Geotechnical Engineering Commons^™

Development Of Soil Water Characteristic Curves Through Control Of Relative Humidity, Lauren E. Johnson, Julia I. Loshelder, Richard A. Coffman

Civil Engineering Undergraduate Honors Theses

The relationship between soil suction and soil water content in unsaturated soil mechanics is important but can be difficult to measure. The objective of the research described herein was to develop soil water characteristic curves (SWCC) from relative humidity values by incorporating the use of glycerin-water mixtures. Glycerin-water mixtures can be used to achieve different relative humidity levels by varying the concentration of glycerin within the mixture. The relative humidity created by each mixture was measured with a relative humidity sensor, and the relative humidity values and Kelvin’s equation were used to compute the total suction.

Soil water characteristic curves …

Investigation Of Micp Based 3d Printed Soils, Kathleen Weston

Civil Engineering Undergraduate Honors Theses

The advent of additive manufacturing, often called 3D printing, offers potential for new and more sustainable soil improvement techniques. Previous research at the University of Arkansas has examined Microbially Induced Calcite Precipitation (MICP) as a possible binder option that is a more sustainable alternative to Portland cement and can be used in remote areas where Portland cement may not be available. The objective of this research is to develop an increased understanding of the potential of utilizing MICP as a spray binding technique for applications in 3D printed soils. The specific goals of this research include: examining the effectiveness of …

Analysis Of Shear-Strength In Weathered Shale Strata Along A Highway Slope Failure Site In Northwest Arkansas, Olivia Overton

Civil Engineering Undergraduate Honors Theses

Slope failures cost millions of dollars per year to repair and can be deadly. Accurate modeling of slope conditions, including soil parameters, water table locations, and depth to bedrock, are essential to determining the overall stability of a slope. This project is a continuation of the work completed in 2019 by a former University of Arkansas researcher, Vanessa LeBow. LeBow RocScience used Slide2 modeling software to model two highway embankment slopes in Northwest Arkansas that experienced slope movement to determine whether increased use of geophysical data could increase the accuracy of slope stability models. A parametric study of shear strengths …

Preliminary Investigation Of Required Bsca Amount For Soil Cement Mixtures, Mariel Mayori Rivero

Civil Engineering Undergraduate Honors Theses

The recent increase of flooding in the United States and the high expenses related to the damage that these floods have caused to waterway structures suggests a potential interest in rapid setting soil cement to make effective repairs. For this thesis, mix designs of soil only at three different sand-clay proportions were prepared and tested for moisture content and maximum dry density. Due to the early closing of the laboratory and research activities, reliable results were collected from the 70% sand and 30% clay proportions. At those proportions of soil, the optimum moisture content was found to be 8.88% with …

Soil Moisture Content Determination By Means Of The Electromagnetic Spectrum, Julia Loshelder

Civil Engineering Undergraduate Honors Theses

Soil moisture content provides information about the strength, permeability, and compressibility of the soil under investigation. In the research described herein, the relationship between moisture content and reflectance values obtained from spectroscopy was developed to investigate whether in-situ moisture content can be determined in a faster and more efficient way than the current methods. The soil under investigation was laboratory-compacted kaolinite clay mixed with pyranine dye. These specimens were placed beneath an ultraviolet light and a halogen illuminator where reflectance values were collected over a 24-hour period. Correlations were developed from the following methods: 1) spectral indices, 2) continuum analyses …

Displacement Derived Energy Levels For Harvard Miniature Compaction, Ana Laura Errigo, Julia Loshelder

Civil Engineering Undergraduate Honors Theses

Previously, the amount of energy provided by the Harvard Miniature tamper was adjusted by changing the number of blows per lift or the number of lifts or was not adjusted at all. However, this research was conducted to investigate the effect of adjusting the displacement of the spring (increased or decreased) to change the potential energy of the spring and therefore change the compacive effort with a specific type of soil. Thus, the objective was to match the compaction energies using the Harvard miniature method with the compaction energies obtained using the Proctor method. Specifically, the goal was to show …

Tension Splitting Strength Of Bcsa Concrete Cylinders, Andrew Steven Deschenes

Civil Engineering Undergraduate Honors Theses

The focus of this research was to compare the tension splitting strength (TSS) of belitic calcium sufloaluminate (BCSA) cement concrete to tensile strength predicted by the American Concrete Institute (ACI) and to similarly proportioned portland cement (PC) concrete. BCSA is a rapid-setting cement with higher early strength, higher ettringite content, and lower calcium silicate hydrate (C-S-H) content than PC. PC and BCSA cement concrete cylinders were broken at different ages in both uniaxial compression and TSS. It was found that BCSA had a similar TSS to both the ACI prediction and PC TSS, but the results require further testing for …

