Quantifying Bridge Element Vulnerability over Time

The bridge has been a crucial element of the transportation system of the U.S.A. for many years. The National Bridge Inventory (NBI) reported more than 615,000 national bridges in 2018. Maintaining and fixing bridges is a crucial task for transportation agencies to keep the road network connected. Louisiana, which has 12,899 bridges, was selected as the study site for this study. The American Road and Transportation Builders Association (ARTBA) reported in 2019 that 13% of all Louisiana bridges were classified as structurally deficient. This study applies a data mining algorithm, the empirical Bayes geometric mean (EBGM) method, to identify critical patterns of the bridge inventory condition at element level as a measure of vulnerability, using NBI rating data from 2015 to 2018. It finds that severe condition is highly associated with the following elements, regardless of their structural importance: bridge joints, and “bridge rail timber,”“bearing other,” and “superstructure floor beam reinforced concrete” elements. Poor condition is highly associated with elements like “top flange reinforced concrete,”“bearing movable,” and “superstructure floor beam reinforced concrete.” The quantification scores developed in this study could help transportation agencies and bridge engineers to identify more easily the key element or combination of elements associated with poor or severe condition, so that they can make data-driven decisions in maintaining and repairing the most needed bridge elements.

Development Of Precast Barrier Wall System For Bridge Decks

As Ontario transportation infrastructure enters the era of maintenance, rehabilitation and replacement, it needs more use of prefabricated elements and systems, which can quickly assembled to overcome relatively longer time to open bridge to the traffic. This thesis reports on both analytical and experimental investigations conducted on various aspects of precast bridge barrier, including design loads, structural design, sequence of construction, connection details between the barriers and bridge, joints between barrier segments and water leakage control. In this study, thru post-tensioned bolted connection system was developed to connect the precast barrier wall with bridge deck. The primary intension behind these connections is to expedite construction cycle simulataneously with minimizing traffic disruption, improve work-zone safety, quality and constructible and lower down lifecycle cost of bridges. A total of five experimental tests on full-scale specimens of the developed system were conducted to verify and substantiate the design procedure used to develop the barrier wall system. Good correlation between theoretical ultimate loads, in the form of bending, shear and punching shear resistance, and the experimental findings was achieved.

Development Of Precast Barrier Wall System For Bridge Decks

As Ontario transportation infrastructure enters the era of maintenance, rehabilitation and replacement, it needs more use of prefabricated elements and systems, which can quickly assembled to overcome relatively longer time to open bridge to the traffic. This thesis reports on both analytical and experimental investigations conducted on various aspects of precast bridge barrier, including design loads, structural design, sequence of construction, connection details between the barriers and bridge, joints between barrier segments and water leakage control. In this study, thru post-tensioned bolted connection system was developed to connect the precast barrier wall with bridge deck. The primary intension behind these connections is to expedite construction cycle simulataneously with minimizing traffic disruption, improve work-zone safety, quality and constructible and lower down lifecycle cost of bridges. A total of five experimental tests on full-scale specimens of the developed system were conducted to verify and substantiate the design procedure used to develop the barrier wall system. Good correlation between theoretical ultimate loads, in the form of bending, shear and punching shear resistance, and the experimental findings was achieved.

Evaluation of vehicular contact force on bridge joints by vibration responses and object detection

<p>Expansion joints on bridges should accommodate cyclic movements to minimize imposition of secondary stresses in the structure. However, these joints are highly susceptible to severe and repeated vehicular impact that results their inherent discontinuity. In this paper, a portable on- board system including accelerometers and a drive recorder to evaluate the vehicular contact force on bridge joints is proposed. First, from the acceleration responses of the vehicle, the contact force exerted on the road surface is estimated from a half-car model by Kalman Filter. Next, extraction of the expansion joints is performed by object detection from videos taken by the drive recorder. Finally, a relative comparison of the contact forces acting on joints is performed, with location identification on the map. The proposed system benefits to utilize the dynamic contact forces results from on-board system to detect the potential risky joints more precisely and efficiently.</p>

A method for replacing lower flange splice plate of a steel I-girder connection using BPL

<p>In recent years, corrosion damages of the steel I-girder bridge joints have been reported. With the increasing demand for the replacement of splice plates of the damaged joints, good workability without using temporary supports is required when considering the cost and time necessary to execute such works. In the present study, FEM analysis has been conducted in order to propose a new replacing method for the lower flange splice plates in steel I-girder, which uses a bypass device of steel plate named BPL that is attached to the web panel. From the analytical results, it has been confirmed that using the BPL and replacing the lower flange splice plates, the stress at the lower flange splice plates is transferred to the BPL and redistributed to the new lower flange splice plates after the removal of BPL. It has also been clarified the geometrical configuration of the BPL that can reduce the stress at the web effectively during replacement of the lower flange splice plates.</p>