Civil and Environmental Engineering Commons^™

Micropile Response To Combined Loading, Kyle Allen Kershaw

Doctoral Dissertations

"The familiarity and acceptance of micropiles by engineers, contractors, and owners has greatly expanded in recent years such that they are routinely considered on many projects. However, research regarding the behavior of micropiles has lagged behind. The goal of this research project was to address some of the fundamental gaps that were not addressed in engineering practice and require further study and testing. Specifically, this research studied the behavior of micropile foundations subjected to simultaneous axial and lateral (combined) loading, including an assessment of the impact of axial load on lateral behavior of micropiles. This research project consisted of three …

Hilbert Transform Applications In Signal Analysis And Non-Parametric Identification Of Linear And Nonlinear Systems, Zuocai Wang

Doctoral Dissertations

"Hilbert Huang Transform faces several challenges in dealing with closely-spaced frequency components, short-time and weak disturbances, and interrelationships between two time-varying modes of nonlinear vibration due to its mixed mode problem associated with empirical mode decomposition (EMD). To address these challenges, analytical mode decomposition (AMD) based on Hilbert Transform is proposed and developed for an adaptive data analysis of both stationary and non-stationary responses. With a suite of predetermined bisecting frequencies, AMD can analytically extract the individual components of a structural response between any two bisecting frequencies and function like an adaptive bandpass filter that can deal with frequency-modulated responses …

Postcyclic Behavior Of Low-Plasticity Silt, Shuying Wang

Doctoral Dissertations

"Liquefaction of low-plasticity silt has been reported during earthquakes in the recent past. Excess pore pressure builds up due to the dynamic loading and then dissipates. The postcyclic behavior of low-plasticity silt was investigated in this research for materials obtained from the Mississippi River Valley. The experimental program involved specimen preparation using a slurry consolidation approach. A special technique was developed for specimen movement, reducing the testing program time by half. Both static and cyclic triaxial tests were conducted to confirm the ability to prepare replica specimens. In order to characterize the monotonic behavior, triaxial tests were conducted to determine …

Estimation Of Pedestrian Safety At Intersections Using Simulation And Surrogate Safety Measures, Nithin K. Agarwal

University of Kentucky Doctoral Dissertations

With the number of vehicles increasing in the system every day, many statewide policies across the United States aim to increase the use of non- motorized transportation modes. This could have safety implications because the interaction between motorists and non-motorists could increase and potentially increasing pedestrian-vehicle crashes. Few models that predict the number of pedestrian crashes are not sensitive to site-specific conditions or intersection designs that may influence pedestrian crashes. Moreover, traditional statistical modeling techniques rely extensively on the sparsely available pedestrian crash database.

This study focused on overcoming these limitations by developing models that quantify potential interactions between pedestrians …

Evaluation And Recommendation Of Mix Design For Emulsion Stabilized Bases, Samuel Franco

Open Access Theses & Dissertations

Asphalt emulsion has been used for base material stabilization in a few TxDOT districts. Results from these practices were quite different. The initial performance of two projects on US287 constructed around 2000 in the Amarillo District has been found to be satisfactory. However, the Yoakum District has reported problems with asphalt emulsion for base work in a project on FM 237. The preliminary conclusion from these trials has been that asphalt emulsion may not perform well in the high humidity/high rainfall areas like east Texas. On the other hand, using calcium-based additives to stabilize base courses in road construction has …

Determination Of Critical Parameters For Solar Probe Plus Shielding, Sergio Rafael Mendez

Open Access Theses & Dissertations

A methodology to determine critical design parameters such as critical "design" particle size, and critical "design" impact speed for the shielding of the Solar Probe Plus spacecraft was developed in this thesis. Several critical components and surfaces of the spacecraft such as the Solar Array North, the Thermal Protection System, and the ISIS Instruments were analyzed in this study. The methodology determines the critical "design" particle size based on the required reliability or probability of no impact. Current NASA methods do not provide means to calculate critical "design" impact speeds for missions such as Solar Probe Plus, where the distributions …

Strategies To Improve And Preserve Flexible Pavements At Intersections, Imad N. Abdallah

Open Access Theses & Dissertations

Many rural intersections originally constructed with thin untreated flexible base and hot mix or a two-course surface treatment 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 vehicle. 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. Pavement sections constructed with the same materials adjacent to the intersection perform adequately until the approach (approximately 150 ft in advance) of the intersection and …

Evaluation Of Nondestructive Technologies To Assess Presence And Extent Of Delamination Of Hot Mix Asphalt Airfield Pavements, Manuel Celaya

Open Access Theses & Dissertations

Sufficient bonding between the hot mix asphalt layers is essential to ensure the desired structural capacity of a pavement. Delamination or debonding problems are particularly more severe on airfield pavements, due to higher traffic loads applied by aircrafts. Further progression of delamination may result in stripping of the lower layers due to the intrusion of moisture or may develop other dangerous distresses such as foreign object debris. The existing nondestructive testing procedures and equipment that have the potential to address the problem were identified and their effectiveness and potential for success were evaluated. The Ground Penetrating Radar, Falling Weight Deflectometer, …

Adaptation Of Low Impact Design To The Desert Southwest, Abubaker Ali Alamailes

Open Access Theses & Dissertations

A low Impact Development (LID) practices were used to design an Integrated Management Practices (IMP) system for a residential lot .The design was adapted to the Desert Southwest region based on twenty years of climate data including precipitation and temperature for three representative cities: El Paso, TX, Albuquerque, NM, and Phoenix, AZ. In order to capture stormwater runoff close to its source and to provide as much stored water as possible for plants, LID practices including bioretention cells and vegetated swales were applied throughout the lawn. The purpose of the design is to maintain the pre-development hydrologic characteristics of the …

Development Of A New Mix Design Method And Specification Requirements For Asphalt Treated Bases, Hector Antonio Hernandez

Open Access Theses & Dissertations

Asphalt stabilized bases in Texas are usually designed and constructed as per Item 292, "Asphalt Treatment (Plant Mixed)," of the 2004 Standard Specification book. This specification is a hybrid of base and hot mix asphalt concrete procedures and requirements, which are sometimes incompatible. In addition, this Item uses a specific Texas Gyratory compactor that is not readily available to all districts. Some districts have started using test method Tex-204-F, Part III, `Mix Design for Large Stone Mixtures Using the Superpave Gyratory Compactor." However, this procedure was originally developed to design Type A and Type B hot mix at 96% density …

Improved Joining Method For Segmental Prestressed Structures, Ralph Warren Jensen

Open Access Theses & Dissertations

This dissertation addresses the need for more robust and materially efficient structures, specifically structures that absorb higher levels of energy, can self-erect and which have variable reaction capabilities. These structures can take much higher levels of strain and loading compared to current technologies in reinforced concrete and carbon fiber composites. These structures are made using a novel method of joining segmental elements. A great advantage with this segmental structural system is it's survivability under overloaded conditions. During an impact, or concentrated pressure load, the structure will wrap around the impact zone thereby widely distributing the contact stresses. This function or …

Impact Of Truck Suspension And Road Roughness On Loads Exerted To Pavements, Shahram Misaghi Bonabi

Open Access Theses & Dissertations

A software package, called IntPave, an Integrated Pavement Damage Analyzer, was developed at the Center of Transportation Infrastructure Systems at The University of Texas at El Paso with the capacity to calculate the pavement distress for flexible pavements under any type of traffic load, and to make a comparison of the level of distress caused by a standard and a non-standard, assuming statically exerted loading. However, what has been lacking is a tool to measure the dynamic impact on the pavement due to vehicle-road interaction. In this report, the interaction of truck suspension systems with the roughness of the road …

