Civil Engineering Commons^™

Hydraulic Computations For Stepped Concrete Overlays Of Embankment Dams, Tony L. Wahl, Sherry L. Hunt, Kem C. Kadavy, Henry T. Falvey

Protections Conference

One method for rehabilitating and modernizing embankment dams is the addition of a concrete overlay that protects the embankment and allows floods to pass safely over the dam. Roller compacted concrete is commonly used, which makes it practical to use a stepped construction that also enhances energy dissipation. Analysis of flow conditions over such structures requires computation of aerated flow and its effects on flow depth, training wall design, and energy dissipation. This paper describes Spillway Pro, an energy-based water surface profile calculation tool for smooth spillway chutes (Wahl et al. 2019), recently improved to also analyze stepped chutes. The …

Field Testing Of The Overflow Erosion Of Rhone River Levees, Christophe Picault, Fabrice Campette, Stéphane Bonelli, Sylvie Nicaise, Naim Chaouch, Faustine Byron, Yves Gremeaux, Alexis Doghmane, Mathys Garoui, Jordan Herbeck, Frédéric Golay

Protections Conference

It is important to quantify the soil resistance against erosion caused by the overflow of dikes and levees. Small-scale tests are not recommended, as they do not provide a correct representation of the actual soil in place and do not take into account the geometry of the structure. For this reason, the National Research Institute for Agriculture, Food and Environment (INRAE) developed an on-site overflow device in 2015. The procedure followed is based on ASTM-D6460 standard. Two tests were performed in May 2022 on a Compagnie Nationale du Rhône (CNR) dike near Avignon (France). The dike is 6.2 m high; …

Recent Case Histories Of Cascade Failures And Overflowing Events Of Embankment Dams, Alexius Vogel, Jean-Robert Courivaud, Katarzyna Jarecka

Protections Conference

Excessive rainfall and extensive flooding within the context of a changing environment show the fact that resistance to overflowing erosion of embankment dams needs to be better assessed because of the increasing number of dam failures caused by overflowing, implying the necessity of a reaction to this kind of challenges. Better understandings of the embankment failure processes and the dominant parameters affecting these kinds of failures are necessary for predicting and modeling the breach processes. Acquiring this better understanding of the physical processes and a numerical prediction capability requires progressing in parallel in laboratory and field test investigations of embankment …

Evaluating Arkansas Weathering Steel Bridge Performance, Yessenia Gonzalez

Graduate Theses and Dissertations

Weathering steel enhances corrosion-resistant steel features over conventional steel when a patina properly forms on the weathering steel surface. Weathering steel is a low carbon steel of less than 0.3% carbon by weight and has a chemical composition including other alloying elements such as nickel, copper, and chromium that develops a patina. The patina is a dense protective oxide film layer that develops on the steel member surface. The patina defends the steel from corrosion by preventing moisture, oxygen, and contaminant penetration. However, long periods of moisture and deicing chemicals applied during wet wintry conditions hinder proper patina formation. Without …

Improving Building Cfd Peak Pressure Computation Using Les With A Focus On Inflow Turbulence Methods And Grid Spacing Size., Zahra Mansouri

Graduate Theses and Dissertations

Structural failures by extreme winds often leads to economic losses and even deaths. Proper design of buildings requires accurate estimation of wind loads to prevent structural damage. Using routine guidelines generally leads to the underestimation of buildings’ peak pressures, in which most failures occur. To estimate wind loads more accurately three different methods (i.e., field measurement, wind tunnel (WT), and computational fluid dynamics (CFD)) are in use. A well-validated CFD provides more flow field details at lower costs compared to field measurements and WT. As strong winds are extremely turbulent, the effects of turbulence in wind should be incorporated into …

Performance Evaluation Of The Modified Moisture Barrier In Stabilizing Shallow Slope Failures, Muhasina Manjur Dola

Civil Engineering Dissertations - Archive

Each year significant number of highway slope failures are reported in the United States, especially in states like Texas where expansive clayey soil is prevalent. Slopes constructed over expansive clay often experience recurring shallow failures following their construction which poses maintenance problems to the Texas Department of Transportation (TxDOT). These shallow slope failures can be primarily attributed to the considerable volume change that expansive clay soil undergoes from seasonal climatic variation. Furthermore, under unsaturated conditions during dry periods, high matric suction (i.e., negative porewater pressure) exists in soil slopes. The existence of matric suction contributes to the shear strength of …

Development Of A Decesion Tree To Rehabilitate Or Replace The St. Francis Bridge Over Ih-30, Md Farhan Abir

