Civil and Environmental Engineering Commons^™

Determination Of Thickness Of Smooth Geomembranes, Nazli Yesiller, Arif Cekic

Civil and Environmental Engineering

Tests were conducted to determine thickness of smooth, nonreinforced geomembranes using three methods: mechanical (according to ASTM and European standards), ultrasonic, and magnetic methods. The mechanical method is the standard procedure used for determining thickness of geomembranes. The ultrasonic and magnetic methods are not commonly used for geomembranes; however, they are used for testing other materials such as metals. Tests were conducted on 15 geomembranes representing five types of polymers (HDPE, LLDPE, PVC, PP, and EPDM). The results of the testing program indicated that the level of pressures applied affected the thickness measurements in mechanical tests. While the low pressures …

Ultrasonic Pulse Velocity In Concrete Using Direct And Indirect Transmission, Ismail Ozgur Yaman, Gokhan Inci, Nazli Yesiller, Haluk M. Aktan

Civil and Environmental Engineering

The relationship between velocities of ultrasonic stress waves transmitted along direct and indirect paths was investigated. Tests were conducted on plain concrete slabs of dimensions 1000 x 1500 mm, with a thickness of 250 mm. Direct ultrasonic wave transmission tests were conducted between top and bottom surfaces of the slabs and indirect tests were conducted along the slab surface. A test procedure, described in BS 1881 to determine indirect wave velocities, was refined by defining the number and spacing of transducers. Comparisons were made between direct and indirect wave velocity measurements using statistical analysis. The statistical analysis revealed that direct …

Evaluation Of Geomembranes Using An Ultrasonic Method, Nazli Yesiller, Sevil Sungur

Civil and Environmental Engineering

An ultrasonic testing procedure was developed to evaluate geomembranes. The pulse-echo inspection technique was used on the surface of geomembranes without disturbing the material. The equipment required consists of a P-wave transducer, a pulser-receiver, and a signal acquisition system. Travel time of ultrasonic waves and waveform energy are measured to evaluate the condition of geomembranes. Laboratory tests were conducted to assess the effectiveness of the method. Defects that simulate installation damage and various in-service degradation conditions were induced on samples. The defects were identified with the ultrasonic method at a success rate higher than 98%. Changes in the thickness or …

Compressive Behavior Of Concrete With Vitrified Soil Aggregate, Shane M. Palmquist, Daniel C. Jansen, Christopher W. Swan

Civil and Environmental Engineering

The compressive behavior of portland cement concrete with vitrified soil coarse aggregate is the focus of this paper. A total of 10 batches of concrete were examined at four different coarse aggregate volume fractions with three different combinations of vitrified and natural coarse aggregates. For comparison purposes, the ratios of cement, water, and fine aggregates were held constant. The stress-strain curves, modulus of elasticity, compressive strength, and Poisson's ratio are examined as a function of coarse aggregate content. Results show a decrease in compressive strength as the volume fraction of vitrified soil aggregate increased. Moduli of elasticity for concrete with …

Simplified Analysis Of Asymmetric Structures With Supplemental Damping, Rakesh K. Goel

Civil and Environmental Engineering

This study investigated the effects of neglecting off‐diagonal terms of the transformed damping matrix on the seismic response of non‐proportionally damped asymmetric‐plan systems with the specific aim of identifying the range of system parameters for which this simplification can be used without introducing significant errors in the response. For this purpose, a procedure is presented in which modal damping ratios computed by neglecting off‐diagonal terms of the transformed damping matrix are used in the traditional modal analysis. The effects of the simplification are evaluated first by comparing the aforementioned modal damping ratios with the apparent damping ratios obtained from the …

Watershed Management Technique To Control Sediment Yield In Agriculturally Dominated Areas, John W. Nicklow, Misgana K. Muleta

Civil and Environmental Engineering

Non-point source pollution is recognized internationally as a critical environmental problem. In Illinois, soil erosion from agricultural lands is the major source of such pollution. The erosion process, which has been accelerated by human activity, tends to reduce crop productivity and leads to subsequent problems from deposition on farmlands and in water bodies. Comprehensive watershed management, however, can be used to protect these natural resources. In this study, a discrete time optimal control methodology and computational model are developed for determining land use and management alternatives that minimize sediment yield from agriculturally-dominated watersheds. The solution methodology is based on an …

Removing Barriers To High-Strength Concrete In Boston, Daniel C. Jansen, Herman Protze

Civil and Environmental Engineering

No abstract provided.

The Role Of The Journal In Mentoring Students, Harold M. Cota

Civil and Environmental Engineering

No abstract provided.

