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Full-Text Articles in Civil and Environmental Engineering

Environmental Engineering Design, Harold M. Cota, Samuel A. Vigil Jun 1997

Environmental Engineering Design, Harold M. Cota, Samuel A. Vigil

Civil and Environmental Engineering

This paper outlines the capstone environmental engineering design course that has been used effectively at California Polytechnic State University. Senior level students work in teams on a multi-media industrial problem. The experience involves literature review, problem formulation, proposal writing, time management, technical and economic analysis and an oral and written presentation of the results. Feedback from alumni and employers has been positive.


Energy Based Approach To Earthquake Response Of Asymmetric Systems, Rakesh K. Goel Apr 1997

Energy Based Approach To Earthquake Response Of Asymmetric Systems, Rakesh K. Goel

Civil and Environmental Engineering

No abstract provided.


Evaluation Of Code Period Formula For Concrete Mrf Buildings, Rakesh K. Goel, Anil K. Chopra Apr 1997

Evaluation Of Code Period Formula For Concrete Mrf Buildings, Rakesh K. Goel, Anil K. Chopra

Civil and Environmental Engineering

The empirical formula specified in US building codes for fundamental vibration period of concrete moment resisting frame buildings is evaluated using periods of buildings measured from their strong motion records. The presented results show that the current code formula may lead to fundamental periods that are much shorter than the measured periods. In order to obtain better correlation between measured and computed periods, regression analysis technique has been used. The results indicate that the value of C, in the current code formula should be increased from its present value of 0.030 to 0.035.


Permeability Study Of Cracked Concrete, Kejin Wang, Daniel C. Jansen, Surendra P. Shah, Alan F. Karr Mar 1997

Permeability Study Of Cracked Concrete, Kejin Wang, Daniel C. Jansen, Surendra P. Shah, Alan F. Karr

Civil and Environmental Engineering

Cracks in concrete generally interconnect flow paths and increase concrete permeability. The increase in concrete permeability due to the progression of cracks allows more water or aggressive chemical ions to penetrate into the concrete, facilitating deterioration. The present work studies the relationship between crack characteristics and concrete permeability. In this study, feedback controlled splitting tests are introduced to generate crack width-controlled concrete specimens. Sequential crack patterns with different crack widths are viewed under a microscope. The permeability of cracked concrete is evaluated by water permeability tests. The preliminary results indicate that crack openings generally accelerate water flow rate in concrete. …


Ultrasonic Method For Evaluation Of Annular Seals For Wells And Instrument Holes, Nazli Yesiller, Tuncer B. Edil, Craig H. Benson Mar 1997

Ultrasonic Method For Evaluation Of Annular Seals For Wells And Instrument Holes, Nazli Yesiller, Tuncer B. Edil, Craig H. Benson

Civil and Environmental Engineering

An ultrasonic testing method employing the pulse-echo inspection technique was developed to assess the integrity of annular seals surrounding casings (i.e., instrument tubes or well casings). This nondestructive testing method permits testing a seal from inside a casing without disturbing the casing, seal, or formation. Seals constructed with cement-based and bentonite-based sealants surrounding various types and sizes of casings can be evaluated using the method. An evaluation is conducted by sending and receiving ultrasonic waves using a single piezoelectric transducer and commercially available hardware (a pulser receiver and a waveform analyzer). A probe was designed and constructed for downhole testing. …


Evaluation Of Bridge Abutment Capacity And Stiffness During Earthquakes, Rakesh K. Goel, Anil K. Chopra Feb 1997

Evaluation Of Bridge Abutment Capacity And Stiffness During Earthquakes, Rakesh K. Goel, Anil K. Chopra

