Civil Engineering Commons^™

Modeling The Effect Of Moisture On Resilient Modulus Of Untreated Reclaimed Asphalt Pavement, Mohamed Attia, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The use of reclaimed asphalt pavement (RAP) as a base layer is increasing as quality aggregate becomes scarcer and more expensive. Moisture content is known to have a great impact on the resilient modulus (M_R) of granular materials, and several researchers have devoted effort to develop and verify analytical models to describe that impact. Limited work has been done to quantify the effect of moisture content on RAP as a base layer. It has not been determined whether the existence of aged binder will allow designers to use the same analytical models developed for granular materials. This study …

Influence Of Shear Key Performance On The Fatigue Life Of Adjacent Beam Bridges, Sara Roberts

All Theses

Adjacent beam bridges, such as box beams and hollow core bridges have been one of the most popular forms of precast prestressed bridges in the past. Recently, an awareness of major durability problems has led owners to make improvements to the old standards or move away from the system completely. These issues usually stem from the breakdown of the shear key which provides continuity between adjacent members. This research focuses on determining the best improvements that will reduce durability issues and increase the bridge's service life.
A review of previous research performed on adjacent beam bridges is performed, focusing on …

The Effects Of Behavioral, Geometric And Heavy Vehicle Traffic Flow Characteristics On Capacity And Emissions At Roundabouts, Cho Honest Sone

Civil Engineering Theses - Archive

Modern roundabouts, first constructed in England in the early 1960s, are becoming increasingly popular replacements for signalized and stop controlled intersections in the United States. Roundabouts were introduced to replace traditional traffic circles and rotaries. With the characteristics of entering traffic that yield to circulating traffic and geometric constraints that slow entering vehicles, roundabouts have proven to be more efficient than traffic circles and in some cases than signalized and stop-controlled intersections. Roundabouts often require drivers to decelerate from, and reaccelerate to, highway speeds, and can involve one or multiple stops. One concern about congested roundabouts is that vehicle emissions …

Testing & Design Life Modeling Of Polyurea Liners For Potable Water Pipes, Mustafa Z. Kanchwala

Civil Engineering Theses - Archive

Currently, there are various renewal methods available for different applications, among which coatings and linings are most commonly used for the renewal of water pipes. Polyurea is a lining material applied to the interior surface of the deteriorated host pipe using spray technique. It is applied to enhance the structural ability of the pipeline. This thesis presents the preliminary results of an ongoing laboratory testing program designed to investigate the renewal of potable water pipes using polyurea spray lining. This research focuses on predicting the long-term behavior of polyurea composite. The goal of this test was to establish a relationship …

Experimental Studies On Shrinkage Induced Pressure Measurements Of Four Expansive Soils, Varagorn Puljan

Civil Engineering Theses - Archive

Civil structures were damaged by expansive soils due to its large volumetric changes caused by moisture fluctuations. During wet and dry season, the ground heaves up and also shrinks noticeably. The significant amount of curling pressure which is induced by soil shrinkage could cause severe damages to the infrastructure. Especially in the eastern and central Texas, pavements encounter severe cracking and premature loss of serviceability. The maintenance costs, in some cases, are greater than the initial construction costs. Residential dwell structures built on problematic expansive soils often become distressed due to volume changes associated with seasonal moisture content variations. This …

Comprehensive Studies On Deep Soil Mixing And Lightweight Aggregates Applications To Mitigate Approach Slab Settlements, Ekarut Archeewa

Civil Engineering Dissertations - Archive

Bridge approach settlement is a common problem to the Transportation Departments nationwide. This uneven transition causes inconvenience to passengers and increases the cost of maintenance and repair of the distressed approach slabs. The Texas Department of Transportation spends millions of dollars annually to mitigate this problem across the state. The potential causes for this problem are numerous and purely site specific. Hence this problem may not have a unique solution. In this research, two methods were selected to mitigate the approach slab settlements. The first one is an improvement of ground foundation technique by using Deep Soil Mixing (DSM) columns …

