Engineering Commons^™

Miniature Cone Penetration Test On Loose Sand, Sepideh Damavandinejad Monfared

Electronic Thesis and Dissertation Repository

Considering the difficulties associated with preparing loose sand samples in large calibration chambers and wide area of research on the behavior of loose sands, miniature calibration chamber experiments are used to perform cone penetration tests on soils in different states. A miniature cone calibration chamber has been designed and developed in this study. Nineteen tests have been performed on Ottawa sand and the results are compared to the available data in the literature. The accuracy of the results is validated by comparing the results with the suggested rate for the cone resistance in sands in literature. More specifically, results are …

Reliability-Based Design And Acceptance Protocol For Driven Piles, Joseph Jabo

Graduate Theses and Dissertations

The current use of the Arkansas Standard Specifications for Highway Construction Manuals (2003, 2014) for driven pile foundations faces various limitations which result in designs of questionable reliability. These specifications are based on the Allowable Stress Design method (ASD), cover a wide range of uncertainties, do not take into account pile and soil types, and were developed for general use. To overcome these challenges it is deemed necessary to develop a new design and acceptance protocol for driven piles. This new protocol incorporates locally calibrated RLFD resistance factors for accounting for local design and construction experiences and practices, as well …

Calibration Of Resistance Factors For Driven Piles Using Static And Dynamic Tests, Deshinka A. Bostwick

Graduate Theses and Dissertations

The field of geotechnical engineering has evolved from Allowable Stress Design (ASD) to Load Factor and Resistance Design (LRFD) which has led to a need to quantify the measures of uncertainty and the level of reliability associated with a project. The measures of uncertainty are quantified by load and resistance factors, while the level of reliability is driven by the amount of risk an owner is willing to take and is quantified by the reliability index. The load factors are defined through structural design codes, but the resistance factors have uncertainties that can be mitigated through reliability based design. The …

Effect Of Caliche On The Behavior Of Drilled Shafts, Rouzbeh Afsharhasani

UNLV Theses, Dissertations, Professional Papers, and Capstones

The current design methodology for a drilled shaft foundation in cohesionless soil is primarily based on ultimate skin friction values of drilled shafts. In order to obtain these values for each soil type, load tests such as Osterberg test are designed and performed. The Osterberg test layout is designed to estimate the capacity of drilled shaft by applying an upward load during the test and then calculating the downward capacity assuming the upward and downward capacity are the same. This method is appropriate for soils not containing caliche layers because caliche layers bond to the shaft and prevent skin friction …

Modeling Pavement Distress Rates Within U.S. Air Force Airfields, Lauren Sahagun

UNLV Theses, Dissertations, Professional Papers, and Capstones

Through the review of Pavement Condition Index (PCI) surveys completed at Air Force installations scattered across the continental United States, pavement engineers at the Air Force Civil Engineer Center propose that the predominant factor contributing to pavement distress development is climate. They suggest that within each pavement distress type (i.e. alligator cracking, rutting, spalling, etc.) a geographic pattern exists that is strongly correlated to the conventional climate zones within the US. Knowledge of these geographic patterns would equip pavement engineers and asset managers with a powerful tool to develop purposeful maintenance strategies specific to each distress type.

The following approach …

Estimating Field At-Rest Lateral Stress Coefficient And Liquefaction Resistance Of Aged Sands, Md Hossian

All Dissertations

Published results of laboratory tests to evaluate the influence of the at-rest lateral stress coefficient (K0) and the overconsoildation ratio (OCR) on liquefaction resistance of sands are reviewed in this dissertation. It is found that significant increase in liquefaction resistance can occur with high K0 and/or high OCR. A unique relationship between liquefaction resistance of isotropic and anisotropic normally consolidated sands exists based on the published laboratory data. Relationships between liquefaction resistance of overconsolidated sands and normally consolidated sands also have been shown in previous laboratory studies. Based on the previous studies, expressions for K0 and OCR correction factors (KK0 …

Performance Of Micropiled Raft In Sand And Clay-Centrifuge And Numerical Studies, Ahmed M. Alnuaim

Electronic Thesis and Dissertation Repository

A micropile is a small diameter “cast-in-place” pile, which was initially used to repair deficient foundations. The overall performance of a micropiled raft (MPR) foundation system is similar to a piled raft foundation where the load is transmitted through both the raft and the micropiles. This thesis explores using micropiled rafts (MPR) as a new highly efficient foundation system that combines the advantages of the piled raft system and the efficient installation of micropiles and associated ground improvement. Currently, there is no guidance available regarding the performance of MPR foundations. Therefore, the main objectives of this research are to evaluate …

