Civil Engineering Commons^™

Contact Phenomenon Of Free-Rolling Wide-Base Tires: Effect Of Speed And Temperature, Jaime Hernandez, Imad L. Al-Qadi

Civil and Environmental Engineering Faculty Research and Publications

The finite-element method was used to quantify the effect of temperature and speed on contact area, deflection, and three-dimensional contact stresses of a free-rolling wide-base tire. The tire model comprised material properties identified in the laboratory and/or provided by the tire manufacturer (hyperviscoelastic rubber and linear elastic reinforcement) and accurate geometry. The model was validated using measured deflection and contact area. The analysis matrix consisted of 81 cases resulting from a combination of three loads, tire-inflation pressures, speeds, and temperatures. Four criteria were used to compare contact stresses: range, average, root-mean-square error, and coefficient of determination. Speed and temperature influence …

Feasibility Study Of Using Recyclable Polyethylene (Pet) Materials As Coarse Aggregate For Concrete Mixtures, Philip M. Angelo

Construction Management

The feasibility of using recyclable household plastics, specifically those made of polyethylene, commonly used in water and soda bottles, as a replacement for concrete coarse aggregate, was assessed. A method was developed for cutting polyethylene materials into fibrous strips. These strips were then used as a replacement for the rock coarse aggregate in batches of concrete. Standard 6” x 12” test cylinders were made using the concrete mixture and subject to destructive compressive testing in order to yield the compressive strength of the concrete mix 7, 14, 21, and 28 days after pouring. Three mixtures were tested, one control with …

Bs News November/December

Building Services Engineering

No abstract provided.

Safety Effectiveness Of Pedestrian Crossing Enhancements, Christopher M. Monsere, Miguel Figliozzi, Sirisha Kothuri, Ali Razmpa, Daniel R. Hazel

Civil and Environmental Engineering Faculty Publications and Presentations

Over the last decade, the Oregon DOT and other agencies have systematically implemented many pedestrian crossing enhancements (PCEs) across the state. This study explored the safety performance of these enhanced crossing in Oregon. Detailed data were collected on 191 crossings. Supplemental data items included crossing location information, route characteristics, surrounding land use and crossing enhancement descriptions. Pedestrian volume at the crossing locations was a highly desirable but unavailable data element. To characterize pedestrian activity, a method was developed to estimate ranges for pedestrian crosswalk activity levels based on the land use classification at the census block level and the presence …

Maintenance And Improvement Of The Florida Public Hurricane Loss Model, Nicholas Wayne Miller

Theses and Dissertations

The Florida Public Hurricane Loss Model (FPHLM) predicts insurance losses due to hurricane events. This thesis describes maintenance tasks of the vulnerability component of the FPHLM. First, it explores the applicability of recent experimental research to the FPHLM opening protection, water intrusion, and roof pressure modeling features of the Personal Residential (PR) and Commercial Residential Low-Rise (CR-LR.) models. These changes were not implemented because either more experimental data is needed or they had no impact on the losses. Next, it discusses an additional update to the CR-LR model that changed the soffit area calculations, sampling bounds within the rain model, …

Building Exposure Study In The State Of Florida And Application To The Florida Public Hurricane Loss Model, Joshua Michalski

Theses and Dissertations

Modeling hurricane events with models such as the Florida Public Hurricane Loss Model (FPHLM) is essential for insurance and reinsurance companies to estimate projected losses. Additionally, the models can be used by public officials to estimate and mitigate damages while also developing public safety policies to reduce the amount of damage and loss of life during a catastrophic event. The FPHLM combines hurricane event simulation and building vulnerability models to predict insurance portfolios losses. Before vulnerability functions are applied to insurance portfolios to determine total losses, these functions are weighted based upon building characteristics statistics representative of a given building …

A Business Intelligence Framework For Network-Level Traffic Safety Analyses, Naveen Kumar Veeramisti

UNLV Theses, Dissertations, Professional Papers, and Capstones

Currently, there are both methodological and practical barriers that together preclude a substantial use of theoretically sound approaches, such as the ones recommended by the Highway Safety Manual (HSM), for traffic safety management. Although the state-of-the-art provides theoretically sound approaches such as the Empirical Bayes method, there are still various important capabilities missing. Methodological barriers include among others (i) lack of a theoretically sound approach for corridor-level network screening, (ii) lack of a comprehensive approach for estimation of Safety Performance Functions based on a simultaneous consideration of both crash patterns and associated explanatory variables, and (iii) lack of theoretically sound …

Evaluating The Effects Of Major Assumptions In Layered Elastic Theory On Railroad Track Response Prediction Through The Development Of An Improved Track Analysis Software, Sadichchha Sharma