Development Of An Accident Model For Construction Industry, Hoda Alavi

Civil Engineering Theses - Archive

Safety has always been a persistent problem in the construction industry. Construction accidents are a major concern for the construction industry and the researchers. In spite of the role of many construction accident causation models in understanding the accident process, none adequately explain the underlying reasons for construction accidents because of their dynamic nature.To overcome this restriction a new advancement in understanding construction accidents has been proposed by Howell et al (2002) based on the work of Rasmussen (1997). The model recognizes that organizational and individual forces push workers in to hazardous conditions. These forces overcome efforts to impose safe …

Characteristics Of Fresh Municipal Solid Waste, Tashfeena Taufiq

Civil Engineering Theses - Archive

The characteristics of fresh municipal solid waste (MSW) are critical in planning, designing, operating or upgrading solid waste management systems. Physical composition, moisture content, compacted unit weight, permeability are the most important MSW characteristics to be considered in planning a system. When the landfill is operated as enhanced leachate recirculation (ELR) landfill, the physical and hydraulic characteristics are of particular interest in determining the amount of moisture to be recirculated and to design the leachate recirculation and gas collection systems. The current study presents the physical and hydraulic characteristics of MSW collected from the working face of Denton Landfill. The …

Development Of A Suction-Controlled Resonant Column Apparatus With Self-Contained Bender Elements, Eduardo Alfonso Suescun-Florez

Civil Engineering Theses - Archive

Small-strain soil stiffness properties such as shear modulus, shear wave velocity, and material damping, are key subsoil parameters for an adequate analysis and design of unsaturated earth structures subject to static and non-static loading. Most conventional geotechnical testing techniques, however, are not able to capture this small-strain behavior and, hence, enormously underestimate the true soil stiffness, primarily due to inaccuracies in small-strain measurements. Around the world, a great deal of research efforts has been dedicated to field and laboratory based measurements of soil suction, assessments of soil-water retention properties, and analyses of swell-collapse behavior. However, very few efforts have been …

Development Of A Preliminary Cost Estimation Method For Water Treatment Plants, Jwala Raj Sharma

Civil Engineering Theses - Archive

Reliable cost estimates for construction, and operation and maintenance (O&M) of water treatment plants are essential for their project planning and design. During the planning phases of the project, preliminary cost estimates are developed for major project components, and for screening of alternatives.Construction and O&M cost curves are widely used for developing preliminary cost estimates. This method is time consuming and there is possibility of human errors. Therefore, for this thesis, construction, and O&M cost equations were developed considering historical cost data for different unit operations and processes involved in a water treatment plant. These equations were developed from historical …

Modeling Studies To Assess Long Term Settlement Of Light Weight Aggregate Embankment, Seema Kalla

Civil Engineering Theses - Archive

Expanded clay and shale (ECS) is a low weight material derived from clay and shale, and has been used in large quantities throughout the world. Very few studies have been performed to investigate the behavior of ECS and how it can reduce the settlements of embankments when used as a fill material. This thesis presents research findings of numerical modeling to assess the long term settlements of ECS embankment on a soft clay deposit and supports both pavement and traffic loading. Observed settlements near the pavement of a light weight ECS embankment built on soft clay indicated that this material …

Field Investigations On Performance Of Short Drilled Shafts Under Inclined Loading, Richard S. Williammee Jr

Civil Engineering Theses - Archive

In the Kaufman County area within the Texas Department of Transportation's Dallas District, several short drilled shaft foundations supporting three-cable median barrier systems wereobserved to be distressed during severe winter storm conditions in late 2006 through early 2007. A research study was initiated at UT Arlington to determine and understand the mechanisms causing these shaft failures. The ends of the three-cable median barrier systems are fastened to a single drilled shaft foundation. In general, these shafts are short in depth and of the same dimensions, diameter, and depth. They are typically used in all soil conditions. This paper presents the …

Effect Of Frame Shape And Geometry On The Global Behavior Of Rigid And Hybrid Frame Under Earthquake Excitations, S.M. Ashfaqul Hoq

Civil Engineering Theses - Archive

The primary focus of this study is to present a shape which will improve building performance in earthquake excitations. The investigation started with 3-, 9-, 12- and 20-story rectangular frame. The seismic performance is observed for different earthquake data with different frequency content. Then, the Rhombus shape is introduced to compare with the Rectangular shape frames, keeping the height-to-width ratio and loading same. For the first part of the investigation, deflection and member forces are compared between rhombus and rectangular shape considering all connections rigid. In the second part of the study partially restrained connections are introduced in mid levels …

Investigation Of The Lower Bound Compressive And Flexural Strengths Of Conventional Concrete And Clay Masonry, Benchmark Henry Harris

Civil Engineering Theses - Archive

Conventional masonry is a handcrafted product in which units are placed by hand in a mortar bedding that is prepared during construction. TMS 402 Building Code Requirements for Masonry Structures (also referred to by the industry as the Masonry Standards Joint Committee or MSJC) and referenced standards consequently permit a range of various field conditions so as to allow practical construction (1). The primary objective of the testing program was to measure a statistically significant number of test results to investigate the lower bound compressive and flexural strengths of conventional concrete and clay masonry under simulated field conditions.96 compression tests …

Effect Of Leachate Recirculation On Methane Generation Of A Bioreactor Landfill, Shahed R. Manzur

Civil Engineering Theses - Archive

Municipal solid waste (MSW) disposal is of current concern due to the green-house effect and rising temperature all around the globe. Landfill gas is generated from aerobic & anaerobic biodegradation of organic materials in municipal solid waste (MSW) landfill. Along with leachate, generation of Methane happens to be a by-product of the entire biodegradation process in MSW landfills. Conventional landfilling or dry cell concept minimizes the amount of moisture infiltration into the waste. In contrast, Enhanced Leachate Recirculation (ELR) or bioreactor operation facilitates leachate recirculation and distribution through the landfill that leads both reduction of time for waste stabilization and …

Impact Of Hurricanes On Structures - A Performance Based Engineering View, Vijay Mishra

Electronic Theses and Dissertations

The magnitude of damage caused to the United States (US) coast due to hurricanes has increased significantly in the last decade. During the period 2004-2005, the US experienced seven of the costliest hurricanes in the country's history (NWS TPC-5, 2007) leading to an estimated loss of ~ $158 billion. The present method for predicting hurricane losses, HAZUS (HAZard US), is solely based on hurricane hazard and damage caused to building envelopes only and not to structural systems (Vickery et al., 2006). This method does not take into account an intermediate step that allows for better damage estimates, which is structural …

On The Use Of Polyurethane Matrix Carbon Fiber Composites For Strengthening Concrete Structures, Zachary Haber

Electronic Theses and Dissertations

Fiber-reinforced polymer (FRP) composite materials have effectively been used in numerous reinforced concrete civil infrastructure strengthening projects. Although a significant body of knowledge has been established for epoxy matrix carbon FRPs and epoxy adhesives, there is still a need to investigate other matrices and adhesive types. One such matrix/adhesive type yet to be heavily researched for infrastructure application is polyurethane. This thesis investigates use of polyurethane matrix carbon fiber composites for strengthening reinforced concrete civil infrastructure. Investigations on mirco- and macro-mechanical composite performance, strengthened member flexural performance, and bond durability under environmental conditioning will be presented. Results indicate that polyurethane …

Condition Assessment Of Bill Emerson Memorial Cable-Stayed Bridge Under Postulated Design Earthquake, Dongming Yan, Wenjian Wang, Genda Chen, Bryan A. Hartnagel

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this study, a three-dimensional finite element model of the Bill Emerson Memorial cable-stayed bridge was developed and validated with the acceleration data recorded during the M4.1 earthquake of May 1, 2005, in Manila, Arkansas. The model took into account the geometric nonlinear properties associated with cable sagging and soil-foundation-structure interaction. The validated model was used to evaluate the performance of a seismic protective system, the behavior of cable-stayed spans, and the accuracy of two simplified bridge models that have been extensively used by the structural control community. The calculated natural frequencies and mode shapes correlated well with the measured …

Characteristic Dynamic Increment For Extreme Traffic Loading Events On Short And Medium Span Highway Bridges, Eugene J. Obrien, Daniel Cantero, Bernard Enright, Arturo González

Articles

More accurate assessment of safety can prevent unnecessary repair or replacement of existing bridges which in turn can result in great cost savings at network level. The allowance for dynamics is a significant component of traffic loading in many bridges and is often unnecessarily conservative. Critical traffic loading scenarios are considered in this paper with a model that allows for vehicle-bridge interaction and takes into account the road surface condition. Characteristic dynamic allowance values are presented for the assessment of mid-span bending moment in a wide range of short to medium span bridges for bi-directional traffic.

