Digital Commons Network^™

Investigation Of Rapid Remote Sensing Techniques For Forensic Wind Analyses, Yijun Liao, Richard L. Wood, Mohammad Ebrahim Mohammadi, Peter J. Hughes, J. Arn Womble

Department of Civil and Environmental Engineering: Faculty Publications

Perishable damage data resulting from severe windstorms require efficient and rapid field collection techniques. Such datasets permit forensic damage investigations and characterization of civil infrastructure. Ultimately, observed structural damage serves as a proxy approach to estimate wind speeds for storms that include hurricanes, tornadoes, straight-line winds, etc. One of the more common methods to collect, preserve, and reconstruct three-dimensional damage scenes is the use of an unmanned aerial system (UAS), commonly known as a drone. Onboard photographic payloads permit scene reconstruction via structure-from-motion; however, such approaches often require direct site access and survey points for accurate results, which limit its …

Behavior Of Cold-Formed Steel Metal Industrial Buildings, Adrianna M. Early, Mohammad Ebrahim Mohammadi, Richard L. Wood, Kara D. Peterma

Department of Civil and Environmental Engineering: Faculty Publications

This paper presents research focused on understanding the observed behavior of cold-formed steel (CFS) metal buildings during Hurricane Harvey, which made landfall Friday, August 25, 2017 between Port Aransas and Port O’Connor, Texas. Through the Geotechnical Extreme Event Reconnaissance (GEER) association (funded by the National Science Foundation) a team of structural engineers and researchers performed rapid and detailed assessments of structural damage caused by the hurricane. The National Science Foundation gathered photographs, damage assessments sheets, and three-dimensional laser point cloud data of severely damaged cold-formed steel industrial buildings. The Port Aransas County Airport experienced severe damage to several cold-formed steel …

Post-Earthquake Structural Damage Assessment Through Point Cloud Data, Mohammad Ebrahim Mohammadi, Richard L. Wood

Department of Civil and Environmental Engineering: Faculty Publications

Structural damage assessment following an extreme event can provide valuable information and insight into unanticipated damage and failure modes to improve design philosophies and design codes as well as reduce vulnerability. Oftentimes, structural engineers create finite element models (FEM) of the structure in which numerous model parameters require calibration to simulate the current state. This information may include structural plan details (geometry), material characteristics (strength and stiffness parameters), as well as observed damage patterns (cracks, spalling, etc.). Ground-based lidar (GBL) scans and Structure-from-Motion (SfM) can rapidly capture dimensionally accurate point clouds of the structure or facility of interest. Furthermore, point …

Damage Assessment Of Built-Up Areas Via Uas-Sfm Derived Point Cloud Data, Mohammad Ebrahim Mohammadi, Richard L. Wood

Department of Civil and Environmental Engineering: Faculty Publications

In the aftermath of extreme events (e.g., earthquakes, tsunami, tornados, etc.), rapid and reliable identification of the damage in a built-up area are crucial in to rescue, recovery, and reconstruction operations. While it is critical to conduct efficient emergency response management, lack of classified or tagged damaged regions due to communications and accessibility limitations can further delay recovery operations, rescue efforts, and resource management. Furthermore, critical and perishable damage scenes can also be lost during recovery and cleanup operations immediately following the event. In recent decades, advances in remote sensing technologies demonstrate a great potential to perform rapid reconnaissance and …

Land Suitability Analysis For Emergency Medical Services Posts Along State Highways: A Case Study Of California, Ernest Tufuor, Laurence Rilett, Yunwoo Nam, Antonio Hurtado Beltran

Department of Civil and Environmental Engineering: Faculty Publications

The response time of Emergency Medical Services (EMS) to road accidents can be the difference between life and death. The California strategic highway safety plan highlight the need to improve the response time and recognizes that: 37% and 8% of the fatal crashes are 30 or more miles away from a trauma center in rural and urban areas respectively.

