Earth Sciences Commons^™

Seismic Loading Effects Within Orthogonally Connected Steel Lateral Force Resisting Systems, Alhussin Faraj Aliwan

Graduate Theses and Dissertations

Steel buildings located within seismically active regions require special design considerations to ensure public safety and prevent collapse during an extreme seismic event. Two commonly used steel systems are special moment frames (SMFs) and buckling-restrained braced frames (BRBFs). When two seismic systems share a common column in an orthogonal configuration (such as at a building corner), design specifications currently consider a 100+30 rule wherein the shared column is designed for 100% fuse demand in one direction, plus 30% fuse demand from the other direction. While this rule has been shown to be reasonable for elastic building response, a few studies …

Paleotectonic Investigation By Successive 3d Seismic Horizon Flattening In The Pennsylvanian Interval Of Western Osage County, Oklahoma, Douglas Cooper Mccabe

Graduate Theses and Dissertations

3D seismic and well log data in Western Osage County, Oklahoma, are utilized to evaluate possible intracratonic tectonic signals present in the subsurface stratigraphy of the Cherokee Platform as a result of the regional tectonic events of Pennsylvanian age. These events include: the Wichita, Ouachita, and Arbuckle orogenies, the Nemaha and Ozark Uplifts, and the Southeast Oklahoma Aulacogen. Horizon flattening within 3D seismic volumes allows for identification of paleotectonic structures and syntectonic depositional features, which may be related to the collateral effects of these orogenies on the Cherokee Platform. Identified structures were assigned geologic ages using precision synthetic seismograms tuned …

Seismic Expressions Of Paleokarst, Olanrewaju Ayodapo Aboaba

Graduate Theses and Dissertations

Paleokarst are characterized by epigene and/or hypogene processes in their formation and hold significant numbers of hydrocarbons and other natural resources. This dissertation examines worldwide seismic expression of paleokarst; and specifically, the characterization of paleokarst reservoirs developed across the Cherokee Platform, and in the Arkoma Basin, Oklahoma.

Worldwide subsurface paleokarst formations are of Precambrian to Miocene age and found at depths less than 200 m to as great as 8000 m. Karst can be are expressed on seismic records as sinkholes, paleocave collapse, and tower morphologies. Seismic modeling indicates that karst can be modeled and imaged to better understand its …

Geospatial Analyses Of Seismic Hazards And Risk Perception In Libya, Somaia Suwihli

Graduate Theses and Dissertations

Libya is not considered a highly active seismic region. However, several earthquakes of magnitude >5.0 have occurred there. This dissertation analyzes the seismicity of Libya in order to better understand earthquake hazards, related geomorphic features, and the current evolution of Libyan perceptions of seismic risk. The first article developed a baseline of past and current seismic inventory in Libya, which represented an assessment of Libya seismic hazard by translating, analyzing, and compiling historical sources and archaeological data. This study shows that Libya has experienced earthquakes in varying degrees since ancient times. Through the spatial and temporal distribution of earthquakes from …

On The Seismic Performance Of Skewed Special Moment Frame Reduced Beam Section Connections, Damaso Daniel Dominguez

Graduate Theses and Dissertations

Special Moment Frames (SMFs) are frequently used in high seismic areas for architecturally constrained designs, as they provide lateral system stiffness without the use of braces which often obstruct views and architectural features. Reduced beam section (RBS) connections are popular SMF connection details developed following the Northridge earthquake to limit brittle fractures within connection welds. Current American Institute of Steel Construction (ASIC) provisions (i.e. AISC 341-16) provide prequalified SMF RBS connection details (including welding requirements); however, all prequalified details only consider orthogonal connections between the beam and column. This dissertation investigates the effect of adding skew within SMF RBS connections …

Development Of Vs Profiles And Site Periods In The Mexico City Basin, Landon Joel Woodfield

Graduate Theses and Dissertations

This study presents dynamic site characterization measurements at 25 sites within the Mexico City Basin. The primary focus of the testing was along the western edge of the Mexico City Basin. At each site, active source Multi-channel Analysis of Surface Waves (MASW) arrays and passive source Microtremor Array Measurements (MAM) L-arrays and circular arrays were used to acquire dispersion data. Horizontal to Vertical Spectral Ratio (HVSR) data was collected to determine site periods at each location. These experimental dispersion data and site periods were fit using a joint inversion of Rayleigh and Love wave dispersion data and HVSR site period …

Understanding Ice Mixtures Under Pluto Simulated Conditions And Their Implications For Geophysical Processes, Caitlin Joannah Ahrens

Graduate Theses and Dissertations

New Horizons at Pluto has given the planetary science community the first images of Pluto’s surface, including geologic wonders and compositional variability. Methane, nitrogen, and carbon monoxide make up the bulk of the volatile plutonian surface along with water ice. In this work, these three main volatiles are specifically investigated in the laboratory setting to understand the spectral properties and behavior of binary and ternary mixtures. The spectra are taken in the near-infrared wavelengths (1 – 2.5 µm) using Fourier transform infrared (FTIR) spectroscopy techniques utilizing the Pluto Simulation Chamber housed at the University of Arkansas, which can reach conditions …

An Isotopic Assessment Of Late Prehistoric Interregional Warfare In The Southcentral Us, John R. Samuelsen

Graduate Theses and Dissertations

Skull burials are found all over the world. The cause of such ancient Native Americans deposits often lead to disagreement among scholars torn between warfare and ancestor veneration. One skull-and-mandible deposit, representing at least 352 people (A.D. 1253-1399), was uncovered at the Crenshaw site, a multiple-mound Caddo ceremonial center in southwest Arkansas. Most previous research suggested they were victims of interregional warfare from the Southern Plains or Mississippi Valley. One previous study hypothesized that this was a Caddo burial practice which expanded during the Middle Caddo period (A.D. 1200-1500) due to the adoption of maize as a staple and a …