Chloride-induced corrosion of reinforcing steel is widely accepted as the primary cause of premature deterioration in concrete bridge decks (Brown, M.C., 2002). Since linear cracking in concrete cover can potentially accelerate chloride ingress to the depth of the reinforcing steel, there is reason to believe that severity of deck cracking can significantly influence the time to first repair and/or rehabilitation of the bridge deck. Surface width, orientation, and length of cracks in 38 Virginia bridge decks were investigated in order to characterize the general distribution of deck cracking in the commonwealth of Virginia. Crack data was correlated to structural/material design parameters and environmental exposure conditions in order to determine significant predictor-response relationships. The majority of surveyed bridge decks were divided into four classifications of deck type based on superstructure type and construction era, either 1968-1971 or 1984-1991. Surveyed bridge decks that did not fit into any of the four classifications were used to form more generalized subsets. These larger subsets were used to determine if significant influence factors could be translated to broader classifications of bridge decks. Transverse beam spacing, annual average daily truck traffic (AADTT), resistivity of the deck concrete, chloride exposure, and the percentage of concrete clear cover depths less than or equal to 38mm (1.5 in) were all determined to have a significant correlation with linear deck cracking. / Master of Science

This architecture thesis is an exploration of an idea, an event, and a place. The idea was to explore design with water. The design had to be thoughtful and have an impact: an event. My place is on the waterfront. This thesis confirmed my ideas about site-specific and site-inspired architecture. I looked to my thoughts about water and tried to incorporate them into my design and enhance it with them. In my design I began to think about materials, about the senses, and about how we experience places through sight, sound, smell, touch, and taste. My exploration led me to design a public park on the Hudson River in Nyack, New York. *note* the printed version of this book is in the format of double sided pages and is best viewed in the format of facing pages. / Master of Architecture

Accurately predicting the deck condition rating of a bridge is crucial for effective maintenance and repair planning. Despite significant research efforts to develop deterioration models, a nationwide model has not been developed. This study aims to identify an appropriate machine learning (ML) algorithm that can accurately predict the deck condition ratings of the nation's bridges. To achieve this, the study collected big bridge data (BBD), which includes NBI, traffic, climate, and hazard data gathered using geospatial information science (GIS) and remote sensing techniques. Two sets of data were collected: a BBD for a single year of 2020 and a historical BBD covering a five-year period from 2016 to 2020. Three ML algorithms, including random forest, eXtreme Gradient Boosting (XGBoost), and Artificial Neural Network (ANN), were trained using 319,404 and 1,246,261 bridge decks in the BBD and the historical BBD, respectively. Results showed that the use of historical BBD significantly improved the performance of the models compared to BBD. Additionally, random forest and XGBoost, trained using the historical BBD, demonstrated higher overall accuracies and average F1 scores than the ANN model. Specifically, the random forest and XGBoost models achieved overall accuracies of 83.4% and 79.4%, respectively, and average F1 scores of 79.7% and 77.5%, respectively, while the ANN model achieved an overall accuracy of 58.8% and an average F1 score of 46.1%. The permutation-based variable importance revealed that the hazard data related to earthquakes did not significantly contribute to model development. In conclusion, tree-based ensemble learning algorithms, such as random forest and XGBoost, trained using updated historical bridge data, including NBI, traffic, and climate data, provide a useful tool for accurately predicting the deck condition ratings of bridges in the United States, allowing infrastructure managers to efficiently schedule inspections and allocate maintenance resources.

