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Civil and Environmental Engineering Faculty Publications

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Articles 331 - 360 of 562

Full-Text Articles in Civil and Environmental Engineering

Data Collection Methodology For Dynamic Temperature Model Testing And Corroboration, Bethany T. Neilson, David King Stevens, S. C. Chapra, Christina J. Bandaragoda Jul 2009

Data Collection Methodology For Dynamic Temperature Model Testing And Corroboration, Bethany T. Neilson, David King Stevens, S. C. Chapra, Christina J. Bandaragoda

Civil and Environmental Engineering Faculty Publications

This article describes a data collection approach for determining the significance of individual heat fluxes within streamswith an emphasis on testing (i.e. identification of possible missing heat fluxes), development, calibration and corroborationof a dynamic temperature model. The basis for developing this approach was a preliminary temperature modelling effort onthe Virgin River in southwestern Utah during a low-flow period that suggested important components of the energy balancemight be missing in the o riginal standard surface-flux temperat ure model. Possible missing heat fluxes were identi fied as bedconduction, hyporheic exchange, dead zone warming and exchange and poor representation of the amount of …

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Energy Losses In Cross Junctions, Zachary B. Sharp, Michael C. Johnson, Steven L. Barfuss, William J. Rahmeyer Jun 2009

Energy Losses In Cross Junctions, Zachary B. Sharp, Michael C. Johnson, Steven L. Barfuss, William J. Rahmeyer

Civil and Environmental Engineering Faculty Publications

Energy losses occurring in pipe junctions have been studied for many years. Head loss coefficients (KK) are commonly used to characterize losses across elbows, tees, crosses, valves, and other pipe fittings. When accurate values of KK are used, the flow rate and corresponding total head at any location in a pipe network can be calculated. While KK is well defined for most pipe junctions and fittings, the literature has limited documentations of KK for crosses. This study was commissioned to determine KK for a wide range of flow combinations in a pipe cross with equal diameter pipes and varied flow …

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Aglite Lidar: A Portable Elastic Lidar System For Investivating Aerosol And Wind Motions At Or Around Agricultural Production Facilities, Christian C. Marchant, Thomas Wilkerson, Gail E. Bingham, Vladimir V. Zavyalov, Jan M. Andersen, Cordell B. Wright, Scott S. Cornelsen, Randy S. Martin, Philip J. Silva, Jerry L. Hatfield Jan 2009

Aglite Lidar: A Portable Elastic Lidar System For Investivating Aerosol And Wind Motions At Or Around Agricultural Production Facilities, Christian C. Marchant, Thomas Wilkerson, Gail E. Bingham, Vladimir V. Zavyalov, Jan M. Andersen, Cordell B. Wright, Scott S. Cornelsen, Randy S. Martin, Philip J. Silva, Jerry L. Hatfield

Civil and Environmental Engineering Faculty Publications

The Aglite Lidar is a portable scanning lidar that can be quickly deployed at agricultural and other air quality study sites. The purpose of Aglite is to map the concentration of PM10 and PM2.5 in aerosol plumes from agricultural and other sources. Aglite uses a high-repetition rate low-pulse energy 3-wavelength YAG laser with photon-counting detection together with a steerable pointing mirror to measure aerosol concentration with high spatial and temporal resolution. Aglite has been used in field campaigns in Iowa, Utah and California. The instrument is described, and performance and lidar sensitivity data are presented. The value of the lidar …

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Shades Of Grey: A Critical Review Of Grey-Number Optimization, David E. Rosenberg Jan 2009

Shades Of Grey: A Critical Review Of Grey-Number Optimization, David E. Rosenberg

Civil and Environmental Engineering Faculty Publications

A grey number is an uncertain number with fixed lower and upper bounds but unknown distribution. Grey numbers find use in optimization to systematically and proactively incorporate uncertainties expressed as intervals plus communicate resulting stable, feasible ranges for the objective function and decision variables. This article critically reviews their use in linear and stochastic programs with recourse. It summarizes grey model formulation and solution algorithms. It advances multiple counter-examples that yield risk-prone grey solutions that perform worse than a worst-case analysis and do not span the stable feasible range of the decision space. The article suggests reasons for the poor …

