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Articles 8401 - 8430 of 10548
Full-Text Articles in Entire DC Network
A New Seismic-Geotechnical Strong Motion Approach, Francois E. Heuze, Tzou-Shin Ueng, Lawrence J. Hutchings, Stephen P. Jarpe, Paul W. Kasameyer
A New Seismic-Geotechnical Strong Motion Approach, Francois E. Heuze, Tzou-Shin Ueng, Lawrence J. Hutchings, Stephen P. Jarpe, Paul W. Kasameyer
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
We have developed a new approach to estimate site-specific strong motion due to earthquakes on specific faults or source zones. It combines seismologic and geotechnical studies. It entails obtaining records of small earthquakes at the site, both at the surface and downhole in bedrock, as well as performing geotechnical dynamic site characterization. This new approach has the dual result of providing an optimized definition of the dynamic geotechnical site properties and providing calculated free-field, strong motion estimates. The procedure is demonstrated at the Painter Street Bridge site in Rio Dell, CA, for which we provide a range of surface motions …
Performance Of Port Facilities During The Northridge Earthquake, K. K. Muraleetharan, S. V. Jagannath, K. Arulmoli, D. A. Thiessen
Performance Of Port Facilities During The Northridge Earthquake, K. K. Muraleetharan, S. V. Jagannath, K. Arulmoli, D. A. Thiessen
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
During the January 17, 1994, Northridge earthquake, two of the Port of Los Angeles' facilities called Berths 121-126 and Pier 300 sustained moderate damage. Lateral displacement of dikes up to five inches and liquefaction of hydraulic fills were observed. Several geotechnical analyses from simplified SPT -based method to sophisticated fully-coupled analyses are presented. Observed lateral displacements are predicted reasonably well by the fully-coupled analysis procedure and an intermediate analysis procedure which incorporates some results from a fully-coupled analysis in to a simplified Newmark-type deformation analysis. The potential for higher pore pressure generation underneath the dike compared to a level ground …
Micromechanics Of Hot Mix Asphalt Material Formulation And Numerical Simulation, Kuo-Neng G. Chang
Micromechanics Of Hot Mix Asphalt Material Formulation And Numerical Simulation, Kuo-Neng G. Chang
Dissertations
Hot Mix Asphalt (HMA), a highway and airfield pavement material, is heterogeneous, granular, and composite. It is traditionally modeled as a homogeneous material using continuum mechanics or semi-empirical methods. As a result, the above models either neglect or over-simply component reactions, failing to predict field performance problems resulting from particle segregation. This research presents micromechanical modeling, a novel approach that accounts for the components.
A micromechanical model is developed for HMA by modeling it as an assembly of asphalt cement coated particles. The asphalt cement is modeled as a viscoelastic material. To represent asphalt cement, several viscoelastic elements (i.e. Maxwell, …
Modeling For Optimal Management Of Agricultural And Domestic Wastewater Loading To Streams, Muhammad Shafqat Ejaz, Richard C. Peralta
Modeling For Optimal Management Of Agricultural And Domestic Wastewater Loading To Streams, Muhammad Shafqat Ejaz, Richard C. Peralta
Civil and Environmental Engineering Faculty Publications
A simulation/optimization (S/0) model to aid managing multiobjective wastewater loading to streams while maintaining adequate downstream water quality is presented. The conflicting objectives are to maximize the human and dairy cattle populations from which treated wastewater can be discharged to the river system. Nonindustrial municipal (domestic) wastewater undergoes primary and secondary treatment by a sewage treatment plant (STP) before entering as a steady point source. Dairy wastewater is treated by overland flow (OLF) land treatment before entering the stream as a controlled steady diffuse source. Maximum dual-source loading strategies which do not degrade downstream water quality beyond specified limits are …
Considering Ecological Constraints While Optimizing Sustained Groundwater Yield, Pahvant Valley, Utah, Getachew Belaineh, Richard C. Peralta
Considering Ecological Constraints While Optimizing Sustained Groundwater Yield, Pahvant Valley, Utah, Getachew Belaineh, Richard C. Peralta
Civil and Environmental Engineering Faculty Publications
