A. James Clark School of Engineering
Permanent URI for this communityhttp://hdl.handle.net/1903/1654
The collections in this community comprise faculty research works, as well as graduate theses and dissertations.
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Item THE TROUBLE WITH VOLUNTARY CARBON TRADING FOR BUILDINGS EXPOSED TO HURRICANE RISK(2017) Liu, Xiaoyu; Cui, Qingbin; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Increased climate risks pose challenges of combining climate mitigation and adaptation goals into building designs. These two goals are often misaligned, as adaptation measures use additional materials and equipment that are sources of carbon emissions. This phenomenon causes building design to involve tradeoffs between enhancing structural resilience and reducing emissions. This dissertation addresses the need to identify the optimal investment mechanisms for the design of buildings in hurricane-prone regions. Dynamic decision-making models are developed for individual investors to characterize emission trading and risk mitigation behaviors over a building’s lifecycle. The models enable the following outcomes: (i) evaluation and selection of baseline rules for sectoral emission trading, (ii) ability to reflect resilience goals in the building design, construction and maintenance, and to balance between climate mitigation and adaptation goals for a wide range of building examples, and (iii) policy implications for improving emission trading efficiencies and achieving environmental and economic sustainability at community level. Modeling results indicate that the trouble of voluntary emission trading is mainly attributed to imperfect market information and future climate risks. The uncertainty in predicting emissions and potential baseline manipulation leads to the production of non-additional carbon offsets and an extension of sectoral emission caps. This situation is even bleaker when emission trading are implemented in the areas that exposure to significant risks of catastrophic events such as hurricanes. The results reveal a trend of a transition from long-advocated low-carbon investment to a risk-oriented portfolio for building retrofits in hurricane-prone regions. The risk mitigation efforts should be pursued with discretion on the accuracy of insurance premium discounts. Meanwhile, subsidies for emission abatements are recommended to accommodate existing emission trading schemes and building property values.Item THE DEVELOPMENT EFFECTIVENESS OF INTERNATIONAL WATER AND SANITATION INFRASTRUCTURE PROJECTS: DEFINING “QUALITY AT ENTRY” OF WORLD BANK PROJECTS.(2016) Kfouri, Claire A.; Baecher, Gregory; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Over the past 15 years, the number of international development projects aimed at combating global poverty has increased significantly. Within the water and sanitation sector however, and despite heightened global attention and an increase in the number of infrastructure projects, over 800 million people remain without access to appropriate water and sanitation facilities. The majority of donor aid in the water supply and sanitation sector of developing countries is delivered through standalone projects. The quality of projects at the design and preparation stage is a critical determinant in meeting project objectives. The quality of projects at early stage of design, widely referred to as quality at entry (QAE), however remains unquantified and largely subjective. This research argues that water and sanitation infrastructure projects in the developing world tend to be designed in the absence of a specific set of actions that ensure high QAE, and consequently have relatively high rates of failure. This research analyzes 32 cases of water and sanitation infrastructure projects implemented with partial or full World Bank financing globally from 2000 – 2010. The research uses categorical data analysis, regression analysis and descriptive analysis to examine perceived linkages between project QAE and project development outcomes and determines which upstream project design factors are likely to impact the QAE of international development projects in water supply and sanitation. The research proposes a number of specific design stage actions that can be incorporated into the formal review process of water and sanitation projects financed by the World Bank or other international development partners.Item Mitigation of High Alkalinity in Leachates of Aged Steel Slag(2015) Ozkok, Enes; Davis, Allen P; Aydilek, Ahmet H; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Steel slag, an abundant by-product of the steel-making industry, after it is aged, has a huge potential for use as an aggregate in road construction. However, the high pH of steel slag seepage (pH≥12) is a major impediment in its beneficial use. Analyses on aged steel slag samples demonstrated that the alkalinity producing capacity of aged steel slag samples strongly correlated to Ca(OH)2 dissolution and that prolonged aging periods have marginal effects on overall alkalinity. Treatment methods that included bitumen-coating, bathing in Al(III) solutions and addition of an alum-based drinking water treatment residual (WTR) were evaluated based on reduction in pH levels and leachate alkalinity. 