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Modeling Integrated Decisions For A Municipal Water System With Recourse And Uncertainties: Amman, Jordan, David E. Rosenberg, Jay Lund Jan 2009

Modeling Integrated Decisions For A Municipal Water System With Recourse And Uncertainties: Amman, Jordan, David E. Rosenberg, Jay Lund

Civil and Environmental Engineering Faculty Publications

Stochastic mixed-integer optimization is used to identify a portfolio of long- and short-term supply and conservation actions for a municipal water system to cost-effectively accommodate a distribution of water shortages. Alternative robust, grey-number, and best/worst case formulations systematically explore implications of uncertainties in action costs, life spans, water volumes gained or saved, shortage levels, and shortage probabilities. A detailed example for Amman, Jordan considers 23 potential actions. Results show: (1) remarkable consistency occurs across the different modeling approaches. (2) Conserving water—reducing leakage and targeting select customers to install water efficient appliances—plays an important and growing role over time. (3) A …

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Impact Of Vegetable Oil On Distribution Of Trichloroethylene In Groundwater During Enhanced Bioremediation, M. Pu, Ryan Dupont, William J. Doucette Oct 2008

Impact Of Vegetable Oil On Distribution Of Trichloroethylene In Groundwater During Enhanced Bioremediation, M. Pu, Ryan Dupont, William J. Doucette

Civil and Environmental Engineering Faculty Publications

Vegetable oils are increasingly being used as long-term carbon donors to stimulate reductive dechlorination of trichloroethylene (TCE). Besides potential enhancement of biodegradation, the addition of vegetables oils may impact TCE fate and distribution within the aquifer by acting as non-aqueous phase liquids (NAPL). Distribution coefficients for TCE between groundwater and four vegetable oils were determined using a slow-stir technique. Log vegetable oil/water distribution coefficients (log Kvw) were found to range from 1.0 to 2.56. TCE/vegetable oil distribution coefficients statistically increased with an increase in oil weathering while the concentration of dissolved organic carbon (DOC) in the water did not change …

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Watershed Management And Water Production Study For State Of Utah, Ibrahim Nourein Mohammed, David G. Tarboton Sep 2008

Watershed Management And Water Production Study For State Of Utah, Ibrahim Nourein Mohammed, David G. Tarboton

Civil and Environmental Engineering Faculty Publications

The amount of water produced from a watershed depends on the climate, soils, geology, land cover and land use. Precipitation water inputs in the form of rain or snow are partitioned by the watershed into evapotranspiration, runoff and groundwater recharge. This study has examined factors that may impact the production of runoff from Utah watersheds, focusing on factors related to land and watershed management. Specifically we are interested in how land use changes, such as afforestation, deforestation, agricultural, urban, industrial and mining development, impact runoff. The scale of interest is regional subbasins at the USGS cataloging unit 8 digit Hydrologic …

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Cryptosporidium Outbreak (Water Treatment Failure): North Battleford, Saskatchewan, Spring 2001, Patrick B. Jameson, Yung-Tse Hung, Chin Y. Kuo, Paul A. Bosela Sep 2008

Cryptosporidium Outbreak (Water Treatment Failure): North Battleford, Saskatchewan, Spring 2001, Patrick B. Jameson, Yung-Tse Hung, Chin Y. Kuo, Paul A. Bosela

Civil and Environmental Engineering Faculty Publications

An outbreak of cryptosporidiosis occurred in the town of North Battleford, Saskatchewan, Canada in the spring of 2001. The outbreak left thousands of people sick including about 50 people hospitalized. The source of the outbreak was from the city's surface water treatment plant. The Sedimentation Contact Unit did not satisfactorily remove suspended solids from the source water, resulting in filter breakthrough. Contaminated water was released into the distribution system causing the outbreak. Communication breakdown and confusion exacerbated the situation, extending the duration of the outbreak. The outbreak prompted the province to change the way it regulated municipal utilities of water …

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Generation Of Monthly Precipitation Under Limited Data And Climate Change: An Example From The Upper Blue Nile River Basin, U. Kim, Jagath J. Kaluarachchi, V. Smakhtin Jul 2008

