The purpose of the dissertation is to develop a framework for equilibration of activity-trip chain demand in an integrated system of activity scheduling and travel choices within a dynamic network equilibrium framework. Activity-based modeling systems generate detailed activity chain schedules for individuals, which have to be assigned to transportation networks....
While infrequent, clay slope failures caused by earthquakes result in loss of life and substantial property damage. In strong seismicity areas, it is sometimes assumed that the stability of clay deposits can be evaluated through the residual undrained strength that is applicable at large deformations. A crucial factor missing in...
An accurate knowledge of the engineering properties of rocks is crucial for a variety of geomechanical problems, ranging from wellbore stability to failure in rock slopes, underground excavations, and crustal faults. While strength and deformation properties are usually obtained from a limited number of in situ and/or laboratory tests, their...
In response to construction activities and loads from permanent structures, soil generally is subjected to a variety of loading modes varying both in time and location. It also has been increasingly appreciated that the strains around well-designed foundations, excavations and tunnels are mostly small, with soil responses at this strain...
The abundance and breadth of condition data generated by advanced inspection technologies have increased the frequency and accuracy of data collection, which is not exploited by the existing performance models. Moreover, simultaneity of deterioration and maintenance causes difficulty of estimating effectiveness of maintenance activities for existing performance models. To address...
Safe design requires a valid mechanical model and correct probabilistic analysis. Concrete, which is an archetypical quasibrittle material, typically exhibits stable crack propagation in many types of failure. Therefore, a scientific approach requires analyzing concrete failure on the basis of fracture mechanics. One of the simplest ways to incorporate fracture...
Two experimental methods have been developed to induce flexural waves in concrete piles for which a portion of the shaft is accessible, and the test results were compared to theoretical solutions of flexural guided wave propagation. The pile response is measured and the results are analyzed to compute the group...
In urban areas, an accurate evaluation of ground deformations from various construction activities requires one to properly consider both the probable ground strain level under expected working conditions and the recent stress history of the soil. For well-designed projects, the levels of ground strains typically are less than 0.5%, emphasizing...
A current challenge to the civil/environmental engineering field is to assist full-scale wastewater treatment facilities through wider use of advances in modeling methods and analytical techniques. To address this challenge I applied modeling tools and, with assistance, the molecular biology analytical method of Fluorescent In-Situ Hybridization (FISH) to the high...
Generalized extreme value (GEV) models provide a convenient way to model choice behavior that is consistent with utility maximization theory, but the development of specific new models within the GEV family has been slow, due to the difficulty of ensuring new formulations comply with all the GEV rules. The network...
The extensive amount of maintenance expenditures on transportation infrastructure systems and their broad impacts in terms of economic and social development has emerged the interests in maintenance management of transportation infrastructure systems. This dissertation contributes an optimization framework for management of transportation systems that comprise of interdependent facilities.
Existing stochastic,...
The overall objective of this thesis is to develop a package of high-resolution, non-invasive experimental and numerical approaches to observe in situ pore-scale geometry modification due to colloid deposition, and quantitatively predict its effects on the large-scale transport properties of the porous medium. High-energy synchrotron-based X-ray difference micro-tomography (XDMT) was...
Recent work points out the importance of the solid-solid interface in explaining the high photoactivity of mixed phase TiO2 catalysts. The goal of this research was to probe the synthesis-structure-function relationships of the solid-solid interfaces created by the reactive direct current (DC) magnetron sputtering of titanium dioxide. I hypothesize that...
Microbiological dating of a crack's age depends upon establishing a viable method of sampling biomass from surfaces. Age is based upon the hypothesis that the amount of biomass on a given crack surface is proportional to the time that has passed since the surface was exposed. Presented herein is the...
Solder joint integrity is recognized as a key issue in the reliability of flip chip and ball grid arrays in integrated circuit packages. Significant reductions in the solder-joint interconnect size results in both the increased volume fraction of brittle intermetallics in the joint and joule heating and electromigration failure due...
The research reported in this dissertation covers the development of two high-performance concrete materials, Very-High-Strength Concrete (VHSC) and Frangible Concrete, and the philosophy of engineering the microstructure of these materials to produce their specific beneficial traits. The underlying problem addressed was how to optimize their design to maximize their desirable...
Beginning in the 1960s, U.S. federal law required ongoing and systematic planning as a condition of federal transportation funding. An ad-hoc system for forecasting future travel, which has come to be referred to as the "four-step" procedure, quickly became established as the ubiquitous analytic tool for transportation planning. The four-step...
While self-consolidating concrete (SCC) may no longer be considered a "new concrete", there are still significant challenges to overcome before there is broader acceptance of SCC. One of these challenges concerns the formwork pressure exerted by SCC. A major advantage of SCC is the accelerated casting process due to the...
Although cementitious construction materials are mainly used in a large scale and in huge quantities, fundamental properties such as strength, ductility, creep, shrinkage, and fracture behavior depend, to a great extent, on structural elements and phenomena which are effective at the micro- and nanoscale. This research involves characterization of the...
The term Connected Vehicle (CV) is broadly used to identify any ‘smart vehicle’ with wireless connectivity to the roadside infrastructure and other vehicles. CVs that can be driven autonomously are called connected autonomous vehicles (CAVs). With real-time communication and data transmission capability, CAVs have the potential to improve the transportation...