Vehicular Overloads: Load Model, Bridge Safety, and Permit Checking
Publication: Journal of Bridge Engineering
Volume 5, Issue 1
Abstract
All states in the United States issue special permits for nondivisible and/or divisible truck overloads exceeding the weight limit of the highway jurisdiction. This causes stress levels higher than those induced by normal truck traffic. The rationality of such overstress levels has not been documented. This paper addresses several aspects of this issue. It presents (1) a method to develop live load models including overload trucks; (2) associated reliability models for assessing structural safety of highway bridges; and (3) proposed permit-load factors for overload checking in the load and resistance factor format. It shows that the proposed overload checking procedure leads to relatively uniform reliability of bridge structures. A sensitivity analysis is also presented here to assure that possible variations of the input data used to prescribe the proposed load factors will not adversely affect bridge safety. The proposed procedure is intended to be used by engineers responsible for checking overload permits. It may be included in evaluation specifications for highway bridges.
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References
1.
Ang, A. H.-S., and Tang, W. L. (1984). Probability concepts in engineering planning and design, Vols. I and II, Wiley, New York,
2.
Bakht, B., and Jaeger, L. G. (1984). “A rational procedure for overweight permits.” Transp. Res. Rec. 950, Transportation Research Board, Washington, D.C., 59.
3.
Cassano, R. C., and LeBeau, R. J. (1978). “Correlating bridge design practice with overload permit policy.” Transp. Res. Rec. 664, Transportation Research Board, Washington, D.C., 230.
4.
Duncan, M. A. G. (1977). “Superloads on highway bridges in South Africa.”J. Struct. Div., ASCE, 103(11), 2165–2179.
5.
Federal Highway Administration (FHWA). (1991). “Overweight vehicles—Penalties & permits: An inventory of state practices for fiscal year 1989.” Rep. to Congress from the Secretary of Transportation, FHWA-MC-91-003, Washington, D.C.
6.
Fu, G., and Hag-Elsafi, O. (1997). “Safety-based bridge overstress criteria for nondivisible overloads.” FHWA/NY/RR-168, Transp. R & D Bureau, New York State Department of Transportation.
7.
Fu, G., and Moses, F. (1991). “Overload permit checking based on structural reliability.” Transp. Res. Rec. 1290, Transportation Research Board, Washington, D.C., 279.
8.
Fu, G., and Tang, J. (1995). “Risk based proof load requirements for bridge evaluation.”J. Struct. Engrg., ASCE, 121(3), 542–556.
9.
Ghosn, M., and Moses, F. (1987). “Calibration of a bridge rating formula for overload permits.” Proc., ASCE Struct. Congr., L. Tall, ed., 15–25.
10.
Gorys, J. M. L., Ripley, G. F., and Little, G. J. (1993). “The characteristics of overweight commercial vehicles on the Ontario Intercity Highway System.” Transp. Quarterly, 47(4), 623.
11.
Guide specifications for strength evaluation of existing steel and concrete bridges. (1989). AASHTO, Washington, D.C.
12.
Manual for maintenance inspection of bridges. (1983). AASHTO, Washington, D.C.
13.
Manual for condition evaluation of bridges. (1994). AASHTO, Washington, D.C.
14.
Standard Specifications for Highway Bridges. (1996). 16th Ed., AASHTO, Washington, D.C.
15.
Moses, F., and Ghosn, M. (1985). “A comprehensive study of bridge loads and reliability.” Rep. FHWA/OH85/005, OhioDOT.
16.
Moses, F., and Verma, D. (1987). “Load capacity evaluation of existing bridges.” Rep. 301, National Cooperative Highway Research Program, Transportation Research Board, Washington, D.C.
17.
“Motor vehicle size and weight regulations, enforcement, and permit operations.” (1980). NCHRP Synthesis of Highway Practice 68, Transportation Research Board, Washington, D.C.
18.
Nowak, A. S. (1995). “Calibration of LRFD bridge code.”J. Struct. Engrg., ASCE, 121(8), 1245–1251.
19.
Nowak, A. S., and Zhou, J. ( 1985). “Reliability models for bridge analysis.” Dept. of Civ. Engrg., University of Michigan, Ann Arbor, Mich.
20.
Roy Jorgensen and Associates. (1969). “Oversize-overweight permit operation on state highways.” NCHRP Rep. 80, National Cooperative Highway Research Program.
21.
Snyder, R. E., Likins, G. E., and Moses, F. (1985). “Loading spectrum experienced by bridge structures in the United States.” FHWA/RD-85/012, Federal Highway Administration, Washington, D.C.
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Received: Sep 2, 1997
Published online: Feb 1, 2000
Published in print: Feb 2000
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