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Civil and Environmental Engineering Commons™
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- Asymmetric buildings (6)
- Torsion (6)
- Earthquake response (5)
- Passive control (5)
- Supplemental damping (5)
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- Watershed management (5)
- Municipal solid waste (4)
- Plan asymmetry (4)
- Protective systems (4)
- Seismic response (4)
- Wastewater treatment (4)
- Adsorption (3)
- Algae (3)
- Bridge (3)
- Cache Valley (3)
- Liquefaction (3)
- Logan (3)
- Pedestrian bridge (3)
- Phosphorus (3)
- Restoration (3)
- Site response (3)
- Steel bridge (3)
- Viscous damping (3)
- Amplification factor (2)
- Bacteria (2)
- Bioreactor (2)
- Calibration (2)
- Campground (2)
- Compaction (2)
- Concrete canoe (2)
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Articles 301 - 330 of 389
Full-Text Articles in Civil and Environmental Engineering
Thermal Properties Of High Water Content Materials, James L. Hanson, Tuncer B. Edil, Nazli Yesiller
Thermal Properties Of High Water Content Materials, James L. Hanson, Tuncer B. Edil, Nazli Yesiller
Civil and Environmental Engineering
Fundamental thermal properties of various high water content materials were determined using a number of thermal testing methods. Tests were conducted on peat soils, solid wastes, industrial sludge, and bentonite slurries. Thermal conductivity, heat capacity, and thermal diffusivity were determined. The thermal conductivity of the materials was determined using a needle probe method. The volumetric heat capacity of the materials was determined using a dual probe method. These values were used together to obtain thermal diffusivity. Analytical methods are also used to determine heat capacity and thermal diffusivity. The theory for determination of thermal parameters using the various methods is …
Unsaturated Performance Comparison Of Compacted Clay Landfill Liners, Carol J. Miller, Saad Merayyan, Nazli Yesiller
Unsaturated Performance Comparison Of Compacted Clay Landfill Liners, Carol J. Miller, Saad Merayyan, Nazli Yesiller
Civil and Environmental Engineering
Tests were conducted to determine the variation in volumetric water content and pore water suction for a variety of compacted clay soils used in the construction of landfill liners. The fit of the experimental data to an existing parametric model was investigated for two different fitting techniques. The first technique involves the use of the retention curve computer program (RETC) developed for the U.S. EPA. The second technique employs the Solver subroutine included in Microsoft Excel. The parametric models resulting from either technique correlated well to the experimental data. However, the individual curve fit parameters varied significantly. The effect of …
Capacity‐Demand‐Diagram Methods Based On Inelastic Design Spectrum, Anil K. Chopra, Rakesh K. Goel
Capacity‐Demand‐Diagram Methods Based On Inelastic Design Spectrum, Anil K. Chopra, Rakesh K. Goel
Civil and Environmental Engineering
An improved capacity‐demand‐diagram method that uses the well‐known constant‐ductility design spectrum for the demand diagram is developed and illustrated by examples. This method estimates the deformation of inelastic SDF systems consistent with the selected inelastic design spectrum, while retaining the attraction of graphical implementation of the ATC‐40 Nonlinear Static Procedure. One version of the improved method is graphically similar to ATC‐40 Procedure A whereas the second version is graphically similar to ATC‐40 Procedure B. However, the improved procedures differ from ATC‐40 procedures in one important sense. The demand diagram used is different: the constant‐ductility demand diagram for inelastic systems …
Lead Binding To Metal Oxide And Organic Phases Of Natural Aquatic Biofilms, Yarrow M. Nelson, Leonard W. Lion, Michael L. Shuler, William C. Ghiorse
Lead Binding To Metal Oxide And Organic Phases Of Natural Aquatic Biofilms, Yarrow M. Nelson, Leonard W. Lion, Michael L. Shuler, William C. Ghiorse
Civil and Environmental Engineering
The role of the composition of surface-coating materials in controlling trace metal adsorption in aquatic environments was investigated using natural biofilms that developed on glass slides in three New York State lakes and a water-supply well. Adsorption isotherms were obtained for Pb binding to each of the biofilms in solutions with defined Pb speciation at 25°C and pH 6.0, with Pb concentrations ranging from 0.2 to 2.0 μM. Adsorption isotherms for Pb binding to laboratory-derived metal oxides and surrogate organic materials were determined under the same conditions. These isotherms, combined with characterization of natural biofilm composition, were used to estimate …
Closure To Period Formulas For Concrete Shear Wall Buildings, Anil K. Chopra, Rakesh K. Goel
Closure To Period Formulas For Concrete Shear Wall Buildings, Anil K. Chopra, Rakesh K. Goel
Civil and Environmental Engineering
No abstract provided.