Generation Of Monthly Precipitation Under Limited Data And Climate Change: An Example From The Upper Blue Nile River Basin, U. Kim, Jagath J. Kaluarachchi, V. Smakhtin

Civil and Environmental Engineering Faculty Publications

This work develops a methodology to project the future precipitation in large river basins under limited data and climate change while preserving the historical temporal and spatial characteristics. The computationally simple and reliable conditional generation method (CGM) is presented and applied to generate reliable monthly precipitation data in the upper Blue Nile River Basin of Ethiopia where rain-fed agriculture is prevalent. The results showed that the temporal analysis with the CGM performs better to reproduce the historical long-term characteristics than other methods, and the spatial analysis with the CGM reproduced the historical spatial structure accurately. A 100-year time series analysis …

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A Relational Model For Environmental And Water Resources Data, Jeffery S. Horsburgh, David G. Tarboton, David R. Maidment, Ilya Zaslavsky May 2008

A Relational Model For Environmental And Water Resources Data, Jeffery S. Horsburgh, David G. Tarboton, David R. Maidment, Ilya Zaslavsky

Civil and Environmental Engineering Faculty Publications

Environmental observations are fundamental to hydrology and water resources, and the way these data are organized and manipulated either enables or inhibits the analyses that can be performed. The Observations Data Model presented here provides a new and consistent format for the storage and retrieval of point environmental observations in a relational database designed to facilitate integrated analysis of large data sets collected by multiple investigators. Within this data model, observations are stored with sufficient ancillary information (metadata) about the observations to allow them to be unambiguously interpreted and to provide traceable heritage from raw measurements to useable information. The …

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Particle Composition And Size Distributions In And Around A Deep Pit Swine Operation, Randy S. Martin, P. J. Silva, Kori D. Moore, M. Erupe, V. S. Doshi May 2008

Particle Composition And Size Distributions In And Around A Deep Pit Swine Operation, Randy S. Martin, P. J. Silva, Kori D. Moore, M. Erupe, V. S. Doshi

Civil and Environmental Engineering Faculty Publications

The contribution of emissions from agricultural facilities is rapidly becoming a major concern for local and regional air quality. Characterization of particle properties such as physical size distribution and chemical composition can be valuable in understanding the processes contributing to emissions and ultimate fate of particulate matter from agricultural facilities. A measurement campaign was conducted at an Iowa, deep-pit, three-barn swine finishing facility to characterize near-source ambient particulate matter. Size-specific mass concentrations were determined using minivol samplers, with additional size distribution information obtain using optical particle counters. Particulate composition was determined via ion chromatographic analysis of the collected filters. A …

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Optimization Model For National Water Master Planning: Design And Documentation, Richard C. Peralta Apr 2008

Optimization Model For National Water Master Planning: Design And Documentation, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

Physical distribution system and Balancing and Allocation and Transfer modules descriptors.

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Lidar Based Emissions Measurement At The Whole Facility Scale: Method And Error Analysis, Gail E. Bingham, Christian C. Marchant, Vladimir V. Zavyalov, Douglas J. Ahlstrom, Kori D. Moore, Derek S. Jones, Thomas D. Wilkerson, Lawrence E. Hipps, Randy S. Martin, Jerry L. Hatfield, John H. Prueger, Richard L. Pfeiffer Jan 2008

Lidar Based Emissions Measurement At The Whole Facility Scale: Method And Error Analysis, Gail E. Bingham, Christian C. Marchant, Vladimir V. Zavyalov, Douglas J. Ahlstrom, Kori D. Moore, Derek S. Jones, Thomas D. Wilkerson, Lawrence E. Hipps, Randy S. Martin, Jerry L. Hatfield, John H. Prueger, Richard L. Pfeiffer

