Engineering Commons^™

Discussion Of “Analyzing Liquefaction-Induced Lateral Spreads Using Strength Ratios" By S.M. Olson And C.I. Johnson, Robb E.S. Moss, Justin Chow Hollenback

Civil and Environmental Engineering

No abstract provided.

Seismic Analysis Of Buildings To Recorded Motions, Rakesh K. Goel

Civil and Environmental Engineering

This investigation focused on developing an improved understanding of challenges associated with computation of nonlinear response of three-dimensional building to recorded ground motions, and if the base shear estimated from recorded motions, denoted as “estimated base shear” in this report, is an accurate indicator of the true base shear. For this purpose, three-dimensional models of two buildings – one reinforced-concrete building and one steel building – are developed in OpenSees and Perform3D¬. The analysis of these models included pushover analysis for lateral force distribution proportional to the first mode in each of the two principle directions, and nonlinear response history …

Cost Of Quality In The Construction Industry, Philip L. Barlow

Construction Management

The construction industry needs to decrease its costs due to nonconformance by implementing an objective model for analyzing the excessive cost of poor quality and the overall savings realized from good quality. Direct cost estimates from rework in commercial building construction average about 5%. A simple calculation based on U.S. construction industry expenditures of $1.246 trillion in 2007 reveals that $62 billion is wasted just on the direct cost construction rework alone! The term quality can be applied in many different ways to various aspects of the construction process. This paper proposes a model which helps illustrate how the various …

Microalgal Biomass For Greenhouse Gas Reductions: Potential For Replacement Of Fossil Fuels And Animal Feeds, D. E. Brune, Tryg Lundquist, J. R. Benemann

Civil and Environmental Engineering

Microalgal biomass production offers a number of advantages over conventional biomass production, including higher productivities, use of otherwise nonproductive land, reuse and recovery of waste nutrients, use of saline or brackish waters, and reuse of CO₂ from power-plant flue gas or similar sources. Microalgal biomass production and utilization offers potential for greenhouse gas (GHG) avoidance by providing biofuel replacement of fossil fuels and carbon-neutral animal feeds. This paper presents an initial analysis of the potential for GHG avoidance using a proposed algal biomass production system coupled to recovery of flue-gas CO₂ combined with waste sludge and/or animal manure …

Algae Grown On Dairy And Municipal Wastewater For Simultaneous Nutrient Removal And Lipid Production For Biofuel Feedstock, Ian Woertz, A. Feffer, Tryg Lundquist, Yarrow Nelson

Civil and Environmental Engineering

Algae grown on wastewater media are a potential source of low-cost lipids for production of liquid biofuels. This study investigated lipid productivity and nutrient removal by green algae grown during treatment of dairy farm and municipal wastewaters supplemented with CO₂. Dairy wastewater was treated outdoors in bench-scale batch cultures. The lipid content of the volatile solids peaked at Day 6, during exponential growth, and declined thereafter. Peak lipid content ranged from 14–29%, depending on wastewater concentration. Maximum lipid productivity also peaked at Day 6 of batch growth, with a volumetric productivity of 17 mg/day/L of reactor and an …

Reduced Uncertainty Of Ground Motion Prediction Equations Through Bayesian Variance Analysis, Robb E.S. Moss

Civil and Environmental Engineering

A ground motion prediction equation estimates the mean and variance of ground shaking with distance from an earthquake source. Current relationships use regression techniques that treat the input variables or parameters as exact, neglecting the uncertainties associated with the measurement of shear wave velocity, moment magnitude, and site-to-source distance. This parameter uncertainty propagates through the regression procedure and results in model uncertainty that overestimates the inherent variability of the ground motion. This report discusses methods of estimating the statistical uncertainty of the input parameters, and procedures for incorporating the parameter uncertainty into the regression of ground motion data using a …

Nutrient Removal & Greenhouse Gas Abatement With Co2 Supplemented Algal High Rate Ponds, Ian Woertz, Laura Fulton, Tryg Lundquist

Civil and Environmental Engineering

High rate algae ponds fed clarified domestic wastewater and CO₂-rich flue gas are expected to remove nutrients to concentrations similar to those achieved in mechanical treatment technologies, such as activated sludge. However, the energy intensity of wastewater treatment with CO₂-supplemented high rate ponds (HRPs) would be less than that of mechanical treatments. In conjunction with anaerobic digestion of algal biomass and co-substrates, the algae-based system would produce a substantial excess of electricity. Greenhouse gas abatement from such CO₂-HRP/digestion systems would stem mainly from energy conservation and the offset of fossil fuel electricity with biogas-derived …

Biogas Production From Algae Biomass Harvested At Wastewater Treatment Ponds, Michael Salerno, Yakup Nurdogan, Tryg J. Lundquist

