Reliability analysis of reinforced concrete slab bridges

Ali Ahmed Mahmood Mahmood; Shadi Najjar; Mounir Mabsout; Kassim Tarhini

doi:10.21660/2017.36.28  0

Reliability analysis of reinforced concrete slab bridges

Ali Ahmed Mahmood Mahmood, Shadi Najjar, Mounir Mabsout, Kassim Tarhini

Research output: Contribution to journal › Article › peer-review

Abstract

Empirical expressions for estimating live load bending moments are typically specified in AASHTO bridge codes. This paper will evaluate the reliability levels that are inherent in the simplified empirical equations in the AASHTO LRFD to design concrete slab bridges. Typical one-span, multilane, straight bridges, with various span lengths are modeled using finite element analysis (FEA) and subjected to AASHTO live loads. FEA results are compared with LRFD moments to quantify biases that might result from the simplifying assumptions in AASHTO. The reliability index β for bridge cases using AASHTO procedures and FEA results were quantified. The results of this analysis showed that current live load factors in AASHTO LRFD procedures were below the required levels of reliability index (β <3.5) for one-lane bridges, and those indices were higher for multilane bridges, yet did not reach the required level, thus proposing to increase the AASHTO live load factors.

Original language	English
Pages (from-to)	44-49
Number of pages	6
Journal	International Journal of Geomechanics
Volume	13
Issue number	36
DOIs	https://doi.org/10.21660/2017.36.28 0
Publication status	Published - 1 Aug 2017

Keywords

concrete slab bridges
finite-element analysis
load-carrying capacity
reliability analysis

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10.21660/2017.36.28 0

Cite this

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title = "Reliability analysis of reinforced concrete slab bridges",

abstract = " Empirical expressions for estimating live load bending moments are typically specified in AASHTO bridge codes. This paper will evaluate the reliability levels that are inherent in the simplified empirical equations in the AASHTO LRFD to design concrete slab bridges. Typical one-span, multilane, straight bridges, with various span lengths are modeled using finite element analysis (FEA) and subjected to AASHTO live loads. FEA results are compared with LRFD moments to quantify biases that might result from the simplifying assumptions in AASHTO. The reliability index β for bridge cases using AASHTO procedures and FEA results were quantified. The results of this analysis showed that current live load factors in AASHTO LRFD procedures were below the required levels of reliability index (β <3.5) for one-lane bridges, and those indices were higher for multilane bridges, yet did not reach the required level, thus proposing to increase the AASHTO live load factors.",

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author = "Mahmood, {Ali Ahmed Mahmood} and Shadi Najjar and Mounir Mabsout and Kassim Tarhini",

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T1 - Reliability analysis of reinforced concrete slab bridges

AU - Mahmood, Ali Ahmed Mahmood

AU - Najjar, Shadi

AU - Mabsout, Mounir

AU - Tarhini, Kassim

PY - 2017/8/1

Y1 - 2017/8/1

N2 - Empirical expressions for estimating live load bending moments are typically specified in AASHTO bridge codes. This paper will evaluate the reliability levels that are inherent in the simplified empirical equations in the AASHTO LRFD to design concrete slab bridges. Typical one-span, multilane, straight bridges, with various span lengths are modeled using finite element analysis (FEA) and subjected to AASHTO live loads. FEA results are compared with LRFD moments to quantify biases that might result from the simplifying assumptions in AASHTO. The reliability index β for bridge cases using AASHTO procedures and FEA results were quantified. The results of this analysis showed that current live load factors in AASHTO LRFD procedures were below the required levels of reliability index (β <3.5) for one-lane bridges, and those indices were higher for multilane bridges, yet did not reach the required level, thus proposing to increase the AASHTO live load factors.

AB - Empirical expressions for estimating live load bending moments are typically specified in AASHTO bridge codes. This paper will evaluate the reliability levels that are inherent in the simplified empirical equations in the AASHTO LRFD to design concrete slab bridges. Typical one-span, multilane, straight bridges, with various span lengths are modeled using finite element analysis (FEA) and subjected to AASHTO live loads. FEA results are compared with LRFD moments to quantify biases that might result from the simplifying assumptions in AASHTO. The reliability index β for bridge cases using AASHTO procedures and FEA results were quantified. The results of this analysis showed that current live load factors in AASHTO LRFD procedures were below the required levels of reliability index (β <3.5) for one-lane bridges, and those indices were higher for multilane bridges, yet did not reach the required level, thus proposing to increase the AASHTO live load factors.

KW - concrete slab bridges

KW - finite-element analysis

KW - load-carrying capacity

KW - reliability analysis

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