Civil and Environmental Engineering Commons^™

Spatial Variation And Correlation Between Undrained Shear Strength And Plasticity Index, Xin Kang, Site Onyejekwe, Louis Ge, Richard Wesley Stephenson

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A Soil Variability Analysis is Presented in This Paper. About 317 Unconsolidated Undrained Triaxial Compression Tests (UU) Were Carried Out on Undisturbed Samples from Four Locations in Missouri. the Spatial Variation of the Undrained Shear Strength and Plasticity Index Was Described by the Second-Moment Statistics (Mean and Variance). Meanwhile, the Correlation between the Undrained Shear Strength and Plasticity Index Was Established and Compared with Other Published Empirical Equations. the Results from the Soil Variability Analysis Provide a Framework to the Reliability-Based Design. © 2011 ASCE.

Effectiveness Of Objective Functions In Soil Model Calibration Through Numerical Optimization, Michelle Deng, Louis Ge

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

When a conventional method such as linear regression is insufficient to identify the constants and parameters of an advanced constitutive model, numerical optimization techniques are often being used. in employing numerical optimization to constitutive model calibration, an objective function essentially needs to be formulated in such way that the difference between the measured and computed data points is quantified. When a minimum value of the objection function is obtained, the corresponding variables are the optimized model constants and parameters. in this paper, a modified Cam-Clay model is calibrated against laboratory data. Three objective functions are proposed in different forms to …

Variability Analysis Of Undrained Shear Strength For Reliability-Based Design, Site Onyejekwe, Xin Kang, Louis Ge, Richard Wesley Stephenson

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Description of the Spatial Variation of Compositional and Mechanical Soil Parameters is Often Paramount in Site Characterization of Geotechnical Design and Analysis. the Values of the Parameters Themselves Largely Depend on In-Situ State Factors Which Are Related to Spatial Locations. Also, for Large-Scale Engineering Projects Such as Earth Dams or Highways, It is Generally Expected that Heterogeneous Site Characteristics Will Be Revealed by Investigations at Spatially Distant Locations. Currently, Most Reliability-Based Design Methods Are based on the Second-Moment Statistics (Mean and Variance). However, They Are Unable to Adequately Describe the Spatial Variation of Soil Properties. in This Paper, Spatial Correlation …

Evaporation From Soils Under Thermal Boundary Conditions: Experimental And Modeling Investigation To Compare Equilibrium- And Nonequilibrium-Based Approaches, Kathleen M. Smits, Abdullah Cihan, Toshihiro Sakaki, Tissa H. Illangasekare

Civil Engineering Faculty Publications - Archive

In the shallow subsurface immediately below the land-atmosphere interface, it is widely recognized that the movement of water vapor is closely coupled to thermal processes. However, their mutual interactions are rarely considered in most soil water modeling efforts or in practical applications where it becomes necessary to understand the spatial and temporal distribution of soil moisture. The validation of numerical models that are designed to capture these processes is difficult due to the scarcity of field or laboratory data with accurately known hydraulic and thermal parameters of soils, limiting the testing and refinement of heat and water transfer theories. The …

Slides: The Costs And Benefits Of Best Management Practices: Insights From The Marcellus Shale, Timothy J. Considine

Best Management Practices (BMPs): What? How? And Why? (May 26)

Presenter: Timothy J. Considine, School of Energy Resources, Department of Economics and Finance, University of Wyoming

15 slides

Slides: Collaborative Planning And Lessons Learned, Matt Sura

Best Management Practices (BMPs): What? How? And Why? (May 26)

Presenter: Matt Sura, University of Colorado Law School

48 slides

Parametric Assessment Of Stress Development And Cracking In Restrained Mortars Containing Internal Curing Under Autogenous And Thermal Loading, Kambiz Raoufi, John Schlitter, Dale Bentz, Jason Weiss

Lyles School of Civil Engineering Faculty Publications

A finite element model is used to examine how the properties of cementitious mortar are related to the stress development in the dual ring test. The results of this investigation are used to explain the thermal cracking behavior of mixtures containing prewetted lightweight aggregates (LWA) by quantifying the contribution of several material properties individually. In addition to the beneficial effects of using the LWA as an internal curing agent to reduce the autogenous shrinkage of concrete, the LWA also helps to reduce the potential for thermal cracking due to a lower elastic modulus and increased stress relaxation. The rate of …

The Green, Blue And Grey Water Footprint Of Crops And Derived Crop Products, Mesfin Mekonnen, Arjen Y. Hoekstra

