Engineering Commons^™

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 …

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 …

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 …