Ultrasonic Assessment Of Stabilized Soils, Nazli Yesiller, James L. Hanson, Mumtaz A. Usmen

Civil and Environmental Engineering

The feasibility of using ultrasonic testing, in particular P-wave velocities, to evaluate stabilized soils was investigated. A high-plasticity clay soil that was stabilized with lime, cement, and lime - fly ash mixtures was used in the study. The testing program consisted of determination of P-wave velocities and compression characteristics of the stabilized soils immediately after compaction and subsequent to 7 days and 28 days of curing. Variation of velocity with stabilizing agent, curing time, and also with the compression characteristics of the soils was investigated. It was observed that P-wave velocities were higher for samples stabilized with cement compared with …

Stress-Temperature Effects On Peat Compression, James L. Hanson, Tuncer B. Edil, Patrick J. Fox

Civil and Environmental Engineering

Laboratory and field tests have shown that accelerated compression of peat soils occurs in response to moderate heating and an effective overconsolidation is produced on subsequent cooling. This phenomenon has been termed thermal precompression. In this study, long-term laboratory and field tests were conducted to investigate secondary compression behavior of peat as a function of stress and temperature. Stepstress and step-temperature compression tests were conducted on two peat soils. Dramatic effects were observed upon heating and cooling. A field test site in Middleton, Wisconsin, USA was constructed to test the thermal precompression concept for in situ peats. The site contained …

Improved Direct Displacement-Based Design Procedure For Performance-Based Seismic Design Of Structures, Rakesh K. Goel, Anil K. Chopra

Civil and Environmental Engineering

Direct displacement-based design requires a simplified procedure to estimate the seismic deformation of an inelastic SDF system, representing the first (elastic) mode of vibration of the structure. This step is usually accomplished by analysis of an “equivalent” linear system using elastic design spectra. In this paper, an equally simple procedure is developed that is based on the well-known concepts of inelastic design spectra. This procedure provides: (1) accurate values of displacement and ductility demands, and (2) a structural design that satisfies the design criteria for allowable plastic rotation. In contrast, the existing procedure using elastic design spectra for equivalent linear …

Using Genetic Algorithms And Swat To Minimize Sediment Yield From An Agriculturally Dominated Watershed, Misgana K. Muleta, John W. Nicklow

Civil and Environmental Engineering

Non-point source pollution is well recognized as one of the most critical environmental hazards of modern times. In Illinois, non-point source pollution is the major cause of water quality problems, and soil erosion from agricultural lands is the major source of such pollution. Accelerated by anthropogenic activities, soil erosion reduces crop productivity and leads to subsequent problems from deposition on farmlands and in water bodies. Watershed management, however, promotes protection and restoration of these natural resources while allowing for sustainable economic growth and development. In this study a discrete time optimal control methodology and computational model are developed for determining …

Effects Of Supplemental Viscous Damping On Inelastic Seismic Response Of Asymmetric Systems, Rakesh K. Goel

Civil and Environmental Engineering

This paper investigates the effects of supplemental viscous damping on the seismic response of one‐storey, asymmetric‐plan systems responding in the inelastic range of behaviour. It was found that addition of the supplemental damping reduces not only deformation demand but also ductility and hysteretic energy dissipation demands on lateral load resisting elements during earthquake loading. However, the level of reduction strongly depends on the plan‐wise distribution of supplemental damping. Nearly optimal reduction in demands on the outermost flexible‐side element, an element generally considered to be the most critical element, was realized when damping was distributed unevenly in the system plan such …

Direct Displacement‐Based Design: Use Of Inelastic Vs. Elastic Design Spectra, Anil K. Chopra, Rakesh K. Goel

Civil and Environmental Engineering

Direct displacement‐based design requires a simplified procedure to estimate the seismic deformation of an inelastic SDF system, representing the first (elastic) mode of vibration of the structure. This step is usually accomplished by analysis of an “equivalent” linear system using elastic design spectra. In this paper, an equally simple procedure is developed that is based on the well‐known concepts of inelastic design spectra. We demonstrate that the procedure provides the following: (1) accurate values of displacement and ductility demands, and (2) a structural design that satisfies the design criteria for allowable plastic rotation. In contrast, the existing procedure using elastic …

A Modal Pushover Analysis Procedure To Estimate Seismic Demands For Buildings: Theory And Preliminary Evaluation, Anil K. Chopra, Rakesh K. Goel

Civil and Environmental Engineering

The principal objective of this investigation is to develop a pushover analysis procedure based on structural dynamics theory, which retains the conceptual simplicity and computational attractiveness of current procedures with invariant force distribution, but provides superior accuracy in estimating seismic demands on buildings.

