Bridge Inspection Practices (2007) / Chapter Skim
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Pages 26-43
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From page 26... ...
• Inspectors -- regulations set minimum qualifications for inspection program managers and inspection team leaders. • Procedures -- regulations include, by reference, the Bridge Inspector's Reference Manual (4)
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From page 27... ...
indicate that although 84% of NBI-length bridges and culverts are water crossings, only 6% require inInspection Description Damage Inspection An unscheduled inspection to assess structural damage resulting from environmental factors or human actions. Fracture-Critical Member Inspection A hands-on inspection of a fracture-critical member or member components that may include visual and other nondestructive evaluation.
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From page 28... ...
Twenty-two DOTs require specific training or experience in personnel for these inspections. The Connecticut DOT identifies bridge complexity in three levels and specifies inspection team size and technical grades of team members for each level of complexity.
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DOT Percentage of Routine Inspections at 48-Month Interval Arizona 44 Illinois 42 New Mexico 35 West Virginia 24 Kentucky 17 Montana 16 Colorado 14 North Dakota 10 Texas 9 South Dakota 7 Connecticut 6 Washington 6 Arkansas 5 Virginia 5 Mississippi 1 Oklahoma 1 TABLE 41 PREVALENCE OF 48-MONTH INSPECTION INTERVAL
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From page 30... ...
Annually Consultant bridge inspector Reports from Users Reports of: impact damage vandalism debris on bridge or road erosion damage In response to user report Principal Thorough and systematic visual inspection of all the components of the bridge 6 years or lessc Directorate bridge inspector Special Collection of more detailed information for decisions on maintenance actions In response to recommendation from routine inspection Consultant bridge inspector Economic Special Inspection Preparation for major repair project for a bridge Development and comparison of remedial strategies In advance of project selection and development Consultant bridge inspector Technical Special Inspection Damage investigations Special investigations Load-carrying capacity evaluations In response to extreme event, or suspect capacity Consultant bridge inspector aNot a formal part of the Directorate bridge inspection program. bSpecially trained personnel.
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From page 31... ...
All bridge components are assigned condition ratings, and inspection data are entered in the bridge registry. General inspections are done by certified bridge inspectors.
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From page 32... ...
Large waterway bridges 8 years Certified inspector with engineering degree Basic For reference bridge group Inspection of all components Includes material sampling and testing to improve deterioration models 5 years Certified inspector with engineering degree Special Methods vary with needs of project For planning and development of repair projects Certified inspector with engineering degree Machinery of movable bridges; includes annual maintenance 1 year Specialist Suspension cables, stay cables 15 years Certified bridge inspection, specialist in cables Underwater Inspection by diving; visual and touch inspection of components 5 years Certified inspectors with special training Intensified Monitoring More frequent inspection Due to poor or weakened condition TABLE 43 TYPES OF BRIDGE INSPECTIONS -- FINLAND
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From page 33... ...
TABLE 45 TYPES OF BRIDGE INSPECTIONS -- GERMANY Inspection Type Interval Performed by Description Routine Visit Frequent Road maintenance agents employed by DDE Drive-by inspection Annual 1 year Road maintenance agents employed by DDE Cursory examination during visit to bridge IQOA 3 years Inspection agent sometimes with certified inspector Visual verification of conditions focusing on known defects 9 years Robust bridges. Arms-length visual examination of all components and noting all defects 6 years Normal bridges.
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From page 34... ...
Class Type Description Acceptance inspection Performed for new construction and after major repair projects Note deficiencies and damage Identify sources of deterioration that may be significant to maintenance First Warranty inspection Performed near the end of the warranty period Verify that repairs required by acceptance inspection are complete Note additional deficiencies and damage Identify additional sources of deterioration that may be of significance to maintenance General inspection Check for any serious damage affecting the load capacity, traffic safety, future maintenance, or environment/aesthetics Major inspection Inspection of all components Determine needs for maintenance or repair Estimate costs of maintenance or repair Measurements and material sampling as needed Major inspection -- Cables Inspection of cables, hangers, clamps and anchorage points Verify adequacy and function of cable systems Determine maintenance needs and costs Routine Major inspection -- Underwater Dive inspection Inspect submerged components Inspect the river bed Determine maintenance needs and costs Additional Special inspection Diverse purposes: investigation of known damage development of repair/rehabilitation projects checking after extreme events checking after problems at bridges of similar type TABLE 46 INSPECTION DESIGNATIONS -- GERMANY TABLE 47 TYPES OF BRIDGE INSPECTIONS -- NORWAY
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From page 35... ...
X X Inspection Type Interval Performed by Description Monitoring At least once each year, usually more frequently Maintenance personnel Quick look for new defects and status of known defects Principal 5 years Inspectors experienced in bridge design or maintenance Full report with photographs of defects Verification ~60 bridges per year Senior bridge inspector QA effort to verify accuracy of inspection data Project-level Before repair project Experienced bridge engineer employed by consulting engineering firm Inspection to collect information for contract documents Acceptance After repair project Experienced bridge engineer employed by consulting engineering firm Inspection of work during and after contract TABLE 48 REQUIREMENTS FOR TESTS -- NORWAY TABLE 49 TYPES OF BRIDGE INSPECTIONS -- SOUTH AFRICA
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From page 36... ...