Civil and Environmental Engineering

Waste-grown microalgae are a potentially important biomass for biofuel production. However, most of the 7,000 wastewater treatment ponds systems in the US do not use algae harvesting. Those that do, typically return the biomass to the ponds, where it decomposes on the pond floor, releasing methane to the atmosphere and degrading water quality. Instead, the algae biomass could be processed in anaerobic digesters. Algae typically yield less methane than wastewater sludge (~0.3 vs. 0.40 L CH4/g volatile solids introduced). Ammonia toxicity and recalcitrant cell walls are commonly cited causes of the lower yields. Ammonia toxicity might be counteracted by co-digesting …

A Novel Approach For Analyzing Severe Crash Patterns On Multilane Highways, Anurag Pande, Mohamed Abdel-Aty

Civil and Environmental Engineering

This study presents a novel approach for analysis of patterns in severe crashes that occur on mid-block segments of multilane highways with partially limited access. A within stratum matched crash vs. non-crash classification approach is adopted towards that end. Under this approach crashes serve as units of analysis and it does not require aggregation of crash data over arterial segments of arbitrary lengths. Also, the proposed approach does not use information on non-severe crashes and hence is not affected by under-reporting of the minor crashes. Random samples of time, day of week, and location (i.e., milepost) combinations were collected for …

Reinvestigation Of Liquefaction And Nonliquefaction Case Histories From The 1976 Tangshan Earthquake, Robb E.S. Moss, Robert Kayen, Liyuan Tong, Songyu Liu, Guojun Cai, Jiaer Wu

Civil and Environmental Engineering

A field investigation was carried out to retest liquefaction and nonliquefaction sites from the 1976 Tangshan earthquake in the People's Republic of China (PRC). These sites were carefully investigated in 1978/1979 using standard penetration test (SPT) and cone penetration test (CPT) equipment; however the CPT measurements are obsolete because of the now nonstandard cone that was used at the time. In 2007 a modern cone was mobilized to retest 18 select sites that are particularly valuable because they experienced intense ground shaking, have high fines content, and are classified as nonliquefaction sites. Of the sites reinvestigated and carefully processed, 13 …

Using Conditional Inference Forests To Identify The Factors Affecting Crash Severity On Arterial Corridors, Abhishek Das, Mohamed Abdel-Aty, Anurag Pande

Civil and Environmental Engineering

Introduction

The study aims at identifying traffic/highway design/driver-vehicle information significantly related with fatal/severe crashes on urban arterials for different crash types. Since the data used in this study are observational (i.e., collected outside the purview of a designed experiment), an information discovery approach is adopted for this study.

Method

Random Forests, which are ensembles of individual trees grown by CART (Classification and Regression Tree) algorithm, are applied in numerous applications for this purpose. Specifically, conditional inference forests have been implemented. In each tree of the conditional inference forest, splits are based on how good the association is. Chi-square test statistics …

Safety Evaluation Of Multilane Arterials In Florida, Mohamed Abdel-Aty, Prem Chand Devarasetty, Anurag Pande

Civil and Environmental Engineering

Resurfacing is one of the more common construction activities on highways. While its effect on riding quality on any type of roadway is obviously positive; its impact on safety as measured in terms of crashes is far from obvious. This study examines the safety effects of the resurfacing projects on multilane arterials with partially limited access. Empirical Bayes method, which is one of the most accepted approaches for conducting before–after evaluations, has been used to assess the safety effects of the resurfacing projects. Safety effects are estimated not only in terms of all crashes but also rear-end as well as …

Video Technology For Interuniversity Collaboration In A Geotechnical Engineering Laboratory, James Hanson

Civil and Environmental Engineering

Advanced video technology was used to incorporate multi-component (inter-university and university-industry) collaborations in geotechnical engineering laboratory courses. The project was conducted between California Polytechnic State University (California), Auburn University (Alabama), and Nippon Koei Co., Ltd. (Japan). Synchronous video conferencing and asynchronous video communications were used between the partners. The conferencing activities included guest lectures and exchange of assignments. New assignments developed in the study included role-playing whereby one class acted as a client on a project that was ordering geotechnical testing to be completed by the students at the other university acting as a consulting firm. New assignments also included …

Multi-Objective Design Of Transient Network Models, Bong Seog Jung, Misgana K. Muleta, Paul F. Boulos

Civil and Environmental Engineering

The optimal design of a water distribution system under transient conditions is formulated as a two-objective optimization problem. The objectives are minimization of the total pipe costs and maximization of the hydraulic reliability for the transient network design model. Unlike most optimization models in which demands are set to their end-of-life levels, this approach assumes that the demand loadings vary throughout the design life of the system. Evolutionary algorithms are applied to support efficient search for Pareto optimal solutions to the dual-objective optimization problem. An example application is presented and relevant conclusions are stated.

