Role of Load History in Reliability-Based Decision Analysis of Aging Bridges
Publication: Journal of Structural Engineering
Volume 125, Issue 7
Abstract
Bridges deteriorate with time due to aggressive environments and are subject to ever-increasing traffic loads. This results in reduction of their reliability, which may eventually fall below an acceptable level. A successful proof load reduces the uncertainty associated with resistance of the bridge and so increases its reliability. Also, if a bridge has survived for T years of service, its resistance is higher than any of the prior imposed loads and so is influenced by its load history. Thus, the reliability of service-proven (i.e., older) bridges would increase. However, the influence of deterioration and increases in traffic loads may negate this expected increase. The paper considers the effects of load history (proof loads and prior service loads) on the reliability of aging bridges. The influence of bridge age and the magnitude of proof loads on updated estimates of bridge reliability is examined. It was found that proof load testing may not be cost effective if the costs of bridge failure (unsuccessful test) and the test itself are considered in a preliminary risk-cost-benefit analysis. The influence of prior service loads on the reliability of existing bridges significantly increased annual bridge reliabilities. The reliability-based approach presented in the paper provides an improved decision-making framework for the assessment of aging bridges.
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References
1.
AASHTO LRFD bridge design specifications. (1994). American Association of State Highway and Transportation Officials, Washington, D.C.
2.
Aktan, A. E., Helmicki, A. J., Hunt, V. J. (1996). “Issues related to intelligent bridge monitoring.” Proc., Struct. Congress XIV, S. K. Ghosh and J. Mohammadi, eds., ASCE, 2, 750–757.
3.
Ariyaratne, W. (1997). “Case history of bridges tested in NSW since 1995.” Proc., AUSTROADS 1997 Bridge Conf., “Bridging the Millennia”, G. J. Chirgwin, ed., AUSTROADS, Haymarket, Australia, 3, 283–290.
4.
cArmaghani, J. M., and Bloomquist, D. G. ( 1994). “Durability specification and ratings for concrete.” Concrete 2000, R. K. Dhir and M. R. Jones, eds., E&FN Spon, London.
5.
Attard, M. N., and Stewart, M. G. (1998). “A two parameter stress block for high strength concrete.” ACI Struct. J., 95(3), 305–317.
6.
Barker, R. M., and Pucket, J. A. (1997). Design of highway bridges based on AASHTO LRFD bridge design specifications. Wiley, New York.
7.
Benjamin, J. R., and Cornell, A. (1970). Probability, statistics, and decision for civil engineers. McGraw-Hill, New York.
8.
Casas, J. R. (1996). “Bridge reliability experience in Spain.” Struct. Reliability in Bridge Engrg.: Des., Inspection, Assessment, Rehabilitation and Mgmt., Proc. of a Workshop, D. M. Frangopol and G. Hearn, eds., McGraw-Hill, New York, 127–138.
9.
Dunker, K. R., and Rabbat, B. G. (1993). “Why America's bridges are crumbling.” Sci. Am., March, 66–72.
10.
Enright, M. P., and Frangopol, D. M. (1998). “Service-life prediction of deteriorating concrete bridges.”J. Struct. Engrg., ASCE, 124(3), 309–317.
11.
Ellingwood, B. (1996). “Reliability-based condition assessment and LRFD for existing structures.” Struct. Safety, 8(2–3), 67–80.
12.
Frangopol, D. M. (1997). Proc., Int. Workshop on Optimal Performance of Civ. Infrastruct. Syst., ASCE, Reston, Va.
13.
Fu, G., and Tang, J. (1995). “Risk-based proof-load requirements for bridge evaluation.”J. Struct. Engrg., ASCE, 12(3), 542–556.
14.
Fujino, Y., and Lind, N. C. (1977). “Proof-load factors and reliability.”J. Struct. Engrg., ASCE, 103(4), 853–870.
15.
Hall, W. B. (1988). “Reliability of service-proven structures.”J. Struct. Engrg., ASCE, 114(3), 608–624.
16.
