Documents / Document
This is the final highway accident report (NTSB-HAR-71-1) from the National Transportation Safety Board, adopted in December 1970. It covers the collapse of the U.S. 35 bridge between Point Pleasant, West Virginia, and Kanauga, Ohio, on December 15, 1967, which killed 46 people. The Board found that the cause was a cleavage fracture in eyebar 330 at joint C13N. That fracture grew from a flaw produced over 40 years by stress corrosion and corrosion fatigue, in a spot that could not be seen or found by inspection.
“R.G.”1 page
Read from the scan by GLM-OCR; expect the odd misread word.
(a) Identify those bridge building materials used over the past, as well as those presently in use, which are susceptible to slow flaw growth by any of the suspected mechanisms. (120) (b) Investigate these same materials to determine critical flaw size under various stress levels. (120) (c) Develop a new generation of inspection equipment for use under field conditions to detect critical or near critical flaws in heavy structures. It will also be necessary to devise analytical procedures by which the data on flaw growth rates, under various types of exposure, can be interpreted to identify critical locations which require such detailed inspection. One hundred percent inspection will probably prove impractical and extremely expensive. (7,32, 46,120) (d) Develop adequate understanding of these problems to permit the incorporation of appropriate safeguards in the design and fabrication of future bridges and for the qualification of materials for these structures. (120) (e) Devise techniques for repair, protection or salvage of bridges damaged by internal flaws. (120) (f) Expand our knowledge of the loading history and life expectancy of bridges. (117, 118, 120) D. With Respect to the Status of Bridge Inspection and Maintenance: 1. The intensive actions of the Department of Transportation to establish standards for the proper safety inspections of bridges, and training programs for bridge inspectors as required by the Federal-Aid-Highway Act of 1968, are positive steps to increase the safety of highway bridges in the Federal-Aid-System. (82, 83) 2. Over 70 percent of the approximate total of 563,500 highway bridges in the United States are not in the Federal-Aid-System, and 94 percent of the approximate number of 373,000 bridges on county secondary roads, rural roads, and city streets were built prior to 1935. These older structures, which are most subject to extensive repair or replacement, must be funded for by State or local governments which, in many instances, have limited funds for such remedial actions. (82,83)
Document, cited by the archive. The PDF is mirrored here; the original link is above. The text was read from the page images by GLM-OCR; expect the odd misread word. 202 pages are in the text index: search them above, or from the library's search.