Environmental Applications Of Gps, Samuel A. Vigil, Dora Zueck
Environmental Applications Of Gps, Samuel A. Vigil, Dora Zueck
Civil and Environmental Engineering
The use of the Global Positioning System (GPS) has revolutionized air travel, ocean navigation, land navigation, and the collection of environmental data. Although a basic civilian GPS receiver can be purchased for as little as $100, the receiver is only the tip of a 12 billion dollar iceberg! This paper will discuss the history and basic operation of the Global Positioning System, a satellite-based precision positioning and timing service developed and operated by the Department of Defense. It will also describe the accuracy limitations of the civil GPS service and how accuracy can be enhanced by the use of differential …
Application Of Noise Control In Environmental Engineering Education, Harold M. Cota, Kristy Grace
Application Of Noise Control In Environmental Engineering Education, Harold M. Cota, Kristy Grace
Civil and Environmental Engineering
Noise control is both a factor in the health and safety of those in the workplace and in the annoyance and interference of the quality of life at home. This falls squarely in the realm of the Environmental Engineering Profession. Noise, its effects and control, is an important element of a few Graduate Environmental Engineering Programs, but it does not have a role in most undergraduate programs. One objective of this paper is to demonstrate that noise is an issue needing to be addressed in Environmental Engineering Programs and to suggest that making it a requirement at the undergraduate level …
Early Experimentation With Civil Engineering Materials, James L. Hanson
Early Experimentation With Civil Engineering Materials, James L. Hanson
Civil and Environmental Engineering
A new project-based teaching method emphasizing laboratory experimentation is being used at Lawrence Technological University. It has excited and energized the students about civil engineering applications. Engineering concepts are introduced early in the students’ academic careers using civil engineering materials. Laboratory activities related to a Civil Engineering Materials course are being used for outreach, recruitment, and an intensive laboratory experience. A departmental effort has included supporting an outreach program and expanding a freshman CE Materials course. This new teaching method has affected and complemented university recruitment and retention efforts. The course introduces incoming students to engineering analysis and the basic …
Possible Explanations Of Phase Transitions In Highway Traffic, C.F. Daganzo, M.J. Cassidy, Robert L. Bertini
Possible Explanations Of Phase Transitions In Highway Traffic, C.F. Daganzo, M.J. Cassidy, Robert L. Bertini
Civil and Environmental Engineering
It is shown that all the phase transitions in and out of freely flowing traffic reported earlier for a German site could be caused by bottlenecks, as are all the transitions observed at two other sites examined here. The evidence suggests that bottlenecks cause these transitions in a predictable way, and does not suggest that stoppages (jams) appear spontaneously in free flow traffic for no apparent reason. It is also shown that many of the complicated instability phenomena observed at all locations can be explained qualitatively in terms of a simple Markovian theory specific to traffic that does not necessarily …
Seismic Control Of Asymmetric Structures, Rakesh K. Goel
Seismic Control Of Asymmetric Structures, Rakesh K. Goel
Civil and Environmental Engineering
No abstract provided.