Civil and Environmental Engineering

The “actual” capacity and stiffness values of the abutment‐soil systems at the US 101/Painter Street Overpass, determined from its earthquake motions, are used to investigate how abutment stiffness varies during earthquakes and to evaluate current modeling procedures. It is found that the “actual” abutment stiffness may be significantly different during different phases of the shaking and decreases significantly as the abutment deformation increases. The CALTRANS modeling procedure leads to a good estimate of the transverse abutment stiffness and capacity. However, this procedure may overestimate the normal abutment stiffness and capacity by a factor of over two, indicating that the assumed …


Effect Of Length On Compressive Strain Softening Of Concrete, Daniel C. Jansen, Surendra P. Shah Jan 1997

Effect Of Length On Compressive Strain Softening Of Concrete, Daniel C. Jansen, Surendra P. Shah

Civil and Environmental Engineering

The concept of localization during the postpeak of compressive strain softening is presented. To explore localization in compression, a feedback-control method using a linear combination of displacement and force that partially subtracts the elastic response of the specimen to give a stable feedback signal is used. Results are presented from two test series (45 and 90 MPa) that use this method to test cylinders with length-to-diameter ratios ranging from 2.0 to 5.5. It is shown that compression failure is in fact a localized phenomenon. The compressive fracture energy is divided into energy dissipated in the prepeak and the postpeak portions …


Assessment Of Cased-Borehole Seals Using An Ultrasonic Method, Nazli Yesiller, Craig H. Benson, Tuncer B. Edil, James Klima Jan 1997

Assessment Of Cased-Borehole Seals Using An Ultrasonic Method, Nazli Yesiller, Craig H. Benson, Tuncer B. Edil, James Klima

Civil and Environmental Engineering

Tests were conducted in Wisconsin from 1994 through 1996 in several boreholes using an ultrasonic method that was developed at the University of Wisconsin-Madison to assess the integrity of annular seals. Initially, three model boreholes simulating monitoring wells were installed to evaluate the effectiveness of the ultrasonic method. Different types of seals were placed around the casings and defects were purposely introduced in the seals to test the ultrasonic method. The ultrasonic method was effective for detecting the presence of different types of seals and defects and also the changes in the condition of seals with time. Then tests were …


Capacity And Stiffness Of Bridge Abutments During Earthquakes, Rakesh K. Goel Dec 1996

Capacity And Stiffness Of Bridge Abutments During Earthquakes, Rakesh K. Goel

Civil and Environmental Engineering

No abstract provided.


Source Reduction And Recycling Programs At A Joint Venture Automobile Assembly Plant, Stuart E. Rupp, Samuel A. Vigil Jun 1996

Source Reduction And Recycling Programs At A Joint Venture Automobile Assembly Plant, Stuart E. Rupp, Samuel A. Vigil

Civil and Environmental Engineering

New United Motor Manufacturing, Inc. (NUMMI) is a vehicle assembly plant in Fremont, California. NUMMI began operations in 1984 as ajoint venture of General Motors Corporation and Toyota Motor Corporation. In 1995, NUMMI produced 94,280 Geo Prizms, 135,112 Toyota Corollas, and 123,257 Toyota Tacoma trucks. NUMMI conducts its manufacturing operations using the Toyota Production System (TPS). A key element of TPS is the elimination of waste. This includes wasted energy, space, labor, and production materials. Waste reduction, i.e., source reduction, is part of NUMMI's corporate culture and every team member is encouraged to continuously seek out new waste reduction opportunities. …


Determination Of Iron Colloid Size Distribution In The Presence Of Suspended Cells: Application To Iron Deposition Onto A Biofilm Surface, Waihung Lo, Yarrow M. Nelson, Leonard W. Lion, Michael L. Shuler, William C. Ghiorse Apr 1996

Determination Of Iron Colloid Size Distribution In The Presence Of Suspended Cells: Application To Iron Deposition Onto A Biofilm Surface, Waihung Lo, Yarrow M. Nelson, Leonard W. Lion, Michael L. Shuler, William C. Ghiorse