The paper seeks to: (1) demonstrate the viability of using spatial multi-criteria analysis in road safety management, and (2) provide a good scientific justification in selecting optimal counties for EMS posts. The goal is to propose areas that are close to …

Analysis Of Low-Cost Bluetooth-Plus-Wifi Device For Travel Time Research, Ernest Tufuor, Laurence Rilett

Department of Civil and Environmental Engineering: Faculty Publications

MOTIVATION • Collecting real-time travel data via intelligent transportation systems (ITS) rely heavily on technologies that are expensive and challenging to maintain. • Bluetooth and Wi-Fi are the most popular low-cost communication protocols that can give a good understanding of spatial and temporal nature of travel.

USEFULNESS: This will be important for two main reasons: • Allow research to be conducted in a cost effective manner on all types of facilities. • Offers the opportunity to undertake comprehensive empirical studies on link and path travel time distributions especially for arterial roads

gBT COMPONENTS AND COST • A unit of the …

Development Of A Test Level 3 Transition Between Guardrail And Portable Concrete Barriers, Robert W. Bielenberg, David Gutierrez, Ronald K. Faller, John D. Reid, Phil Tenhulzen

Department of Civil and Environmental Engineering: Faculty Publications

Road construction often requires that work zones be created and shielded by portable concrete barriers (PCBs) to protect workers and equipment from errant vehicles as well as to prevent motorists from striking other roadside hazards. For an existing W-beam guardrail system installed adjacent to the roadway and near the work zone, guardrail sections are removed so a PCB system can be placed. A study was done to develop a crashworthy transition between W-beam guardrail and PCB systems. Design concepts were developed and refined through computer simulation with LS-DYNA. Additionally, a study of critical impact points was conducted to determine impact …

Field-Scale Testing And Numerical Investigation Of Soil-Boulder Interaction Under Vehicular Impact Using Fem And Coupled Fem-Sph Formulations, Lynsey Reese, Tong Qiu, Daniel Linzell, Zoltan Rado

Department of Civil and Environmental Engineering: Faculty Publications

A computational approach that couples the Finite Element Method and the Smoothed Particle Hydrodynamics method may be advantageous for simulating the response of complex, physical systems involving large deformations. However, comparisons of this modeling technique against field-scale test data are remarkably sparse in literature. This study presents three field-scale tests involving vehicular impact into three landscape vehicular anti-ram barriers. Each barrier consisted of a single boulder embedded in compacted American Association of State Highway and Transportation Officials soil and physical testing resulted in one of the following outcomes: minimal boulder/soil movement (Test 1), moderate boulder/soil movement (Test 2), and severe …

Expedient Airfield Runway Repair Using Folded Fiberglass Mat, Christopher Y. Tuan, Willaim C. Dass

Department of Civil and Environmental Engineering: Faculty Publications

For expedient airfield runway repair, the US Air Force has developed a folded fiberglass mat to cover craters repaired with a well-compacted granular base material. The objective of this study was to evaluate the adequacy of using polymer plugs to anchor the mat to a repaired asphalt pavement for heavy aircraft operations. The effort consisted of materials testing, field experiments and analytical modeling. An 89,800-kg (198,000-pound) load cart having the footprint of a single C-5 main gear was pulled on a mat with wheels locked to simulate full braking forces. Anchor bushings were instrumented to measure anchor loads. A simplified …

Dynamic Characteristics And Seismic Response Analysis Of A Long-Span Steel-Box Basket-Handle Railway Arch Bridge, Xuhui He, Biao Wei, Yunfeng Zou, Dongyang Hu, Daniel G. Linzell

Department of Civil and Environmental Engineering: Faculty Publications

The inside oblique angle between the vertical plane and the arch rib has been shown to be one of the main factors influencing dynamic properties of long-span steel-box basket-handle arch bridges. Details related to the extent, that the inside oblique angle influenced the dynamic characteristics and the seismic response of the arch bridge under the combined longitudinal and vertical seismic excitation and under the combined lateral and vertical seismic excitation, were reported herein. Four oblique angles (0°, 3°, 4.8°, and 6°) were selected based on the arch ribs height and bridge deck width. Findings suggested that a larger inside oblique …