10% (wt./wt.) alum-based drinking water treatment residual (WTR) addition to slag was determined to be the most successful mitigation method, providing 65−70% reduction in alkalinity both in batch-type and column leach tests, but final leachate pH was only 0.5−1 units lower and leachates were contaminated by dissolved Al(+III) (≥3−4 mM). Based on the interpretation of calculated saturation indices and SEM and EDX analyses, formation of calcium sulfoaluminate phases (i.e., ettringite and monosulfate) was suggested as the mechanism behind alkalinity mitigation upon WTR-modification. The residual alkalinity in WTR-amended slag leachates was able to be completely eliminated utilizing a biosolids compost with high base neutralization capacity. In column leach tests, effluent pH levels below 7 were maintained for 58−74 pore volumes worth of WTR-amended slag leachate using 0.13 kg compost (dry wt.) per 1 kg WTR-amended slag on average; also, dissolved Al(+III) was strongly retained on the compost.Item SUSTAINABLE INFRASTRUCTURE MODELING AND POLICY ANALYSES: CONSTRUCTION, ENERGY AND TRANSPORTATION INDUSTRIES(2013) Avetisyan, Hakob; Gabriel, Steven A.; Miller-Hooks, Elise D.; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Sustainable infrastructure operation assumes consideration of interrelated elements and problems within interacting industries in which the decisions made for one industry may affect those in interrelated industries. Problems related to global climate change and resource scarcity are main concerns for a society trying to build a sustainable infrastructure. These problems are targeted from many perspectives, including government-enforced policies and regulations that call for energy efficiency and transportation efficiency to build a sustainable infrastructure. There is a growing interest among engineers in accounting for sustainability under the impact of climate change policies that limit the amount of pollutants being released from projects and facilities. While specific problems can be targeted by specialists in each industry or field, an optimal sustainable solution will be very difficult to find if considered separately. Despite that directions for improvement are defined, the methods and techniques for reaching these specified goals are not yet well developed. Decision-makers do not have the necessary models to evaluate the impact of proposed carbon policies supporting sustainable infrastructure development. Yet, it is important to analyze the problem in a systematic fashion to find cost-efficient, technically well-designed and constructed and sustainable solutions. In this dissertation, an interdisciplinary approach is used with the aim of analyzing programs geared at reducing emissions and costs, and determining optimal allocation of resources along with profit maximization by developing and employing optimization, regression and game-theoretic models for the construction, energy and transportation industries. These models can be used by national, state, local and private agencies for assessing carbon-mitigation policies and low-cost carbon policy developments. Concepts from integer programming, multi-objective decision-making, bi-level programming, simulation and regression are employed in the development of models to support informed decision-making and policy analyses in the construction, transportation and energy sectors. The models incorporate industry-specific details covering engineering, economic and environmental aspects of sustainable practices. The application of these models to real-world case studies provides insights that will allow defined specific goals to be achieved in a cost-efficient way. Results of case studies were optimal and most importantly not intuitive.Item Risk Analysis and Damage Assessment For Flood Prone Areas in Washington DC(2011) Lessani, Arian; Baecher, Gregory B; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This thesis presents a loss estimation method regarding areas of District of Columbia susceptible to flooding, specifically the Southwest quadrant, the National Mall, and Federal Triangle. This thesis develops data for input to a flood model that considers parameters such as detailed digital elevation data, global warming potential, and storm surge for a category IV hurricane. The main goal of this study is to employ a standard method for estimating flooding damages in Washington by supplying combination of the mentioned parameters to the HAZUS-MH 2.0 program. The results of this research is useful for planning purposes, such as reducing natural hazard losses and preparing emergency response and recovery. It is predicted that in the projected storm surge flood more than 1500 buildings would be damaged and about ten thousand people would seek temporary refuge in public shelters. The estimate of total loss for flooding is approximately $1,300 million dollars.