Civil and Environmental Engineering

Transport and deposition of colloidal Fe, Mn and Al oxides play key roles in the cycling of toxic transition metals in aquatic environments because these colloids strongly bind transition metals. Further, attachment of biological cells and biofilm growth on surfaces can indirectly affect toxic metal distribution by influencing the deposition of colloidal oxides to surfaces. To elucidate the mechanisms governing these processes, deposition of colloidal oxides onto surfaces must be evaluated in the presence of suspended and adherent bacterial cells. Both particle size and concentration are expected to influence deposition. An experimental protocol was developed to determine the size distribution …


Pc Windows Finite Element Modeling Of Landfill Gas Flow, Stephen R. Mull, Robert L. Lang, Samuel A. Vigil, Harold M. Cota Mar 1996

Pc Windows Finite Element Modeling Of Landfill Gas Flow, Stephen R. Mull, Robert L. Lang, Samuel A. Vigil, Harold M. Cota

Civil and Environmental Engineering

A two dimensional demonstration program, GAS, has been developed for the solution of landfill gas (LFG) flow problems on a personal computer (PC). The program combines a Windows™ graphical user interface, object oriented programming (OOP) techniques, and finite element modeling (FEM) to demonstrate the practicality of performing LFG flow modeling on the PC. GAS is demonstrated on a sample LFG problem consisting of a landfill, one gas extraction well, the landfill liner, cap, and surrounding soil. Analyses of the program results are performed for successively finer grid resolutions. Element flux imbalance, execution time, and required memory are characterized as a …


Testing Of Concrete Under Closed-Loop Control, Ravindra Gettu, Barzin Mobasher, Sergio Carmona, Daniel C. Jansen Mar 1996

Testing Of Concrete Under Closed-Loop Control, Ravindra Gettu, Barzin Mobasher, Sergio Carmona, Daniel C. Jansen

Civil and Environmental Engineering

Closed-loop testing systems provide the ability to directly control the deformation of the loaded specimen. This considerably enhances the precision, stability, and scope of the experiments. Closed-loop machines can be used to determine the stable response of test specimen or structure by monitoring and controlling the physical quantities that are sensitive to its behavior. The importance of the various components of the closed-loop controlled system and the test configuration is reviewed in the paper. The most critical aspect of designing the test is the choice of the controlled variable. With appropriate controlled variables and good system performance, several interesting and …


Comparison Of Load Restriction Timings Determined Using Fhwa Guidelines And Frost Tubes, Nazli Yesiller, Craig H. Benson, Peter J. Bosscher Mar 1996

Comparison Of Load Restriction Timings Determined Using Fhwa Guidelines And Frost Tubes, Nazli Yesiller, Craig H. Benson, Peter J. Bosscher

Civil and Environmental Engineering

The Federal Highway Administration (FHwA) method and frost-tube measurements are used in Wisconsin to determine the timing and duration of spring load restrictions. In both methods, depth of freeze or thaw is used to determine when to apply load restrictions and to determine their duration. Average daily air temperatures are used in the FHwA method to predict the start and end of freeze and/or thaw. Frost tubes are used to directly determine depth of freeze and/or thaw. An analysis is conducted to compare these two methods using air-temperature data (for the FHwA method) and frost-tube data obtained in Wisconsin. The …


Hazardous Waste Management, Harold M. Cota, David Wallenstein Jan 1996

Hazardous Waste Management, Harold M. Cota, David Wallenstein

Civil and Environmental Engineering

Hazardous waste management is a broad and evolving field. Applicable state and federal regulations comprising over 60,000 pages are continually being updated. Many of these regulations overlap and are subject to differences in interpretation that often lead to court rulings. Regulations, economic pressures and public perception are forcing companies to rapidly change the way they manufacture products in order to minimize hazardous waste generation. Over 200 million tons of solid hazardous waste are generated annually in the United States. Huge quantities of hazardous waste deposited in landfills, ponds, fields, and other locations require removal or in situ treatment. Common hazardous …


Ultrasonic Nondestructive Testing Method For Evaluation Of Annular Seals, Nazli Yesiller Dec 1995

Ultrasonic Nondestructive Testing Method For Evaluation Of Annular Seals, Nazli Yesiller

Civil and Environmental Engineering

No abstract provided.