Lidar Scanning With Supplementary Uav Captured Images For Structural Inspections, Richard L. Wood, Mohammad Ebrahim Mohammadi

Department of Civil and Environmental Engineering: Faculty Publications

Structural assessment using remote sensing technologies can be performed efficiently and effectively using such technologies as LiDAR (light detection and ranging). LiDAR can be employed for various structural assessments, such as as-built conditions for a newly constructed facility, routine inspection during its service life, or structural collapse evaluation after a natural hazard or extreme event. However, the main disadvantage of LiDAR is that it is a line-of-sight technology that can result in significant occlusions. Architectural or structural components can be partially or fully occluded by another object with respect to the location of the laser scanner. Supplemental photogrammetry techniques, such …

Numerical Simulations Of Dynamic Behavior Of Polyurea Toughened Steel Plates Under Impact Loading, Chien-Chung Chen, Daniel G. Linzell

Department of Civil and Environmental Engineering: Faculty Publications

The objective of the work discussed herein is to develop a nonlinear 3D finite element model to simulate dynamic behavior of polyurea toughened steel plates under impact loading. Experimental and numerical work related to model development are presented. Material properties are incorporated into numerical models to account for strain-rate effects on the dynamic behavior of polyurea and steel. One bare steel plate and four polyurea toughened steel plates were tested under impact loading using a pendulum impact device. Displacement time-history data from experimental work was used to validate the numerical models. Details on material model construction, finite element model development, …

Assessment Of Load Sharing Members In An Anti-Ram Bollard System, Scott Kinney, Daniel Linzell, Edward O'Hare

Department of Civil and Environmental Engineering: Faculty Publications

Due to the increased frequency, scale, and danger of malicious attacks carried out by Vehicle Borne Improvised Explosive Devices (VBIEDs), anti-ram bollards have become a key element in the protection of critical structures. This study focused on the evaluation of above grade load sharing members in a steel anti-ram bollard system in an attempt to develop efficient load sharing mechanisms that improve the structure’s ability to resist vehicle impacts, while concurrently remaining aesthetically pleasing to the general public. A computational assessment was completed using calibrated LS-DYNA finite element models to determine if effective load sharing member configurations and designs could …

Field Tests And Numerical Modeling Of Vehicle Impacts On A Boulder Embedded In Compacted Fill, Lynsey Reese, Tong Qiu, Daniel Linzell, Edward O'Hare, Zoltan Rado

Department of Civil and Environmental Engineering: Faculty Publications

Landscape Vehicular Anti-Ram (LVAR) systems are a group of protective barriers, which are designed using natural materials (e.g., boulders) and have proven to both effectively protect sensitive structures against threats and be aesthetically pleasing. This paper presents two consecutive vehicular crash tests hitting the same single boulder embedded in AASHTO coarse aggregate fill. A LS-DYNA model was developed to simulate the field-scale tests, which were instrumented with high-speed cameras and pressure cells. A readily available truck model from the National Crash Analysis Center was modified and implemented in the LS-DYNA model. The boulder and surrounding soil were modeled using the …

A Simple Method For Estimation Of Queue Length, S. P. Anusha, Lelitha Devi Vanajakshi, Anuj Sharma

Department of Civil and Environmental Engineering: Faculty Publications

Urban arterials are characterized by frequent intersections. Queue length and delay are the two primary measures of performance of intersection. These measures play a primary role in determining the arterial performance. This article presents a methodology to determine the number of vehicles in queue at a signalized intersection for under saturated traffic conditions. The results obtained were validated using actual values that are manually extracted. The root-mean-square error is of the range 1.3 vehicles for estimation of number of vehicles in queue. The various aspects that have to be considered in accurate estimation of performance measures are also discussed.