Estimating Dilemma Zone Hazard Function At High Speed Isolated Intersection, Anuj Sharma, Darcy Bullock, Srinivas Peeta

Anuj Sharma Publications

The traditional surrogate measures of safety (like number of vehicles in dilemma zone) fail to quantify the risk of crash. Traffic conflict has been proposed as an improved surrogate measure of safety for operations at isolated intersections to quantify the risk. This paper develops a dilemma zone hazard function estimating procedure to obtain the probability of traffic conflict occurring. This approach is an extension of the current approach of dilemma zone boundaries to determine the risk of traffic conflict for an individual vehicle in the case of a dilemma zone incursion. Field data collected from the intersection of SR37 and …

Theory Of Breakup Of Core Fluids Surrounded By A Wetting Annulus In Sinusoidally Constricted Capillary Channels, Igor A. Beresnev, Wen Deng

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Analysis of core-annular dynamics in the presence of base flow for arbitrary fluid viscosities leads to an equation describing the temporal evolution of the fluid/fluid interface. The equation follows from the conservation of mass in the "small-slope" approximation. Its useful applications occur, for example, in chemical engineering and petroleum recovery. The nonlinear equation allows inexpensive numerical analysis. For sinusoidally constricted pores, a purely geometric criterion exists that enables or prohibits the core-fluid breakup in the necks of the constrictions. The geometrically favoring condition sets up capillary-pressure gradients that ensure a continuous outflow of the core fluid from the necks into …

Integration Of Mechanistic-Empirical Pavement Design Guide Distresses With Local Performance Indices, Scott Schram, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The pavement management system (PMS) is the organizational entity within a state highway agency responsible for the condition of the pavement network. Visual distress surveys are typically combined into an index to provide an overall measure of performance. Decision makers use these familiar indices in a number of facets. A recent survey suggests every state highway agency has implemented or plans to implement the Mechanistic-Empirical Pavement Design Guide (MEPDG). As they do so, maintaining the role these local indices play is critical for upholding the system's continuity. However, using the MEPDG output directly in calculating performance indices becomes problematic because …

Integrated, Multi-Attribute Decision Support System For The Evaluation Of Underground Utility Construction Methods, John C. Matthews

Doctoral Dissertations

The dissertation research work described herein is comprised of three primary objectives: (1) the development of a rehabilitation method selection software (TAG-R) for the National Association of Sewer Service Companies (NASSCO) and its subsequent validation and combination with TAG (a sister decision support system (DSS) software developed by the author in an earlier work); (2) the development of a social cost calculator (SCC) and its validation; and (3) the development of a proposed framework for multi-segment optimization for construction methods selection using the tools developed in the first two objectives as well as additional project related data.

The selection of …

Pseudo-Probabilistic User Equilibrium Assignment In Travel Corridor Networks Containing Managed Facilities, Alireza Khaleghi-Soroush

Civil Engineering Dissertations - Archive

Throughout the years, transportation organizations and agencies have been unable to keep up with increasing demand for roadway facilities. Similarly, traditional public-sector funding such as motor fuel taxes is falling short in meeting the growing demand for new transportation infrastructure. With deficit financing and congestion problems common to many highways throughout the United States, DOTs are turning to tolling the roadway facilities as a means of financing transportation improvements for inter-urban and urban facilities.In turn, in order for managed facilities such as toll roads or managed lanes to be attractive and viable for the potential investors, the facilities must be …