Lead Distribution In A Simulated Aquatic Environment: Effects Of Bacterial Biofilms And Iron Oxide, Yarrow M. Nelson, Waihung Lo, Leonard W. Lion, Michael L. Shuler, William C. Ghiorse Aug 1995

Lead Distribution In A Simulated Aquatic Environment: Effects Of Bacterial Biofilms And Iron Oxide, Yarrow M. Nelson, Waihung Lo, Leonard W. Lion, Michael L. Shuler, William C. Ghiorse

Civil and Environmental Engineering

Biofilms influence the transport and fate of heavy metals in aquatic environments both directly by adsorption and complexation reactions and indirectly via interactions with oxides of iron and manganese. These reactions were investigated by introducing lead into a continuous-flow biofilm reactor that was designed to simulate conditions in a flowing freshwater aquatic environment. The reactor provided controlled conditions, and use of a chemically-defined growth medium allowed calculation of lead speciation with a chemical equilibrium program (MINEQL). Pseudomonas cepacia was employed as a test cell strain because of its ability to grow and form biofilms in the defined medium. This bacterium …


Development Of A Graduate Integrated Waste Management Course Using The Case Study Approach, Samuel A. Vigil Jun 1995

Development Of A Graduate Integrated Waste Management Course Using The Case Study Approach, Samuel A. Vigil

Civil and Environmental Engineering

Solid waste management is an integral part of the environmental engineering profession. At California Polytechnic State University (Cal Poly), solid waste management is taught as a required course in an undergraduate environmental engineering curriculum. The undergraduate course is described in Reference 1. This paper discusses the development of a graduate level integrated waste management course entitled "Resource and Energy Recovery from Waste", which uses a case study approach. The course focuses on resource and energy recovery technologies including composting, unit operations of resource recovery, recycling, and thermal waste conversion including combustion and gasification. The bioconversion of wastes in landfills and …


Application Of Macro Material Flow Modeling To The Decision Making Process For Integrated Waste Management Systems, Samuel A. Vigil, Gregory M. Holter Apr 1995

Application Of Macro Material Flow Modeling To The Decision Making Process For Integrated Waste Management Systems, Samuel A. Vigil, Gregory M. Holter

Civil and Environmental Engineering

Computer models have been used for almost a decade to model and analyze various aspects of solid waste management. Commercially available models exist for estimating the capital and operating costs of landfills, waste-to-energy facilities and compost systems and for optimizing system performance along a single dimension (e.g. cost or transportation distance).

An alternative to the use of currently available models is the more flexible macro material flow modeling approach in which a macro scale or regional level approach is taken. Waste materials are tracked through the complete integrated waste management cycle from generation through recycling and reuse, and finally to …


Closure To "Seismic Code Analysis Of Buildings Without Locating Centers Of Rigidity", Rakesh K. Goel, Anil K. Chopra Apr 1995

Closure To "Seismic Code Analysis Of Buildings Without Locating Centers Of Rigidity", Rakesh K. Goel, Anil K. Chopra

Civil and Environmental Engineering

No abstract provided.


Comparison Of The Environmental Effects Of Aerobic And Anaerobic Composting Technologies, Samuel A. Vigil, George Tchobanoglous Jun 1994

Comparison Of The Environmental Effects Of Aerobic And Anaerobic Composting Technologies, Samuel A. Vigil, George Tchobanoglous

Civil and Environmental Engineering

The biological conversion of yard wastes and municipal solid waste by aerobic composting is an established technology. Anaerobic conversion of these wastes is less practiced but is being widely advocated for the next generation of bioconversion systems. Although the operational characteristics of both types of systems is well known, there is a lack of quantifiable data in the literature on the environmental effects of these technologies. It is widely assumed that they are environmentally benign, especially as compared to other processing and conversion technologies such as incineration or mechanical processing. The process microbiology, design, and operational characteristics of aerobic and …


Seismic Response Study Of The Us 101/Painter Street Overpass Using Strong Motion Records, Rakesh K. Goel, Anil K. Chopra May 1994

Seismic Response Study Of The Us 101/Painter Street Overpass Using Strong Motion Records, Rakesh K. Goel, Anil K. Chopra

Civil and Environmental Engineering

Abutment stiffnesses are determined directly from the earthquake motions recorded at the US 101/Painter Street Overpass using a simple equilibrium-based approach without finite-element modeling of the structure or the abutment-soil systems. The calculated abutment stiffnesses, which include the effects of soil-structure interaction and nonlinear behavior of the soil, are used to investigate variation of the abutment stiffness with its deformation during the earthquake and torsional motions of the road deck. Also evaluated are the CALTRANS, ASSHTO-83, and ATC- 6 procedures for estimating the abutment stiffness. It is demonstrated that stiffness of the abutment depends significantly on its deformation during the …


Dual-Level Approach For Seismic Design Of Asymmetric-Plan Buildings, Rakesh K. Goel, Anil K. Chopra Jan 1994

Dual-Level Approach For Seismic Design Of Asymmetric-Plan Buildings, Rakesh K. Goel, Anil K. Chopra

Civil and Environmental Engineering

Buildings should be designed to resist moderate ground motion without structural damage and resist intense ground motion with controlled damage. However, most codes do not consider both these requirements explicitly and specify a single design earthquake that generally corresponds to intense ground motion. Investigated in this study is the response of one-story, asymmetric-plan systems designed according to torsional provisions of seismic codes to the two levels of ground motions with the objective of evaluating whether such systems satisfy these requirements. The presented results demonstrate that such systems may not remain elastic during moderate ground motion resulting in structural damage and …


Seismic Code Analysis Of Buildings Without Locating Centers Of Rigidity, Rakesh K. Goel, Anil K. Chopra Oct 1993

Seismic Code Analysis Of Buildings Without Locating Centers Of Rigidity, Rakesh K. Goel, Anil K. Chopra

Civil and Environmental Engineering

Static force procedures of most building codes require that the lateral earthquake force at each floor level of an asymmetric-plan building be applied eccentrically from the centers of rigidity. To implement such procedures, it seemed necessary in the past to determine the locations of the centers of rigidity, an often confusing and cumbersome process. This paper presents a new approach for code lateral force analysis of asymmetric-plan buildings without locating the centers of rigidity. This procedure combines the results from three static analyses, which can be implemented directly on most commercially available computer programs for analysis of multistory buidings. The …


Vinyl Chloride Biodegradation With Methanotrophic Attached Films, Yarrow M. Nelson, William J. Jewell Sep 1993

Vinyl Chloride Biodegradation With Methanotrophic Attached Films, Yarrow M. Nelson, William J. Jewell

Civil and Environmental Engineering

Methanotrophic degradation of vinyl chloride (VC) is investigated using a laboratory-scale methanotrophic attached-film expanded-bed (MAFEB) bioreactor. This study provides a basis for applying a microbial cometabolizing reaction to practical treatment of toxic chlorinated compounds. The MAFEB reactor was operated at 20°C with influent VC concentrations ranging from 1,800 to 9,600 µg/L and bed hydraulic retention times ranging from 3.7 to 7.6 h. VC effluent concentrations during steady continuous operation ranged from 3 to 140 µg/L, with most values less than 26 µg/L, resulting in removal efficiencies of 96.3% to 99.8%. The maximum continuous-flow VC degradation rate observed at 20°C was …


The Naval Reserve Civil Engineer Corps Environmental Engineering Program, William A. Heine, Samuel A. Vigil Jun 1993

The Naval Reserve Civil Engineer Corps Environmental Engineering Program, William A. Heine, Samuel A. Vigil

