Geotechnical Engineering Commons^™

Use Of Pushed-In Pencel Pressuremeter Test For Shallow Foundation Design In Florida Fine Sands, Brhane Weldeanenya Ygzaw

Theses and Dissertations

A comprehensive evaluation was conducted on the performance, consistency, and practical application of various in-situ geotechnical testing methods for predicting the settlement and bearing capacity of shallow foundations in Florida’s fine sands. The methods assessed include the Standard Penetration Test (SPT), Cone Penetration Test (CPT), Dilatometer Test (DMT), pushed-in PENCEL Pressuremeter Test (PPMT), and the pre-bored TEXAM Pressuremeter Test. A dual approach controlled indoor testing at the FDOT State Materials Office (SMO) and field investigations at three representative sites (Kingsley, Trenton, and the UCF research site), formed the experimental foundation.

Over thirty settlement prediction techniques and thirteen bearing capacity estimation …

The Prototype Of A Fully Automated Pressuremeter For Various Geotechnical Applications, Anuar Akchurin

Theses and Dissertations

The geotechnical engineering field requires high-quality in-situ testing equipment that ensures consistency in the test execution. This research focuses on developing and testing a prototype of a fully automated pressuremeter control unit to allow the industry to obtain reliable and controlled stress-strain data, thereby improving efficiency and reducing testing time.

The objectives of this work are to design and develop a system with the necessary components to perform the pressuremeter test, integrate the testing procedure into the state machine design, enable automated testing, and validate the results by comparing the stress-strain data with that obtained from the existing hand-operated pressuremeter …

Calibrating Airfield Pavement Asset Management For A Changing Global Climate: A Case Study At Fairchild Air Force Base, Emily L. Worthy

Theses and Dissertations

Military airfields and civilian airports serve as foundational nodes in the global transportation network, enabling travel, economic growth, and the projection of national security. This study investigates the relationship between climate variables projected through climate change and pavement degradation, with a focus on Fairchild Air Force Base (AFB). Using principal component regression (PCR), the research integrates historical pavement condition index (PCI) data with climate variables, including snowfall, precipitation, freeze-thaw cycles, solar irradiance, and wind speed to develop a predictive model of pavement performance under future climate scenarios, Representative Concentration Pathway (RCP) 4.5 and RCP 8.5. These models, for both Portland …

Selection Of Soil Stabilization Methods For Low-Volume Road Applications, Peter J. Spinks

Theses and Dissertations

This study examines a potential method of selecting an ideal soil additive to assist road planners in selecting an ideal soil stabilizer for low-volume road construction with in-situ soils. Essential for the socioeconomic success of rural communities, low-volume soil or gravel roads account for approximately 54% of US road expenditures to maintain and remediate. Soil stabilization can provide significant savings in regards to the cost, effectiveness, and environmental impacts of these roads. With hundreds of commercially available soil treatment products available with significant variations to their effects, it can be difficult for road planners to select the most appropriate product. …

Effect Of Environmental And Geometrical Factors On Microstructure, Desiccation Cracking, And Carbon Dioxide Flux In Clays, Charles Clayton Goodman

Theses and Dissertations

Studying the effects of extreme conditions, such as high temperatures and low humidity, on soil properties is important to various disciplines, including geotechnical engineering, soil science, waste management, crop management, and ceramics. The goal of this research is to investigate the effect of environmental and geometrical factors on microstructure, desiccation cracking, and CO₂ flux in clays. The objectives of this research are threefold. (1) Understand the effects of temperature on the microstructure of clay soils; (2) develop a standardized procedure for studying desiccation cracking in a laboratory setting with reliable and repeatable results; and (3) develop an environmental chamber …

Physics-Based Modeling Of Post-Wildfire Landslides In Unsaturated Hillslopes, Masood Abdollahi

Theses and Dissertations

Changes in climatic regimes and land use have led to increases in wildfire activities around the world. Wildfires are now happening more frequently, at higher altitudes, and higher severities. Adverse impacts of wildfires can last years after the fire has been contained through post-fire geohazards, such as shallow landslides. Post-wildfire shallow landslides are often mobilized by rainfall and due to fire-induced changes in soil and land cover properties and near-surface processes. This study aims to develop a physics-based framework to evaluate the stability of burned hillslopes against rainfall-triggered shallow landslides. A coupled hydromechanical infiltration model is developed by employing a …

Lateral Swelling Pressure In Variably Saturated Expansive Clay, Steven Ray Garrett

Theses and Dissertations

Lateral swelling pressure induced in expansive soils upon wetting can adversely impact the performance and integrity of earthen structures and foundations. The yearly cost associated with damage to structures from expansive clays in the United States is estimated to exceed the loss associated with natural disasters such as earthquakes, floods, and hurricanes. The main objective of this dissertation is to provide new insight into the evolution of lateral swelling pressure in variably saturated expensive soils under infiltration via physical testing. In the first part of this study, a new laboratory-scale testing apparatus was built to measure lateral and vertical swelling …

Hazard Mapping For Infrastructure Planning In The Arctic, Christopher I. Amaddio

Theses and Dissertations

Using modern high-resolution aerial photographs, LiDAR, historical aerial photographs, and facility data, a hazard mapping effort identified risks to infrastructure at Thule Air Base, Greenland, based on visible terrain features, surface hydrology, and slope; the distribution of these risks were then compared to existing foundation damage. The analysis indicated abundant and widespread geotechnical hazards at Thule Air Base and a weak relationship to existing foundation damage that requires more research to understand. The resulting hazard maps provide a critical tool for risk assessment and planning as well as a model for other locations to follow.