Daugherty Water for Food Global Institute: Faculty Publications

Abstract. This study quantifies the green, blue and grey water footprint of global crop production in a spatially-explicit way for the period 1996–2005. The assessment improves upon earlier research by taking a high-resolution approach, estimating the water footprint of 126 crops at a 5 by 5 arc minute grid. We have used a grid-based dynamic water balance model to calculate crop water use over time, with a time step of one day. The model takes into account the daily soil water balance and climatic conditions for each grid cell. In addition, the water pollution associated with the use of nitrogen …

Optimizing High Volume Traffic Surges Using Discrete Event Simulation, Claire L. Johnson

Doctoral Dissertations and Master's Theses

The purpose of this applied research study is to determine the fidelity of a discrete event simulation tool called the Evacuation Simulation Prediction Tool (ESP) in predicting transit times during a high volume surge in traffic flow. The ESP tool was developed for the purpose of predicting and optimizing large-scale evacuations of counties or regions as an aide in emergency and disaster preparedness planning. The goal of the ESP model is to ascertain the balance of traffic flow capacity by managing the human factor events that impinge upon orderly highway travel without immobilizing the travel route. The objective of this …

Effects Of Coupling In Understanding The Surface Energy Balance In The Snake River Basin, Idaho, Thilinl Jaksa, Kevin Nuss, Venkataramana Sridhar

Civil Engineering Faculty Publications and Presentations

An accurate estimation of surface fluxes and evapotranspiration is critical in understanding the hydrological and meteorological processes linking the land and the atmosphere. Due to difficulties in obtaining extensive and timely field measurements, land surface and atmospheric models are widely employed in estimating such fluxes. This study focuses on testing the ability of Noah LSM to simulate the surface fluxes both in an uncoupled mode and coupled within an atmospheric model. An agricultural area in the Snake River Basin in Idaho and its surrounding natural vegetation regions are the study area. Two model improvements are tested in this investigation: modification …

The Adaptability And Sustainability Of Surface Water Diversions Along The Main Stem Of The Snake River In Southern Idaho, David J. Hoekema, Venkataramana Sridhar, Xin Jin

Civil Engineering Faculty Publications and Presentations

Agriculture in southern Idaho depends heavily on the conversion of snowpack into spring runoff. The Natural Resource Conservation Service (NRCS) has developed a Surface Water Supply Index (SWSI) as a tool to predict whether or not forecasted runoff and reservoir storage will be adequate to meet irrigator’s needs at a basin scale. This research by comparing SWSI to diversions for individual canals advances the use of SWSI to develop a Surface Water Supply Metric (SWSM) that can be used to estimate the reliability and sustainability of diversions under historic and projected time periods. An historic analysis of diversions during three …

Modeling Erosion And Sedimentation Processes In The Chorro Creek Subwatershed To Evaluate And Develop Effective Watershed Management Approaches, Michael Randall, Misgana K. Muleta

Civil and Environmental Engineering

The Morro Bay Watershed, located in San Luis Obispo County, California, covers more than 48,000 acres of land and discharges into Morro Bay through the Morro Bay National Estuary (MBNE). The Chorro Creek Subwatershed consists of approximately 30,000 acres of the overall watershed. The MBNE provides an ecosystem that supports a variety of wildlife, from the common sea gull to the endangered sea otter. The estuary is also home to over 200 species of birds. The operational waterfront of the Morro Bay Harbor was and continues to be a strong supporter to the local economy of the City of Morro …

Improving Model Performance Using Dynamic Evaluation And Proper Objective Function, Misgana K. Muleta

Civil and Environmental Engineering

Models have become important decision making aids. Model evaluation (i.e., global sensitivity analysis, calibration and uncertainty analysis), is crucial to improve their prediction accuracy and reduce the likelihood of making decisions that could lead to undesirable policy outcomes. The conventional approach assumes that model parameters are insensitive to season irrespective of the temporal variability of input forcings such as rainfall. This assumption could significantly compromise model performance for low flow seasons and/or high flow seasons depending on the calibration method pursued. This study will demonstrate the advantage of dynamic (seasonal) model evaluation in improving performance compared to the traditional approach. …

Hospital Vozandes Del Oriente Wastewater Treatment System Design, James Dykstra, Rachel Koopman, Ben Vander Plas, Sungmin Youn

All Engineering Faculty Research

Shell is a town located in the Eastern foothills of the Ecuadorian Andes approximately 94 miles Southeast of Quito. Hospital Vozandes del Oriente (HVO) is a hospital located in Shell owned and operated by Hoy Cristo Jesús Bendice (HCJB) Global. HCJB is a non-profit mission organization committed to Biblical values and community development principles.