Studying Platoon Dispersion Characteristics Under Heterogeneous Traffic In India, Jijo Mathew, Helen Thomas, Anuj Sharma, Lelitha Devi, Laurence Rilett

Department of Civil and Environmental Engineering: Faculty Publications

Platoons are created by signalized intersections which control travel patterns of vehicles. It is common for platoons to disperse during normal traffic operations. While platoon dispersion has been studied extensively under homogenous and lane disciplined traffic conditions, this characteristic under heterogeneous conditions has not been addressed adequately. This study will be one of the first steps in this direction and will lead to better understanding and simulation of platoon dispersion under Indian conditions.

Data describing platoon dispersion was collected with video recording systems along an arterial in Chennai, India. The Robertson’s model parameters calibrated for this data was found to …

Impact Of Signal Timing Information On Safety And Efficiency Of Signalized Intersections, Anuj Sharma, Lelitha Vanajakshi, V. Girish, M. S. Harshitha

Department of Civil and Environmental Engineering: Faculty Publications

Signalized intersections are provided in traffic networks to improve the safety and efficiency of vehicular and pedestrian movement. There are various measures under education, enforcement and engineering headings that are being attempted to improve safety and efficiency of operations at a signalized intersection. Provision of signal countdown timer, a timer showing the remaining red and green time in a phase, is one such measure and is commonly adopted in India. However, studies on effects of countdown timer under Indian traffic conditions are very scarce. Traffic heterogeneity and lack of lane discipline makes transferability of models developed in other countries (with …

Optimal Advance Detector Location For Green Termination Systems On High-Speed Isolated Rural Intersections, Lili Du, Anuj Sharma, Srinivas Peeta

Department of Civil and Environmental Engineering: Faculty Publications

This study seeks to identify the optimal location of an advance point traffic detector (APTD) to support green termination algorithms for enhanced dilemma zone protection systems at high-speed isolated signalized rural intersections. This is done by developing a nonlinear optimization model with the objective to maximize the opportunities to predict empty dilemma zones during a look-ahead time period subject to the prediction accuracy which is manifested through prediction efficiency and safety constraints in the model. The distance of the APTD from the stop bar of the intersection represents the decision variable. The Golden-Section line search algorithm combined with numerical integration …

Head Ejection During Barrier Impacts, Scott K. Rosenbaugh, Ronald K. Faller, Dean L. Sicking

Department of Civil and Environmental Engineering: Faculty Publications

During oblique vehicular impacts with longitudinal barriers, an occupant’s head is often ejected out of a side window. When this occurs, the occupant’s head can contact the barrier or an object attached thereto. This impact event, often termed head slap, normally produces a serious injury or fatality. Roadside barriers and any attached hardware should be designed with sufficient offset at the top to preclude head slap for most impact conditions. The goal of this study was to identify the extent of head ejection that can be expected during high-speed crashes with longitudinal barriers. High-speed videos of full-scale vehicle crash tests …

Drop Weight Testing On Sandwich Panels With A Novel Thermoplastic Core Material, Christopher Y. Tuan

Department of Civil and Environmental Engineering: Faculty Publications

A series of drop weight tests were conducted to evaluate the dynamic flatwise compression strength and flexural strength of sandwich panels with a novel core structure. This sandwich core material, known as Norcore, consists of interconnected cells in a unique configuration of truncated pyramid with sloping cell walls. Core materials made of thermoplastic including virgin Lexan, polycarbonate, polycarbonate regrind, high-impact polystyrene, and acrylonitrile butadiene styrene were tested. The test results showed that these sandwich panels have good strength as well as energy absorption capacities.

