Breakout Resistance of Objects Embedded in Ocean Bottom

Abstract

This study is devoted to factors affecting the magnitude of force needed to cause complete withdrawal of objects embedded in sediments of the ocean bottom. Following a literatare review, most discussions are centered around the basic problem of a centrally loaded object pulled by I a vertical force from a sediment with level surface. Considerations of effects of eccentric and inclined loading, as well as of slope of the L~i 1) The effect of soil liquidity and/or compressibility on failure pattern in the overburden soil a!,d magnitude of breakout factors. 2) The effect of time on development of adhesion between objects and the surrounding soil; the relationship between adhesion in te nsion and adhesion in shear. 3) The nature and magnitude of force of soil suction on objects; the effects of load inclination ?nd eccent-icity on magnitude of this force. 4) The nature and magnit,ide of breakout force in liquid soils; connection between composition Fnd structure of such soils and their rheological constants of lquid an, semi-liquid soils.

Geotechnical Behavior of Helical Piles Via Physical Modeling by Frustum Confining Vessel (FCV)

“…3b. In the first state, total capacity of helical pile in compression or tension is the sum of the capacities of the individual helices plus shaft resistance (Meyerhof and Adams (1968);Vesic (1971);Canadian Geotechnical Society (2006). In the second state a cylindrical shear failure surface is formed with the connecting uppermost to lowermost helices.…”

“…In compression loading, the axial capacity is derived from the bearing resistance below the bottom helix and the shear resistance along the cylindrical surface as mentioned above (Vesic (1971); Mitsch and Clemence (1985); Das (1990);Zhang (1999); CGS (2006); Tappenden et al (2009) . Fig-3.…”

Explosive Anchor for Salvage Operations - Progress and Status

“…One method for sands is based upon Vesic's (1969) analysis of the problem of the expansion of a spherical cavity close to the surface of a semi-infinite plastic solid. Vesic's theoretical analysis was chosen because it showed good agreement with results of model tests on loose to medium dense sand which would be typical of ocean depositions.…”

“…For each soil, there is a characteristic relative depth D/B (D/B = ratio of depth of embedment to fluke diameter) beyond which anchor plates start behaving as "deep" anchors and beyond which breakout factors reach constant final values (Vesic, 1969). Experimental data concerning "deep" anchors behavior are available for uniform circular and square anchor plates, however, nothing is available for rectangular sections.…”

Pullout capacity of small ground anchor: a least square support vector machine approach

“…Because of the small capacities and the temporary nature of their functions, engineers rarely put efforts into collecting engineering properties of soils for the design of small ground anchors. These constraints lead to design uncertainty even though various methods are available for determining the pullout capacity of ground anchors (Meyerhof and Adams, 1968;Vesic, 1971;Meyerhof, 1973;Das and Seeley, 1975;Das, 1978;1980;1987;Rowe and Davis, 1982a;1982b;Vermeer and Sutjiadi, 1985;Murray and Geddes, 1987;Dickin, 1988;Sutherland, 1988;Koutsabeloulis and Griffiths, 1989;Rao and Kumar, 1994;Basudhar and Singh, 1994). Shahin and Jaksa (2003) initiated a different approach and paved the way for a rational design of small anchors at a nominal cost.…”