Capacity-Demand-Diagram Methods For Estimating Seismic Deformation Of Inelastic Structures: Sdf Systems, Anil K. Chopra, Rakesh K. Goel
Capacity-Demand-Diagram Methods For Estimating Seismic Deformation Of Inelastic Structures: Sdf Systems, Anil K. Chopra, Rakesh K. Goel
Civil and Environmental Engineering
The ATC-40 and FEMA-274 documents contain simplified nonlinear analysis procedures to determine the displacement demand imposed on a building expected to deform inelastically. The Nonlinear Static Procedure in these documents, based on the capacity spectrum method, involves several approximations: The lateral force distribution for pushover analysis and conversion of these results to the capacity diagram are based only on the fundamental vibration mode of the elastic system. The earthquake-induced deformation of an inelastic SDF system is estimated by an iterative method requiring analysis of a sequence of equivalent linear systems, thus avoiding the dynamic analysis of the inelastic SDF system. …
Capacity-Demand-Diagram Methods For Estimating Seismic Deformation Of Inelastic Structures: Sdf Systems, Anil K. Chopra, Rakesh K. Goel
Capacity-Demand-Diagram Methods For Estimating Seismic Deformation Of Inelastic Structures: Sdf Systems, Anil K. Chopra, Rakesh K. Goel
Civil and Environmental Engineering
The ATC-40 and FEMA-274 documents contain simplified nonlinear analysis procedures to determine the displacement demand imposed on a building expected to deform inelastically. The Nonlinear Static Procedure in these documents, based on the capacity spectrum method, involves several approximations: The lateral force distribution for pushover analysis and conversion of these results to the capacity diagram are based only on the fundamental vibration mode of the elastic system. The earthquake-induced deformation of an inelastic SDF system is estimated by an iterative method requiring analysis of a sequence of equivalent linear systems, thus avoiding the dynamic analysis of the inelastic SDF system. …
Some Traffic Features At Freeway Bottlenecks, Michael J. Cassidy, Robert L. Bertini
Some Traffic Features At Freeway Bottlenecks, Michael J. Cassidy, Robert L. Bertini
Civil and Environmental Engineering
Observations from two freeway bottlenecks in and near Toronto, Canada indicate that the average rate vehicles discharge from a queue can be 10% lower than the flow measured prior to the queue's formation. Absent any influences from downstream, the queue discharge flows exhibited nearly stationary patterns that alternated between higher and lower rates. These alternating flow patterns were especially evident at one of the two sites, although the feature occurred at both sites during periods that immediately followed the onset of upstream queuing; i.e. a queue's formation was always accompanied by a relatively low discharge rate followed later by a …
Production Of Biogenic Mn Oxides By Leptothrix Discophora Ss-1 In A Chemically Defined Growth Medium And Evaluation Of Their Pb Adsorption Characteristics, Yarrow M. Nelson, Leonard W. Lion, William C. Ghiorse, Michael L. Shuler
Production Of Biogenic Mn Oxides By Leptothrix Discophora Ss-1 In A Chemically Defined Growth Medium And Evaluation Of Their Pb Adsorption Characteristics, Yarrow M. Nelson, Leonard W. Lion, William C. Ghiorse, Michael L. Shuler
Civil and Environmental Engineering
Biogenic Mn oxides were produced by the bacterium Leptothrix discophora SS-1 (= ATCC 3182) in a chemically defined mineral salts medium, and the Pb binding and specific surface area of these oxides were characterized. Growth of SS-1 in the defined medium with pyruvate as a carbon and energy source required the addition of vitamin B12. Complete oxidation of Mn(II) within 60 h required the addition of ≥0.1 μM FeSO4. Pb adsorption isotherms were determined for the biogenic Mn oxides (and associated cells with their extracellular polymer) and compared to the Pb adsorption isotherms of cells and …
Model For Trace Metal Exposure In Filter-Feeding Flamingos At Alkaline Rift Valley Lake, Kenya, Yarrow M. Nelson, Ramesh J. Thampy, Gideon K. Motelin, Jackson A. Raini, Cynthia J. Disante, Leonard W. Lion