Field-Obtained Soil Water Characteristic Curves And Hydraulic Conductivity Functions, Elvis Ishimwe

Graduate Theses and Dissertations

A compacted clay liner (test pad) was constructed and instrumented with volumetric water content and soil matric potential sensors to determine soil water characteristic curves (SWCC) and hydraulic conductivity (k) functions. Specifically, the compacted clay liner was subjected to an infiltration cycle during a sealed double ring infiltrometer (SDRI) test followed by a drying cycle. After the drying cycle, Shelby tube samples were collected from the compacted clay liner and flexible wall permeability (FWP) tests were conducted on sub-samples to determine the saturated hydraulic conductivity. Moreover, two computer programs (RETC and UNSAT-H) were utilized to model the SWCCs and k-functions …

Development And Use Of Moisture-Suction Relationships For Geosynthetic Clay Liners, Jacob Law Risken

Master's Theses

A laboratory test program was conducted to determine the moisture-suction relationships of geosynthetic clay liners (GCLs). Moisture-suction relationships were determined by combining suction data from pressure plate tests, contact filter paper tests, and relative humidity tests, then fitting water retention curves (WRCs) to the data. WRCs were determined for wetting processes and drying processes in terms of gravimetric moisture content and volumetric moisture content.

The effects of GCL type, hydration solution, wet-dry cycles, and temperature on the moisture-suction relationships were analyzed. The three GCLs of the test program consisted of configurations of woven and nonwoven geotextiles reinforced with needlepunched fibers. …

Evaluation Of Volatile And Semi-Volatile Organic Compounds Potentially Associated With The Gas Shale Fracturing Process In The Fayetteville And Marcellus Shale, Karl Albert Oetjen

Theses - ALL

With the recent growth of the natural gas industry coupled with technological advancements, gas shale fracturing has become an effective and highly profitable method for natural gas production. Unlike conventional natural gas extraction which may require vertical fracturing, gas shale fracturing relies on a method known as horizontal fracturing to remove gas trapped within the impermeable facies. Compared to vertical fracturing, horizontal fracturing requires larger amounts of fluids to be injected downhole under high pressure. These fracturing fluids can contain high concentrations of petroleum hydrocarbons with known adverse health effects. Due to the large volumes used, the potential for groundwater …

Thermal Numerical Analysis Of Vertical Heat Extraction Systems In Landfills, Michael Thomas Onnen

Master's Theses

An investigation was conducted to determine the response of landfills to the operation of a vertical ground source heat pump (i.e., heat extraction system, HES). Elevated landfill temperatures, reported various researchers, impact the engineering performance of landfill systems. A numerical model was developed to analyze the influence of vertical HES operation on landfills as a function of climate and operational conditions.

A 1-D model of the vertical profile of a landfill was developed to approximate fluid temperatures in the HES. A 2-D model was then analyzed over a 40 year time period using the approximate fluid temperatures to determine the …

Characterization Of Dredged Sediment Used In Coastal Restoration And Marsh Creation Projects, Gregory A. Mattson Ii

University of New Orleans Theses and Dissertations

To minimize coastal land loss and create new land, dredged sediment has been in use in coastal Louisiana during the last several years. Engineering properties and material characteristics of dredged material are input parameters in several mathematical models used to predict the long-term hydrodynamic behavior of the coast. Therefore, proper characterization of the dredged material is of utmost importance in the correct design of coastal restoration and land creation projects. The sedimentation characteristics of the dredged material, among other factors, depends on the (a) grain size distribution of the dredged material, (b) salinity (fresh, brackish, or saltwater environment) of the …

Stability, Erosion, And Morphology Considerations For Sustainable Slope Design, Isaac Andres Jeldes Halty

Doctoral Dissertations

The construction of more natural and sustainable earth slopes requires the consideration of erosion and runoff characteristics as an integral part of the design. These effects not only result in high costs for removal of sediment, but also a profound damage to the ecosystem. In this dissertation, innovative techniques are developed such that more natural appearing slopes can be designed to minimize sediment delivery, while meeting mechanical equilibrium requirements. This was accomplished by: a) examining the fundamental failure modes of slopes built with minimum compaction (FRA) to enhance quick establishment of forest, b) investigating the geomechanical and erosion stability of …

Geotechnical Report For Appalachian Community Health And Disaster Readiness: Interprofessional Practice, Ali Leib

Chancellor’s Honors Program Projects

No abstract provided.