Civil and Environmental Engineering Faculty Publications

Particulate emissions from agricultural sources vary from dust created by operations and animal movement to the fine secondary particulates generated from ammonia and other emitted gases. The development of reliable facility emission data using point sampling methods designed to characterize regional, well-mixed aerosols are challenged by changing wind directions, disrupted flow fields caused by structures, varied surface temperatures, and the episodic nature of the sources found at these facilities. We describe a three-wavelength lidar-based method, which, when added to a standard point sampler array, provides unambiguous measurement and characterization of the particulate emissions from agricultural production operations in near real …

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Final Report For Irrigation Water Quality Monitoring Of The Jordan River, 2008, Richard C. Peralta, Bassel Timani Jan 2008

Final Report For Irrigation Water Quality Monitoring Of The Jordan River, 2008, Richard C. Peralta, Bassel Timani

Civil and Environmental Engineering Faculty Publications

The goal of the Jordan River Water Quality Project is to assess the quality of irrigation water removed from the Jordan River at three diversion locations: Jordan Narrows (JN), Cahoon and Maxfield (CM), and Jordan & Salt Lake Canal (JSLC). During 2008, Salt Lake City Corporation personnel took water samples on 12 dates from April 18 to September 25, 2008. Utah State University Analytical Laboratories (USUAL), an EPAcertified laboratory, performed water analyses on the samples. USUAL is located at Utah State University (USU) in Logan, Utah.

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Optimal In-Situ Bioremediation System Design Using Simulated Annealing, H. J. Shieh, Richard C. Peralta Jan 2008

Optimal In-Situ Bioremediation System Design Using Simulated Annealing, H. J. Shieh, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

The presented procedure combines continuous simulated annealing (CSA) heuristic optimization with BIOPLUME II simulation for optimizing in-situ bioremediation system design. The design goal is to minimize the total cost of facility installation and operation needed to achieve contaminant plume containment and cleanup. System design elements include pumping rates and well locations. During optimization, pumping rates are treated as continuous variables, differing from previously reported simulated annealing combinatorial optimization for groundwater management. To improve computation efficiency, CSA annealing schedules employing four different temperature update functions (TUF) are contrasted. Each yields somewhat different optimal designs and requires different computation effort. An adaptive …

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Integrated Modeling Of Nitrate Contamination Of Groundwater In Agriculture-Dominated Watersheds, M. Almasri, Jagath J. Kaluarachchi Sep 2007

Integrated Modeling Of Nitrate Contamination Of Groundwater In Agriculture-Dominated Watersheds, M. Almasri, Jagath J. Kaluarachchi

Civil and Environmental Engineering Faculty Publications

This paper presents and implements a framework for modeling the impact of land use practices and protection alternatives on nitrate pollution of groundwater in agricultural watersheds. The framework utilizes the national land cover database (NLCD) of the United State Geological Survey (USGS) grid and a geographic information system (GIS) to account for the spatial distribution of on-ground nitrogen sources and corresponding loadings. The framework employs a soil nitrogen dynamic model to estimate nitrate leaching to groundwater. These estimates were used in developing a groundwater nitrate fate and transport model. The framework considers both point and non-point sources of nitrogen across …

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Urban Particulate Matter Casues Er Stress And The Unfolded Protein Response In Human Lung Cells, T. L. Watterson, B. Hamilton, Randy S. Martin, R. A. Coulombe Jr. Sep 2007

Urban Particulate Matter Casues Er Stress And The Unfolded Protein Response In Human Lung Cells, T. L. Watterson, B. Hamilton, Randy S. Martin, R. A. Coulombe Jr.

Civil and Environmental Engineering Faculty Publications

Because of its presumed adverse health effects, particulate air pollution (PM) has received growing attention, but the cellular mechanisms by which PM exerts toxicity are not well elucidated. PM has been associated with early mortality from illnesses that share endoplasmic reticulum (ER) stress as a mechanism of pathogenesis. In this study, we examined whether PM would induce the unfolded protein response (UPR) which is a cellular response to ER stress. Coarse (PM10) and fine (PM2.5) PM was collected from a single location in Northern Utah's Cache Valley during atmospheric inversions occurring in January 2002 and January 2003. Extracts of PM …

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Effects Of Pm2.5 Collected From Cache Valley, Ut On Genes Associated With The Inflammatory Response In Human Lung Cells, T L. Watterson, J. Sorensen, Randy S. Martin, R. A. Coulombe Jr. Sep 2007

Effects Of Pm2.5 Collected From Cache Valley, Ut On Genes Associated With The Inflammatory Response In Human Lung Cells, T L. Watterson, J. Sorensen, Randy S. Martin, R. A. Coulombe Jr.