Model For Trace Metal Exposure In Filter-Feeding Flamingos At Alkaline Rift Valley Lake, Kenya, Yarrow M. Nelson, Ramesh J. Thampy, Gideon K. Motelin, Jackson A. Raini, Cynthia J. Disante, Leonard W. Lion
Civil and Environmental Engineering
Abstract—Toxic trace metals have been implicated as a potential cause of recent flamingo kills at Lake Nakuru, Kenya. Chromium (Cr), copper (Cu), lead (Pb), and zinc (Zn) have accumulated in the lake sediments as a result of unregulated discharges and because this alkaline lake has no natural outlet. Lesser flamingos (Phoeniconaias minor) at Lake Nakuru feed predominantly on the cyanobacterium Spirulina platensis, and because of their filter-feeding mechanism, they are susceptible to exposure to particle-bound metals. Trace metal adsorption isotherms to lake sediments and S. platensis were obtained under simulated lake conditions, and a mathematical model was …
Investigation Of A Cyclic Laterally Loaded Model Pile Group, Robb E.S. Moss, Joseph A. Caliendo, Loren R. Anderson
Investigation Of A Cyclic Laterally Loaded Model Pile Group, Robb E.S. Moss, Joseph A. Caliendo, Loren R. Anderson
Civil and Environmental Engineering
In certain regions of the world, designing deep foundations to withstand seismic loading is a reality. Seismic loading of structures and foundations reaches its most critical state as a cyclic lateral force. The response of soils and foundations to repetitive lateral forces is highly complex, relegating most design methods to be based upon overly conservative rules-of-thumb. The primary objective of this research was to analyze the mechanics of seismic loading on pile groups in clay soils. To achieve this a model testing facility was constructed to house a fully instrumented 1 X 5 model pile group that was subjected to …
Seismic Code Improvements Based On Recorded Motions Of Buildings During Earthquake, Anil K. Chopra, Rakesh K. Goel, Juan Carlos De La Llera
Seismic Code Improvements Based On Recorded Motions Of Buildings During Earthquake, Anil K. Chopra, Rakesh K. Goel, Juan Carlos De La Llera
Civil and Environmental Engineering
Summarized in this paper are the results of two recent investigations utilizing recorded motions of buildings to develop improvements in two aspects of seismic code provisions for buildings: (1) fundamental vibration period formulas, and (2) accidental torsion.
Preliminary Development Of A Certification Protocol For Conventional Fireplaces, Paul L. Reitz, Harold M. Cota
Preliminary Development Of A Certification Protocol For Conventional Fireplaces, Paul L. Reitz, Harold M. Cota
Civil and Environmental Engineering
In order to attain and maintain federal and state air quality standards for particulate matter, some local agencies in California have adopted rules and regulations to control emissions from wood burning devices. Some of these rules restricted the use or installation of new masonry fireplaces. The purpose of this study was to begin development of a test protocol that would provide for consistent measurement of particulate emissions from conventional fireplaces and could be useful for compliance determinations or possible certification of a fireplace design or model. A modified California Air Resources Board Stationary Source Test Method 5 was used to …
Techniques For Modeling Hazardous Air Pollutant Emissions From Landfills, Robert J. Lang, Samuel A. Vigil, Henryk Melcer
Techniques For Modeling Hazardous Air Pollutant Emissions From Landfills, Robert J. Lang, Samuel A. Vigil, Henryk Melcer
Civil and Environmental Engineering
The Environmental Protection Agency’s Landfill Air Estimation Model (LAEEM), combined with either the AP-42 or CAA landfill emission factors, provide a basis to predict air emissions, including hazardous air pollutants (HAPs), from municipal solid waste landfills. This paper presents alternative approaches for estimating HAP emissions from landfills. These approaches include analytical solutions and estimation techniques that account for convection, diffusion, and biodegradation of HAPs. Results from the modeling of a prototypical landfill are used as the basis for discussion with respect to LAEEM results.