Young’S Modulus As A Measurement To Estimate Damage Related With Alkali-Silica Reaction In Concrete., Anazaria J. Ortega Gonzalez

Civil Engineering Undergraduate Honors Theses

The main purpose of this research is to compare two nondestructive methods to assess Alkali-Silica reaction (ASR) in concrete. Fifteen concrete prisms were cast using aggregates with different Alkali-Silica reactivity such as Jobe sand and Van Buren sand. The change in strain, shear wave velocity and Young’s modulus were determined according to ASTM C129 and ASTM C215, respectively. This data was collected by Dillon K Self, who determined that the shear wave velocity and strain are inversely proportional. However, when single cracking in the concrete specimen transition to map cracking, the shear wave velocity dropped significantly, whereas the strain value …

Controlling Relative Humidity Using Glycerin, Juan Martinez

Civil Engineering Undergraduate Honors Theses

A series of tests were conducted to control relative humidity (RH) using a bubbler system that contained a series of glass jars and glass vials filled with different concentrations of glycerin. The relative humidity within the glass jars was measured. The total time interval for each laboratory test was 48 hours. During the first 24 hours a pump was used to bubble air through the glycerin solution. During the second 24 hours, the pump was turned off, and the RH within the system was monitored within the closed system. Target RH measurements from 100% to a 0% were obtained. The …

Evaluation Of A Centrifuge Consolidation Technique To Determine The Effects Of Temperature And Time On Kaolinite Properties, Esteban Miranda Pinzon

Civil Engineering Undergraduate Honors Theses

Abstract

The effects of time and temperature on the moisture content and unit weight profiles, as developed during a centrifuge consolidation process, were observed during the research program that is described herein. Specifically, a Beckman-Coulter Model J6-MI centrifuge with a six-place JS-4.2A swinging bucket rotor was utilized to consolidate kaolinite slurry samples. The consolidation procedure utilized specially designed slurry consolidometers, made from acrylic tubes with inside diameters of 2.63 inches (6.67 cm) and heights of 5.13 inches (13.04 cm). The tested kaolinite slurry samples were created by mixing 400 grams of dry kaolinite clay powder with 200 grams of de-aired …

Development Of A Hydraulic Conductivity Placement Window Using Centrifuge Techniques, Greg Thomas

Civil Engineering Undergraduate Honors Theses

A centrifuge soil testing device, currently operated by researchers at the University of Arkansas, was used to develop a technique to determine a hydraulic conductivity placement window. The purpose of this research was to develop a placement window by means of a centrifuge instead of by means of a panel board. Soil specimens were created at standard PRcotor energy and at 50 percent of Standard Proctor energy at -3 percent of optimum, -1.5 percent of optimum, two specimens at optimum, +1.5 percent of optimum, and +3 percent of optimum water content. Values of hydraulic conductivity for the respective specimens were …

Induced Earthquakes And Public Safety, Lyndsey L. Dickson

Civil Engineering Undergraduate Honors Theses

Like the number of earthquakes felt in Oklahoma, the number of media reports regarding large-magnitude earthquakes in Oklahoma has increased in recent years. News headlines that mention property damage and question who is responsible have sparked heated debated. In this document, a discussion is presented over the responsibility of engineers for the public’s safety in relation to earthquakes. Input from various groups is discussed, the action taken in Oklahoma is outlined, and ethical obligations presented by the American Society of Civil Engineers are considered. The United States Geological Survey (USGS) has reported a major grievance against building-code committees, but many …

Effectiveness Of Small Strain Shear Wave Velocity As A Property For Assessing Damage Associated With Alkali-Silica Reaction In Concrete, Dillon K. Self

Civil Engineering Undergraduate Honors Theses

This research paper details the monitoring of expansion and shear wave velocity for fifteen concrete prisms cast in accordance with ASTM C1293 utilizing five mix designs with varying levels of ASR reactivity. Jobe sand and sodium hydroxide pellets were added in various quantities to increase the reactivity of the prisms. Strain measurements of the prisms were taken according to ASTM C129 and the shear wave velocity of the prisms was measured using ASTM C215. These measurements were taken weekly, then monthly for over a year. It was determined that shear wave velocity of the prisms decrease linearly as strain in …

Validation Of An Internal Camera Based Volume Determination System For Triaxial Testing, Leah D. Miramontes

