Spelling suggestions: "subject:"shear strength off soils"" "subject:"shear strength oof soils""
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A model for predicting narrow tool behavior under dynamic conditionsSwick, W. Christopher January 1984 (has links)
Most models available today for predicting the forces encountered by tillage tools apply to slow moving tools and do not take into account speed effects. However, most tillage operations are performed at speeds in the range of 2-8 km/h, and experimental studies show that tool forces increase significantly with tool speed.
This effort of developing a model for predicting the forces on narrow tools under dynamic conditions was carried out in three steps. First, a series of laboratory tests was conducted to determine the effect of shear rate on soil shear strength and soil-metal friction parameters. Second, a model was developed to include dynamic effects. Third, the model was verified experimentally under laboratory conditions.
Direct shear tests using a conventional shear box were conducted on an artificial soil at shear rates between 0. 5 and 12 7 cm/min. Experimental results showed that for the soil tested, the angle of internal friction, soil-metal friction angle, cohesion, and adhesion are independent of shear rate.
A soil-tillage tool interaction model developed for quasi-static soil failure was modified to include shear rate effects and accelerational force effects.
Experimental verification tests for the model were conducted under controlled conditions using an indoor soil bin facility. Tests were conducted with flat tines at speeds from 5. 4 to 120 cm/s. The overall trend was for the model to underpredict the observed total tool force by 16 %. However, the model demonstrated that terms including accelerational force effects can account for a large portion of the increase in tool force observed to occur with an increase in tool speed. / Master of Science
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A unified elasto-plastic model for saturated loosely compacted completely decomposed graniteTo, Chiu-yin., 杜昭彥. January 2008 (has links)
published_or_final_version / Civil Engineering / Master / Master of Philosophy
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Experimental study of shear behavior of soils with abundant coarse particles associated with slip zones of large landslides in the ThreeGorges reservoir, ChinaLi, Yanrong, 李彥榮 January 2009 (has links)
published_or_final_version / Earth Sciences / Doctoral / Doctor of Philosophy
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The influence of halloysite content on the shear strength of kaoliniteGabor, Reka Katalin 01 January 1981 (has links)
The objective of this thesis is to determine the relative shear strengths of halloysite, kaolinite, synthetic mixtures, and local soils, to investigate the influence of halloysite content on the shear strength of kaolinite, and to explore the possibility that the strength properties of soil clays might be controlled by the relative content of their component minerals.
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Failure of saturated sandy soils due to increase in pore water pressureJunaideen, Sainulabdeen Mohamed. January 2005 (has links)
published_or_final_version / abstract / toc / Civil Engineering / Doctoral / Doctor of Philosophy
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Soil property determination through a knowledge-based system with emphasis on undrained shear strength馮可達, Fung, Ho-tat. January 1997 (has links)
published_or_final_version / Civil and Structural Engineering / Doctoral / Doctor of Philosophy
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A model of stress distribution and cracking in cohesive soils produced by simple tillage implements /Ibarra, Sandra. January 2001 (has links)
The objective of this research was to further understand the behavior of the soil under the action of a tillage tool, with the purpose of finding a relation between the tool geometry and the resultant soil seed bed. Thus the problem consisted of understanding the mechanics of producing soil break up and to find a logical method of analyzing it. / The problem was solved using fundamental principles of soil mechanics and force equilibrium analyzis. As a result, a mathematical model was developed which describes three failure zones within the cut soil volume. The model can be programmed into a computer to generate maps of normal and shear stresses to visualize the three failure zones. / The failure zones are the shear failure zone, the tensile fracturing zone and the no failure zone. The tensile fracturing zone is delimited by the tensile stress reaching the tensile strength of the soil at the given soil moisture content and soil density. The tensile strength of the soil was measured using an apparatus and method designed in this research. / The mathematical model gives an explanation of the mechanics of crumbling and the shape of the failed volume, but it does not give information concerning soil aggregate quality and arrangement within the soil furrow. Then, a method of analyzing the formed aggregates was developed which considers some soil physical properties of aggregates. / The study concluded that the smaller tool width and the smaller tool rake angle, among the ones used in this research, produced the most efficient geometry in producing the largest amount of soil break up, the most uniform aggregate formation and the most stable aggregate arrangement. The same tool geometry requires less energy per unit volume of soil disturbed. The best performance is produced at the lowest soil water content among those tested.
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A critical assessment of moist tamping and its effect on the initial and evolving structure of dilatant triaxial specimensPark, Jin Young 12 1900 (has links)
No description available.
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Strain rate effects in pressuremeter testing and neural network approach for soil modelingPenumadu, Dayakar 05 1900 (has links)
No description available.
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Laboratory modeling of reinforced earthHornbeck, David Earl 12 1900 (has links)
No description available.
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