The purpose of this research was to investigate and create preliminary design aids for the determination of lateral resistance capacity and spacing requirements of deck tie fasteners in curved railroad bridges with smooth top girders. In railroad bridge design, required lateral resistance dictates the spacing of deck tie fasteners. Currently, no provisions exist to aid in the calculation of lateral resistance for systems that include bridge ties, fasteners, and girders which experience centrifugal or lateral forces. Thus, design practices specific to each railroad vary, producing inconsistent fastener spacing in existing railroad bridges. This project identified and quantified three factors contributing to lateral resistance through experimental testing: resistance due to friction at the tie-girder interface; resistance from the fastener; and resistance from dapped ties bearing against the girder flange. Three fastener types were studied in this research: Square body hook bolts, Lewis Forged hook bolts, and Quikset Anchors. Results indicated that frictional resistance is a product of the train wheel load and the friction coefficient. Fastener resistance was determined to be a function of fastener type and lateral track displacement. Finally, dap resistance was found to be a function of the area of the shear plane in a dapped tie. A preliminary equation for calculating the total lateral resistance capacity was developed utilizing superposition of all three resistance contributions. Lateral demand loads were compared with reported lateral capacity to create a preliminary design aid to determine fastener spacing. / Master of Science / Railroad bridges are constructed by securing wooden ties to I-shaped steel beams (girders) using deck tie fasteners. Curved railroad bridges should provide lateral resistance to resist lateral loads from trains negotiating the curve. Currently, there is no official practice for determining lateral strength, which is a function of fastener spacing. Thus, each railroad company uses a proprietary fastener spacing, producing inconsistencies in existing railroad bridges. The purpose of this research was to create a preliminary table or equation for determining the lateral strength and spacing requirements of deck tie fasteners through experimental testing. This project identified and quantified three factors contributing to lateral resistance: resistance due to friction at the tie-girder interface; resistance from the fastener; and resistance from dapped ties (ties that are notched to sit on the girder flanges). Three fastener types were studied. Results showed that frictional resistance was directly proportionate to the magnitude of the vertical wheel load. Fastener resistance was found to be a function of the type of fastener used. Finally, the dap was determined to be a function of the area of the shear plane in a dapped tie. A preliminary equation for calculating the total lateral resistance capacity was developed by summing the resistance contributions from all three resistance factors. Lateral loads were compared with lateral capacity to create a preliminary design aid to determine fastener spacing.

Integral bridges (IBs) are defined as a class of rigid frame bridges with a single row of piles at the abutments cast monolithically with the superstructure. In the last decade, IBs have become very popular in North America and Europe as they provide many economical and functional advantages. However, standard design methods for IBs have not been established yet. Therefore, most bridge engineers depend on the knowledge acquired from performance of previously constructed IBs and the design codes developed for conventional jointed bridges to design these types of bridges. This include the live load distribution factors used to account for the effect of truck loads on bridge components in the design as well as issues related to the seismic design of such bridges. Accordingly in this study issues related to live load effects as well as seismic effects on IB components are addressed in two separate parts. In the first part of this study, live load distribution formulae for IB components are developed and verified. For this purpose, numerous there dimensional and corresponding two dimensional finite element models (FEMs) of IBs are built and analyzed under live load. The results from the analyses of two and three dimensional FEMs are then used to calculate the live load distribution factors (LLDFs) for the components of IBs (girders, abutments and piles) as a function of some substructure, superstructure and soil properties. Then, live load distribution formulae for the determination of LLDFs are developed to estimate to the live load moments and shears in the girders, abutments and piles of IBs. It is observed that the developed formulae yield a reasonably good estimate of live load effects in IB girders, abutments and piles. In the second part of this study, seismic performance of IBs in comparison to that of conventional bridges is studied. In addition, the effect of several structural and geotechnical parameters on the performance of IBs is assessed. For this purpose, three existing IBs and conventional bridges with similar properties are considered. FEMs of these IBs are built to perform nonlinear time history analyses of these bridges. The analyses results revealed that IBs have a better overall seismic performance compared to that of conventional bridges. Moreover, IBs with thick, stub abutments supported by steel H piles oriented to bend about their strong axis driven in loose to medium dense sand are observed to have better seismic performance. The level of backfill compaction is found to have no influence on the seismic performance of IBs.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22414号 / 工博第4675号 / 新制||工||1729(附属図書館) / 京都大学大学院工学研究科社会基盤工学専攻 / (主査)教授 杉浦 邦征, 教授 河野 広隆, 教授 八木 知己 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

京都大学 / 新制・論文博士 / 博士(医学) / 乙第13428号 / 論医博第2232号 / 新制||医||1053(附属図書館) / (主査)教授 湊谷 謙司, 教授 佐藤 俊哉, 教授 福田 和彦 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

Diploma thesis is focused on design of road bridge bearing structure over road in Jihlava. The construction is girder with 3 fields beard by local supports. Calculations were made in the program called Scia Engineer. Appraisals were made by hand.

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