Methodology To Convert A Transportation Planning Origin-Destination Matrix Into A Microscopic Traffic Simulation Origin-Destination Matrix, Jose Osiris Vidana-Bencomo

Open Access Theses & Dissertations

Microscopic traffic simulation (MTS) is a cost-effective approach for the evaluation of traffic conditions in urban highways networks. In MTS models, traffic demand that is entered into the network is specified by one or several Origin-Destination (O-D) matrices. A major challenge in the application of MTS for large urban networks is the specification of the O-D matrices. This dissertation proposes a methodology that may be used to transform a O-D matrix from a transportation planning model (which is based on Traffic Analysis Zone, or TAZ, and is readily available) into a O-D matrix for a MTS model (which is traffic …

Study Of Probabilistic Approach For Structural Health Assessment Of Aerospace Structures, Jose Antonio Garcia

Open Access Theses & Dissertations

Current practical approaches used in structural health assessment programs of aerospace structures involve performing a fracture mechanics analysis to verify the safe life of structural components. The analysis typically makes several conservative assumptions implemented by NASA fracture control standard practices for critical structural components. This well-established paradigm for fracture control follows a deterministic approach and, in some cases, the calculations may produce overly conservative remaining life estimates.

This thesis describes the results of a study to approach the health assessment challenge of several critical components using probabilistic methods. The probabilistic analysis takes the current deterministic model and identifies variables that …

Evaluation Methods For Health Monitoring Of Aerospace Structure Rotary Joints, Sergio Armando Navarro

Open Access Theses & Dissertations

In September 2007, the excessive vibrations played a significant role in the station operation since one of the rotary joints, which provides the station electrical energy, presented an anomaly. The replacement of its bearing components and re-lubrication were necessary to reduce the problem. To avoid a new anomaly, the inspection of the rotary joints performance continues by using the accelerometers data. This thesis presents three new approaches to monitor the vibrations at the International Space Station based on Root-Mean-Square, kurtosis, and Approximate Entropy (ApEn). MATLAB functions and codes were necessary to implement the three monitoring techniques results from the provided …

Modeling Extreme Traffic Loading On Bridges Using Kernel Density Estimators, Cathal Leahy, Eugene J. Obrien, Bernard Enright

Conference papers

Kernel density estimators are a non-parametric method of estimating the probability density function of sample data. In this paper, the method is applied to find characteristic maximum daily truck weights on highway bridges. The results are then compared with the conventional approach

Monitoring And Improving The Effectiveness Of Quality Control And Quality Assurance In Road Construction At Al-Ain Municipality, Mohammed Muftah Sultan Al Aryani

Theses

A good roads network has an important bearing on the economic growth of the country. Construction of quality roads, which is considered a primary objective of any highway agencies and contractors, requires concerted efforts on many fronts. Over the past several years, agencies have been working with the construction industry to implement Quality Assurance/Quality Control activities (QA/QC) in an effort to improve the quality of highway construction. They are used as a mean to describe the materials, workmanship, and other general requirements for the project that the highway agencies expect from the contractors. Good specifications should be easy to understand …

Universal Design Of Transportation Systems: A Case Study Of Access And Mobility Of People With Disabilities At Selected Intersections In Dar Es Salaam, Nurdin Mushule

Tanzania Journal of Engineering and Technology (TJET)

The pedestrian facilities at intersections must be usable by pedestrians of all ages and capabilities. Intersections in particular must be designed to safely accommodate pedestrians of all ages and physical and mental abilities. Often, however, intersection designs fail to accommodate people with visual and mobility disabilities. In this regard, for pedestrians with disabilities, intersections can prove to be a challenge. Some of those challenges include provision of insufficient pedestrian clearance time due to use of inappropriate design pedestrian speed. Most importantly, the required facilities to enable People With Disabilities (PWD) to use the intersection without hindrance may be missing. Obstacles …

Comparison Of Safety Performance By Design Types At Freeway Diverge Areas And Exit Ramp Sections, Hongyun Chen

USF Tampa Graduate Theses and Dissertations

The primary objective of the study is to evaluate the safety performance of different freeway exit types used in current practical designs. More specific, the research objectives include the following two parts: 1) to compare the safety performance of different design types at freeway diverge areas and exit ramp sections; and 2) to identify the impact factors contributing to the crashes happening at these two specific segments.