Remediation Of Desiccation Cracking In Clayey Soils Through Bio-Cementation And Bottom Ash, Mark Vail

Theses and Dissertations

Desiccation cracking considerably impairs the hydraulic and mechanical properties of clayey soils and is critical to the long-term performance of infrastructure foundations and earth structures. Classical crack remediation methods are associated with high labor and maintenance costs or the usage of environment-unfriendly chemicals. Recycling waste materials and developing bio-mediated techniques have emerged as green and sustainable soil stabilization solutions. The objective of this study is to investigate the feasibility of soil crack remediation through the usage of microbial-induced calcite precipitation (MICP) and bottom ash admixtures. We carry out monotonic drying and cyclic drying-wetting tests to characterize the effects of bottom …

Evaluating Cracking Performance Of Polymer Enhanced And Fiber Reinforced Microsurface Mixtures Using Asphalt Laboratory Testing, George Joseph Shackil

Theses and Dissertations

This study presents a method to improve and evaluate the cracking resistance of microsurfacing mixtures using common asphalt laboratory testing. A preliminary optimal timing study and a study to evaluate improvements to cracking performance were conducted. The control mixture was based on NJDOT standard mix design specifications. Three mixtures were tested in this study: a fiber reinforced mixture using one-quarter inch glass fibers, an emulsion with increased SBR (polymer) contents, and a mixture using the one-quarter inch glass fibers combined with the increased polymer contents. Three laboratory tests were used to evaluate three different cracking resistance parameters: crack initiation (Semi-Circular …

Evaluation Of The Cracking Performance Of Geogrid-Reinforced Hot-Mix Asphalt For Airfield Applications, Daniel Offenbacker

Theses and Dissertations

The objective of this study was to evaluate the fatigue cracking performance of geogrid-reinforced Hot-Mix Asphalt (HMA) for use in airfield runways. An airfield HMA mixture with four different geogrid types were selected for this study. The geogrids varied in tensile strength, coating type, opening size, thickness, and fiber material. Several different laboratory performance tests were conducted (Dynamic Complex Modulus, DCM, Overlay Test, OT, and Indirect Tensile Strength, ITS) and the fatigue and/or cracking performance was evaluated. Additionally, different approaches were adopted or developed for the modeling of geogrids in HMA using Finite Element Modeling (FEM). Finally, a Life-Cycle Cost …

Recommended Selective Maintenance And Rehabilitation Treatment Approach For Air Force Primary Rigid Runway Pavement Systems, Christopher M. Twigg

Theses and Dissertations

The Air Force is facing the challenge to preserve the current inventory of 154 million square yards of paved airfield assets while at the same time reducing the budget by $36.2 billion between fiscal years 2015-2019. This research sought to determine a selective maintenance and rehabilitation treatment approach that allocates resources efficiently to preserve the degrading pavement assets in the financially constrained environment. Air Force pavement inspection reports from the past five years provided 4289 observed pavement distress data points for this research. The data was inputted into the pavement management software, PAVER, to calculate the Pavement Condition Index (PCI) …

Determination Of Non-Nuclear Alternative To The Nuclear Density Gauge Through Laboratory And Field Testing, Janine Abyad

Theses and Dissertations

Pavement performance is dependent on the compaction quality of unbound subgrade and base/subbase layers beneath flexible pavements. Pavement distresses can be linked to compaction defects within these layers. In current practice, the New Jersey Department of Transportation (NJDOT) utilizes the nuclear density gauge (NDG) for evaluating compaction quality based on minimum density requirements, typically 95% of the Proctor maximum dry density (MDD). However, there are concerns with using the NDG. The goal of this study was to replace the NDG with non-nuclear alternative method(s) as acceptance tools during field compaction. To achieve this, a laboratory procedure for compacting large samples …

Use Of Infrared Spectrometry To Determine The Effect Of Trichloroethylene Resident Time On Desorption Rates From Flint Clay, Peter T. Lapuma

Theses and Dissertations

This laboratory based thesis investigated the desorption rate of trichloroethylene (TCE) from flint clay while varying the resident time of TCE exposed to the clay. It is thought that in long contaminated soil, a majority of contaminant mass will become entrained within the interior of the soil particles to slowly desorb out of the soil over long periods of time. Recent studies suggest that the longer a contaminant is resident in soil, the longer the contaminant will take to desorb from the soil. To understand more about soil desorption, this experiment was developed using infrared spectroscopy to detect TCE vapor …