Hall, W. B., and Tsai, M. (1989). “Load testing, structural reliability and test evaluation.” Struct. Safety, 6, 285–302.
17.
Lichtenstein, A. G. ( 1995). “Bridge rating through nondestructive load testing.” NCHRP Project No. 12-28(13) A.
18.
Mass limits review. (1996). National Road Transport Commission, Melbourne, Australia.
19.
Melchers, R. E. (1987). Structural reliability: analysis and prediction. Ellis Horwood, Chichester, U. K.
20.
Mirza, S. A., Hatzinikolas, M., and MacGregor, J. G. (1979). “Statistical descriptions of strength of concrete.”J. Struct. Div., ASCE, 105(6), 1021–1037.
21.
Mirza, S. A., MacGregor, J. G. (1979a). “Variations in dimensions of reinforced concrete members.”J. Struct. Div., ASCE, 105(4), 751–766.
22.
Mirza, S. A., and MacGregor, J. G. (1979b). “Variability of mechanical properties of reinforcing bars.”J. Struct. Div., ASCE, 105(5), 921–937.
23.
cMoses, F. ( 1996). “Bridge evaluation based on reliability.” Struct. Reliability in Bridge Engrg.: Des., Inspection, Assessment, Rehabilitation and Mgmt., Proc. of a Workshop, D. M. Frangopol and G. Hearn, eds., McGraw-Hill, New York, 42–53.
24.
Moses, F., Lebet, J. P., Bez, R. (1994). “Applications of field testing to bridge evaluation.”J. Struct. Engrg., ASCE, 120(6), 1745–1762.
25.
Nowak, A. S. (1993). “Live load model for highway bridges.” Struct. Safety, 13, 53–66.
26.
Nowak, A. S. (1994). “Calibration of LRFD bridge design code.” Proc., ICOSSAR'93-Int. Conf. on Struct. Safety and Reliability, Rotterdam, the Netherlands, 927–932.
27.
Nowak, A. S. (1995). “Calibration of LRFD bridge code.”J. Struct. Engrg., ASCE, 121(8), 1245–1251.
28.
Nowak, A. S., and Hong, Y.-K. (1991). “Bridge live-load models.”J. Struct. Engrg., ASCE, 117(9), 2757–2767.
29.
Nowak, A. S., and Tharmabala, T. (1988). “Bridge reliability evaluation using load tests.”J. Struct. Engrg., ASCE, 114(10), 2268–2279.
30.
Ransom, A. L., and Heywood, R. J. (1997). “Recommendation for proof load testing in Australia.” Proc., AUSTROADS 1997 Bridge Conf., Bridging the Millennia,” G. J. Chirgwin, ed., AUSTROADS, Haymarket, Australia, 1, 232–244.
31.
Stewart, M. G. (1995). “Workmanship and its influence on probabilistic models of concrete compressive strength.” ACI Mat. J., 92(4), 361–372.
32.
Stewart, M. G. (1997). “Time-dependent reliability of existing RC structures.”J. Struct. Engrg., ASCE, 123(7), 896–903.
33.
Stewart, M. G. (1998). “Reliability-based bridge design and assessment.” Progress in Struct. Engrg. and Mech., 1(2), 214–222.
34.
Stewart, M. G., and Melchers, R. E. (1997). Probabilistic risk assessment for engineering systems. Chapman & Hall, London.
35.
Tabsh, S. W., and Nowak, A. S. (1991). “Reliability of highway girder bridges.”J. Struct. Engrg., ASCE, 117(8), 2372–2388.
36.
Val, D. V., Stewart, M. G., and Melchers, R. E. (1998). “Assessment of existing RC structures: statistical and reliability issues.” Proc., 2nd RILEM Int. Conf. on Rehabilitation of Struct., D. Ho, I. Godson, and F. Collins, eds, RILEM, Cachan Cedex, France, 91–101.
Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 125 • Issue 7 • July 1999
Pages: 776 - 783
History
Received: Jun 19, 1998
Published online: Jul 1, 1999
Published in print: Jul 1999
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