The study area includes four subjects, the freeway widely-spaced diverge areas; the freeway closely-spaced diverge areas; the left-side off-ramps and the exit ramp sections. For the freeway diverge areas, design types were defined …

Effects Of Warm-Mix Asphalt Additives On Asphalt Mixture Characteristics And Pavement Performance, Jun Zhang

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

The primary objective of this research is to evaluate the feasibility of several WMA mixtures as potential asphalt paving mixtures for Nebraska pavements. To that end, three well-known WMA additives (i.e., Sasobit, Evotherm, and Advera synthetic zeolite) were evaluated. For a more realistic evaluation of the WMA approaches, trial pavement sections of the WMA mixtures and their HMA counterparts were implemented in Antelope County, Nebraska. More than one ton of field-mixed loose mixtures were collected at the time of paving and were transported to the NDOR and UNL laboratories to conduct comprehensive laboratory evaluations and pavement performance predictions of the …

Soil Behavior Under Blast Loading, Jichong An

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Understanding the behavior of soil under blast loading is very important to engineers in mining, tunneling, and military construction. Due to the very complex structure of a soil mass it is very difficult to describe its constitutive relation, especially when it has different water contents and it is under blast loading conditions. New protective system designs subjected to blast loading need to be proved its validation prior to predict effect of explosive before implementation. Full-scale, buried explosive tests are costly. Finite element simulations play a significant role in the design of protective systems, for example a bottom platform of lightweight …

A Generalized Non-Parametric Approach For Uncertainty Evaluation In Travel Time Prediction Models, Bhaven Naik

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

A core component within Advanced Traveler Information Systems is travel time information because it is easily understood and perceived by travelers. However, the suggested travel time information should be based not only on historical and real-time conditions, but also on forecasted or “unknown” future conditions.

Existing research has focused primarily on developing models that forecast point estimates of the mean travel time that are in close comparison to their respective field values. There has been limited research on any insight into the reliability or uncertainty margin that exists around the forecasted point estimate. As well, these researches have a limitation …

Embedded Radio Frequency Identification Device License Plates For Roadside Use In Nebraska, Dwight L. Mosby Jr.

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

The transportation industry has many stakeholders with different needs that work with advanced technologies. Radio Frequency Identification (RFID) is an emerging technology that is used to track inventory and it holds promise for the transportation industry. This research identifies how to evaluate transportation stakeholder requirements for RFID technologies using a tool described as the House of Quality (HOQ). This research investigates RFID’s ability to work in license plates and may provide infrastructure to support identifying RFID enabled commercial vehicles. This research considers variables that affect the performance of a RFID License Plate System that will use a scanner located at …

Closure To "Estimation Of The Water Balance Using Observed Soil Water In The Nebraska Sandhills", Venkataramana Sridhar, K. G. Hubbard

Civil Engineering Faculty Publications and Presentations

We are thankful to Szilagyi [2010] for providing us an opportunity to discuss the important points of our paper [Sridhar and Hubbard, 2010]. We demonstrated a seasonal water balance assessment using the Modified Thornthwaite-Mather (TM) model in the Nebraska Sandhills. We computed the water budget for a few representative weather monitoring stations located in the Sandhills using the high resolution soil moisture data to assess the storage. In our water balance analysis, soil moisture storage is determined based on observed soil moisture and actual evapotranspiration, ET_act was computed for each month using the change in storage in soil water …

