Engineering Commons^™

Evaluation Of Current Nonlinear Static Procedures For Concrete Buildings Using Recorded Strong-Motion Data, Rakesh K. Goel, Charles Chadwell

Civil and Environmental Engineering

This study evaluates current Nonlinear Static Procedures (NSPs) specified in the FEMA356, ASCE-41, ATC-40, and FEMA-440 documents using strong-motion data from reinforced-concrete buildings. For this purpose, three-dimensional computer models of five reinforced concrete buildings – Imperial County Services Building, Sherman Oaks Commercial Building, North Hollywood Hotel, Watsonville Commercial Building, and Santa Barbara Office Building – are developed. When appropriate, springs at the building’s base are included to account for the soil-structure interaction effects. These buildings are selected because they were strongly shaken, several deformed beyond their linear-elastic range, during past earthquakes and their recorded motions are available. The recorded motions …

Evaluation Of Current Nonlinear Static Procedures For Concrete Buildings Using Recorded Strong-Motion Data, Rakesh K. Goel, Charles Chadwell

Civil and Environmental Engineering

This paper evaluates current Nonlinear Static Procedures (NSPs) specified in the FEMA- 356, ASCE-41, ATC-40, and FEMA-440 documents using strong-motion data from reinforcedconcrete buildings. For this purpose, peak roof (or target node) displacements estimated from the NSPs are compared with the value derived from recorded motions. It is shown that: (1) the NSPs either overestimate or underestimate the peak roof displacement for several of the buildings considered in this investigation; (2) the ASCE-41 Coefficient Method (CM), which is based on recent improvements to the FEMA-356 CM suggested in FEMA-440 document, does not necessarily provide better estimate of roof displacement; and …

Multiobjective Optimization For Optimal Design Of Urban Drainage Systems, Misgana K. Muleta, Paul F. Boulos

Civil and Environmental Engineering

Control of sewer overflows, the leading cause of water pollution in the nation’s water bodies, is vital to reducing risks to public health and protecting the environment. The most common solutions for mitigating sewer overflows include adding storage volume, increasing conduit capacity, expanding pumping capacity, and implementation of real time operational controls to more effectively utilize existing system storage. Obviously, comprehensive modeling and analysis of these sewer systems becomes necessary for developing sound cost-effective and reliable solutions for enhancing system integrity and performance to convey sewer flows without causing overflows. However, identification of the optimal remedial solution that effectively circumvents …

Diluent Hydrocarbon Biodegredation In Laboratory Microcosms Using Anoxic Eletctron Acceptors, Meghann Chell, Laleh Rastagarzadeh, Yarrow Nelson

Civil and Environmental Engineering

Abstract of Paper Presented at Conference.

On The Nature Of Over-Dispersion In Motor Vehicle Crash Prediction Models, Sudeshna Mitra, Simon Washington

Civil and Environmental Engineering

Statistical modeling of traffic crashes has been of interest to researchers for decades. Over the most recent decade many crash models have accounted for extra-variation in crash counts—variation over and above that accounted for by the Poisson density. The extra-variation – or dispersion – is theorized to capture unaccounted for variation in crashes across sites. The majority of studies have assumed fixed dispersion parameters in over-dispersed crash models—tantamount to assuming that unaccounted for variation is proportional to the expected crash count. Miaou and Lord [Miaou, S.P., Lord, D., 2003. Modeling traffic crash-flow relationships for intersections: dispersion parameter, functional form, and …

Chemical Composition Of Groundwater Hydrocarbon Mixtures Before And After Aerobic Biodegradation, Eileen Mick, Kevin Crossley, Yarrow Nelson

Civil and Environmental Engineering

No abstract provided.

Sensitivity Of A Distributed Watershed Simulation Model To Spatial Scale, Misgana K. Muleta, John W. Nicklow, Elias G. Bekele

Civil and Environmental Engineering

The results of distributed watershed models could be sensitive to spatial and temporal scales at which inputs and model parameters are aggregated. This paper reports findings of a detailed sensitivity analysis conducted on the U.S. Department of Agriculture’s distributed watershed simulation model, known as the Soil and Water Assessment Tool (SWAT). The Big Creek Watershed, located in southern Illinois, is used for the study. The model is calibrated to improve accuracy of its streamflow and sediment concentration predictions using observed data at two locations in the study watershed. Streamflow and sediment concentrations that are simulated by the calibrated model at …

Estimating The Probability Of Failure And Associated Risk Of The California Bay Delta Levee System, Robb E.S. Moss, J. Michael Eller

Civil and Environmental Engineering

Recent events in New Orleans have shown the magnitude of life loss and property damage that can occur due to the failure of man-made levees. The California Bay Delta and Sacramento levee systems in California pose a similar or greater level of risk to life and property. In order to effectively mitigate the hazard associated with levee failure a systematic evaluation of risk must be carried out. This paper presents preliminary research into the risk associated with the California Bay Delta. A comprehensive list of failure modes for man-made levees is presented. Preliminary empirical data on the temporal frequency of …

Final Report: Production Of Biodiesel From Algae Applied To Agricultural Wastewater Treatment, Yarrow M. Nelson, Adam Feffer, Andrew Kean, Tryg Lundquist, Walter Mark, Linda Vanasupa, Sam Vigil, Ian Woertz

Civil and Environmental Engineering

No abstract provided.

Crash Data Analysis: Collective Vs. Individual Crash Level Approach, Mohamed Abdel-Aty, Anurag Pande

Civil and Environmental Engineering

Introduction

Traffic safety literature has traditionally focused on identification of location profiles where “more crashes are likely to occur” over a period of time. The analysis involves estimation of crash frequency and/or rate (i.e., frequency normalized based on some measure of exposure) with geometric design features (e.g., number of lanes) and traffic characteristics (e.g., Average Annual Daily Traffic [AADT]) of the roadway location. In the recent past, a new category of traffic safety studies has emerged, which attempts to identify locations where a “crash is more likely to occur.” The distinction between the two groups of studies is that the …

Multiple-Model Framework For Assessment Of Real-Time Crash Risk, Anurag Pande

Civil and Environmental Engineering

This study is based on real-time models of risk assessment for rear-end and lane-change-related crashes on freeways. These models were developed in recent studies on the basis of historical crash data and corresponding traffic data collected through underground loop detectors on Interstate-4 in Orlando, Florida. In this study the potential of these models was explored for identification of crashes that were not part of the database used to develop the models. These crashes include single-vehicle crashes that might result from evasive actions taken by drivers to avoid vehicles in front (i.e., a rear-end crash) or in a neighboring lane (i.e., …