Design And Economic Analysis Of A Geothermal Vertical Coupled Heat Pump System For The University Of Tennessee, Knoxville Campus, Joseph W. Birchfield Iv, Will Kester, Jason Cho

Chancellor’s Honors Program Projects

No abstract provided.

Finite Difference Modeling Of Surface-~Wave Scattering For Shallow Cavity Detection, Heston Travis Norcott

UNLV Theses, Dissertations, Professional Papers, and Capstones

Data collection and analysis of scattering of Rayleigh-type surface waves are investigated for locating shallowly buried cavities. Surface-based seismic experiments conducted by others at the University of Nevada, Las Vegas (UNLV) Engineering Geophysics Test Site (EGTS) demonstrate scattering of Rayleigh waves caused by buried empty barrels (essentially air-filled cavities). The interpretation of the data is complicated by factors such as the presence of a high-velocity geologic layer just below the cavity.

This research uses a finite-difference seismic wave propagation code to compute time histories for a model that represents the Engineering Geophysics Test Site. By adding cavities to a background …

Small Strain Stiffness Of A Carbonatic Fine Grained Soil, Sulaiman Dawood

Open Access Theses

The work presented in this thesis is part of a broad effort aimed at the characterization of the engineering properties, microstructure and mineralogy of soft fine-grained carbonatic soil deposit in Southwestern Indiana (Daviess Co.). The specific focus of this thesis is the characterization, through both field and laboratory measurements, of the small strain behavior of this soil, commonly referred to as a "marl."

Index tests indicate that the 3.5 m marl layer present at the site is characterized by two soil types alternating in small sublayers: a high plasticity silt (soil M) with wn ∼60% and CaCO3 ∼60%, mostly in …

Rheological Properties Of Laponite And Chemically Modified Laponite Suspensions, Meng Shen

Open Access Theses

This research investigates the rheological properties of concentrated laponite RD suspensions modified through the addition of laponite RDS and sodium pyrophosphate (SPP). The work is aimed at establishing the possible suitability of these materials for treating liquefaction susceptible sands. This application requires that a laponite suspension initially exhibits liquid like behavior and low viscosity that allow its delivery into the pore space of a sand, but that over time the suspension develop a gel structure with solid like behavior that can serve to restrict sand particle mobility during earthquake shaking.

The experimental program made use of a Physica MCR 301 …

Static And Seismic Performance Of Geosynthetics-Strengthened Pile Foundations, Ahmed M. Taha

Electronic Thesis and Dissertation Repository

Geosynthetic reinforcement in earth structures has been used extensively over the last two decades. Extensive research has been carried out to investigate solutions to enhance the lateral stability of pile foundations. This research is motivated by the need to install piles in sites characterized by soft subsurface soil conditions, and often times, in seismic active areas. This research work explores an innovative use of geosynthetics to enhance the lateral performance of pile foundations. The static and seismic soil-structure-interaction behaviors of geosynthetics-reinforced pile foundation systems were evaluated using a series of reduced scale physical model tests performed on a shaking table …

Characterization Of Dynamic Structures Using Parametric And Non-Parametric System Identification Methods, Ayad Al Rumaithi

Electronic Theses and Dissertations

The effects of soil-foundation-structure (SFS) interaction and extreme loading on structural behaviors are important issues in structural dynamics. System identification is an important technique to characterize linear and nonlinear dynamic structures. The identification methods are usually classified into the parametric and non-parametric approaches based on how to model dynamic systems. The objective of this study is to characterize the dynamic behaviors of two realistic civil engineering structures in SFS configuration and subjected to impact loading by comparing different parametric and non-parametric identification results. First, SFS building models were studied to investigate the effects of the foundation types on the structural …

Measurements And Transient Multistep Outflow Simulation Of Soil-Water Characteristic Curve For Soils Modified With Biopolymers, Xiaoyi Zhao

Masters Theses

"In recent decades, biopolymers have shown promising applications in soil modification due to its environmental friendly nature. Most of the studies, however, focused on mechanical properties at saturated or unsaturated conditions. The study on unsaturated soil behaviors under controlled pore air and pore water pressures were limited. Soil-water characteristic curve (SWCC), relating water content with matric suction is a key property to evaluate unsaturated soils. With SWCC, other soil properties, such as hydraulic conductivity and shear strength can be estimated. In this study, SWCC of sands modified with different biopolymers were measured with both Tempe cell and Fredlund SWCC device. …

Calibration Of Non-Nuclear Devices For Construction Quality Control Of Compacted Soils, Joshua E. R. Wells