Capacity Reduction And Fire Load Factors For Lrfd Of Steel Members Exposed To Fire, Shahid Iqbal, Ronald S. Harichandran

Civil Engineering Faculty Publications

A general reliability-based methodology is proposed for developing capacity reduction and fire load factors for design of steel members exposed to fire. The effect of active fire protection systems (e.g., sprinklers, smoke and heat detectors, fire brigade, etc.) in reducing the probability of occurrence of a severe fire is included. The design parameters that significantly affect the fire design of steel members are chosen as random variables. Raw experimental data published in the literature was analyzed to obtain the statistics of parameters for which no statistical information was available in the literature. Model errors associated with the thermal analysis models …

A Numerical And Experimental Study Of Differential Settling In Cohesive Sediment, Chad Heiliger

All Theses

Accurate sedimentation modeling has important applications in a number of fields. This includes modeling the accumulation of sediment in harbor channels and modeling the sedimentation and accumulation of particles in retention ponds in the still waters behind dams in order to calculate the trap efficiency. By accurately modeling sedimentation, engineering failures such as the 2008 TVA spill at the Kingston Fossil Plant could possibly be avoided. Three different numerical models comparing the settling rates of individual particles in quiescent waters were created to compare the change of settling velocity due to particle size distributions, change of local concentrations, and flocculation …

Identifying Barriers To Address During The Delivery Of Sustainable Building Renovation Projects, Corey Cattano

All Theses

Architects, engineers, and contractors are continuously searching for tools and methods to reduce the unique risks associated with the delivery of construction projects. Since national policies to reduce carbon emissions and energy consumption will require drastic improvements to the existing building stock, one specific area in need of such tools is the sustainable renovation of existing buildings. The purpose of this research is to identify the barriers to address during the delivery of sustainable renovation projects and offer solutions that overcome these barriers. For example, typical renovation projects do not coordinate energy retrofits with building system renovations, resulting in poor …

Assessment And Analysis Of Emotional Intelligence In Engineering Students, Xiaodan Zhou

All Theses

ABSTRACT
Current research on the importance and relevance of the relationship between emotional intelligence and work outcomes has continuously gained momentum since the publication of Daniel Goleman's best seller Emotional Intelligence: Why It Can Matter More Than IQ (Goleman, 1995). Professional expertise is no longer the only standard by which to evaluate graduates. 'Soft skills', like emotional intelligence are viewed as effective ways, to distinguish potential high-performance workers and those who will be 'no more than' a worker. This paper made an attempt to correlate emotional intelligence with academic performance of civil engineering students. The emotional capability of the students …

Correcting Liquefaction Resistance Of Partially Saturated Soil Using Compression Wave Velocity, Md Hossain

All Theses

Empirical relationships for correcting liquefaction resistance of partially saturated soil using longitudinal (P-) wave velocity (V_P) and shear (S-) wave velocity (V_S) are developed and evaluated in this thesis. The relationships are based on the laboratory test results for four different types of sands and one silt published by other investigators. The data used to develop the relationship with V_P exhibit less scatter than the data used to develop the relationship with V_P/V_S. For this reason, the V_P based relationship is recommended for correcting liquefaction resistance of partially saturated soil. …

Safety Enhancement Of The Indot Network Pavement Friction Testing Program: Macrotexture And Microtexture Testing Using Laser Sensors, Shuo Li, Samy Noureldin, Karen Zhu

JTRP Technical Reports

The Indiana Department of Transportation has conducted annual network inventory friction testing using the locked wheel trailer to reduce wet pavement crashes. However, issues have arisen concerning the data credibility and field operation safety on high-speed highway facilities. Some researchers have investigated the evaluation of pavement friction using macrotexture measurements and found the relationship between friction and macrotexture is extremely weak. Currently, macrotexture can be readily measured at highway speeds, but microtexture is evaluated using friction at low speeds from a surrogate device. Microtexture plays an important role in friction force. The evaluation of pavement friction from texture measurements will …