Pure Pastaza, a senior design team from Calvin College, in conjunction with HCJB, has designed a wastewater treatment system for HVO. The design promotes the protection of human and environmental health by providing a sustainable solution to wastewater treatment and sets an example of stewardship to …

Surface Reaction Rate And Probability Of Ozone And Alpha-Terpineol On Glass, Polyvinyl Chloride, And Latex Paint Surfaces, Shi Shu, Glenn Morrison

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Ozone can react homogeneously with unsaturated organic compounds in buildings to generate undesirable products. However, these reactions can also occur on indoor surfaces, especially for low-volatility organics. Conversion rates of ozone with α-terpineol, a representative low-volatility compound, were quantified on surfaces that mimic indoor substrates. Rates were measured for α-terpineol adsorbed to beads of glass, polyvinylchloride (PVC), and dry latex paint, in a plug flow reactor. a newly defined second-order surface reaction rate coefficient, k2, was derived from the flow reactor model. the value of k2 ranged from 0.68 - 10-14 cm 4s-1molecule-1 for α-terpineol adsorbed to PVC to 3.17 …

College Of Engineering Senior Design Competition Spring 2011, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge.

The senior design competition helps focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects on …

College Of Engineering Senior Design Competition Fall 2011, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge. The senior design competition helps focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects on …

Historical Legacies, Information And Contemporary Water Science And Management, Daniel J. Bain, Jennifer A. S. Arrigo, Mark B. Green, Brian A. Pellerin, Charles J. Vörösmarty

Advanced Science Research Center

Hydrologic science has largely built its understanding of the hydrologic cycle using contemporary data sources (i.e., last 100 years). However, as we try to meet water demand over the next 100 years at scales from local to global, we need to expand our scope and embrace other data that address human activities and the alteration of hydrologic systems. For example, the accumulation of human impacts on water systems requires exploration of incompletely documented eras. When examining these historical periods, basic questions relevant to modern systems arise: (1) How is better information incorporated into water management strategies? (2) Does any point …

How Much Do U.S. University Students Know, And Want To Know, About Sustainability And Green Building? The Findings Of A Survey, And Possible Implications For General Elective Curricula., Jeremy R. Farner

Purdue Polytechnic Masters Theses

Using the survey approach, this investigation examined the attitudes and interest of college students at two universities in different geographic locations within the United States.  Approximately 24,000 students from all disciplines and majors at Weber State University (WSU) in Utah, and 4,000 at Purdue University in Indiana, were invited to participate in a study to determine current knowledge, familiarity, and interest in topics within the sustainability and Green Building educational arena. The goal of this study was to determine what students already know, would like to know, and how much interest there would be in developing …

Rate-Dependent Behavior Of Clay, Harry F. Martindale Iv

Master's Theses

This thesis presents a strain-rate dependent two-surface plasticity constitutive model for clays based on the critical-state soil mechanics.  The model reproduces the mechanical response of clays under multi-axial loading conditions and predicts both drained and undrained behaviors at small and large strains.  Model parameter values are determined for Boston Blue Clay, London Clay and Kaolin Clay.  The performance of the model in simulating the mechanical response of clays is demonstrated for a variety of strain rates. Sensitivity of each model parameter is checked for ±5, ±10 and ±20% of the deterministic values. Probabilistic analysis using Monte Carlo simulations were done …

Public Transit Accessibility And Need Indices: Approaches For Measuring Service Gap, Sha Mamun

Master's Theses

The integration of transit needs into transit accessibility indexing is important for the evaluation of existing transportation systems and, service gaps, and for the identification of priority areas for future investments in transportation infrastructure. This thesis details an accessibility-based transit need indexing model that focuses on the necessity of evaluating transit needs and transit accessibility simultaneously. A need index is developed to identify areas in high need of public transit services using economic and socio-demographic information and a composite accessibility index is developed to identify levels of access to transit services and shortcomings in service provision. The need for transit …

Public Perception Of Public Transportation And Its Built Environment In The New Haven - Springfield Corridor, Garrett S. Bolella