Concern for groundwater quality and availability is increasing in Pahvant Valley. Ground-water levels are declining due to intense groundwater extraction for irrigation; water having high total dissolved solids concentration is flowing from the southwest toward the pumping sites; and discharge from natural springs in a wildlife refuge is declining. Transient simulation of aquifer response to 20 years of the 1985 pumping rates (beginning with 1985 groundwater level) predicted that spring discharge would decrease by as much as 87% from 1985 rates. Presented are preliminary pumping strategies that maximize sustainable, steady-state groundwater extraction without unacceptably reducing discharge from the springs. A …
Optimizing Irrigation Management For Pollution Control And Sustainable Crop Yield, Ghassan R. Musharrafieh, Richard C. Peralta, Lynn M. Dudley, Ronald J. Hanks
Optimizing Irrigation Management For Pollution Control And Sustainable Crop Yield, Ghassan R. Musharrafieh, Richard C. Peralta, Lynn M. Dudley, Ronald J. Hanks
Civil and Environmental Engineering Faculty Publications
Irrigation strategies which maximize crop yield while preventing salt from leaching to the groundwater or undesirable salt increases in the root zone are computed by using a one-dimensional simulation/optimization management model. The included constraint equations maintain a water volume balance and salt transport in the unsaturated zone. Implicit finite difference forms of the unsaturated water flow equation (Richards' equation), the diffusion-convection solute transport equation, functions describing the hydraulic properties of the medium, a root extraction function, and other constraints are used. The model uses a large discretization in time. A cyclic prediction and correction type of approach is adopted to …
Maximizing Tce Removal From A Contaminated Aquifer, Richard C. Peralta, Alaa H. Aly
Maximizing Tce Removal From A Contaminated Aquifer, Richard C. Peralta, Alaa H. Aly
Civil and Environmental Engineering Faculty Publications
A methodology for developing pumping strategies to maximize contaminant extraction is presented. The methodology consists of approximating the mass removal integral using a quadrature rule. Contaminant mass extraction is expressed as a function of the extraction rates. The relation of contaminant extraction to pumping rates is used as one of several constraints within a simulation/optimization model. The implementation and application of the methodology are described. The result is a set of pumping rates which are optimal in the sense that they maximize the mass of contaminant removed by the extraction system for a posed management scenario.
Proceedings Of The 1995 Annual Symposium On Engineering Geology And Geotechnical Engineering (No. 31), Joseph A. Caliendo
Proceedings Of The 1995 Annual Symposium On Engineering Geology And Geotechnical Engineering (No. 31), Joseph A. Caliendo
Reports
No abstract provided.
Groundwater Model Parameter Estimation Using Response Surface Methodology, Richard M. Cotman
Groundwater Model Parameter Estimation Using Response Surface Methodology, Richard M. Cotman
Theses and Dissertations
This thesis examined the use of response surface methodology (RSM) to estimate the parameters of a finite-element groundwater model. An existing two-dimensional, steady-state flow model of a fractured carbonate groundwater system in southwestern Ohio served as the calibration target data set. A Plackett-Burman screening design showed that only four of the ten hydraulic conductivity zones significantly contributed to the output of the finite-element model. Also, the effective porosity parameter did not significantly affect the model's output. Using only the four significant hydraulic conductivity parameters; four two-level, four-factor designed experiments were conducted to exploit the first-order response surface defined by a …
Assuring A Long Term Groundwater Supply: Issues, Goals And Tools, Richard C. Peralta
Assuring A Long Term Groundwater Supply: Issues, Goals And Tools, Richard C. Peralta
Civil and Environmental Engineering Faculty Publications
Groundwater is a hidden, but important resource. We can practicably define groundwater as water beneath the ground surface that can be extracted by wells. Other water in the ground that is not considered to be available for man’s direct use is commonly called “subsurface water.” Subsurface water includes moisture within the root zone.
