Civil Engineering Commons^™

Decision Support Tools For Bus Rapid Transit Corridor Planning, Luis David Galicia

Open Access Theses & Dissertations

Bus Rapid Transit (BRT) Systems have been gained popularity in the United States and worldwide as a cost-effective solution of mass transit. There are certain elements and characteristics that such a system should accomplish to be considered a BRT. However, a uniform definition, defined phases to be deployed, and a reliable methodology to estimate ridership are not well structured and clear yet. The purpose of this research was to help BRT stakeholders with an effective method to plan and assess BRT projects. The first goal of this research was to provide a comprehensive description of the essential characteristics of BRT …

Impact Of Moisture Content And Density On Stiffness-Based Acceptance Of Geomaterials, Lourdes Guadalupe Pacheco

Open Access Theses & Dissertations

Modulus-based quality management of compacted layers has been considered by a number of highway agencies. Even though simple in concept, the paradigm shift from density to modulus for quality acceptance has generated some technical and institutional challenges. One of these complications is that for a given density, the modulus can vastly vary depending on the moisture content at the time of compaction and at the time of acceptance. The results of a systematic study carried out to qualify and quantify the impact of compaction moisture content, moisture content at the time of field testing and density on the modulus and …

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 …

Probabilistic Analysis Of Concrete Fracture, Mustafa Abushaala Aldalinsi

Open Access Theses & Dissertations

It is well known to civil engineers that fatigue leads to the bulk of structural failures. In plain and reinforced concrete structures, fatigue might account for excessive deformation, excessive of crack widths, de-bonding of reinforcement and rupture of the reinforcement, all of these can lead to structural collapse. Fatigue crack propagation can be a method to predict a remaining life of a structures. Herein will show some works that have been done in order to analyze the fatigue crack growth for plain concrete specimen. The goals of this study are to estimate the critical crack length and remaining life of …

Effects Of Unbalanced Approach Volumes On Roundabout Operations, Marilyn Valdez

Open Access Theses & Dissertations

Modern roundabouts are increasingly popular in the United States due to their advantages in improving safety and reducing delay at intersections. A roundabout is an intersection in which traffic enters the intersection and travels in a circular counterclockwise motion around a center island. In a roundabout, priority is given to vehicles traveling in the circular roadway, and incoming traffic at the roundabout approach must yield to the circulating traffic. If there is an unbalance in approach volume, the approaches with higher input volumes may dominate the circulating flow preventing vehicles the other approaches to enter the roundabout. This may consequently …

Development Of A Land Use Regression Model To Predict Nitrogen Dioxide Concentrations, Teresa Sosa

Open Access Theses & Dissertations

Air pollution is a major environmental concern in the El Paso-Juárez region. According to the Ministry of Environment and Natural Resources (Secretaría de Medio Ambiente y Recursos Naturales, SEMARNAT) the city of Juárez is one of the city's in México with the highest atmospheric levels of pollution because of its accelerated and unplanned urban growth. One air pollutant of concern is nitrogen dioxide (NO2) due to its detrimental health effects that have been associated with airway inflammation in healthy people and increased respiratory symptoms in people with asthma. Land use regression modeling is a GIS based approach that seeks to …

A Risk Analysis Framework For Toll Road Revenue Forecasts, Gabriel Alejandro Valdez Ceniceros

Open Access Theses & Dissertations

In the United States, the shortage for traditional public sector funding sources for a safer and more effective highway infrastructure has made it more increasingly difficult for transportation agencies to keep up with the increasing demand. As a consequence, transportation agencies are considering a number of alternatives to raise funds such as charging tolls or cooperating with the private sector. One of the most important steps when analyzing the feasibility of a toll road is the traffic forecast process. However, the uncertainty of the traffic forecast has become apparent across the U.S. as evident in the common overestimation of traffic …

Applicability Of Mepdg For India Based On Texas Pavement And Environmental Conditions, Vamsi Krishna Pinnamaneni

Open Access Theses & Dissertations

The Indian pavement design guide uses empirical models which were adopted and modified from US design guides. As with any empirical model, the prediction capabilities are limited to the conditions for which it was developed. In USA, Mechanistic Empirical Pavement Design Guide (MEPDG) has been recently developed to account for increase in truck traffic and minimize premature failure of pavements. Since the new design uses mechanistic approach, it is expected that the design guide can better predict performance of pavements. In addition, mechanistic approach allows use of design guide for different pavement and environmental conditions by calibrating model parameters for …