The standard response spectrum analysis (RSA) for elastic buildings is reformulated as a Modal Pushover Analysis (MPA). The peak response of the elastic structure due to its nth vibration mode can be exactly determined by pushover analysis of the structure subjected to lateral forces distributed over the height of the building according to s^*_n = …

Enhanced Biodegradation Of Hydrocarbon Contaminants Using Photocatalytic Pretreatment, Chad E. Green, Anita Stansberry, Jeff Sczechowski, Yarrow Nelson

Civil and Environmental Engineering

Photocatalysis was investigated as a pretreatment for hydrocarbon groundwater contamination at an abandoned oil field in Guadalupe, CA. A laboratory photoreactor, with a UV fluorescent lamp submerged in a suspension of TiO₂ catalyst particles, was used to determine oxidation rates and the increase in biodegradability of the hydrocarbon mixture. Chemical oxidation demand (COD) and 5-day biological oxygen demand (BOD₅) were measured as a function of exposure time using standard methods. During eight-hour photoreactor runs in a nitrogen atmosphere, the COD of diluent solutions in de-ionized water and diluent solutions in simulated groundwater both decreased by approximately 50%, …

Environmental Management Of Wastes In The Semiconductor And Electronics Industries, Samuel A. Vigil

Civil and Environmental Engineering

The management of wastes in the semiconductor and electronics industries requires a multidisciplinary approach that considers the health and safety of employees as well as the treatment and recycling of waste materials. The manufacturing of semiconductor devices requires the use of many toxic chemicals and gases. Air emissions from manufacturing tools must be carefully monitored both inside and outside of the fabrication facility. Liquid effluents must be collected and pretreated before discharge to local wastewater systems. The subsequent use and eventual discard of electronic devices such as television sets and personal computers by consumers has created a new set of …

Effects Of Supplemental Viscous Damping On Inelastic Seismic Response Of Assymetric Systems, Cecilia A. Booker, Rakesh K. Goel

Civil and Environmental Engineering

This study investigates the effects of supplemental viscous damping on the seismic response of one-story, asymmetric-plan systems responding in the inelastic range of behavior. It was found that addition of the supplemental damping reduces not only deformation demand but also ductility and hysteretic energy dissipation demands on lateral load resisting elements during earthquake loading. However, the level of reduction strongly depends on the plan-wise distribution of supplemental damping. Nearly optimal reduction in demands on the outermost flexible-side element, an element generally considered to be the most critical element, was realized when damping was distributed unevenly in the system plan such …

Direct Displacement-Based Design Using Inelastic Design Spectrum, Rakesh K. Goel, Anil K. Chopra

Civil and Environmental Engineering

No abstract provided.

Thermally Treated Coal Tar Contaminated Soil As A Concrete Aggregate, Katherine E. Leblanc, John L. Durant, Christopher Swan, Michael J. Weaver, Daniel C. Jansen

Civil and Environmental Engineering

The current practice of landfilling thermally treated and untreated coal tar-contaminated soil is expensive, and it is a waste of a potentially useful material and landfill space. A less expensive and possibly more practical alternative is to use coal tar-contaminated soil as an aggregate in concrete. Because little work has been done in this area, the present study was undertaken to evaluate the effects of coal tar-contamination and thermal treatment on the physical properties of soil and the strength of concrete containing contaminated soil as an aggregate. Also assessed was the leachability of coal tar constituents (specifically, polycyclic aromatic hydrocarbons …

Field Case Histories For Spt-Based In Situ Liquefaction Potential Evaluation, K. Onder Cetin, Raymond B. Seed, Robb E.S. Moss, Armen Der Kiureghian, Kohji Tokimatsu, Leslie F. Harder, Jr., Robert E. Kayen

Civil and Environmental Engineering

This report provides documentation of the field performance case histories and site response analyses described in the report entitled "SPT-Based Probabilistic and Deterministic Assessment of Seismic Soil Liquefaction Initiation Hazard," by Cetin, et al. (2000).

Table 3-5, taken from that report, summarizes the interpreted field performance case histories from the original database of Seed et al. (1984) that were found to conform to the standards of Data Classes A, B or C, and so were used in the studies of Cetin et al. Table 3-7, also taken from that report, summarizes the cases that were deleted from the overall database …

Supplemental Viscous Damping Effects On Seismic Demands Of Linear Elastic Systems, Linda M. Tam, Rakesh K. Goel

Civil and Environmental Engineering

The objective of this study is to examine the effects of viscous supplemental damping on response quantities of asymmetric-plan structures responding in a linearly elastic fashion. The response quantities which will be investigated include: element deformations, base shears, and base torques. These response quantities will be normalized, evaluated, and then analyzed.