Experimental Analysis Of Desiccation Crack Propagation In Clay Liners, Carol J. Miller, Hong Mi, Nazli Yesiller
Experimental Analysis Of Desiccation Crack Propagation In Clay Liners, Carol J. Miller, Hong Mi, Nazli Yesiller
Civil and Environmental Engineering
A laboratory investigation on a scaled model of a landfill liner was conducted to provide data regarding the occurrence and extent of desiccation cracking of prototype liners. The crack intensity factor, CIF, was introduced as a descriptor of the extent of surficial cracking. CIF is defined as the ratio of the surface crack area A, to the total surface area of the clay liner, At. A computer aided image analysis program was used to determine CII’ values from scanned photographs of the desiccation process. The variation of the CII’ was related to duration of drying and measured soil moisture suctions. …
Evaluation Of The Us Epa Recommended Approach To Predicting Air Emissions From Pulp And Paper Industry Landfills, Samuel A. Vigil
Evaluation Of The Us Epa Recommended Approach To Predicting Air Emissions From Pulp And Paper Industry Landfills, Samuel A. Vigil
Civil and Environmental Engineering
There is growing indication that the pulp and paper industry will be required to comply with Clean Air Act (Title V) requirements to estimate emissions of bulk bases and HAPs from landfills. One method of such estimation is through the use of the Landfill Air Emissions Estimation Model (LAEEM), which was developed and calibrated specifically for municipal solid waste (MSW) landfills. The industry is concerned with the applicability of LAEEM because the nature of the materials placed in industry landfills is considered to be so different from those in MSW landfills, that emissions will likely be lower than model predictions. …
Energy Efficient Resource Recovery Project, Daniel Panetta, Douglas Williams, Walter Bremer, Gary Karner, Harap Mallareddy, Margot Mcdonald, Samuel A. Vigil, Bailey Green, Henry Hammer, William J. Oswald, William Roley, Jr.
Energy Efficient Resource Recovery Project, Daniel Panetta, Douglas Williams, Walter Bremer, Gary Karner, Harap Mallareddy, Margot Mcdonald, Samuel A. Vigil, Bailey Green, Henry Hammer, William J. Oswald, William Roley, Jr.
Civil and Environmental Engineering
No abstract provided.
Period Formulas For Concrete Shear Wall Buildings, Rakesh K. Goel, Anil K. Chopra
Period Formulas For Concrete Shear Wall Buildings, Rakesh K. Goel, Anil K. Chopra
Civil and Environmental Engineering
Most seismic codes specify empirical formulas to estimate the fundamental vibration period of buildings. Evaluated first in this paper are the formulas specified in present U.S. codes using the available data on the fundamental period of buildings "measured" from their motions recorded during eight California earthquakes, starting with the 1971 San Fernando earthquake and ending with the 1994 Northridge earthquake. It is shown that current code formulas for estimating the fundamental period of concrete shear wall buildings are grossly inadequate. Subsequently, an improved formula is developed by calibrating a theoretical formula, derived using Dunkerley's method, against the measured period data …
Effects Of Supplemental Viscous Damping On Seismic Response Of Asymmetric-Plan Systems, Rakesh K. Goel
Effects Of Supplemental Viscous Damping On Seismic Response Of Asymmetric-Plan Systems, Rakesh K. Goel
Civil and Environmental Engineering
Coupling between lateral and torsional motions may lead to much larger edge deformations in asymmetric‐plan systems compared to systems with a symmetric plan. Supplemental viscous damping has been found to be effective in reducing deformations in the symmetric‐plan system. This investigation examined how supplemental damping affects the edge deformations in asymmetric‐plan systems. First, the parameters that characterize supplemental viscous damping and its plan‐wise distribution were identified, and then the effects of these parameters on edge deformations were investigated. It was found that supplemental damping reduces edge deformations and that reductions by a factor of up three are feasible with proper …
Seismic Code Analysis Of Multi-Storey Asymmetric Buildings, Anthony P. Harasimowicz, Rakesh K. Goel
Seismic Code Analysis Of Multi-Storey Asymmetric Buildings, Anthony P. Harasimowicz, Rakesh K. Goel
Civil and Environmental Engineering
Static torsional provisions in most seismic codes require that the lateral force at each floor level be applied at some distance from the reference centre at that floor. However, codes do not specify how to determine the locations of these centres. As a result, several different definitions of the reference centres are being used to implement the code analysis. This investigation examined how the results using various reference centres differ and which of these centres would lead to results that are in agreement with those of dynamic analysis. For this purpose three different buildings ranging form torsionally stiff to torsionally …
