What is this blog about?

We are destroying the planet at an alarming rate. It's happening due to the ignorance of the world we live in, and in our age of online data access and sharing there is really no excuse for that any more.

This blog investigates novel ways of looking at large datasets. The kind everyone should care about.


This is my personal blog. The views expressed on these pages are mine alone and not those of my employer.

Saturday, September 13, 2008

Bridge rating explanations

This is the explanation of the 2007 US DOT bridge safety data (taken from their document). See main post for a general introduction.


Page 38: ratings for deck, superstructure and substructure (items 58, 59, 60).

CodeDescription
9EXCELLENT CONDITION
8VERY GOOD CONDITION ‑ no problems noted.
7GOOD CONDITION ‑ some minor problems.
6SATISFACTORY CONDITION ‑ structural elements show some minor deterioration.
5FAIR CONDITION ‑ all primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
4POOR CONDITION ‑ advanced section loss, deterioration, spalling or scour.
3SERIOUS CONDITION ‑ loss of section, deterioration, spalling or scour have seriously affected primary structural components. Local failures are possible. Fatigue cracks in steel or shear cracks in concrete may be present.
2CRITICAL CONDITION ‑ advanced deterioration of primary structural elements. Fatigue cracks in steel or shear cracks in concrete may be present or scour may have removed substructure support. Unless closely monitored it may be necessary to close the bridge until corrective action is taken.
1"IMMINENT" FAILURE CONDITION ‑ major deterioration or section loss present in critical structural components or obvious vertical or horizontal movement affecting structure stability. Bridge is closed to traffic but corrective action may put back in light service
0FAILED CONDITION ‑ out of service ‑ beyond corrective action


Page 40: ratings for channel and channel protection (item 61).

CodeDescription
9There are no noticeable or noteworthy deficiencies which affect the condition of the channel.
8Banks are protected or well vegetated. River control devices such as spur dikes and embankment protection are not required or are in a stable condition.
7Bank protection is in need of minor repairs. River control devices and embankment protection have a little minor damage. Banks and/or channel have minor amounts of drift.
6Bank is beginning to slump. River control devices and embankment protection have widespread minor damage. There is minor stream bed movement evident. Debris is restricting the channel slightly.
5Bank protection is being eroded. River control devices and/or embankment have major damage. Trees and brush restrict the channel.
4Bank and embankment protection is severely undermined. River control devices have severe damage. Large deposits of debris are in the channel.
3Bank protection has failed. River control devices have been destroyed. Stream bed aggradation, degradation or lateral movement has changed the channel to now threaten the bridge and/or approach roadway.
2The channel has changed to the extent the bridge is near a state of collapse.
1Bridge closed because of channel failure. Corrective action may put back in light service.
0Bridge closed because of channel failure. Replacement necessary.



Page 41: ratings for culverts (item 62)


CodeDescription
9No deficiencies.
8No noticeable or noteworthy deficiencies which affect the condition of the culvert. Insignificant scrape marks caused by drift.
7Shrinkage cracks, light scaling, and insignificant spalling which does not expose reinforcing steel. Insignificant damage caused by drift with no misalignment and not requiring corrective action. Some minor scouring has occurred near curtain walls, wingwalls, or pipes. Metal culverts have a smooth symmetrical curvature with superficial corrosion and no pitting.
6Deterioration or initial disintegration, minor chloride contamination, cracking with some leaching, or spalls on concrete or masonry walls and slabs. Local minor scouring at curtain walls, wingwalls, or pipes. Metal culverts have a smooth curvature, non-symmetrical shape, significant corrosion or moderate pitting.
5Moderate to major deterioration or disintegration, extensive cracking and leaching, or spalls on concrete or masonry walls and slabs. Minor settlement or misalignment. Noticeable scouring or erosion at curtain walls, wingwalls, or pipes. Metal culverts have significant distortion and deflection in one section, significant corrosion or deep pitting.
4Large spalls, heavy scaling, wide cracks, considerable efflorescence, or opened construction joint permitting loss of backfill. Considerable settlement or misalignment. Considerable scouring or erosion at curtain walls, wingwalls or pipes. Metal culverts have significant distortion and deflection throughout, extensive corrosion or deep pitting.
3Any condition described in Code 4 but which is excessive in scope. Severe movement or differential settlement of the segments, or loss of fill. Holes may exist in walls or slabs. Integral wingwalls nearly severed from culvert. Severe scour or erosion at curtain walls, wingwalls or pipes. Metal culverts have extreme distortion and deflection in one section, extensive corrosion, or deep pitting with scattered perforations.
2Integral wingwalls collapsed, severe settlement of roadway due to loss of fill. Section of culvert may have failed and can no longer support embankment. Complete undermining at curtain walls and pipes. Corrective action required to maintain traffic. Metal culverts have extreme distortion and deflection throughout with extensive perforations due to corrosion.
1Bridge closed. Corrective action may put back in light service.
0 Bridge closed. Replacement necessary.



Page 45: comparison with modern criteria (items 67-72)

CodeDescription
9Superior to present desirable criteria
8Equal to present desirable criteria
7Better than present minimum criteria
6Equal to present minimum criteria
5Somewhat better than minimum adequacy to tolerate being left in place as-is
4Meets minimum tolerable limits to be left in place as is
3Basically intolerable requiring high priority of corrective action
2Basically intolerable requiring high priority of replacement
1This value of rating code not used
0Bridge closed

No comments: