Three-tiered enterprise GIS architecture offers a robust, efficient, and secure mechanism as a potential revolution to disaster management systems. This paper addresses the severe limitations of existing disaster management systems and proposes an integrated management information system as an alternative. The value of such a 3-tiered enterprise GIS is its ability to function as reliable and efficient system during a disaster. Issues related to data storage, handling, timely distribution of processing power, efficient retrieval and dissemination of information, and data security against unauthorized access have to addressed using the state-of-the-art technology. Recent advancements in (1) standardized data specification, (2) middleware services, and (3) web-enabled distributed computing provide key resources to design and implement a tool of unprecedented flexibility and capacity for disaster management. This paper presents the critical details of such a system.

This research study examines the behavior of prestressed concrete beams retrofitted with Fiber Reinforced Polymer (FRP) materials. Due to deficiencies in the built environment, engineers may be asked to retrofit or upgrade the capacity of an existing concrete structural member. This could be a result of new demands on the structure, or a repair of damage from an unforeseen event. Retrofits are possible using the traditional building materials of concrete and steel. The cross-section of the structural element can be increased, or steel plates can be bolted or adhesively affixed to the structure to increase capacity. Many of these techniques are costly, and some perform poorly under service conditions. The main benefit for using FRP materials for the strengthening of existing structures is the lightweight nature of the composite material, which makes the use of extensive scaffolding (required in the installation of steel plates) obsolete. The objectives of this research are twofold. First, the overall structural behavior of an FRP strengthened or repaired concrete beam is studied. Two different loading conditions are examined: extreme loading simulated by a monotonic load to failure, and fatigue loading designed to simulate service loads. The structural behavior of the system is evaluated under these different conditions, and an analytical model is presented which predicts the flexural behavior of the system assuming certain failure modes. The second objective of this research is to evaluate the bond behavior of an FRP strengthened reinforced or prestressed concrete flexural member. A database of experimental failures was constructed, and an analytical model is proposed which predicts the bond failure of the FRP strengthening system.

The benefits of using hydrated lime as an additive in asphalt concrete are well known. When added to asphalt concrete mixtures hydrated lime shows the beneficial effects of filler, while also improving resistance to moisture damage. This study presents findings from four studies into the impact of hydrated lime, the impact of lime introduction method on the volumetric optimums, and the performance evaluation of unmodified and lime-modified hot mix asphalt (HMA) mixtures at varying asphalt contents using Simple Performance Tests developed from the NCHRP projects 9-19 and 9-29 and the viscoelastic continuum damage (VECD) finite element analysis. The performance characteristics evaluated in this study include fatigue cracking and rutting behavior in both dry and moisture-conditioned states. Test methods adopted in this evaluation are: the dynamic modulus test for stiffness characterization; the triaxial repeated load permanent deformation test for rutting characterization, and the direct tension test for fatigue cracking characterization. From the experimental investigation it is found that the method of lime introduction can have an important effect on the optimum volumetric asphalt content. Regarding dynamic modulus it is found that hydrated lime has a minimal impact on the mixtures in this study. However, the findings from this study support conventional understanding of the effects of asphalt content, lime modification, and moisture conditioning on the fatigue cracking and rutting performance of HMA mixtures. That is, as asphalt content increases, the resistance to fatigue cracking improves and rutting performance worsens. Another accepted fact is that lime modification reduces the susceptibility for moisture damage in terms of both fatigue cracking and rutting. The contribution of this paper, therefore, is to demonstrate advanced test methods and models that can be used in the performance evaluation of various mixtures. With additional validation and calibration, the comprehensive methodology described in this paper may serve as the foundation for a performance-based HMA mix design and performance-related HMA specifications.

Fuel life-cycle analyses were performed to compare the affects of hydrogen on annual U.S. light-duty transportation emissions in future year 2030. Five scenarios were developed assuming a significant percentage of hydrogen fuel cell vehicles to compare different feedstock fuels and technologies to produce hydrogen. The five hydrogen scenarios are: Central Natural Gas, Central Coal Gasification, Central Thermochemical Nuclear, Distributed Natural Gas, and Distributed Electrolysis. The Basecase used to compare emissions was the Annual Energy Outlook 2006 Report that estimated vehicle and electricity mix in year 2030. A sixth scenario, High Hybrid, was included to compare vehicle technologies that currently exist to hydrogen fuel cell vehicles that commercially do not exist. All hydrogen scenarios assumed 30% of the U.S. light-duty fleet to be hydrogen fuel cell vehicles in year 2030. Energy, greenhouse emissions, and criteria pollutant emissions including volatile organic compounds, particulate matter, sulfur dioxides, nitrogen dioxides, and carbon monoxide were evaluated. Results show that the production of hydrogen using thermochemical nuclear technology is the most beneficial in terms of energy usage, greenhouse gas emissions, and criteria pollutant emissions. Energy usage decreased by 36%, greenhouse gas emissions decreased by 46% or 9.6 x 108 tons, and criteria emissions were reduced by 28-47%. The centrally-produced hydrogen scenarios proved to be more energy efficient and overall release fewer emissions than the distributed hydrogen production scenarios. The only hydrogen scenario to show an increase in urban pollution is the Distributed Natural Gas scenario with a 60% increase in SOx emissions..

