Finite Element Model-Based Weight-Over Process Philosophy for Bridge Loading Capacity Evaluation and Rating Factor Estimation

Ali Karimpour,Hossein Bolboli Ghadikolaee,Salam Rahmatalla,Wonseok Chung

doi:10.1155/2021/2244202

Ali Karimpour, Hossein Bolboli Ghadikolaee + Show 2 more

Open Access

https://doi.org/10.1155/2021/2244202

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Abstract

Existing rating methods estimate bridge loading capacity and demand from secondary actions due to live loads in the primary structural components. In these methods, uniaxial yielding stress is traditionally used to detect component capacity using either stress quantities or shear-moment actions to compute the capacity demand of the bridge. These approximations can lead to uncertainties in load capacity estimation. This article presents the weight-over process (WOP), a novel computer-aided approach to bridge loading capacity evaluation based on tonnage and rating factor estimation. WOP is expected to capture different forms of failure in a more general manner than existing methods. In WOP, a bridge finite element model (FEM) is discretized into many sections and element sets, each containing a single material type, and each assigned a suitable 3D failure criterion. Then, factored gross vehicle weights (GVWs) are incrementally imposed on the bridge FEM with those predefined ultimate unfavored loading scenarios in a manner similar to proof load testing. WOP code runs nonlinear analysis at each increment until a stopping criterion is met. Two representative bridges were selected to confirm WOP’s feasibility and efficacy. The results showed that WOP-predicted values at the interior girders were between those of the conventional AASHTO and the nondestructive testing (NDT) strain measurement methods. That may put WOP in a favorable zone as a new method that is less conservative than AASHTO but more conservative than real NDT testing.

Highlights

Highway bridges are vital infrastructure that must be evaluated periodically to ensure their safe operation under traffic loading
Bridges age, deteriorate, and sustain damage, becoming structurally deficient. e load-carrying capacity index is a comprehensive integrity assessment tool that engineers can use for bridge rating. e service live load that can be safely carried over a bridge is called the load rating (LR) and is expressed as a rating factor (RF)
In the USA, the LR must be biennially executed based on American Association of State Highway Transportation Officials guidelines [1] and Federal Highway Administration rules [2]. e load and resistance factor rating (LRFR) method provides the RF formula for new and existing bridges as the ratio of specific live loads (LLs) resistance to design LL, including its dynamic effects and associated uncertainties. e RF quantity can be interpreted as the number of a particular LL that can safely cross the bridge

Summary

Research Article

Received 13 August 2021; Revised 6 November 2021; Accepted 24 November 2021; Published 17 December 2021. Existing rating methods estimate bridge loading capacity and demand from secondary actions due to live loads in the primary structural components. In these methods, uniaxial yielding stress is traditionally used to detect component capacity using either stress quantities or shear-moment actions to compute the capacity demand of the bridge. Is article presents the weight-over process (WOP), a novel computer-aided approach to bridge loading capacity evaluation based on tonnage and rating factor estimation. WOP is expected to capture different forms of failure in a more general manner than existing methods. En, factored gross vehicle weights (GVWs) are incrementally imposed on the bridge FEM with those predefined ultimate unfavored loading scenarios in a manner similar to proof load testing. Two representative bridges were selected to confirm WOP’s feasibility and efficacy. e results showed that WOP-predicted values at the interior girders were between those of the conventional AASHTO and the nondestructive testing (NDT) strain measurement methods. at may put WOP in a favorable zone as a new method that is less conservative than AASHTO but more conservative than real NDT testing

Introduction

GVW Wlane

Enhanced Concrete Case

AASHTO RFs