Evaluation Of Ice-Melting Capacities Of Deicing Chemicals, B. M. Gerbino-Bevins, Christopher Y. Tuan, M. Mattison

Department of Civil and Environmental Engineering: Faculty Publications

Common deicing chemicals include sodium chloride, magnesium chloride, calcium chloride, calcium magnesium acetate, potassium acetate, potassium formate, and corn or beet-based deicer solution. Liquid deicers are commonly used for pre-wetting road salt, sand or other solid deicers, or mixed with salt brine as liquid deicer. Although manufacturers provide performance data under specific conditions, a standardized test is very much needed. Samples of sodium chloride, magnesium chloride, calcium chloride, potassium acetate, and beet juice-based chemical deicers were selected for performance evaluation. The SHRP Ice-Melting Capacity Test has been used in many research projects, but the results do not always correlate well …

Evaluating The Cost-Effectiveness Of Roadside Culvert Treatments, Francisco Daniel B. De Albuquerque, Dean L. Sicking, Ronald K. Faller, Karla A. Lechtenberg

Department of Civil and Environmental Engineering: Faculty Publications

Roadside cross-drainage culverts have been found to affect vehicle accident injury levels. As a result, highway designers have commonly used three safety treatments to protect errant motorists from striking culvert openings. These safety treatments have included: culvert extension, guardrail installation, and the application of safety grating. However, the identification of the most appropriate safety treatment for roadside culverts may be challenging; accident costs may dramatically change under different road and traffic characteristics. The purpose of this study was to estimate accident costs for a wide range of road and traffic scenarios and then define the safest treatment (i.e., treatment with …

An Enzymatic Treatment Of Soil-Bound Prions Effectively Inhibits Replication, Samuel Saunders, Jason C. Bartz, Kurt C. Vercauteren, Shannon L. Bartelt-Hunt

Department of Civil and Environmental Engineering: Faculty Publications

Chronic wasting disease (CWD) and scrapie can be transmitted through indirect environmental routes, possibly via soil, and a practical decontamination strategy for prion-contaminated soil is currently unavailable. In the laboratory, an enzymatic treatment under environmentally relevant conditions (22°C, pH 7.4) can degrade soil-bound PrPSc below the limits of Western blot detection. We developed and used a quantitative serial protein misfolding cyclic amplification (PMCA) protocol to characterize the amplification efficiency of treated soil samples relative to controls of known infectious titer. Our results suggest large (104- to >106-fold) decreases in soil-bound prion infectivity following enzyme treatment, demonstrating that a mild enzymatic …

Impact Of Signal Timing Information On Safety And Efficiency Of Signalized Intersections, Anuj Sharma

Department of Civil and Environmental Engineering: Faculty Publications

Signalized intersections are provided in traffic networks to improve the safety and efficiency of vehicular and pedestrian movement. There are various measures under education, enforcement and engineering headings that are being attempted to improve safety and efficiency of operations at a signalized intersection. Provision of signal countdown timer, a timer showing the remaining red and green time in a phase, is one such measure and is commonly adopted in India. However, studies on effects of countdown timer under Indian traffic conditions are very scarce. Traffic heterogeneity and lack of lane discipline makes transferability of models developed in other countries (with …

Role Of Information On Probability Of Traffic Conflict On The Onset Of Yellow, Nathaniel P. Burnett, Anuj Sharma

Department of Civil and Environmental Engineering: Faculty Publications

This paper examines the effect of information provided to drivers through advance warning flashers (AWFs) on driver’s probability of conflict at the onset of yellow at a high-speed intersection. AWFs are specifically designed to minimize the number of vehicles trapped in their respective dilemma zones at the onset of yellow. A probit modeling technique was used to establish dilemma zone boundaries. Based on the dilemma zone boundaries probability of a perceived conflict curves was computed and compared against actual conflicts observed at each of the studied intersections. The comparison between the actual and theoretical probability of conflict curves generated a …

Role Of Information On Probability Of Traffic Conflict On The Onset Of Yellow, Nathaniel P. Burnett, Anuj Sharma

