FATIGUE-BASED METHODOLOGY FOR MANAGING IMPACT OF HEAVY-PERMIT TRUCKS ON STEEL HIGHWAY BRIDGES

Special permits are issued frequently to extra heavy vehicles without detailed evaluations of individual components. Consequently, a large number of special permits have been issued to extra heavy vehicles and the only consideration has been the ultimate capacity of the overall bridge inventory. The authors of this paper study the ultimate and cumulative effect of this overload on steel highway bridge components. It is found that bridge members have adequate ultimate capacity to handle these overloads; however, fatigue damage may occur from the cumulative effect of the overloads. A fatigue-based procedure is developed to determine the reduction in service life of bridges due to heavy-permit trucks. Using this new method, it is found that a fairly large number of permits can be issued at small reductions in fatigue life; however, stress ranges in excess of the constant-amplitude fatigue limit significantly alter the shape of the S-N curve, suggesting that the concept of infinite fatigue life is unrealistic.

Language

  • English

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Filing Info

  • Accession Number: 00712783
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Oct 28 1995 12:00AM