Engineering Commons^™

Construction Effects On The Side Shear Of Drilled Shafts, Lucas Caliari De Lima

USF Tampa Graduate Theses and Dissertations

Design methods for side shear of drilled shafts, including the resistance factors that should be applied, do not account for any specific construction procedure. Instead, design often relies on analysis of case studies which include all construction methods used in each geomaterial type (e.g. clays, sands and rocks), or on parametric analysis. Nonetheless, literature suggests that different construction procedures result in varying side shear.

This research investigated 2 types of construction: (1) slurry stabilization in sandy soils using bentonite and polymer products that are commonly used on the field, with exposure times from near 0h to 96h, and (2) temporary …

Dns And Les Of Scalar Transfer Across An Air-Water Interface During Inception And Growth Of Langmuir Circulation, Amine Hafsi

USF Tampa Graduate Theses and Dissertations

Direct numerical simulations (DNS) of an initially quiescent coupled air-water interface driven by an air flow with free stream speed of 5 m/s have been conducted. The DNS solves a scalar advection-diffusion equation for dissolved gas (or scalar) concentration in order to determine the impact of the water-side turbulence on scalar (mass) transfer from the air side to the water side and subsequent vertical transport in the water column. Two simulations are compared: one with a freely deforming interface and a second one with a flat interface. In the first simulation, the deforming interface evolves in the form of gravity-capillary …

Analysis Of Distresses In Asphalt Pavement Transitions On Bridge Approaches And Departures, Manvitha Rajalingola

USF Tampa Graduate Theses and Dissertations

Some highway agencies in the United States are experiencing frequent distresses in asphalt pavements on bridge approaches/departures. Commonly observed distresses include alligator cracking and rutting, which reduce roadway smoothness and safety. To lessen the distresses in pavements it is needed to investigate the extent and root causes of the problem. Based on Florida highway conditions, this research study mainly focused on1. Literature review and identification of the extent of the problem; 2. Collection of relevant pavement condition data and descriptive analysis; 3. Development of statistical models to determine factors influencing the distresses in asphalt pavements on bridge approaches/departures. To the …

How Transportation Network Companies Could Replace Public Transportation In The United States, Matthew L. Kessler

USF Tampa Graduate Theses and Dissertations

The quantity of cell phone applications or mobile apps have seen an upsurge at an exponential rate in under a decade. Many have been created for a variety of industries, including transportation. The advent and subsequent commercialized implementation of near-instant transport by a middleman-type of app is now known as a Transportation Network Company or TNC. Examples of the more renowned TNCs are Uber, Lyft and Sidecar.

In recent years, TNCs have cultivated a tremendous following, to the degree of taxicab desertion. Moreover, the massive success of TNCs led to expansion of its capacities into public transportation.

The TNC’s expeditious …

The Effect Of Chemical Composition Of Blast-Furnace Slag On Compressive Strength And Durability Properties Of Mortar Specimens, William J. Johnson

USF Tampa Graduate Theses and Dissertations

In an effort to make structures more sustainable and durable, supplementary cementitious materials are often used to replace cement. Ground granulated blast furnace slag, for instance, is an industrial by-product of iron refinement and is frequently used in concrete mixture design to not only reduce cost, but also increase later-age strength as well as durability. However, published literature indicates that slags with a high alumina content may have a detrimental effect when concrete is exposed to a sulfate environment. ASTM standard C989 does not suggest any information or guidelines regarding using slags with an alumina content between 11-18%. Therefore, the …

Sustainability Of Community-Managed Rural Water Supply Systems In Amazonas, Peru: Assessing Monitoring Tools And External Support Provision, Jacob E. Mangum

USF Tampa Graduate Theses and Dissertations

Globally, there is still a large number of people without access to safe drinking water; a known health risk. In rural areas of countries like Peru, when potable water systems are built the responsibility for maintaining these systems is given to volunteer water committees. Despite its prevalence as a management model, there is a consensus that community management alone cannot ensure sustainable water service. Therefore, the overall goal of this research is to assess the sustainability of community-managed water systems in rural areas of the department of Amazonas, Peru. Specifically, this research examines two mechanisms that have been shown to …