Boise State University Theses and Dissertations

Railway transportation has been recently gaining popularity due to its efficiency and environmental-friendly technology which has led to its increased usage for both passenger and freight transport. For railway transport to be a sustainable component of the transportation infrastructure in the United States, adequate structural and functional design of track components is essential. This is primarily dependent on thorough understanding of track mechanics and track structural response under loading, and can be accomplished through mechanistic analysis of railway track structure response under loading. Considering the need for a mechanistic track analysis program that can serve as a link between the …

Alkali-Activated Natural Pozzolan/Slag Binder For Sustainable Concrete, Meysam Najimi

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study aimed to fully replace Portland cement (PC) with environmentally friendly binders capable of improving longevity of concrete. The new binders consisted of different proportions of natural Pozzolan and slag which were alkaline-activated with various combinations of sodium hydroxide and sodium silicate. A step-by-step research program was designed to (1) develop alkali-activated natural Pozzolan/slag pastes with adequate fresh and strength properties, (2) produce alkali-activated natural Pozzolan/slag mortars to assess the effects of dominant variables on their plastic and hardened properties, and (3) finally produce and assess fresh, mechanical, dimensional, transport and durability properties of alkali-activated natural Pozzolan/slag concretes. The …

An Assessment Of Post-Encroachment Times For Bicycle-Vehicle Interactions Observed In The Field, A Driving Simulator, And In Traffic Simulation Models, Ali Razmpa

Dissertations and Theses

Most safety analysis is conducted using crash data. Surrogate safety measures, such as various time-based measures of time-to-collision can be related to crash potential and used to gain insight into the frequency and severity of crashes at a specific location. One of the most common and acknowledged measures is post-encroachment time (PET) which defines the time between vehicles occupying a conflicting space. While commonly used in studies of motor vehicle interactions, studies of PET for bicycle-vehicle interactions are few. In this research, the PET of bicycle-vehicle interactions measured in the field, a driving simulator, and in a micro-simulation are compared. …

Experimental Investigation Of Cfrp Wrapped Square Non-Ductile Reinforced Concrete Columns, Hayder Lateef Al-Khafaji

Dissertations and Theses

The use of fiber-reinforced polymers (FRP) for retrofitting or strengthening deficient concrete columns noticeably increased in the past few decades. Plenty of research has been conducted on the behavior of FRP-strengthened circular concrete columns, but far less research has dealt with non-circular columns. In the current study, the focus was to investigate the behavior of square columns with low to medium grade concrete and low steel reinforcement that were strengthened using carbon fiber reinforced polymer (CFRP) wrap. In the experimental portion of this investigation, twelve short square reinforced concrete columns (5" x 5" in cross section and 12" high) were …

Advancements In Thermal Integrity Profiling Data Analysis, Kevin Russell Johnson

USF Tampa Graduate Theses and Dissertations

Thermal Integrity Profiling (TIP) is a relatively new non-destructive test method for evaluating the post-construction quality of drilled shafts. Therein anomalies in a shaft are indicated by variations in its thermal profile when measured during the curing stages of the concrete. A considerable benefit with this method is in the ability to detect anomalies both inside and outside the reinforcement cage, as well as provide a measure of lateral cage alignment. Similarly remarkable, early developments showed that the shape of a temperature profile (with depth) matched closely with the shape of the shaft, thus allowing for a straightforward interpretation of …

Investigation Of Self-Organizing Traffic Signal Control With Graphical Signal Performance Measures, Christopher M. Day, Darcy M. Bullock

Lyles School of Civil Engineering Faculty Publications

Adaptive signal control is the subject of an increasing amount of research, as well as development and implementation. Most existing adaptive control systems achieve coordination by applying system control as a constraining layer on top of local control. Some researchers have suggested that, with the right local-control logic, coordination might be achieved as an dynamically emergent phenomenon without the need for a management layer. This paper explores the potential of a self-organizing signal control algorithm using a variety of performance measures. First, the initially reported algorithm performance is reproduced in an idealized environment; next, the algorithm is applied in a …

Characteristics And Products Of The Reductive Degradation Of 3-Nitro-1,2,4-Triazol-5-One (Nto) And 2,4-Dinitroanisole (Dnan) In A Fe-Cu Bimetal System, Elsie Kitcher, Washington Braida, Agamemnon Koutsospyros, Julius Pavlov, Tsang-Liang Su