Life-Cycle Cost Analysis For Radioactive Waste Remediation Alternatives, Thomas P. White, Ronald J. Toland, Dorian Y. Buitrago
Life-Cycle Cost Analysis For Radioactive Waste Remediation Alternatives, Thomas P. White, Ronald J. Toland, Dorian Y. Buitrago
Theses and Dissertations
This research has two primary objectives. The first is to develop a generic, interactive, spreadsheet-based life-cycle cost model that uses net present value and risk analysis techniques for cost comparison. The second is to apply the model specifically to the vitrification and cementation methods of waste remediation. By using spreadsheet analysis and graphics capabilities, the model will provide direct and objective comparisons of remediation alternatives. Since vitrification is a new technology, the plant design and operations are conceptual. Therefore, computer simulation and engineering judgement are integral to the vitrification LCC estimate.
A Comparison Between Revealed Preference (Rp) And Stated Preference (Sp) Based On Results Of Simulations, Qiuzi Chen
A Comparison Between Revealed Preference (Rp) And Stated Preference (Sp) Based On Results Of Simulations, Qiuzi Chen
Theses
This research quantifies the potential biases resulted from two different data generation methods used in transportation modeling: Revealed Preference (RP) and Stated Preference (SP) techniques. Revealed Preference technique is the conventional approach to generate data. It relies on observed or reported data of actual behavior. Stated preference technique is a new data generation method. It creates transportation scenarios using hypothetical data. Conventional studies favor the use of revealed reference. However, full description of advantages and weaknesses of using revealed preference technique is not available in literature, neither point-to-point comparison between stated preference and revealed preference techniques. This research contributes to …
Mechanical Behavior Of Polystyrene Foam Bead Lightweight Concrete, Hai-Ying Ni
Mechanical Behavior Of Polystyrene Foam Bead Lightweight Concrete, Hai-Ying Ni
Theses
This thesis is designed to investigate the effect of porosity on the mechanical properties (strength and modulus) of concrete, and to evaluate the effect of silica fume on the mechanical properties of the polystyrene foam bead lightweight concrete. In this research we made the lightweight concrete by using polystyrene foam beads as light weight aggregate and studied its mechanical properties in detail. Due to the near zero density and modulus of foam beads, we were able to consider it as "porosity". We could then control porosity in concrete by varying foam bead volume fraction.
In our experiments we used the …
Impact Of Erosion, Mass Wasting, And Sedimentation On Human Activities In The Río Grande Basin, Jujuy Province, Argentina, Waldo Chayle, William J. Wayne
Impact Of Erosion, Mass Wasting, And Sedimentation On Human Activities In The Río Grande Basin, Jujuy Province, Argentina, Waldo Chayle, William J. Wayne
Department of Earth and Atmospheric Sciences: Faculty Publications
Nearly all dry mountainous regions are affected by severe erosion, floods, and debris flows during times of intense precipitation. The lithology, geologic structure, and climate in Jujuy Province, Argentina combine to place at serious risk the people who live along the Río Grande, the major river that drains the east side of the Cordillera Oriental and the west side of the Sierras Subandinas. Nearly all precipitation falls during summer (January–March) with little during the remainder of the year; most of the basin is semiarid to arid, although the southern end has a humid subtropical climate. Relief is great, as much …
Personal Computer (Pc) Program For Analysis Of Embankments With Tensile Elements, Mikhail E. Slepak, Tommy C. Hopkins
Personal Computer (Pc) Program For Analysis Of Embankments With Tensile Elements, Mikhail E. Slepak, Tommy C. Hopkins
Kentucky Transportation Center Research Report
UKSLOPE is a comprehensive, PC-based, slope stability computer program that can be used to design and analyze reinforced and unreinforced earth structures. The computer program consists of two parts: limit equilibrium models and a computerized method for determining the spacing, length, Md number of tensile reinforcement elements. The design of reinforcement elements generally follows guidelines developed by the Tensar® Corporation. However, some modifications and improvements to the original methods have been made. The slope stability analysis portion of UKSLOPE is based partly on the original mainframe version. The following are the main features of the program:
- UKSLOPE is an extremely …
Construction Resource Allocation Using A Genetic Algorithm, Siripong Malasri, Jennifer R. Martin
Construction Resource Allocation Using A Genetic Algorithm, Siripong Malasri, Jennifer R. Martin
Journal of the Arkansas Academy of Science
A proper allocation of limited resources (men, machines, materials, and money) is critical in a construction project. Traditionally, resource allocation problems have been solved using methods in operations research (OR), such as mathematical programming. In recent years, genetic algorithms (GA) have emerged as an effective optimization methodology. One major advantage of the GA approach over the OR approach is that the GA approach is universal for various types of optimization problems, unlike the OR approach which varies depending on the types of problems at hand. This paper shows an application of GA to a resource allocation problem in the construction …
Teaching Civil Engineering Design: Observations And Experiences, Charles Darwin Morris, Roger A. Laboube
Teaching Civil Engineering Design: Observations And Experiences, Charles Darwin Morris, Roger A. Laboube
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Civil engineering design is an inspired activity. It offers the engineer a high degree of autonomy to conceive or create a unique, state-of-the-art, functional, costeffective facility. Civil engineering design calls on the talent of the engineer to balance the client's end-use requirements and financial resources, with the safety ofthe occupants. Because the process of engineering design has such a vast degree of freedom, teaching the concepts inherent in design is a very challenging, and at times frustrating, endeavor. The present paper discusses the many facets of the senior design course developed at the University of Missouri- Rolla to include a …
Solid Waste Disposal Site Characterization Using Non-Intrusive Electromagnetic Survey Techniques And Geostatistics, Gary N. Kuhn, Wayne E. Woldt, David D. Jones, Dennis D. Schulte
Solid Waste Disposal Site Characterization Using Non-Intrusive Electromagnetic Survey Techniques And Geostatistics, Gary N. Kuhn, Wayne E. Woldt, David D. Jones, Dennis D. Schulte
Department of Agricultural and Biological Systems Engineering: Faculty Publications
Prior to the research reported in this paper, a site-specific hydrogeologic investigation was developed for a closed solid waste facility in Eastern Nebraska using phased subsurface characterizations. Based on the findings of this prior investigation, a surface based geoelectric survey using electromagnetic induction to measure subsurface conductivity was implemented to delineate the vertical and horizontal extent of buffed waste and subsurface contamination. This technique proved to be a key non-intrusive, cost-effective element in the refinement of the second phase of the hydrogeologic investigation.
Three-dimensional ordinary kriging was used to estimate conductivity values at unsampled locations. These estimates were utilized to …
Locally Weighted Polynomial Regression: Parameter Choice And Application To Forecasts Of The Great Salt Lake, Upmanu Lall, Young-Ii Moon, Ken Bosworth
Locally Weighted Polynomial Regression: Parameter Choice And Application To Forecasts Of The Great Salt Lake, Upmanu Lall, Young-Ii Moon, Ken Bosworth
Reports
Relationships between hydrologic variables are often nonlinear. Usually the functional form of such a relationship is not known a priori. A multivariate, nonparametric regression methodology is provided here for approximating the underlying regression function using locally veighted polynomials. Locally weighted polynomials consider the approximation of the target function through a Taylor series expansion of the function in the neighborhood of the point of estimate. Cross validatory procedures for the selection of the size of the neighborhood over which this approximation should take place, and for the order of the local polynomial to use are provided and shown for some simple …
Optimal Pumping Strategy To Capture Tce Plume At Base Boundary, Norton Afb, California, Richard C. Peralta, A. H. Aly
Optimal Pumping Strategy To Capture Tce Plume At Base Boundary, Norton Afb, California, Richard C. Peralta, A. H. Aly
Civil and Environmental Engineering Faculty Publications
Ground water contaminated by trichloroethylene (TCE) at Norton AFB (NAFB) has reached off-base supply wells. Utah State University (USU) computed an optimal steady pumping strategy to eventually halt off-base migration of TCE exceeding 5 ppb. (A steady pumping strategy is a spatially distributed set of extraction and injection rates.)