Linear Analysis Of Ordinary Bridges Crossing Fault-Rupture Zones, Rakesh K. Goel, Anil K. Chopra

Civil and Environmental Engineering

Rooted in structural dynamics theory, two approximate procedures for estimating peak responses of linearly elastic “ordinary” bridges crossing fault-rupture zones are presented: response spectrum analysis (RSA) procedure and a linear static analysis procedure. These procedures estimate the peak response by superposing peak values of quasi-static and dynamic responses. The peak quasi-static response in both procedures is computed by static analysis of the bridge with peak values of all support displacements applied simultaneously. In RSA, the peak dynamic response is estimated by dynamic analysis including all significant modes, which is simplified in the latter procedure to static analysis of the bridge …

Nonlinear Analysis Of Ordinary Bridges Crossing Fault-Rupture Zones, Rakesh K. Goel, Anil K. Chopra

Civil and Environmental Engineering

Rooted in structural dynamics theory, three approximate procedures for estimating seismic demands for bridges crossing fault-rupture zones and deforming into their inelastic range are presented: modal pushover analysis (MPA), linear dynamic analysis, and linear static analysis. These procedures estimate the total seismic demand by superposing peak values of quasi-static and dynamic parts. The peak quasi-static demand in all three procedures is computed by nonlinear static analysis of the bridge subjected to peak values of all support displacements applied simultaneously. In the MPA and the linear dynamic analysis procedures, the peak dynamic demand is estimated by nonlinear static (or pushover) analysis …

Housing Market Outlook: San Luis Obispo, Ca And Surrounding Area, Gabe Randall, Scott D. Kelting

Construction Management

Starting between 1999 and 2000, national home prices began a period of unprecedented growth, increasing at a pace more than 8 times their annual average until peaking in early 2006. National home prices appreciated over 100% on average during the 6 year period before declining 27% from 2006 through Q4 2008. Markets across the sunbelt, namely Florida, Southern California, and Arizona saw prices appreciate as much as 180 % from 2000 to their peak in 2006; these areas have also declined the fastest and hardest, falling as much as 50% and boasting the highest foreclosure rates in the country.

Case Study In Implementing A Service-Learning Class In A Construction Management Curriculum, Philip L. Barlow

Construction Management

Service-learning is a pedagogical approach which gives the students an opportunity to develop professional and social skills in concert with learning and reflecting on curricular material. This is achieved through a student’s active participation in a meaningful community service project, open and interactive reflection, formal class lectures, and discussions. This case study discusses the results of implementing a pilot service-learning undergraduate class in a state university construction management program. The course was offered as a two-credit hour voluntary technical elective in the Spring quarter of 2008. The organization of this study first puts service-learning into context by giving a brief …

Uncertainty Propagation In Geotechnical Earthquake Engineering, Robb E.S. Moss

Civil and Environmental Engineering

This paper describes recent advances in evaluating, quantifying, and propagating various forms of uncertainty in geotechnical earthquake engineering problems. Important developments in the fields of liquefaction engineering, dynamic slope stability, engineering seismology, and lifeline engineering are discussed. The benefits gained through proper treatment of uncertainty include; a well defined measure of the most likely engineering results, a well defined estimate of extreme results, a probability of likelihood ascribed to different realizations, and a mathematical format that lends to performance-based engineering assessment. This paper is by no means comprehensive but highlights some recent studies that contribute to improved probabilistic methodology in …

Relationship Of Two-Fluid Model Parameters With Safety On Arterials, Vinayak V. Dixit, Anurag Pande, Mohamed A. Abdel-Aty, Essam Radwan, Abhishek Das

Civil and Environmental Engineering

The two-fluid model for vehicular traffic flow explains the traffic on arterials as a mix of stopped and running vehicles. It describes the relationship between the vehicles’ running speed and the fraction of running vehicles. Two parameters of the model essentially represent ‘free flow’ travel time and level of interaction among vehicles, respectively, and may be used to evaluate urban roadway networks and urban corridors with partially limited access. These parameters are supposed to be related not only with the characteristics of the roadway but also with behavioral aspects of driver population, e.g., aggressiveness. In this study two-fluid models were …

Two Simplified Dynamic Lane Merging System (Sdlms) For Short Term Work Zones, Rami Harb, Essam Radwan, Shankar Ramasamy, Mohamed Abdel-Aty, Anurag Pande, Khaled Shaaban, Sastry Putcha

Civil and Environmental Engineering

ITS-based lane management technologies were introduced to work zones in an attempt to reduce congestions and diminish queue lengths. Two forms of lane merging namely the early merge and the late merge were designed to advise drivers on definite merging locations. This study suggests two Simplified Dynamic Lane Merging Systems (SDLMS) (early merge and late merge) to supplement the current Florida maintenance of traffic (MOT) plans. Data was collected in work zones on I-95, Florida for three different maintenance of traffic plan treatments. The first maintenance of traffic plan treatment was the standard MOT plan employed by FDOT. The second …

Market Basket Analysis Of Crash Data From Large Jurisdictions And Its Potential As A Decision Support Tool, Anurag Pande, Mohamed Abdel-Aty

Civil and Environmental Engineering

Data mining applications are becoming increasingly popular for many applications across a set of very divergent fields. Analysis of crash data is no exception. There are many data mining methodologies that have been applied to crash data in the recent past. However, one particular application conspicuously missing from the traffic safety literature until recently is association analysis or market basket analysis. The methodology is used by retailers all over the world to determine which items are purchased together. In this study, crashes are analyzed as supermarket transactions to detect interdependence among crash characteristics. The results from the analysis include simple …