Seismic Response Of Asymmetric Systems: Energy-Based Approach, Rakesh K. Goel
Seismic Response Of Asymmetric Systems: Energy-Based Approach, Rakesh K. Goel
Civil and Environmental Engineering
An energy-based approach has been used to investigate the seismic behavior of code-designed asymmetric-plan systems. The systems considered in this investigation had large eccentricities in both directions, were designed for bidirectional earthquake loading, and their responses were computed with both components of ground motion acting simultaneously. The presented results demonstrate that the total input energy is about the same whether the system plan is symmetric or asymmetric. Furthermore, flexible-side elements in asymmetric- plan systems may be more vulnerable to earthquakes than the same elements in symmetric-plan systems if they are not designed to accommodate the higher hysteretic-energy demands. This observation …
Earthquake Characteristics Of Bridges With Integral Abutments, Rakesh K. Goel
Earthquake Characteristics Of Bridges With Integral Abutments, Rakesh K. Goel
Civil and Environmental Engineering
Earthquake analysis of bridges requires that the period and damping ratio be determined for each significant mode of vibration. Data on these vibration properties, identified from motions of bridges recorded during actual earthquake events, provide the most direct means of verifying and improving the current guidelines. Thus, the aim of this investigation was to measure the vibration properties of a two-span concrete bridge from its motions recorded during actual earthquake events. These data were then used to investigate how abutment participation affected the vibration properties of bridges with integral abutments. It is shown that the vibration period elongated and the …
Period Formulas For Moment-Resisting Frame Buildings, Rakesh K. Goel, Anil K. Chopra
Period Formulas For Moment-Resisting Frame Buildings, Rakesh K. Goel, Anil K. Chopra
Civil and Environmental Engineering
Most seismic codes specify empirical formulas to estimate the fundamental vibration period of buildings. Evaluated first in this paper are the formulas specified in present U.S. codes using the available data on the fundamental period of buildings "measured" from their motions recorded during eight California earthquakes, starting with the 1971 San Fernando earthquake and ending with the 1994 Northridge earthquake. It is shown that, although the code formulas provide periods that are generally shorter than measured periods, these formulas can be improved to provide better correlation with the measured data. Subsequently, improved formulas for estimating the fundamental periods of reinforced …
Field Evaluation Of Ultrasonic Method For Assessing Well Seals, Nazli Yesiller, Craig H. Benson, Tuncer B. Edil
Field Evaluation Of Ultrasonic Method For Assessing Well Seals, Nazli Yesiller, Craig H. Benson, Tuncer B. Edil
Civil and Environmental Engineering
Field tests were conducted in three boreholes using an ultrasonic testing method to evaluate its ability to assess contact between the seal and riser (casing). The ultrasonic method is used inside the riser without disturbing the riser, seal, or formation soil. The risers were 50-mm-diameter (2-inch) Schedule 40 steel pipes that are used for ground water monitoring wells. Different types of seals were placed around the risers and defects were purposely introduced in the seals to test the ultrasonic method. The ultrasonic response changed as the neat-cement seals cured or hydration of the bentonite seals changed. When adequate moisture was …
Studying Initiation And Growth Of Shear Cracks In Reinforced Concrete Beams Using Full-Field Digital Imaging, Daniel C. Jansen, Sokhwan Choi, Surendra P. Shah
Studying Initiation And Growth Of Shear Cracks In Reinforced Concrete Beams Using Full-Field Digital Imaging, Daniel C. Jansen, Sokhwan Choi, Surendra P. Shah
Civil and Environmental Engineering
The mechanisms which lead to shear failure of longitudinally reinforced concrete beams are complex and often misunderstood. In this paper, a combination of a special closed loop test technique and machine vision are applied to tests on two reinforced concrete beams failing in shear: one made of normal strength concrete and the second of high strength concrete. To control the progression of the shear crack, a closed-loop test technique was devised and employed such that the crack propagation was stable even during the post peak. To locate the crack and to measure the crack displacements, machine vision, a nondestructive measuring …