Geological Engineering Commons^™

Imaging A Fly Ash Landfill Using Non-Invasive Technologies (Ert And Masw), Atiat Shaban Qasim Alsaaideh

Doctoral Dissertations

"Electrical resistivity tomography (ERT) data were acquired across a segment of an existing fly ash landfill in southwestern Missouri. The objective was to map potential karst features and identify probable groundwater seepage through and beneath the landfill.

Variations in the moisture content were mapped below and above the two liners (clay and synthetic) systems, the soil and bedrock. Seepage pathways were mapped through the fly ash and the underlying soil and rock. No visual evidence was found on any of the 3D ERT profiles of the presence of either pre-existing air-filled voids or pre-existing or newly infilled clay-filled voids. There …

Characterizing Long-Term Groundwater Conditions And Lithology For The Design Of Large-Scale Borehole Heat Exchangers, David Charles Smith

Doctoral Dissertations

"Construction of large scale ground coupled heat pump (GCHP) systems that operate with hundreds or even thousands of boreholes for the borehole heat exchangers (BHE) has increased in recent years with many coming on line in the past 10 years. Many large institutions are constructing these systems because of their ability to store energy in the subsurface for indoor cooling during the warm summer months and extract that energy for heating during the cool winter months.

Despite the increase in GCHP system systems constructed, there have been few long term studies on how these large systems interact with the subsurface. …

In-Situ Assessment Of Concrete Bridge Decks And Pavements Using Stress-Wave Based Methods, Mengxing Li

Doctoral Dissertations

"Concrete infrastructure of United States is aging and deteriorating. Accurate assessment the condition of concrete infrastructure is critical for its maintenance and rehabilitation. Stress-wave based methods, including ultrasonic surface wave (USW) and impact echo (IE), are becoming popular for characterizing defects and mechanical properties of concrete infrastructures. In this dissertation, a comprehensive literature review of seismic wave theory and common types of defects identified in concrete infrastructures, as well as stress-wave based methods used for concrete infrastructure monitoring and characterizing on a selected concrete bridge deck and two concrete pavement segments are present. The utility and reliability of both methods …

The Use Of Geophysical Methods For Dam Seepage Investigations And Dredged Oyster Deposit Characterization, Stanley Chinedu Nwokebuihe

Doctoral Dissertations

"The dissertation is made up of three papers, which discuss the utility of geophysical tools in earthfill dam investigations and dredged oyster bed characterization.

In the first paper, an earthfill dam in Warren County, Missouri was effectively investigated for seepage through the dam and its outlet works using an integration of the electrical resistivity tomography, induced polarization and spontaneous potential geophysical tools. Recommendations were subsequently made based on the results of the study on grout locations to prevent further seepage. In the second paper, a similar study of earthfill dam seepage was conducted on a different dam in Southern Missouri. …

Dissolution-Enlarged Fractures Imaging Using Electrical Resistivity Tomography (Ert), Elnaz Siami-Irdemoosa

Doctoral Dissertations

"In recent years the electrical imaging techniques have been largely applied to geotechnical and environmental investigations. These techniques have proven to be the best geophysical methods for site investigations in karst terrain, particularly when the overburden soil is clay-dominated. Karst is terrain with a special landscape and distinctive hydrological system developed by dissolution of rocks, particularly carbonate rocks such as limestone and dolomite, made by enlarging fractures into underground conduits that can enlarge into caverns, and in some cases collapse to form sinkholes.

Bedding planes, joints, and faults are the principal structural guides for underground flow and dissolution in almost …

Geophysical Assessment Of Soil And Rock In The New Madrid Seismic Zone, Faraj Mohamed Eljabri

Doctoral Dissertations

"The research presented here consists of two case studies: the first from a study site in Illinois and the second from a site in Arkansas. In both instances, geophysical investigations were conducted to characterize the subsurface. At the Illinois site, borehole control, downhole seismic (DHS), seismic refraction tomography (SRT) and multichannel analysis of surface waves (MASW) data were acquired for the purpose of seismic site characterization. Shear wave and compressional wave velocities were used to estimate depth to bedrock and to generate 1-D plots depicting variations in Poisson's Ratio, elastic moduli and density. The average shear wave velocity in the …

Acquisition Of Active Multichannel Analysis Of Surface Waves (Masw) Data In Karst Terrain, Ghassan Salem Alsulaimani

Doctoral Dissertations

"This study was designed to verify the effects and data reproducibility when the length of receiver array, receiver spacing, source offset and array orientation parameters are changed for data acquired using multichannel analysis of surface waves (MASW), at intended target depth of 30ft (9m), and to compare the results with electrical resistivity tomography (ERT) data obtained for the same study site.

The MASW data acquired for 34 sites, along four profiles for each site using variable source offsets of 10ft (3m) and 30ft (9.1m), and variable receiver spacings of 2.5ft (0.76m) and 5.0ft (0.76m), concurrently. Out of the 272 profiles …