Browsing by Subject "Wrap"

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Bridging the gap: unifying transportation planning and operations through enhanced travel demand modeling
(2024-05) Alexander, William Eric ; Boyles, Stephen David, 1982-; Bhat, Chandra R.; Hasenbein, John J.; Hainen, Alexander M.; Machemehl, Randy B.
Travel demand modeling is a necessary and useful tool for municipalities to better allocate resources, and much research has been developed on how best to calibrate and apply these models. This dissertation identifies and addresses a disconnect which exists between the modeling and operations fields, seeking to bridge the gap for improved performance in both the predictive capabilities of these models as well as the operational efficiency of the ensuing equilibrium that will develop between road users’ route choices and managers’ traffic signal timing decisions made based on these models. A major engineering contribution we detail is the development of wrap, a cross-platform, free-and-open-source travel demand modeling software package. Scientific contributions presented in this dissertation include a novel method for calibrating trip generation rates based on a sample of roadway volume data as well as a detailed investigation of pressure-based traffic signal timing optimization. This latter investigation introduces three novel pressure functions, offering improved route choice equilibria by balancing signal timings and drivers’ anticipated efforts to minimize their cost of travel. This work also introduces preliminary contributions of practical benefit, including the use of machine learning for corridor travel time predictions and reinforcement learning for traffic signal control to better position this research for application in the field. The collaborative potential between improved travel demand models and transportation operations policies is strongly emphasized, with the contributions of this work intended to facilitate synergy in these two fields for the development of a more efficient transportation network.
Seismic retrofit of RC columns with FRP composites and anchorage system
(2015-05) Psaros Andriopoulos, Apostolos; Jirsa, J. O. (James Otis); Hrynyk, Trevor
Research on the use of composite materials in structural applications started more than 30 years ago but still remains active. The challenges that accompany those applications are diverse and seem to increase as the variety of applications grows. There are several fiber-reinforced polymer (FRP) systems that have been introduced through the years for strengthening reinforced concrete (RC) structures. Those systems focus on strengthening of slabs, beams and columns. The present study pertains to seismic retrofit of rectangular RC columns. The typical FRP materials used in structural applications are introduced, as well as, how FRP materials become an integral part of the force-resisting system. In addition, analysis work pertaining to a series of strengthened RC columns was conducted and the results were compared to the experimental data. Moreover, deficiencies of typical material models were highlighted. Design guidelines are discussed and recommendations about current design practices are provided. Finally, research gaps and future research recommendations are identified.