Engineering Commons^™

Evaluation Of Helical Piles As Anchors For Floating Offshore Wind Turbine Foundation Systems, Martha Shannon Harris

Geotechnical Engineering Masters Projects

The development of floating offshore wind energy is essential for growth of the renewable energy industry, and to decrease the reliance on fossil fuels and emission of greenhouse gasses. Advances in ease of construction and installation of turbines can make the floating offshore wind industry more marketable and feasible on a large scale; this can in part be achieved by innovation in foundation anchoring systems.

This thesis presents an evaluation of helical pile foundations for offshore deep-water application as anchors for floating offshore wind systems with catenary mooring lines in clay and sandy soils. This research outlines the influence of …

Lateral Behavior Comparison Of Driven And Screw Piles In Stiff Clay, Sophie Moore

Architectural Engineering

This study is concerned with the comparison of driven and screw piles when exposed to lateral forces and the effects of gapping on stiffness and displacement. Stiffness contributions were determined from force-displacement profiles, gap depth formation curves, strain profiles, bending moment profiles, and P-Y curves. Driven piles were found to be about twice as stiff as screw piles at lower displacements. At larger displacements, the stiffness of the two pile types start to converge. When the piles are in full contact with the soil, stiffness contribution is derived from both the soil and the pile. When gapping is exhibited, the …

Liquefaction-Induced Dragload And/Or Downdrag On Deep Foundations Within The New Madrid Seismic Zone, Ishimwe Elvis

Graduate Theses and Dissertations

Deep foundation elements are typically used to transfer structural loads for multi-story buildings and large-span bridges to a competent soil layer when 1) the soil close to the ground surface has no sufficient bearing capacity, and when 2) liquefiable soils are encountered. The majority of the bridges constructed within seismic zones rely upon the stability of earthen embankments and deep foundation that are installed above or within liquefiable soil deposits. Despite large factor of safety values or different load and resistance factors being used to adequately design deep foundations within seismic areas, soil liquefaction may cause extensive damage to the …

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 …

Computational And Experimental Modeling Of Dynamic Foundation Interactions With Sand, Phd Thesis, Jeramy C. Ashlock

Jeramy C. Ashlock

The subject of dynamic soil-structure interaction (SSI) is fundamental to the design of structures and foundations to withstand dynamic events such as earthquakes, explosions and vibrations from traffic, wind, waves and machinery. With the tools of modern experimental and computational methods, a critical evaluation of current concepts and capabilities for the dynamic characterization of both surface foundations and embedded piles in granular soils is the first target. Well suited for this kind of fundamental study, a variety of scaled-model surface and pile foundations are designed and tested in a large geotechnical centrifuge using dynamic forced excitations. Used as a rigorous …