Civil and Environmental Engineering Faculty Publications

In January 2004, the normally picturesque Cache Valley in northern Utah made national headlines with the highest PM2.5 levels in the nation. Epidemiological studies linked exposure to particulate air pollution in other locations with stroke and Alzheimer's disease and to early mortality from all causes, cancer, and cardiopulmonary diseases. To determine potential effects of these particles on human health, human bronchial epithelial cells (BEAS-2B) were cultured with PM2.5collected from various locations in the Cache Valley. These particles were slightly cytotoxic, but more potent than NH4NO3, the major chemical component of Cache Valley PM2.5. Gene expression analysis of PM2.5-exposed cells was …

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Love Canal Tragedy, Alicia Saunte Phillips, Yung-Tse Hung, Paul A. Bosela Jul 2007

Love Canal Tragedy, Alicia Saunte Phillips, Yung-Tse Hung, Paul A. Bosela

Civil and Environmental Engineering Faculty Publications

The purpose of this environmental failure case study paper is to provide educational materials for environmental engineering courses dealing with design and operation of landfills for hazardous waste. In 1978, it was discovered that hazardous waste had contaminated homes and schools in the Love Canal area, a former chemical landfill which became a 15 acre neighborhood of the City of Niagara Falls, New York. On August 7, 1978, the United States President Jimmy Carter declared a federal emergency at the Love Canal. The Love Canal became the first man-made disaster to receive such a designation based on a variety of …

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Regulating Waste Discharge With Fuzzy Effluent Limitations For Toxic Pollutants, Tong Yin, David King Stevens Apr 2007

Regulating Waste Discharge With Fuzzy Effluent Limitations For Toxic Pollutants, Tong Yin, David King Stevens

Civil and Environmental Engineering Faculty Publications

Many traditional water quality standards are based on extreme percentiles; often, there is the risk of making wrong decisions with these standards because of high estimation uncertainty. Standards expressed as fuzzy intervals in the form of [trigger, enforcement limitation] make it possible to control the risks for the discharger and the consumer simul taneously. With fuzzy interval compliance, corrective action is initiated when the trigger is exceeded; noncompliance is declared when the en forcement limitation is exceeded. Fuzzy intervals would digest the risks that are inherent when a single enforcement limitation is used to determine compliance; the risks can be …

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Production Of Bio-Hydrogen By Mesophilic Anaerobic Fermentation In An Acid-Phase Sequencing Batch Reactor, D. Y. Cheong, C. L. Hansen, David King Stevens Feb 2007

Production Of Bio-Hydrogen By Mesophilic Anaerobic Fermentation In An Acid-Phase Sequencing Batch Reactor, D. Y. Cheong, C. L. Hansen, David King Stevens

Civil and Environmental Engineering Faculty Publications

The pH and hydraulic retention time (HRT) of an anaerobic sequencing batch reactor (ASBR) were varied to optimize the conversion of carbohydrate-rich synthetic wastewater into bio-hydrogen. A full factorial design using evolutionary operation (EVOP) was used to determine the effect of the factors and to find the optimum condition of each factor required for high hydrogen production rate. Experimental results from 20 runs indicate that a maximum hydrogen production rate of 4,460-5,540 mL/L/day under the volumetric organic loading rate (VOLR) of 75 g-COD/L/day obtained at an observed design point of HRT = 8 h and pH = 5.7. The hydrogen …

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A New Method For Determination Of Most Likely Landslide Initiation Points And The Evaluation Of Digital Terrain Model Scale In Terrain Stability Mapping, P. Tarolli, David G. Tarboton Sep 2006

A New Method For Determination Of Most Likely Landslide Initiation Points And The Evaluation Of Digital Terrain Model Scale In Terrain Stability Mapping, P. Tarolli, David G. Tarboton