It is shown that supplemental damping is indeed effective in reducing element deformations and base torques. In some cases, supplemental damping is also effective in reducing base shears. In order to achieve the largest reduction in flexible element deformation, it is recommended that all fluid viscous dampers be placed …

Desiccation And Cracking Behavior Of Three Compacted Landfill Liner Soils, N. Yesiller, C. J. Miller, G. Inci, K. Yaldo

Civil and Environmental Engineering

Tests were conducted to investigate desiccation cracking of three compacted liner soils obtained from local landfills in southeast Michigan. The soils had low plasticity with varying fines content. Large-scale samples of the soils were subjected to wetting and drying cycles. Surficial dimensions of cracks and suction in the soils were monitored. Surficial dimensions of cracks were quantified using the crack intensity factor (CIF), which is the ratio of the surface area of cracks to the total surface area of a soil. All of the soils were subjected to a compaction–dry cycle (i.e. soils were allowed to dry after compaction) and …

Modified Testing Procedure For The Two Parameter Fracture Model For Concrete, Daniel C. Jansen, W. Jason Weiss, Stefan H.F. Schleuchardt

Civil and Environmental Engineering

No abstract provided.

Control Of Earthquake Induced Vibrations In Asymmetric Buildings Using Passive Damping, Rakesh K. Goel

Civil and Environmental Engineering

This paper summarizes the results of a recent investigation on the dynamic response of asymmetric-plan buildings with supplemental viscous damping to harmonic ground motion using modal analysis techniques. It is shown that most modal parameters, except modal damping ratios and dynamic amplification factors, are affected very little by the plan-wise distribution of supplemental damping in the practical range of system parameters. The first modal damping ratio increases while the second decreases as CSD moves from right to left of the system plan, and their values increase with larger plan-wise spread of the supplemental damping. Trends for the dynamic amplification factors …

Application Of Inelastic Design Spectrum To Capacity-Demand Diagram Methods, 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.

Evaluation Of Nsp To Estimate Seismic Deformation: Sdf Systems, Anil K. Chopra, Rakesh K. Goel

Civil and Environmental Engineering

Investigated in this paper is the approximation in the ATC-40 nonlinear static procedure (NSP) that the earthquake-induced deformation of an inelastic single-degree-of-freedom (SDF) system can be estimated by an iterative method requiring analysis of a sequence of equivalent linear systems. Several deficiencies in the ATC-40 Procedure A are demonstrated. This iterative procedure did not converge for some of the systems analyzed. It converged in many cases, but to a deformation much different than dynamic (nonlinear response history or inelastic design spectrum) analysis of the inelastic system. The ATC-40 Procedure B always gives a unique value of deformation, same as that …

Seismic Behaviour Of Asymmetric Buildings With Supplemental Damping, Rakesh K. Goel

Civil and Environmental Engineering

This paper investigates the response of asymmetric‐plan buildings with supplemental viscous damping to harmonic ground motion using modal analysis techniques. It is shown that most modal parameters, except dynamic amplification factors (DAFs), are affected very little by the plan‐wise distribution of supplemental damping in the practical range of system parameters. Plan‐wise distribution of supplemental damping significantly influences the DAFs, which, in turn, influence the modal deformations. These trends are directly related to the apparent modal damping ratios; the first modal damping ratio increases while the second decreases as CSD moves from right to left of the system plan, and their …

Adsorption Of Pb And Cd Onto Metal Oxides And Organic Material In Natural Surface Coatings As Determined By Selective Extractions: New Evidence For The Importance Of Mn And Fe Oxides, Deming Dong, Yarrow M. Nelson, Leonard W. Lion, Michael L. Shuler, Whilliam C. Ghiorse

Civil and Environmental Engineering

Surface coatings (biofilms and associated minerals) were collected on glass slides in the toxic surface waters of Cayuga Lake (New York State, U.S.A.) and were used to evaluate the relative contributions of Fe, Mn and Al oxides and organic material to total observed Pb and Cd adsorption by the surface coating materials. Several alternative selective extraction techniques were evaluated with respect to both selectivity and alteration of the residual unextracted material. Pb and Cd adsorption was measured under controlled laboratory conditions (mineral salts solution with defined metal speciation, ionic strength 0.05 M, 25°C and pH 6.0) before and after extractions …

Ultrasonic Testing For Compacted Clayey Soils, Nazli Yesiller, Gokhan Inci, Carol J. Miller

Civil and Environmental Engineering

In this study, tests were conducted to investigate the use of ultrasonic methods to determine compaction characteristics of clayey soils. In particular, through-transmission test method was used to determine P-wave velocities in compacted clayey soils. Effects of soil type and compaction conditions on velocity were investigated. Tests were conducted on three soils that had low, medium, and high plasticity. Soils were prepared at water contents ranging from dry to wet of optimum using standard and modified compaction efforts. It was observed that velocity increased with increasing compactive effort and decreasing plasticity and clay content. Moreover, the variation of ultrasonic velocity …