Civil Engineering Faculty Publications

It has been shown previously that, under acidic conditions, 3-nitro-1,2,4-triazol-5-one (NTO) and 2,4-dinitroanisole (DNAN) degrade in the presence of iron/copper bimetal particles; the reactions can be modeled by pseudo-first-order kinetics. This study investigates the reaction mechanisms of the degradation processes under different conditions. Batch studies were conducted using laboratory-prepared solutions and an industrial insensitive munition-laden (IMX) wastewater. The influence of parameters such as initial pH of the solution, copper/iron (Fe-Cu) contact, and solid/liquid ratio were systematically investigated to assess their impact on the reaction kinetics. These parameters were subsequently incorporated into pseudo-first-order decomposition models for NTO and DNAN. The activation …

Scalable Dashboard For Identifying Split Failures And Heuristic For Reallocating Split Times, Howell Li, Lucy Richardson, Christopher M. Day, James Howard, Darcy M. Bullock

Lyles School of Civil Engineering Faculty Publications

The three fundamental parameters of a traffic signal system are split, cycle, and offset. This paper describes the use of high-resolution data (a) to identify time periods during which split parameters may be insufficient and (b) to help practitioners identify opportunities for reallocating split time. A case study of seven corridors with 47 intersections is presented. A drill-down approach was developed to identify movements that could be improved by a reallocation of split times. A heuristic that can reallocate up to 5 seconds of underutilized green time on a competing phase was applied to those corridors. …

Detector-Free Optimization Of Traffic Signal Offsets With Connected Vehicle Data, Cristopher Day, Howell Li, Lucy Richardson, James Howard, Tom Platte, Jim Sturdevant, Darcy M. Bullock

Lyles School of Civil Engineering Faculty Publications

It has recently been shown that signal offset optimization is feasible using vehicle trajectory data at low levels of market penetration. This study performs offset optimization on two corridors using this type ofdata. Six weeks oftrajectory splines were processed for two corridors including 25 signalized intersections, in order to create vehicle arrival profiles, using a proposed procedure called "virtual detection." After processing and filtering the data, penetration rates between 0.09-0.80% were observed, varying by approach. The arrival profiles were statistically compared against those measured with physical detectors, with the majority of the approaches showing statistically significant goodness-of-fit at a 90% …

Effective Post-Tensioned Splicing System For Prestressed Concrete Piles, Zhongxin Wu

USF Tampa Graduate Theses and Dissertations

Precast prestressed concrete piles are widely used in deep foundation construction. Due to unexpected site soil conditions and difficulties associated with transportation and handling long precast piles, splicing is sometimes necessary at the construction site.

Available splicing methods utilize steel type connections that are more suitable for reinforced concrete construction and result in limited tensile capacity at the splice. This dissertation describes studies associated with the development of a new post-tensioned splicing system using staggered, embedded anchorages. The new system has the potential to provide the same tensile capacity as a one piece prestressed pile.

To develop the post-tensioned splicing …

Simulation Of Value Stream Mapping And Discrete Optimization Of Energy Consumption In Modular Construction, Md Mukul Chowdhury

Theses and Dissertations

With the increased practice of modularization and prefabrication, the construction industry gained the benefits of quality management, improved completion time, reduced site disruption and vehicular traffic, and improved overall safety and security. Whereas industrialized construction methods, such as modular and manufactured buildings, have evolved over decades, core techniques used in prefabrication plants vary only slightly from those employed in traditional site-built construction. With a focus on energy and cost efficient modular construction, this research presents the development of a simulation, measurement and optimization system for energy consumption in the manufacturing process of modular construction. The system is based on Lean …

Understanding The Behavior Of Embankment Dams Under Blast Loading, Courtney L. Busch

Civil Engineering ETDs

This purpose of this study is to investigate the deformation-induced stability of earthen embankment dams to explosive airblast loading. This study specifically investigated the effects of close-in explosive airblast loads on the downstream toe of a homogeneous earthen embankment dam composed of cohesive soils. Small-scale explosive airblast experiments were performed on cohesive soils to obtain an experimental data set with which to compare numerical analyses. Experimental measurements included crater geometry, ground vibration energy, and air overpressure from the blast events. Laboratory tests were conducted on the experiment soils to obtain engineering properties including shear strength and compressibility indices. Finite element …

Pyrolysis Of Wastewater Biosolids Significantly Reduces Estrogenicity, T. C. Hoffman, Daniel Zitomer, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

Most wastewater treatment processes are not specifically designed to remove micropollutants. Many micropollutants are hydrophobic so they remain in the biosolids and are discharged to the environment through land-application of biosolids. Micropollutants encompass a broad range of organic chemicals, including estrogenic compounds (natural and synthetic) that reside in the environment, a.k.a. environmental estrogens. Public concern over land application of biosolids stemming from the occurrence of micropollutants hampers the value of biosolids which are important to wastewater treatment plants as a valuable by-product. This research evaluated pyrolysis, the partial decomposition of organic material in an oxygen-deprived system under high temperatures, as …