Tapping Environmental History To Recreate America’S Colonial Hydrology, Christopher L. Pastore, Mark B. Green, Daniel J. Bain, Andrea Muñoz-Hernandez, Charles J. Vörösmarty, Jennifer Arrigo, Sara Brandt, Jonathan M. Duncan, Francesca Greco, Hyojin Kim, Sanjiv Kumar, Michael Lally, Anthony J. Parolari, Brian Pellerin, Nira Salant, Adam Schlosser, Kate Zalzal

Civil and Environmental Engineering Faculty Research and Publications

To properly remediate, improve, or predict how hydrological systems behave, it is vital to establish their histories. However, modern-style records, assembled from instrumental data and remote sensing platforms, hardly exist back more than a few decades. As centuries of data is preferable given multidecadal fluxes of both meteorology/climatology and demographics, building such a history requires resources traditionally considered only useful in the social sciences and humanities. In this Feature, Pastore et al. discuss how they have undertaken the synthesis of historical records and modern techniques to understand the hydrology of the Northeastern U.S. from Colonial times to modern day. Such …

Variability In Resilient Modulus Of Reclaimed Asphalt Pavement As Base Layer And Its Impact On Flexible Pavement Performance, Mohamed Attia, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The use of reclaimed asphalt pavement (RAP) as a base layer is gaining popularity, but there are gaps in the literature about its material performance. One problem not well investigated is the variability in the resilient modulus (M_R) of RAP as a base layer, as compared with typical granular material, and the impact of this variability on pavement performance. Selection of one M_R value has its own variability, beyond the expected variability in the base layer _R that results from the use of aggregates with different qualities. This paper investigates the effect of three sources of variability …

Bridge Lessons Learned From The Wenchuan China, Earthquake, W. Phillip Yen, Genda Chen, Mark Yashinski, Youssef M. A. Hashash, Curtis J. Holub, Kehai Wang, Xiaodong Guo

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A strong earthquake of M7.9 occurred in Wenchuan County in Sichuan Province, China, on May 12, 2008. This paper presents the field observations on various types of bridge damages, including unseating of girders, longitudinal and transverse offset of decks, pounding at expansion joints, shear key failure, bearing displacement, column shear, and flexible cracks. Plausible causes of damages and collapses are discussed and the lessons learned from this event are briefly summarized. Some of the postearthquake temporary constructions are also reported.

Importance Of The Tail In Truck Weight Modeling For Bridge Assessment, Eugene J. Obrien, Bernard Enright, Abraham Getachew

Articles

To predict characteristic extreme traffic load effects, simulations are sometimes performed of bridge loading events. To generalize the truck weight data, statistical distributions are fitted to histograms of weight measurements. This paper is based on extensive WIM measurements from two European sites and shows the sensitivity of the characteristic traffic load effects to the fitting process. A semi-parametric fitting procedure is proposed: direct use of the measured histogram where there are sufficient data for this to be reliable and parametric fitting to a statistical distribution in the tail region where there are less data. Calculated characteristic load effects are shown …

A Tool To Improve And Preserve Flexible Pavement At Intersections, Carlos Jesus Solis

Open Access Theses & Dissertations

Rural intersections originally constructed with thin untreated flexible base and hot mix or a two-course surface treatment tend to experience severe pushing, shoving and rutting. These failures cause an extremely rough surface that can cause damage to small vehicles and potentially cause motorists to lose control of their vehicles. These distresses almost always result in complete failure of the existing pavement that must be repaired several times during the life of the roadway by maintenance forces. In most cases, pavements constructed with the same materials and cross-sections adjacent to the intersection perform adequately.

The sources of and solutions for failure …

A New Congested Traffic Load Model For Highway Bridges, Colin C. Caprani, Colm Carey, Bernard Enright

Conference papers

Long span highway bridges are critical components of any nation’s infrastructure. Therefore accurate assessment of highway bridge loading is essential, and it is well known that congested traffic governs load effect for such bridges. Current congestion models use conservative assumptions about traffic and inter-vehicle gaps. This research investigates congested traffic flow through the use of traffic microsimulation which has the ability to reproduce complex traffic phenomena based on driver interactions. A time series model has been developed to produce a speed time-series similar to the results of the microsimulation. The speed time-series from the new model, combined with the established …