Civil and Environmental Engineering

The Navy is engaged in a national effort to bring its shore facilities into compliance with all applicable local, state, and federal environmental regulations. This work is being completed by civil service employees, consultants, and contractors under the supervision of Navy Civil Engineer Corps officers. To supplement these active duty and civilian resources, the Reserve Division of the Naval Facilities Engineering Command (RDNAVFAC) has identified Reserve officers with substantial environmental engineering skills who are being assigned to assist Navy shore activities all over the world in this essential task. The Naval Reserve Civil Engineer Corps (CEC) is composed of over …


Evaluation Of Us Seismic Code Provisions For Asymmetric-Plan Systems, Rakesh K. Goel, Anil K. Chopra Apr 1993

Evaluation Of Us Seismic Code Provisions For Asymmetric-Plan Systems, Rakesh K. Goel, Anil K. Chopra

Civil and Environmental Engineering

The effects of plan asymmetry on the earthquake response of code-designed, one-story systems are identified with the objective of evaluating how well these effects are represented by torsional provisions in US building codes. The earthquake-induced deformations and ductility demands on resisting elements of asymmetric-plan systems, are compared with their values if the system plan were symmetric. The presented results demonstrate that the design eccentricity in US building codes should be modified in order to achieve the desirable goal of similar ductility demands on asymmetric-plan and symmetric-plan systems. The design eccentricity should be defined differently depending on the design value of …


Methanotrophic Bacteria For Nutrient Removal From Wastewater: Attached Film System, William J. Jewell, Yarrow M. Nelson, Mark S. Wilson Sep 1992

Methanotrophic Bacteria For Nutrient Removal From Wastewater: Attached Film System, William J. Jewell, Yarrow M. Nelson, Mark S. Wilson

Civil and Environmental Engineering

It was hypothesized that nutrient removal from wastewater could be achieved by using methane oxidizing bacteria (methanotrophs). Because methane is inexpensive. it can be used as an energy source to encourage bacterial growth to assimilate nitrogen and phosphorus and other trace elements. This initial feasibility study used synthetic nutrient mixtures and secondary sewage effluent as feed to a laboratory-scale methanotrophic attached-film expanded bed (MAFEB) reactor operated at 35°C and 20°C. The MAFEB system operated successfully at low nutrient concentrations under a variety of nutrient-limited conditions. Using a synthetic nutrient mixture with a nitrogen:phosphorus feed ratio (w/w) …


Graphical Integrated Waste Management Model For Puerto Rico, Samuel A. Vigil, Hilary M. Theisen May 1992

Graphical Integrated Waste Management Model For Puerto Rico, Samuel A. Vigil, Hilary M. Theisen

Civil and Environmental Engineering

The application of STELLA, a commercially available, graphically based simulation language for the Macintosh computer, to solid waste facility planning is described. This paper discusses a STELLA model which was developed for the Commonwealth of Puerto Rico Solid Waste Management Authority (SWMA). The model simulates the existing solid waste management system in Puerto Rico and also the proposed system of regional landfills, transfer stations, and waste-to-energy plants. The model incorporates population projections for all 78 municipalities in Puerto Rico from 1990 to 2010, solid waste generation factors for all municipalities, data on remaining life for the existing landfills, and projected …


Development Of Solid Waste Management Courses At The Undergraduate And Graduate Level, Samuel A. Vigil, George Tchobanoglous May 1992

Development Of Solid Waste Management Courses At The Undergraduate And Graduate Level, Samuel A. Vigil, George Tchobanoglous

Civil and Environmental Engineering

Management of solid wastes in a cost effective and environmentally sensitive manner has become one of the most challenging infrastructure issues facing municipalities today. The problem is exacerbated by a shortage of qualified engineers. In this paper, both undergraduate and graduate courses in solid waste management that have been taught by the authors at their respective universities for over 20 years are described and available textbooks and reference materials are discussed.