Department of Civil and Environmental Engineering: Faculty Publications

This paper examines the effect of information provided to drivers through advance warning flashers (AWFs) on driver’s probability of conflict at the onset of yellow at a high-speed intersection. AWFs are specifically designed to minimize the number of vehicles trapped in their respective dilemma zones at the onset of yellow. A probit modeling technique was used to establish dilemma zone boundaries. Based on the dilemma zone boundaries probability of a perceived conflict curves was computed and compared against actual conflicts observed at each of the studied intersections. The comparison between the actual and theoretical probability of conflict curves generated a …

Improving Safety And Mobility At High-Speed Intersections With Innovations In Sensor Technology, Anuj Sharma, Darcy M. Bullock, Senem Velipasalar, Mauricio Casares, Jacob Schmitz, Nathaniel P. Burnett

Department of Civil and Environmental Engineering: Faculty Publications

A series of innovations has been made in the vehicle sensors field. Technologies such as IntelliDrive and radar-based smart sensors make it pos­sible to track each vehicle in proximity to an intersection. However, current technologies have limitations, such as lack of robustness, accuracy, or level of penetration. This paper assumes an accurate wide-area detector (WAD), which might be soon available, and highlights the potential benefits that might be derived in safety and efficiency of oper­ations at high-speed intersections from the deployment of the WAD. Two critical areas in which wide-area detection can lead to significant improvements are discussed: (a) location …

Changes In The Structure And Function Of Microbial Communities In Drinking Water Treatment Bioreactors Upon Addition Of Phosphorus, Xu Li, Giridhar Upadhyaya, Wangki Yuen, Jess Brown, Eberhard Morgenroth, Lutgarde Raskin

Department of Civil and Environmental Engineering: Faculty Publications

Phosphorus was added as a nutrient to bench-scale and pilot-scale biologically active carbon (BAC) reactors operated for perchlorate and nitrate removal from contaminated groundwater. The two bioreactors responded similarly to phosphorus addition in terms of microbial community function (i.e., reactor performance), while drastically different responses in microbial community structure were detected. Improvement in reactor performance with respect to perchlorate and nitrate removal started within a few days after phosphorus addition for both reactors. Microbial community structures were evaluated using molecular techniques targeting 16S rRNA genes. Clone library results showed that the relative abundance of perchlorate-reducing bacteria (PRB) Dechloromonas and Azospira …

Effects Of The Antimicrobial Tylosin On The Microbial Community Structure Of An Anaerobic Sequencing Batch Reactor, Toshio Shimada, Xu Li, Julie L. Zilles, Eberhard Morgenroth, Lutgarde Raskin

Department of Civil and Environmental Engineering: Faculty Publications

The effects of the antimicrobial tylosin on a methanogenic microbial community were studied in a glucosefed laboratory-scale anaerobic sequencing batch reactor (ASBR) exposed to stepwise increases of tylosin (0, 1.67, and 167 mg/L). The microbial community structure was determined using quantitative fluorescence in situ hybridization (FISH) and phylogenetic analyses of bacterial 16S ribosomal RNA (rRNA) gene clone libraries of biomass samples. During the periods without tylosin addition and with an influent tylosin concentration of 1.67 mg/L, 16S rRNA gene sequences related to Syntrophobacter were detected and the relative abundance of Methanosaeta species was high. During the highest tylosin dose of …

Precast Post-Tensioned Segmental Pole System: U.S. Patent No. Us 6,851,231 B2, Maher K. Tadros, E. Terence Foster, Sherif A. Yehia, Audra L. Hansen

Department of Civil and Environmental Engineering: Faculty Publications

A precast post-tensioned segmental pole system capable of supporting a load is provided. The pole system includes a plurality of pole segments that use connectors and strands to anchor them together. The strands extend within a cavity formed in the pole segments and are external to the wall structure of the pole segments. The strands may be coupled between both of the pole segments, or be anchored to a connector. The connector includes an upper piece that is coupled to one pole segment, and a lower piece that is coupled to the other pole segment. Upper and lower pieces interlock …