Master's Theses

Studying and quantifying public perception of public transportation and the built environment in which it operates is crucial to understanding the symbiotic relationship between transportation and land use. This paper presents a choice experiment which places respondents into personalized hypothetical scenarios and examines their preferences for new transit service and the environment in which it operates. The choice experiment survey instrument investigates public response to hypothetical bond referenda to fund new transit projects with particular service and built environment attributes. Service options are characterized by six attributes: service type, service reliability, comfort, stop environment, parking availability at final destination, and …

Development & Application Of The Transportation Index For Sustainable Places (Tisp), Jason Zheng

Master's Theses

The purpose of transportation systems go beyond the movement of people and goods. These systems shape the natural and built environment which subsequently affects social and economic interactions. However, conventional metrics typically only address the mobility aspect of transportation via measures such as level of service and congestion. Metrics are needed to evaluate the broader impacts of transportation.

This work describes the Transportation Index for Sustainable Places (TISP), a performance metric designed to assess the sustainability of transportation systems with respect to environmental, social, and economic outcomes. The development of the TISP was guided through literature review focused on understanding …

The Impacts Of Road Capacity Removal, Jason E. Billings

Master's Theses

The road infrastructure of North America is aging, and many governments are faced with a critical decision:  do we repair or remove freeways from our urban centers?  Freeway repair is exceptionally expensive, but removing a freeway is widely seen as a risky venture which may result in negative traffic effects.  Therefore, it is necessary to gain a clearer understanding of how removing road capacity effects traffic distribution.  Three freeway segments were ultimately selected for case study analysis: two in San Francisco and one in Milwaukee.  This analysis consisted of identifying changes in the traffic volumes and volume-capacity (V/C) ratios in …

Comprehensive Analysis Of Effluent Organic Matter From Five Wastewater Treatment Plants In Connecticut And Comparison To Natural Organic Matter, Matthew L. Quaranta

Master's Theses

Natural organic matter is an important driver of biotic and abiotic processes in aquatic environments. Wastewater treatment plants discharge a substantial amount of organic matter into the environment; however effluent organic matter has not been well studied. In this study, traditional organic geochemical techniques were applied to characterize effluent organic matter. Effluent organic matter was isolated by DAX8 (hydrophobic fraction) and XAD4 (transphilic fraction) Amberlite resins. Extraction efficiencies of effluent organic matter by DAX8 resins ranged from 18 to 42 percent as a result of larger content of hydrophilic organic matter than natural organic matter. Average organic matter molecular weights …

Wired For Business: The Roebling Story., Kelley Marie Hatch-Draper

Electronic Theses and Dissertations

John Augustus Roebling, a classically educated civil engineer and young Hegelian, immigrated to America in 1831 in search of freedom from a repressive political system that afforded him no opportunity for advancement. Arriving in the midst of the American market revolution, his dream of establishing an agrarian farming colony changed in response to societal transformations resulting from mechanization and the rise of industry. Within forty years, Roebling achieved fame as a canal engineer and bridge designer while establishing the American wire rope industry. Without Roebling's innovation in wire-rope, modern suspension bridges, high-rise elevators, construction cranes, and cable cars would not …

Residual Strength Of Ultra-High Performance Concrete After Exposure To Elevated Temperatures, Brian T. Burke

Master's Theses

This paper presents the results of a study on the effect of elevated temperatures on the compressive strength of ultra-high-performance fiber-reinforced concrete (UHPFRC). Two different mixtures of a commercially available UHPFRC were considered in this study. The standard mixture offered by the manufacturer incorporates only steel-fibers to improve the tensile properties of the concrete. The enhanced mixture, which is of primary focus in the study, incorporates additional polypropylene fibers to improve the fire-resistance behavior. Specimens from each mixture were cast into 76 mm (3 in.) diameter cylinders and 51 mm (2 in.) cubes. After exposure to elevated temperatures …

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Ecosystem Management Of The Missouri River From Gavins Point Dam To Ponca State Park, Nebraska, Robert S. Nebel

United States Army Corps of Engineers, Omaha District

•Authorized by a 1978 amendment to the National Parks and Recreation Act (PL 95- 625) which amended the Wild and Scenic Rivers Act of 1968 (PL 90-542)

• Corps is authorized to construct recreational development, bank stabilization, and other recreational river features as necessary to support the values for which the river was designated

• Life-of-project funding ceiling of $21 million; approximately $3.2 million spent to date

• The Corps and National Park Service signed a 1980 Cooperative Agreement outlining each agency's responsibilities

• The General Management Plan has recently been updated (1999) with an environmental emphasis

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