Civil Engineering Theses - Archive

ABSTRACT: The ASCE infrastructure report card indicated that about 42% of the nation’s bridges are over 50 years old, and 7.5% of the bridges are structurally deficient. The 61-year-old St. Francis bridge over IH-30 is one of the Texas Department of Transportation (TxDOT) bridges that exhibit significant deterioration in the superstructure, including potholes and delamination in the deck. The bridge was load posted to 28,000 lb. limit and has substandard vertical and horizontal clearances to the bottom chord of the beams and supporting piers, respectively, which creates a high risk for vehicle impact. In 2017, an over-height truck struck the …

Study Of The Impact Of Atmospheric Variability On Subsurface Methane Emissions: Application To Leak Detection And Quantification For Underground Natural Gas Pipeline Leaks, Shanru Tian

Civil Engineering Dissertations - Archive

Natural gas (NG), taken as a bridging fuel for achieving a low-carbon future, has rapidly grown to be a significant component of the global energy system and requires extensive pipeline infrastructures, most of them buried underground. Fugitive methane (CH4) emissions from NG pipeline leaks pose environmental, safety, and economic threats to the public. An effective leak detection and quantification (LDAQ) survey method is critical to identifying a leak and assessing the size when it has occurred, thus initiating appropriate response actions to repair it and accounting for the environmental risks accurately. However, gaps exist between LDAQ survey methods, and the …

Investigation Of Models To Predict The Remaining Useful Life Of Prestressed Concrete Cylinder Pipe, Ahmad Mahmoud Jibreen

Civil Engineering Dissertations - Archive

The water distribution system in the United States consists of 2.2 million miles of pipelines with water main breaks that the American Society of Civil Engineers (ASCE) 2021 Report Card estimated results in six billion gallons of drinking water lost daily. Detecting the state of pipeline deterioration should always be a top priority in the water pipeline industry This dissertation statistically evaluates data from more than 70,000 electromagnetic inspections that have been performed since the installation of these pipes in 1971. The scope of this dissertation is related to performance and degradation of prestressed concrete cylinder pipe (PCCP) which is …

Investigation Of Geopolymer Based Soil Stabilization Methods For Expedient Airfield Pavement Surfaces, Brett Albertson

All Theses

The United States Air Force (USAF) has the unique capability of being able to interdict superior airpower anywhere, at any time. However, superior airpower is only as effective as the amount of time an aircraft can spend in a particular area. The closer an aircraft can get to the mission need, the more time that can be spent in the air, or the less time that must be spent moving in and out of the operational area. Through the use of skilled and experienced men and women, the USAF is able to apply expedient and unsurfaced airfield paving techniques that …

Performance Based Design And Machine Learning In Structural Fire Engineering: A Case For Masonry, Deanna Craig

All Theses

The volatile and extreme nature of fire makes structural fire engineering unique in that the load actions dictating design are intense but not geographically or seasonally bound. Simply, fire can break out anywhere, at any time, and for any number of reasons. Despite the apparent need, fire design of structures still relies on expensive fire tests, complex finite element simulations, and outdated procedures with little room for innovation. This thesis will make a case for adopting the principles of performance-based design and machine learning in structural fire engineering to simplify the process and promote the consideration of fire in all …

Finite Element Approach On Minimization Of Cracks At I-Girder Ends Induced By Prestress, Sangit Rauniyar

Civil Engineering Dissertations - Archive

Prestressed I-girders are one of the very commonly and widely used girders for bridges. It is produced at precast plant and transported to bridge site. To produce a prestressed I-girder, strands are first pulled and concrete is poured in I-girder’s formwork. Once the concrete reaches a desired strength, strands are released which induce prestress in I-girder. There are mainly two types of design for I-girders-one that requires debonding of strands at the end of I-girders and another that requires harping of strands at the end of I-girders. The debonding and harping of strands are done to reduce tension at the …

Improving The Analysis And Prediction Of Coastal Flooding During Hurricane Landfalls Through Coupled And Integrated Modeling, Md Arifur Rahman

Civil Engineering Dissertations - Archive

ABSTRACT: As the intensity and frequency of landfalling tropical storms are likely on the rise in a warming climate, coastal communities are increasingly being exposed to flooding caused by storm surges compounded by heavy rainfall. Prediction and reanalysis of storm surges, especially compound flooding, rely on wind and pressure fields either from parametric tropical cyclone wind models or numerical weather model reanalysis. Both are subject to significant errors during landfall. Besides, land surface attributes and different storm structures influence the intensity and location of compound flooding in coastal areas. Therefore, this dissertation aims to improve the analysis and prediction of …

Performance Evaluation Of Recycled Plastic Pins In Two Layers To Stabilize Deep Slope Failures, Sachini Madanayake