Recurrent congestion is a continually growing problem on urban freeways. Facility expansions cannot keep pace with the growing vehicle demand. Low-cost mitigation measures are one way to alleviate the congestion at recurring bottleneck locations. Low-cost measures typically have a life of approximately 10 years and costs ranging from $8,000 to $2.45 million. While benefits have been realized in field applications, there hasn?t been a lot of study regarding the performance of these measures in terms of added capacity. While modeling has long been a tool for planning and analyzing freeway networks, there has been little reported regarding its use for estimating the benefits of low-cost freeway improvements. In this study, the author tested proposed treatments at two sites using both a macroscopic and microscopic model. Because empirical performance information of these measures is not available, a quantitative analysis would not be reasonable since confidence in the values reported would be low. Current bottleneck identification methods typically either predict breakdown in real-time, or analyze detector data off-line. In order to identify bottlenecks from recorded aggregated data in an off-line model, criteria were generated to identify active bottlenecks and analyze the models? performance in an empirical and qualitative manner. Application of the criteria has been shown to provide reliable bottleneck identification to the calibrated pre-treatment case and expected results in the post-treatment cases.

The physical parameters of past experimental riparian buffer studies were used to develop a riparian buffer classification framework (RBCF) that uses high resolution remotely sensed data to identify the physical parameters of a riparian buffer and assign an estimate of total suspended solids (TSS) removal efficiency. Topographic data with a contour interval of 2 feet, color digital orthophotography with 1-foot resolution, and hydrography data covering a 1.8 square mile study area located within the city limits of Raleigh, North Carolina were utilized to test the RBCF. A cartographic model was developed to prepare each data layer for analysis. Applying the RBCF within the framework of the cartographic model produced highly detailed maps of existing riparian areas, and also provided an estimate of a riparian buffer?s efficiency in removing TSS from stormwater runoff. In this study, riparian buffers are identified through remote sensing at spatial scales of sufficient detail to determine regulated widths and also to examine the separate management zones within a buffer. Automated processing techniques for remotely sensed data, used in combination with specific resource classification schemes such as the RBCF will enable the assessment and analysis of site-specific conditions at county-wide scales.

The problem of pile foundation reuse provides an ideal opportunity to evaluate the validity of superposition as a design paradigm for ground intervention and ground reinforcement (GIGR) techniques when used in combination with in situ foundations. Grouted, helical piers, a relatively new technology, are proposed as a capacity improvement option for existing pile foundations. The relationship between these geotechnical elements was evaluated through the axial and lateral testing of small-scale, cast-in-place foundations in uniform, dry sand. These tests showed that the implementation of ground modification techniques caused an increase in the axial and lateral load-deflection performance of the foundation, with superposition as the most probable design methodology.

MOMEN, MOSTAFA HASSAN. Dynamic Modulus Determination of Asphalt Concrete Mixtures Using Indirect Tension Test. (Under the direction of Dr. Y. Richard Kim). The purpose of this research is to present the results from an analytical/experimental study on the dynamic modulus testing of hot mix asphalt (HMA) using the indirect tension (IDT) mode. The analytical solution for dynamic modulus determination in IDT was developed by Kim (14) using the theory of linear viscoelasticity. To verify the analytical solution, temperature and frequency sweep tests were conducted on 24 asphalt mixtures commonly used in North Carolina, using both axial compression and IDT test methods. In doing so, a modified dynamic modulus test protocol is introduced that reduces the required testing time by using more frequencies and fewer temperatures based on the time-temperature superposition principle. A comparison of results from the axial compression and IDT test methods shows that the dynamic modulus mastercurves and shift factors derived from the two methods are in good agreement. It was also found that Poisson?s ratio is a weak function of the loading frequency; its effect on the phase angle mastercurve is discussed. After verification of the analytical solution, another study was conducted to evaluate the effect of aggregate size on the variability of test results, where the coefficient of variation (CV) was computed for each aggregate size and the results were compared. It was found that mixes with a larger nominal maximum size of aggregate (NMSA) had a greater CV than those with a smaller NMSA. Digital image Correlation was used to further support the findings and reveal physical explanations for the results obtained from this statistical analysis.

Foam and honeycomb core sandwich composites are widely used in structural applications. Nevertheless, possibilities of core-to-face sheet delamination, crushing and buckling instability are major concerns. This study presents an innovative system for FRP panels designed to overcome delamination problems typically encountered in traditional FRP panels. The panels consist of GFRP laminates and foam core sandwich where top and bottom skin GFRP layers are connected together with through-thickness fibers. Addition of the through-thickness fibers increases the out of plane properties of the panel, delays delamination-type failures, allows low cost manufacturing and ensures full utilization of the panel strength. Fundamental material properties in tension, compression, flexure and shear are evaluated both experimentally and analytically. Failure modes and mechanisms are investigated. The influence of the panel thickness, through thickness fiber configuration and density and other parameters on the tension, compression, flexure and shear behavior of the panels will be discussed. Application of sandwich beam theories, Elementary Sandwich Theory and Advanced Sandwich Theory, are studied in the full behavior of the 3-D FRP sandwich beams. A finite element model is developed to be able to predict the behavior of sandwich panels with different panel thicknesses, through thickness fiber configurations, facing sheet thicknesses and different material properties.

Development of a comprehensive laboratory experimental program provided insight into the effects of jetting parameters (i.e. water volume flowrate and jet nozzle velocity) on maximum pile insertion depth, pile insertion rate, volume of debris transported to the ground surface, and the extent of the debris zone area (installation characteristics). This research is a two-part process involving laboratory and full-scale field jetting applications to determine the environmental impacts of jetting and the possibility of minimizing these impacts through jetting parameter optimization. The laboratory experimental program involved jetting installations in several soil types with unique grain-size distribution characteristics. Installation characteristics were compared for different sand types for the various jetting parameters investigated in order to develop a model for full-scale jetted pile installations. Results of the experimental program show that optimizing the jetting parameters for a given soil type may have positive effects on decreasing the surface impact of jetted pile installations. Recommended design procedures for using the jetted pile model are presented.