TIME-DEPENDENT RELIABILITY ANALYSIS OF REINFORCED-CONCRETE BRIDGES UNDER THE COMBINED EFFECT OF CORROSION, CREEP AND SHRINKAGE

Introduction. The author presents the results of the reliability analysis of the structural systems in spans of bridges.Materials and methods. The analysis of published materials for the purpose of using them in the design of reinforced concrete bridges, in connection with changes in design standards and tightening of regulatory requirements for safety is made by the author.Results. The results of surveys of slab superstructures indicate the reliability and durability of typical structures operated under normal conditions, but in emergency situations there is a danger of progressive collapse. Therefore, in such conditions, split schemes of multi-span structures are unacceptable. The research tasks to ensure the durability of slab superstructures are formulated. In particular, the task of developing the method of durability calculation in case of one of the pillars failure in the continuous span structure, taking into account the dynamic effect is illustrated.Discussion and conclusion. Changes in design of slab structures of bridge cause the necessity to study the reliability and failure in emergency situations.

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INNOVATIVE APPROACHES IN THE FIELD OF REINFORCED CONCRETE BRIDGES STRENGTHENING BASED ON THE APPLICATION OF COMPOSITE MATERIALS

European Journal of Technical and Natural Sciences ◽

10.29013/ejtns-20-5.6-25-35 ◽

2020 ◽

pp. 25-35

Author(s):

D. J. Razmukhamedov ◽

A. M. Polatov ◽

F. B. Abdullaev

Keyword(s):

Reinforced Concrete ◽

Composite Materials ◽

Concrete Bridges ◽

Reinforced Concrete Bridges ◽

Innovative Approaches

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Time-Dependent Reliability Analysis of Reinforced Concrete Beams Subjected to Uniform and Pitting Corrosion and Brittle Fracture

Materials ◽

10.3390/ma14081820 ◽

2021 ◽

Vol 14 (8) ◽

pp. 1820

Author(s):

Mohamed El Amine Ben Seghier ◽

Behrooz Keshtegar ◽

Hussam Mahmoud

Keyword(s):

Reinforced Concrete ◽

Brittle Fracture ◽

Reliability Analysis ◽

Pitting Corrosion ◽

Structural Reliability ◽

Time Dependent ◽

State Function ◽

Rc Beams ◽

Highly Nonlinear ◽

Reliability Method

Reinforced concrete (RC) beams are basic elements used in the construction of various structures and infrastructural systems. When exposed to harsh environmental conditions, the integrity of RC beams could be compromised as a result of various deterioration mechanisms. One of the most common deterioration mechanisms is the formation of different types of corrosion in the steel reinforcements of the beams, which could impact the overall reliability of the beam. Existing classical reliability analysis methods have shown unstable results when used for the assessment of highly nonlinear problems, such as corroded RC beams. To that end, the main purpose of this paper is to explore the use of a structural reliability method for the multi-state assessment of corroded RC beams. To do so, an improved reliability method, namely the three-term conjugate map (TCM) based on the first order reliability method (FORM), is used. The application of the TCM method to identify the multi-state failure of RC beams is validated against various well-known structural reliability-based FORM formulations. The limit state function (LSF) for corroded RC beams is formulated in accordance with two corrosion types, namely uniform and pitting corrosion, and with consideration of brittle fracture due to the pit-to-crack transition probability. The time-dependent reliability analyses conducted in this study are also used to assess the influence of various parameters on the resulting failure probability of the corroded beams. The results show that the nominal bar diameter, corrosion initiation rate, and the external loads have an important influence on the safety of these structures. In addition, the proposed method is shown to outperform other reliability-based FORM formulations in predicting the level of reliability in RC beams.

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