Civil Engineering Dissertations - Archive

Slope failures are a common occurrence in highway embankments throughout Texas due to the presence of high plastic clays with expansive behavior. Although shallow slope failures are prevalent, slope failures extending deeper into the slope occur due to the development of micro and macro cracks. The cracks facilitate the infiltration of rainwater deeper into the slope over time. Slope failures incur thousands of dollars’ worth of repairs every year for transportation departments across the country. Recycled Plastic Pins (RPP) have been identified as an effective, cost efficient, and sustainable solution to stabilize shallow failures. The resistance of RPP is mobilized …

Influence Of Climate And Droughts On Visibility Degradation In Saudi Arabia, Saleh Alhathloul

All Dissertations

The spatial and temporal distribution of temperature and precipitation determines the availability of water resources for ecosystems. The hydrological cycle can be disrupted by differences in meteorological variables and the random nature of water demand. Horizontal visibility degradation is an indicator of the changes in local meteorological variables, rainfall deficits, and drought conditions. Long-term analysis of meteorological variables and visibility records helps understand the causes of visibility degradation. The first objective of this dissertation is to investigate the long-term variability of horizontal visibility along with metrological variables based on annual and seasonal time scales over Saudi Arabia. The second objective …

Measuring Acoustic Nonlinearity Of Elastic Materials Using Thermal Modulation Of Ultrasonic Waves, Bibo Zhong

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

Nonlinear acoustic techniques have been used to determine the nonlinear properties of materials. Existing methods either require complex equipment to measure absolute nonlinear coefficients or can only be used on laboratory-sized specimens. A recently developed thermal modulation method addresses the limitations of existing methods, but further theoretical analysis and validation are required.

In this dissertation, theoretical analyses were first conducted to study the mechanically and thermally induced acoustoelastic effect. Beginning with the wave equation, the relationship of the ultrasonic wave velocity with respect to mechanical strain and the thermal strain was derived in detail. These analyses provided theoretical support for …

The Rise Of Terrorism In Africa And What It Means For U.S. Policymakers, Bridget Mary Hughes

Master's Theses

This thesis utilizes three case studies to measure the rise of terrorism in Africa. This qualitative data leads the reader to one ultimate question: what does the rise in terrorism in Africa mean for the United States (U.S.) and U.S. policymakers, National Security academia, students in National Security, if anything at all? The answer is: if civilian and military compounds are being targeted by these violent extremists, as these three case studies demonstrate, it is my recommendation that U.S. policymakers cease sending troops to the African theater and, instead, allocate funding to the citizens and nonprofits of the countries whom …

Flexural Testing Of Precast Reinforced Concrete Bridge Slabs, Evaluation Of Deterioration And Strengthening Applications, Alyssa Leaman

All Theses

This thesis investigates the strength of flat precast concrete slabs that were taken from decommissioned South Carolina bridges. The specimens tested spanned 14 ft (4.3 m) or 15 ft (4.6 m), were 5 ft (1.5 m) or 5.5 ft (1.7 m) wide, and 8.25 in (210 mm) thick. In South Carolina, there are approximately 3000 similar bridges that use these slab members. Testing was conducted to determine the flexural capacity of “typical” slabs and the residual strength of slabs having visible deterioration of both the rebar and the concrete. For the slabs that were load rated below the new standards, …

Evaluation Of Relationship Between Sulfate Content And Electrical Resistivity, Zobair Ahmed

Civil Engineering Theses - Archive

Texas soils typically have sulfate content due to certain geologic formation types. Soil sulfate needs to be identified and quantified to minimize damage to infrastructure caused by sulfate-induced heave. Electrical Resistivity Imaging can identify the presence of sulfate content in the soil. Electrical Resistivity Imaging (ERI) is a non-destructive and fast way of obtaining continuous soil substructure profiles. Moisture fluctuations and soil heterogeneities can be found using an ERI approach. As a result, ERI is growing in popularity as a tool in geotechnical engineering, yet at the moment, it only offers qualitative data. It can be challenging to determine quantitative …

Erosion And Resuspension Of Cohesive Sediments In Coastal Louisiana, Laith Qasem Shamaileh

LSU New Orleans Theses and Dissertations

The research presented in this study is motivated by the need to improve the predictions of cohesive sediment erosion and subsequent transport. In addition, the knowledge of the geotechnical engineering soil properties related to the erosion of sediments in coastal Louisiana has broad implications as these properties are used in transport models guiding the current restoration efforts. The erosion measuring device used in the study is the Cheng-Han Tasi and Wilbert Lick Shaker. Previous studies have been conducted before using the Shaker, but challenges with the calibration of the shear stress hampered the resuspension results produced by the Shaker. Therefore, …