Optimal Perennial Groundwater Yield Planning For Complex Nonlinear Aquifers: Methods And Examples, Shu Takahashi, Richard C. Peralta
Optimal Perennial Groundwater Yield Planning For Complex Nonlinear Aquifers: Methods And Examples, Shu Takahashi, Richard C. Peralta
Civil and Environmental Engineering Faculty Publications
Optimal perennial groundwater yield pumping strategies were computed for a complex multilayer aquifer with: (i) confined and unconfined flow, and (ii) many flows typically described by piecewise-linear (nonsmooth) equations. The latter flows account for over 50% of the aquifer discharge from the test area, the eastern shore of the Great Salt Lake in Utah. Normally utilized response matrix (RM) and embedding (EM) simulation/optimization modelling procedures did not converge to optimal solutions for this area; they diverged or oscillated. However, the newly presented linear RM and EM approaches satisfactorily addressed the nonlinearities posed by over 2000 piecewise-linear constraints for evapotranspiration, discharge …
Methsnotrophic Biodegradation Of Trichloroethylene In A Hollow Fiber Membrane Bioreactor, Carol E. Aziz, Mark W. Fitch, Larry K. Linquist, Jonathan G. Pressman, George Georgiou, Gerald E. Speitel
Methsnotrophic Biodegradation Of Trichloroethylene In A Hollow Fiber Membrane Bioreactor, Carol E. Aziz, Mark W. Fitch, Larry K. Linquist, Jonathan G. Pressman, George Georgiou, Gerald E. Speitel
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Biodegradation of Trichloroethlyene (TCE) in a Hollow Fiber Membrane Bioreactor Was Investigated using a Mutant of the Methanotrophic Bacteria, Methylosinus Trichosporium 0B3b. Contaminated Water Flowed through the Lumen (I.e., Fiber Interior), and the Bacteria Circulated through the Shell Side of the Membrane Module and an External Growth Reactor. in Mass Transfer Studies with a Radial Cross-Flow Membrane Module, 78.3-99.9% of the TCE Was Removed from the Lumen at Hydraulic Residence Times of 3-15 Min in the Lumen and the Shell. in Biodegradation Experiments, 80-95% of the TCE Was Removed from the Lumen at Hydraulic Residence Times of 5-9 Min in …
Use Of Time Domain Reflectometry For Determination Of Water Content An Density Of Soil, Shafiqul I. Siddiqui, Vincent P. Drnevich
Use Of Time Domain Reflectometry For Determination Of Water Content An Density Of Soil, Shafiqul I. Siddiqui, Vincent P. Drnevich
JTRP Technical Reports
A new method is developed for measuring in-place density and moisture content of soil using the technique of Time Domain Reflectometry (TDR). The method is applicable for construction control of earthworks. The method is extended for measuring moisture content of soil in the laboratory and in the field for various other geotechnical purposes. Laboratory uses include measuring moisture content of soil in compaction molds; field uses include measuring moisture content of soil in Shelby tubes and soil retrieved during drilling and sampling operations. In the course of achieving these goals, this study develops the principles of TDR probe design, test …
Optimum Geometrical Parameters For Prismatic Folded Plate Roofs: System- Atic Search Approach, N Mwitta
Optimum Geometrical Parameters For Prismatic Folded Plate Roofs: System- Atic Search Approach, N Mwitta
Tanzania Journal of Engineering and Technology (TJET)
Folded plate structures have unique structural advantages over conven- nonal beam-and-slab structural forms. Selection of optimum geometrical parameters in design would make folded plate roofs more appealing to the national construction industry in terms ofcost. This paper presents a study on shape optimization of prismatic folded plate roofs for minimum weight of the structure per unit covered area. A computer based systematic search approach has been employed.for the optimization study, while the tranyeer matrix method has been used for analysis. Curves opriinum geometrical parameters versus span have been pre sented for three commonly used shapes of prismatic folded plate roofs. …
Predicting Solute Transport In Natural Streams - A Stochastic Approach, Xueqing Zhou
Predicting Solute Transport In Natural Streams - A Stochastic Approach, Xueqing Zhou
Dissertations and Theses
The existing theories for predicting longitudinal dispersion in straight open channels have long been recognized as inadequate when applied to natural rivers. These theories tend to grossly underestimate dispersion in real streams since an important mixing mechanism due to nonuniform river cross-section variations is not explicitly taken into account. Recognizing the important role of stream irregularities on solute transport and the analytical difficulties of classical deterministic analysis, we develop a stochastic approach for analyzing solute transport in natural streams. Variations in river width and bed elevation are conveniently represented as one-dimensional random fields, characterized by their autocorrelation functions. Advection and …
A Guide To Floodplain Cattle Fencing, Department Of Agriculture, Western Australia, Main Roads, Western Australia
A Guide To Floodplain Cattle Fencing, Department Of Agriculture, Western Australia, Main Roads, Western Australia
Animal production and livestock published reports
A seminar and workshop was held at Fitzroy Crossing in October 1993 to address the consequences of flooding to landholders and communities.