Civil Engineering Undergraduate Honors Theses

Accurate strain and volume measurements are critical to phase relationships and strength determination for saturated and unsaturated soils. In recent years, laboratory-based photographic techniques of monitoring soil specimens have become more common. These techniques have been used to reconstruct 3D models and to determine strain and volumetric changes of triaxial specimens. A new technique that utilized digital photographs of the soil specimen, captured from within a triaxial testing cell, was utilized. Photographs were processed using photogrammetry software to reconstruct 3D models of the soil specimens. By placing camera equipment within the cell, the technique eliminated the need to account for …

Comparative Analysis Of Buckling-Restrained Braced Frames In Eccentric Configuration (Brbf-Es) And Eccentrically Braced Frames (Ebfs), Peter T. Vayda

Civil Engineering Undergraduate Honors Theses

Continuing on the findings of “Using Buckling-Restrained Braced Frames in Eccentric Configuration,” by Dr. Gary S. Prinz, P.E., which determined that, from a performance standpoint, BRBF-Es could be a viable alternative for EBFs. A comparative analysis was conducted on the design procedures and initial cost estimates of BRBF-Es and EBFs. Upon designing four 12-Story buildings (two BRBF-Es and two EBFs), it was determined that BRBF-Es were easier to design due to the statically determinant system. The initial costs estimates of BRBF-Es; however, ranged upwards of 30% more cost than EBFs. Therefore, the initial investment of more intensive structural engineering design …

Alkali-Silica Reaction Mitigation Using High Volume Class C Fly Ash, Sydney Marie Dickson

Civil Engineering Undergraduate Honors Theses

Fly ash is the residue produced from coal combustion in electric generating plants. There are two types of fly ash, Class C and Class F. Approximately 40 percent of fly ash generated from coal combustion can be used as a partial replacement of cement in concrete. Incorporating fly ash improves concrete properties and extends its service life. Alkali-silica reaction (ASR) is an expansive reaction between reactive silica typically found in aggregates (rock and sand) and alkalis in cement. This reaction results in the formation of a gel that absorbs water and swells, which exerts an internal pressure in concrete. This …

A Study Of The Influence Of Particle Gradation In Bonded Assemblies, Matthew P. Watters

Civil Engineering Undergraduate Honors Theses

The discrete element method (DEM) has been used extensively to study soil, rock, and masonry behavior because of its ability to model the materials as individual particles or bonded clumps of particles. DEM allows for examination of the macro- and micro-scale response and provides a means to study the fundamental material behavior, but it is still considered computationally expensive in relation to other methods. To lower computational costs, the smallest particle sizes are often considered negligible and are left out of the model. Additionally, rock or intact materials are often modeled as a bonded assembly of uniform spheres. To date, …

One-Dimensional Compressibility Of Intermediate Non-Plastic Soil Mixtures, Sean E. Salazar

Civil Engineering Undergraduate Honors Theses

The results of high stress, one-dimensional compression testing on intermediate soils are presented. Nevada Sand and silica silt mixtures were subjected to very high vertical stresses (140 MPa) in one-dimensional, monotonic compression. Each soil mixture was tested in a nominally loose condition. A specially designed mold with an integrated sensor array was fabricated to contain the soil during pre-consolidation and loading. The 1-D compression curve was plotted for each mixture in the double-logarithmic void ratio (e), and vertical effective stress (σ’v) space and characteristics of the Limiting Compression Curve (LCC) were identified. Initial and post test grain size distribution curves …

Analysis Of Aggregate Distribution In Self-Consolidating Concrete, Brendan Ho

Civil Engineering Undergraduate Honors Theses

Concrete consists of several key ingredients: cement, water, and coarse and fine aggregate. Depending on the proportions of these ingredients, the strength and workability of a concrete mix can be affected adversely. Segregation is the separation of aggregate and cement paste, resulting in a lack of homogeneity. Self-consolidating concrete (SCC) does not require traditional consolidation; however, it can be affected by segregation. This project examines different SCC mixtures and establishes ranges of values for slump flow, T20 , Visual Stability Index (VSI), J-ring flow and J-ring flow spread that ensures proper aggregate distribution and therefore reduces the potential of segregation. …

Hydraulic Conductivity Of Environmentally Controlled Landfill Liner Test Pad, Camila Maldonado Soria Galvarro

Civil Engineering Undergraduate Honors Theses

Laboratory and field hydraulic conductivity tests have been conducted on soil samples to develop and verify the zone of acceptance for liner placement. Compaction testing and flexible wall hydraulic conductivity tests were performed on fifteen (15) samples to determine the dry unit weight, molding water content, and laboratory permeability. Five of the fifteen samples were compacted at Standard proctor energy, five were compacted at 75 percent of Standard proctor energy, and five were compacted at 50 percent of Standard proctor energy. The results obtained from the laboratory portion of the testing program (the zone of acceptance) are presented. A ten …