Civil and Environmental Engineering Faculty Publications

This paper introduces a new approach for determining the most likely initiation points for landslides from potential instability mapped using a terrain stability model. This approach identifies the location with critical stability index from a terrain stability model on each downslope path from ridge to valley. Any measure of terrain stability may be used with this approach, which here is illustrated using results from SINMAP, and from simply taking slope as an index of potential instability. The relative density of most likely landslide initiation points within and outside mapped landslide scars provides a way to evaluate the effectiveness of a …

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Collapse Of The Quebec Bridge, 1907, Cynthia Pearson, Norbert Delatte Feb 2006

Collapse Of The Quebec Bridge, 1907, Cynthia Pearson, Norbert Delatte

Civil and Environmental Engineering Faculty Publications

In the late 19th century, the transportation needs of Quebec led to proposals for bridging the St. Lawrence River. The Quebec Bridge was the longest cantilever structure attempted until that time. In its final design, the clear span was 548.6 m (1,800 ft) long. The bridge project was financially troubled from the beginning. This caused many setbacks in the design and construction. Construction finally began in October 1900. In August 1907, the bridge collapsed suddenly. Seventy five workers were killed in the accident, and there were only 11 survivors from the workers on the span. A distinguished panel was assembled …

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Treating Soil Pentachlorophenol (Pcp) At Optimal Conditions Using Heme And Peroxide, Shyi Tien Chen, David King Stevens, Guyoung Kang, M. J. Hsieh Jan 2006

Treating Soil Pentachlorophenol (Pcp) At Optimal Conditions Using Heme And Peroxide, Shyi Tien Chen, David King Stevens, Guyoung Kang, M. J. Hsieh

Civil and Environmental Engineering Faculty Publications

The environmental impact of pentachlorophenol (PCP) has been the subject of extensive research in recent years. Investigations of PCP degradation using both biotic and abiotic methods are extensively reported in literature. Based on some preliminary tests (not shown), an abiotic method was found for oxidative PCP degradation in soil under unsaturated conditions and a neutral pH. Reagents used were heme (a catalyst) and peroxide (an oxidant). From two screening tests (not shown), the heme and peroxide were identified as the most important factors on PCP degradation in highly PCP-contaminated soil. The objective of this study was to determine the optimum …

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Impacts Of The 2004 Tsunami On Groundwater In Sri Lanka, T. Illangasekare, S. W. Tyler, T. P. Clement, K. G. Villholth, A. P.G.R.L. Perera, J. Obeysekera, A. Gunatilaka, C. R. Panabokke, D. W. Hyndman, K. J. Cunningham, W-G. Yeh, Jagath J. Kaluarachchi, M-Rien Van Genuchten, K. Jensen Jan 2006

Impacts Of The 2004 Tsunami On Groundwater In Sri Lanka, T. Illangasekare, S. W. Tyler, T. P. Clement, K. G. Villholth, A. P.G.R.L. Perera, J. Obeysekera, A. Gunatilaka, C. R. Panabokke, D. W. Hyndman, K. J. Cunningham, W-G. Yeh, Jagath J. Kaluarachchi, M-Rien Van Genuchten, K. Jensen

Civil and Environmental Engineering Faculty Publications

The 26 December 2004 tsunami caused widespread destruction and contamination of coastal aquifers across southern Asia. Seawater filled domestic open dug wells and also entered the aquifers via direct infiltration during the first flooding waves and later as ponded seawater infiltrated through the permeable sands that are typical of coastal aquifers. In Sri Lanka alone, it is estimated that over 40,000 drinking water wells were either destroyed or contaminated. From February through September 2005, a team of United States, Sri Lankan, and Danish water resource scientists and engineers surveyed the coastal groundwater resources of Sri Lanka to develop an understanding …

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Modular Neural Network To Predict The Distribution Of Nitrate In Ground Water Using On-Ground Nitrogen Loading And Recharge Data, M. Almasri, Jagath J. Kaluarachchi Jul 2005

Modular Neural Network To Predict The Distribution Of Nitrate In Ground Water Using On-Ground Nitrogen Loading And Recharge Data, M. Almasri, Jagath J. Kaluarachchi