Damage to flood plain fencing was identified as one of the major concerns to landholders.
An outcome from the workshop was the decision to draw on local knowledge and collate information on options for fence and floodgate designs.
This information was to be made available to land holders and other interested parties - hence this publication.
Modelling For Optimal Conjunctive Water Management: Irrigated Crop Production Versus Nps Pollution Prevention, O. H. Daza, Richard C. Peralta
Modelling For Optimal Conjunctive Water Management: Irrigated Crop Production Versus Nps Pollution Prevention, O. H. Daza, Richard C. Peralta
Civil and Environmental Engineering Faculty Publications
Conjunctive water management{CWM)involves coordinating use of ground and surface water sources. Agricultural (A) and nonagricultural {NA)users compete for available water of adequate quality. A Simulation/Optimization (S/0) conjunctive water management model was developed to aid estimating the effects of water and environmental management decisions on crop yield and water quality. Included subsystems are groundwater, surface water, reservoir, delivery system, drainage, and A and NA water users. The nonlinear model addresses flows described by nonsmooth piecewise-linear functions which have discontinuous derivatives. Embedded constraints describe all significant subsystem flows. For example 1 deep percolation and runoff from surface irrigation are explicitly described as …
Two Dimensional Finite Element Modeling Of Swift Delta Soil Nail Wall By "Abaqus", Richard James Barrows
Two Dimensional Finite Element Modeling Of Swift Delta Soil Nail Wall By "Abaqus", Richard James Barrows
Dissertations and Theses
Soil nail walls are a form of mechanical earth stabilization for cut situations. They consist of the introduction of passive inclusions (nails) into soil cut lifts. These nailed lifts are then tied together with a structural facing (usually shotcrete) . The wall lifts are constructed incrementally from the top of cut down. Soil nail walls are being recognized as having potential for large cost savings over other alternatives. The increasing need to provide high capacity roadways in restricted rights of way under structures such as bridges will require increasing use of techniques such as combined soil nail and piling walls. …
Analytical And Simulation Models Of Weaving Area Operations Under Non-Freeway Conditions, Muhammad Shahid Iqbal
Analytical And Simulation Models Of Weaving Area Operations Under Non-Freeway Conditions, Muhammad Shahid Iqbal
Dissertations
The Highway Capacity Manual covers adequately the operation of weaving areas on freeways. Weaving on non-freeway facilities, however, has not been addressed as yet. This research effort presents a state-of-the-art procedural analytical approach and simulation models for the analysis of the level of service and operation of non-freeway weaving areas. Weaving under non-freeway conditions is classified into two broad categories; basic weave and ramp weave. The analytical models for these two weaving categories are calibrated and validated based on data obtained from several sites selected in the states of New Jersey and New York. New level of service criteria are …
The Influence Of Hydrodynamics And Particle Size On The Rejection Properties Of Ultrafiltration Membranes, Usama M. Shahin
The Influence Of Hydrodynamics And Particle Size On The Rejection Properties Of Ultrafiltration Membranes, Usama M. Shahin
Theses
A mathematical model based on the flow hydrodynamics is developed to calculate the treatment efficiency of ultrafiltration process. This model relates the treatment efficiency with the consideration of both fixed parameters and variable parameters. The fixed parameters are function of the intrinsic rejection coefficient, diffusion coefficient, and viscosity whereas the variable parameters can be related to the fluid velocity, volume flux, and cartridge dimensions. The model has been examined by solutions with solutes that have different molecular weights. The experimental data fits the proposed mathematical model very closely suggesting its suitability to evaluate the rejection efficiency in ultrafiltration. As such …