Autonomous Vehicles: An Empirical Assessment Of Consumers’ Perceptions, Intended Adoption, And Impacts On Household Vehicle Ownership, Nikhil Menon

USF Tampa Graduate Theses and Dissertations

Emerging automotive and transportation technologies have provided revolutionary possibilities in the way we might travel in the future. Major car manufacturers and technology giants have demonstrated significant progress in advancing and testing autonomous vehicles in real-life traffic conditions. Governmental agencies are grappling with how to plan transportation systems for a world with autonomous vehicles. Past research has shown that not all technologies are immediately welcomed by the public. Autonomous Vehicles would have to likely go through a similar phase, and would need to overcome not just technological challenges but also social barriers for successful penetration into the marketplace. Most previous …

Quantifying And Modeling Surface Inflow And Groundwater Infiltration Into Sanitary Sewers In Southern Pinellas County, Fl, Megan E. Long

USF Tampa Graduate Theses and Dissertations

Following large rain events, excess flow in sanitary sewers from inflow and infiltration (I/I) cause sanitary sewer overflows (SSO), resulting in significant problems for Pinellas County and the Tampa Bay area. Stormwater enters the sanitary sewers as inflow from improper or illegal surface connections, and groundwater enters the system as infiltration through cracks in subsurface infrastructure. This pilot study was designed to develop methods to separate and quantify the components of I/I and to build a predictive model using flowmeter and rainfall data.

To identify surface inflow, daily wastewater production and groundwater infiltration patterns were filtered from the flow data, …

Recommendation Of A New Transit Performance Measure In The National Transit Database, Fatemeh Baratian-Ghorghi, Hossein Ahmadianyazdi

Journal of Public Transportation

The frequency of incidents negatively changes public perception with regard to the public safety in transit systems. The level of safety expressed as performance measures, ensures contractors and users that a quality safety level is maintained. Both the private and public sectors in the U.S. annually report accurate data to the National Transit Database (NTD) to be used in assessing the progress of the nation's public transportation systems. Although they must provide both the annual report and monthly reports including Safety and Security data, measures are only grouped into the indicators of efficiency and effectiveness of a system and there …

Evaluating The Effect Of Temporary Casing On Drilled Shaft Rock Socket Capacity, Daniel J. Hagerman

USF Tampa Graduate Theses and Dissertations

The purpose of this study was to determine the effect on side shear resistance in limestone when temporary casing is used. Due to testing in actual limestone being an unrealistic goal, simulated limestone mixes were prepared and cast into 6 – 42 in. diameter beds. Limestone throughout Florida can be quite varied (e.g. 50-5000 psi) but where stronger limestone is not likely to be penetrated by casing installation. Therefore, target unconfined compressive strengths of the study specimens ranged between 60 psi to 850 psi.

A simulated limestone material was developed based on over 200 cylinders cast for unconfined compression testing …

Mechanism Of Cathodic Prevention Of Carbon Steel In Concrete, Krittin Rattakham

USF Tampa Graduate Theses and Dissertations

In this work, I aim to clarify the mechanism that allows steel to attain higher chloride threshold as it is cathodically polarized. Specifically, I seek to provide empirical information on whether an intrinsic (predominantly interfacial effects of polarization) or an extrinsic (predominantly concentration changes due to polarization) mechanism may be dominant in the beneficial effect of polarization. I carried out this experiment with 12 identical concrete specimens, each with a cast-in steel plate, constantly exposed them to high-chloride environment. The specimens were divided into 4 triplicates and polarized at 4 different level from OCP, -200, -300 to -400 mV_{SCE …}

Electrochemical Methods To Characterize Drilled Shaft Deficiencies, Sarah Jo Mobley

USF Tampa Graduate Theses and Dissertations

In recent years drilled shafts have become the preferred foundation method for marine bridges. Typically, the drilled shaft is selected over traditional driven piles due to soil strata encountered, construction economy, increased lateral stiffness requirements, and/or vibration control considerations. The most critical component in drilled shaft construction is borehole stabilization. Wall sloughing or groundwater inclusion can have devastating effects on the strength of the finished shaft however recent research has shown that the materials, more specifically the slurry, used to accomplish stabilization may be having a negative impact on the durability of the finished product. This thesis investigates the durability …