Civil and Environmental Engineering Faculty Publications

Artificial neural networks have proven to be an attractive mathematical tool to represent complex relationships in many branches of hydrology. Due to this attractive feature, neural networks are increasingly being applied in subsurface modeling where intricate physical processes and lack of detailed field data prevail. In this paper, a methodology using modular neural networks (MNN) is proposed to simulate the nitrate concentrations in an agriculture-dominated aquifer. The methodology relies on geographic information system (GIS) tools in the preparation and processing of the MNN input–output data. The basic premise followed in developing the MNN input–output response patterns is to designate the …

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Ronan Point Apartment Tower Collapse And Its Effect On Building Codes, Cynthia Pearson, Norbert Delatte May 2005

Ronan Point Apartment Tower Collapse And Its Effect On Building Codes, Cynthia Pearson, Norbert Delatte

Civil and Environmental Engineering Faculty Publications

In the early morning hours of May 16, 1968, the occupant of apartment 90 on the 18th floor of the 22-story Ronan Point apartment tower, in London, lit a match to brew her morning cup of tea. The resulting gas explosion initiated a partial collapse of the structure that killed four people and injured 17 (one of whom subsequently died). On investigation, the apartment tower was found to be deeply flawed in both design and construction. The existing building codes were found to be inadequate for ensuring the safety and integrity of high-rise precast concrete apartment buildings. The Larsen–Nielson building …

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Failure Of Cold-Formed Steel Beams During Concrete Placement, Norbert Delatte May 2005

Failure Of Cold-Formed Steel Beams During Concrete Placement, Norbert Delatte

Civil and Environmental Engineering Faculty Publications

During a concrete placement on the second story of a building under construction, the supporting cold-formed steel beams collapsed. Four workers were injured. The collapse occurred while concrete was being placed onto steel decking on the second floor of the structure. Cold-formed steel beams, without shoring, supported the steel decking. Analysis of the steel beams under the weight of concrete and workers using the applicable American Concrete Institute and American Iron and Steel Institute documents indicated that the beams were overstressed for construction loads. After the collapse, part of the structure was rebuilt using thicker beams. For the reconstruction, the …

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Multi-Criteria Decision Analysis For The Optimal Management Of Nitrate Contamination Of Aquifers, Mohammad N. Almasri, Jagath J. Kaluarachchi Mar 2005

Multi-Criteria Decision Analysis For The Optimal Management Of Nitrate Contamination Of Aquifers, Mohammad N. Almasri, Jagath J. Kaluarachchi

Civil and Environmental Engineering Faculty Publications

We present an integrated methodology for the optimal management of nitrate contamination of ground water combining environmental assessment and economic cost evaluation through multi-criteria decision analysis. The proposed methodology incorporates an integrated physical modeling framework accounting for on-ground nitrogen loading and losses, soil nitrogen dynamics, and fate and transport of nitrate in ground water to compute the sustainable on-ground nitrogen loading such that the maximum contaminant level is not violated. A number of protection alternatives to stipulate the predicted sustainable on-ground nitrogen loading are evaluated using the decision analysis that employs the importance order of criteria approach for ranking and …

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Assessment Of Aquifer Vulnerability Due To Heavy Metals Using Ordinal Logistic Regression Analysis, N. K. Twarakavi, Jagath J. Kaluarachchi Mar 2005

Assessment Of Aquifer Vulnerability Due To Heavy Metals Using Ordinal Logistic Regression Analysis, N. K. Twarakavi, Jagath J. Kaluarachchi

Civil and Environmental Engineering Faculty Publications

A methodology using ordinal logistic regression is proposed to predict the probability of occurrence of heavy metals in ground water. The predicted probabilities are defined with reference to the background concentration and the maximum contaminant level. The model is able to predict the occurrence due to different influencing variables such as the land use, soil hydrologic group (SHG), and surface elevation. The methodology was applied to the Sumas-Blaine Aquifer located in Washington State to predict the occurrence of five heavy metals. The influencing variables considered were (1) SHG; (2) land use; (3) elevation; (4) clay content; (5) hydraulic conductivity; and …

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