Theses and Dissertations--Civil Engineering

Inadequate compaction of a soil subgrade can lead to detrimental outcomes that are not only costly but dangerous to the general public. To avoid this, quality control (QC) devices such as the nuclear density gauge (NDG) are currently being used to monitor the compaction and moisture content of soil subgrades. However, regulatory concerns associated with the NDG have encouraged federal and state agencies, as well as the heavy civil construction industry to consider non-nuclear devices for QC testing of compacted soils. One such non-nuclear device is the Soil Density Gauge (SDG), which utilizes electromagnetic wave propagation to obtain soil properties …

Quantifiying The Effectiveness Of A Grout Curtain Using A Laboratory-Scale Physical Model, Elliot N. Magoto

Theses and Dissertations--Civil Engineering

In the past decade, the grouting industry has made significant technological advancements in real-time monitoring of flow rate and pressure of pumped grout, stable grout mix design, and with grout curtain concepts dealing with placement and orientation. While these practices have resulted in improved construction practices in the grouting industry, current design guidelines for grout curtains are still predominately based on qualitative measures such as engineering judgment and experience or are based on proprietary methods. This research focused on the development of quantitative guidelines to evaluate the effectiveness of a grout curtain in porous media using piezometric and hydraulic flow …

Shear Strength Parameters Of Sand Fly Ash Cement Mixtures, Oksana Nikolayevna Spears

UNF Graduate Theses and Dissertations

According to a 2012 American Coal Ash Association Coal production Survey Report, US coal fired power plants produced more than 109 million tons of waste that year. Approximately half of this waste is the valuable by-product fly ash. There are three classes of fly ash: cementitious class C and non-cementitious classes F and N. Over half of the fly ash produced is used in the geotechnical/construction industries. Most geotechnical soil stabilization studies using fly ash are focused on controlling shrink-swell potential of clays. This study utilized the less desirable class F fly ash to assess the improvement of shear strength …

Why Ricker Wavelets Are Successful In Processing Seismic Data: Towards A Theoretical Explanation, Afshin Gholamy Salehabady

Open Access Theses & Dissertations

In many engineering applications ranging from engineering seismology to petroleum engineering and civil engineering, processing seismic data plays a key role. In processing seismic data, it turns out to be very efficient to describe the signal's spectrum as a linear combination of Ricker wavelet spectra.

In this Thesis, we provide a possible theoretical explanation for this empirical efficiency. Specifically, signal propagation through several layers is discussed, and it is shown that the Ricker wavelet is the simplest non-trivial solution for the corresponding data processing problem, under the condition that the described properties of the approximation family are satisfied.

Pile-Soil Interaction In Unsaturated Soil Conditions, Megan Hamilton

Honors Theses and Capstones

The degree of saturation has been proven to significantly affect geotechnical engineering designs for foundations. The changes in water content will influence the way the soil behaves, including its strength and stiffness parameters. These characteristics were analyzed for a uniform silty sand by developing P-Y curves, which relate lateral loading to lateral deformations. These P-Y curves were input into FB-Multipier, a software developed by the Bridge Software Institute. The software is capable of generating deformations as a result of user-defined loading cases. The results indicated that the middle range of degrees of saturation produced the least amount of deformation. This …

Deformation And Shear Behaviors Of Weathered Compacted Shale, Xu Zhang

Theses and Dissertations--Civil Engineering

As an abundant sedimentary rock, shale is widely used as construction material around the world. However, shale is a fissile and laminated material and is therefore subject to deterioration due to environmental and chemical forces (i.e., weathering), which is possible to cause high maintenance cost on associated structures and failures of earth slopes and embankments. However, currently, there is lack of efficient method to monitor the weathering process of shale. This thesis uses several shale samples collected from the commonwealth of Kentucky to study the deformation and shear behaviors of weathered compacted shale. A new electrical approach was developed to …

Geotextile Tubes And Their Application To Dewatering, Kevin R. Morgan

Electronic Theses and Dissertations

Geotextile tubes are a proven cost-effective technology offering speed, efficiency, and minimal impact to the environment for dewatering of sediment or sludge from dredging operations. Common applications include: removal of solids from municipal water and waste water treatment, agricultural remediation, marine dredging operations, construction dewatering, and beach preservation and protection. Geotextile tubes are manufactured in a variety of configurations.

Geotextile tubes are used for a wide variety of environmental applications including dewatering and slurry containment. One of the most important design aspects of the tubes themselves is the ability to be flexible and expand and hold form under high pressure …