Generalized reliability model for local scour around bridge piers of various shapes

Excessive local scour around piers and abutments is known as a major cause of bridge failure induced by hydraulic deficiencies. Complexity of the scouring phenomenon and high degrees of uncertainties in governing parameters lead to an unavoidable risk in bridge pier design. In this paper, a generalized reliability model based on static resistance-loading interference is developed for the assessment of reliability of bridge scour for various pier shapes. In the model, the relative maximum scour depth and the linear combination of the relative approach flow depth and flow Froude number are defined as the system resistance and external loading, respectively. By examining sets of data, a two-parameter bivariate lognormal distribution is found to represent the joint probability density function of the resistance and loading. Reliability expressions are developed for various pier shapes. To obtain relevant information for decision-making, the model is applied to a case study in which a relationship is obtained between the reliability and safety factors for cylindrical and non-cylindrical piers under various return periods.
Turkish Journal of Engineering and Environmental Sciences


Dynamic Reliability in Bridge Pier Scouring
Yanmaz, Ali Melih (2002-09-01)
Many bridges crossing wide rivers fail due to excessive local scour around piers and abutments during heavy floods. Because of the random nature and complexity of the overall scouring phenomenon through the bridge opening, there exist uncertainties leading to an unavoidable risk in bridge foundation design. A reliability-based assessment of bridge pier scour is required to examine the relationship between safety factors and reliability, which are key parameters for decision making in design. Herein, a dynam...
Composite reliability model for local scour around cylindrical bridge piers
Yanmaz, Ali Melih (2001-06-01)
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Uncertainty of local scouring parameters around bridge piers
Yanmaz, Ali Melih (2001-03-01)
Reliability-based assessment of local scouring mechanism around bridge piers provides information for decision-making regarding the pier footing design. Parameter uncertainties that may arise from various sources due to the inability to precisely quantify a parameter need to be estimated in order to quantify the level of risk of pier failure during the physical life of a bridge. By examining extensive experimental data from the literature on local scour depth around various shapes of bridge pier the functio...
A Case Study on Bridge-Scour Risk Assessment
Yanmaz, Ali Melih (2010-09-27)
Many bridges fail or subject to considerable stability problems because of excessive scouring at infrastructural elements, such as piers and abutments. Computation of maximum possible depth of scour at these elements would lead to safe and economical design of footings. Scour depth computation is also of importance for existing bridges to assess their vulnerability against this phenomenon throughout their remaining life spans. A ...
Computer aided analysis of flow through river bridges
Yanmaz, Ali Melih (null; 2001-05-20)
The major failure mode of a bridge results mainly from hydraulic deficiencies in the design. Flow conditions through bridge openings should be investigated to observe the degree of hydraulic conformity for the given structural system. A computer program is developed to carry out hydraulic and structural computations jointly for bridges crossing rivers having irregular cross-sections with flood plains. The program has analysis and design options. In the analysis part of the program, steady state water surfac...
Citation Formats
A. M. Yanmaz, “Generalized reliability model for local scour around bridge piers of various shapes,” Turkish Journal of Engineering and Environmental Sciences, pp. 687–698, 2001, Accessed: 00, 2021. [Online]. Available: