015Columbia, MO
Missouri Structure Totals
• 2014 National Bridge Inventory
• NBI Length Bridges (i.e. >20’ Length)
MoDOT—10,371
Local—13,977
Total—24,348
Map—MoDOT Structures
Structure Lengths
Longest
Local 5,731’ (McKinley-St. Louis)MoDOT 7,845’ (Double Decker-St.
Louis)
Distribution
>5000’—11 >4000’—24>3000’—43 >2000’—86>1000’—224 <300’—22,759
Average Local—69’MoDOT—196’ Statewide—123’
Posted Structures
MoDOT—1,367
Local—3,495
Total—4,862
Deficient Structures
Structural
1,058—MoDOT2,200—Local3,258—Total
Functional
908—MoDOT1,666—Local2,574—Total
Total Deficient
1,966—MoDOT3,866—Local5,832—Total
Inspections
Why do we do it?• Federal Law
• NBIS Regulations
• Public Safety
Inspections
• Failures—65% from Scour/Hydraulic issues
• Others from a widevariety of causes
Inspections
Types/Frequency (Defined by Federal Law)
General/Routine (24 months)
Special (Varies, 60 months max)
Fracture Critical (24 months)
Underwater (60 months)
In Depth (Per State Policy)
Qualifications (Federal Law)• Team Leader qualified person required on site
during all inspections
• Divers required to meet specific inspection training requirements
Inspections
General/Routine
• Majority of State/Local done by District Offices
• State ones that require special access equipment are done by Bridge Division out of Jefferson City
• Four local agencies do their own inspections with oversight by MoDOT
• Statewide around 70 people full/part time people are involved at a cost of $3 million per year
• Most done September thru March, but there are some going on year round
Inspections
Fracture Critical (950 Total)
MoDOT (235)—Bridge Division UBI Crews
Local (715)—Districts/Consultants Perform
Inspections
Underwater• Dives—163 (NBI)• Deep Wades—about 200 • Bridge Division/Consultants• Districts may Assist
Inspections
In Depth• Total—694
• Common Examples• Major Lake• Major River
• Others are for things hardto see from the ground, known problematic areas, and things that just need an occasional closer look
Example—Non FC Cantileverarea with crack. Repaired.
Inspections
Specials• Around 300 statewide• Typically done by UBI Crews• Occasionally Districts/Consultants
• Example—visual inspection found suspected crack. Dyepenetrant was used toto define extent. Pin mayhave had ultrasound done as well. Bridge was closedand later replaced.
Inspections
Element Level Inspections
• New MAP21 Requirement
• NHS Structures Only
• Started October 1, 2014
• 3,729 total NHS structures
• Have 800+ currently completed
• Minimum set of elements required to be collected and reported to FHWA
• MoDOT has chosen to only do the minimum that is required by MAP21
Inspections
Required Elements
• National Bridge Elements• Deck/Slab, Railings, Superstructure,
Substructure, Culverts, Bearings, Railings
• Bridge Management Elements
• Joints, Wearing Surface, Steel Protective Coating, Concrete Protective Coating
• Report Total Quantity for each Element
• Report Quantities for one of four Condition States CS1 (best), CS2, CS3, and CS4 (worst)
• Quantities—Square Feet, Linear Feet, Each