Analyses on catastrophic collapse of some adjacent precast concrete box bean bridges reveal the fact that the function loss of shear keys can result in the formation of the "Single Plate Load Effect"; as a result, loads cannot transfer between adjacent beams and damage to both the structure and vehicles can be triggered on the loaded beam by heave trucks. This leads to the concern that the system safety of adjacent precast concrete beam bridges becomes insufficient when the shear keys deteriorate to a certain degree. To understand the system performance of this type of bridges, this dissertation studied the system performance of a model bridge over the full load range through an experimental investigation and finite element simulation. The results confirmed that the assumption that the robustness of certain adjacent precast concrete beam bridges may be considered safe according to the traditional safely check standards, but may not be sufficient in terms of the system safety criteria. Thus, a system factor is recommended to be applied in the safety check equation of this type of bridges. Even though some codes have already incorporated the criteria for evaluating the system behavior of highway bridges in the design and evaluating procedure, little guidance has been provided on how to determine corresponding redundancy or system factors. On the basis of the experiment findings and theoretical analysis, a simplified framework was proposed to address the particular structural feature and topology of adjacent precast concrete bean bridges, which can reduce the computation complexity compared to existing approaches for redundancy and robustness assessment. Sensitive parameters for system reliability were investigated and system reliability indices were computed using a finite element response surface method. The rationality and calibration of system factors were analyzed. In the end, the procedure for system safety and reliability assessment of adjacent precast concrete box beam bridges was applied on a bridge in service with different transverse connections and damage scenarios. The case study verified the proposed approach and outlined the procedure that can be adopted for routine bridge evaluation practice.

At head of title: National Cooperative Highway Research Program.

Adjacent box beam bridges have a history of poor long-term performance including premature deterioration and failures. Leaking joints between box beams allow chloride-laden water to migrate through the superstructure and initiate corrosion. The nature of this deterioration leads to uncertainty of the extent and effect of deterioration on structural behavior. Due to limitations in previous research and understanding of the strength of deteriorated box beam bridges, conservative assumptions are made for the assessment and load rating of these bridges. Furthermore, the design of new box beam bridges, which can offer an efficient and economical solution, is often discouraged due to poor past performance. The objective of this research is to develop recommendations for inspection, load-rating, and design of adjacent box beam bridges. The research is presented in two volumes. Volume 1 focuses on the evolution of box beam design in Indiana to understand the lack of performance and durability. The Indiana Department of Transportation (INDOT) standards and bridge design manuals were reviewed to track the historical development of box beam bridges in the State. Two timelines were produced tracking important updates to box beam design. Adjacent box beam bridges within INDOT's bridge database were also analyzed. Superstructure ratings were compared with bridge age as well as bridge characteristics to highlight possible causes for deterioration. Analyzing the INDOT inventory, data shows that the condition of adjacent box beam bridges may be affected by location, type of wearing surface, and the use of deck membranes. Six bridges were then inspected to identify common deficiencies and specific problems. Exterior beams and beams within the wheel load path tend to have higher levels of deterioration. Furthermore, leaking joints between beams leads to corrosion of reinforcement, ultimately resulting in spalling, fracture of prestressing strands, and loss of structural capacity. Volume 2 focuses on evaluating the capacity of deteriorated adjacent box beams, the development of improved load rating procedures, and new box beam design. Through a series of bridge inspections, deteriorated box beams were identified and acquired for experimental testing. The extent of corrosion was determined through visual inspection, non-destructive evaluation, and destructive evaluation. Non-destructive tests (NDT) included the use of connectionless electrical pulse response analysis (CEPRA), ground penetrating radar (GPR), and half-cell potentials. Deteriorated capacity was determined through structural testing, and an analysis procedure was developed to estimate deteriorated behavior. A rehabilitation procedure was also developed to restore load transfer of adjacent beams in cases where shear key failures are suspected. Based on the understanding of deterioration developed through study of deteriorated adjacent box beam bridges, improved inspection and load rating procedures are provided along with design recommendations for the next generation of box beam bridges.

Discusses "the safety concepts which form the basis of modern bridge design and assessment codes" and "the background work carried out in the development of the new UK bridge and route-specific traffic loading requirements, and the proposed whole life performance-based assessment rules" -- Preface.

Bridge Safety, Maintenance, Management, Life-Cycle, Resilience and Sustainability contains lectures and papers presented at the Eleventh International Conference on Bridge Maintenance, Safety and Management (IABMAS 2022, Barcelona, Spain, 11–15 July, 2022). This e-book contains the full papers of 322 contributions presented at IABMAS 2022, including the T.Y. Lin Lecture, 4 Keynote Lectures, and 317 technical papers from 36 countries all around the world. The contributions deal with the state-of-the-art as well as emerging concepts and innovative applications related to the main aspects of safety, maintenance, management, life-cycle, resilience, sustainability and technological innovations of bridges. Major topics include: advanced bridge design, construction and maintenance approaches, safety, reliability and risk evaluation, life-cycle management, life-cycle, resilience, sustainability, standardization, analytical models, bridge management systems, service life prediction, structural health monitoring, non-destructive testing and field testing, robustness and redundancy, durability enhancement, repair and rehabilitation, fatigue and corrosion, extreme loads, needs of bridge owners, whole life costing and investment for the future, financial planning and application of information and computer technology, big data analysis and artificial intelligence for bridges, among others. This volume provides both an up-to-date overview of the field of bridge engineering and significant contributions to the process of making more rational decisions on bridge safety, maintenance, management, life-cycle, resilience and sustainability of bridges for the purpose of enhancing the welfare of society. The volume serves as a valuable reference to all concerned with and/or involved in bridge structure and infrastructure systems, including students, researchers and practitioners from all areas of bridge engineering.

Recent surveys of the U.S. infrastructure‘s condition have rated a staggering number of bridges structurally deficient or functionally obsolete. While not necessarily unsafe, a structurally deficient bridge must be posted for weight and have limits for speed, due to its deteriorated structural components. Bridges with old design features that canno