Superficial inspections are frequent visits to bridges made by the road maintenance contractor. Superficial inspections do not yield condition ratings.
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From page 37... ...
Country Type Interval Notes Dive None When ordered by regional bridge inspectorDenmark Wade 6 years Performed during Principal inspection Finland Dive 5 years Schedule set by district bridge engineer Dive, Intensity 1 6 years Arms-length inspection Performed separately from other inspections France Dive, Intensity 2 None Includes measurements and material sampling Performed as needed Germany Dive 6 years Performed during Major test South Africa Dive None Few bridges require inspection by divers Dive 6 yearsSweden Channel profile None At discretion of inspection team United Kingdom Dive or wading 6 years Highways Agency Area Structures Manager reviews/approves contractor's proposed method(s) for underwater inspections TABLE 52 UNDERWATER INSPECTION INTERVALS -- FOREIGN AGENCIES
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From page 38... ...
Condition ratings (Table 53) are built up (literally summed)
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From page 39... ...
. Norway Norwegian practice reports condition ratings for bridge elements and identifies specific types of damage that are observed.
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From page 40... ...
Immediate repair or rehabilitation is needed TABLE 60 CONDITION RATINGS FOR TRAFFIC SAFETY -- GERMANY TABLE 61 CONDITION RATINGS FOR DURABILITY -- GERMANY Grade Description 1.0–1.4 Very good structural condition Continue normal maintenance 1.5–1.9 Good structural condition, but may have less long-term durability Continue normal maintenance 2.0–2.4 Satisfactory structural condition, but may have less long-term durability Continue normal maintenance and consider a plan for repair 2.5–2.9 Unsatisfactory structural condition Traffic safety may be affected Structure is not sufficiently durable Continue normal maintenance and plan for repair Restrictions on traffic use or load may be needed 3.0–3.4 Critical structural condition Traffic safety is affected Structure is not durable Immediate repair is needed Restrictions on traffic use or load are needed 3.5–4.0 Inadequate structural condition Traffic safety is not adequate Structure is not durable Immediate repair or rehabilitation is needed Restrictions on traffic use or load are needed TABLE 62 GERMANY: COMPUTED CONDITION RATINGS FOR COMPONENTS Rating Description 1 Minor damage or defects that might not require any remedial action within the next 10 years 2 Average or slight damage or defects that require remedial action within 4 to 10 years 3 Serious damage or defects that require remedial action within 1 to 3 years 4 Critical damage or defects that require remedial action within 0 to 1/2 year 9 Not inspected TABLE 63 NORWAY: CONDITION RATINGS
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From page 41... ...
Rating Description 1E Minor damage/defect that might affect the environment/aesthetics if not repaired within the next 10 years 2E Average damage/defect that might affect environment/aesthetics if not repaired within 3 to 10 years 3E Serious damage/defect that might affect environment/aesthetics if not repaired within 1 to 3 years 4E Critical damage that affects environment/aesthetics; needs immediate repair or repair within 6 months TABLE 66 NORWAY: CONDITION RATINGS FOR MAINTENANCE COSTS TABLE 67 NORWAY: CONDITION RATINGS FOR AESTHETICS Damage Code Description 201 Settlement of concrete element 202 Movement of concrete element 203 Deformation of concrete element 204 Cracks in concrete element 205 Rupture of concrete element 206 Damage to concrete surface treatment 207 Leakage/dampness of concrete element 208 Discoloration of concrete elements 209 Insufficient/damaged cover of concrete element 210 Weathering of concrete element 211 Honeycombing of concrete element 212 Delamination of concrete element 213 Spalling of concrete element 214 Corrosion of reinforcement 215 Wash out of concrete element 216 Inadequate cleaning of concrete element 217 Inadequate clearing-up/removal 218 Poor concrete quality 219 Scoring/undermining of concrete element 220 Missing part(s) of concrete element 290 Other damage to concrete element Damage Code Description 100 Elements in ground 200 Concrete elements 300 Steel, aluminum, and iron elements 400 Stone/masonry elements 500 Timber elements 600 Deck surfacing 700 Bearings and joints 800 Drainage, approaches, and accessories TABLE 68 NORWAY: CODES FOR DAMAGE TO CONCRETE ELEMENTS TABLE 69 NORWAY: SERIES FOR DAMAGE TYPES Rating Description 1C Minor damage/defect that might reduce strength if not repaired within the next 10 years.
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From page 42... ...
United Kingdom During Principal inspections, defect severity is reported on a 1 to 5 scale, and defect extent on an "A" to "E" scale. These condition ratings are used in Structures Management Information System to generate the performance indicator for visual condition.
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