الفهرس 
Literature ReviewOnly 14 pages are availabe for public view
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Abstract
This research deals with the effect of the slope inclination and the proximity of the pile from the crest of the slope on the lateral capacity of a single vertical pile, embedded in cohesive soil. A case study conducted at the Caltran’s site in Oregon State University was implemented to support the research and validate the acquired results. The case study consisted of full scale lateral load tests conducted on a single vertical pile. The tests were performed in separate stages. First, a lateral load test on a single vertical pile embedded in levelled, cohesive soil, was carried out to provide the reference curves or backbone curves for comparison purposes. Then, a slope of 2H:1V was constructed at the site location, and the lateral load tests continued for different positions of the pile from the crest of the slope. Throughout this thesis, the distance of the pile from the crest is expressed in terms of “D”, where “D” is the pile diameter. The case study provided load-deformation curves for positions of 0D, 2D, 4D and 8D.
In order to determine the position of the pile from the crest of the slope where the presence of the slope has no effect on the lateral capacity of the pile, a numerical analysis was performed, implementing PLAXIS 3D 2020. A three dimensional finite element model was constructed, using appropriate boundary conditions, meshing
and constitutive models to simulate the field case. The model was first verified using the case of the pile positioned at the crest, to determine the validity of the applied material properties, and the load deformation curves obtained from the software. Afterwards, the numerical analysis was extended to cover all previously stated positions of the pile from the crest of the slope, including the case of the pile placed in levelled ground.
Backcalculated p-y curves, as well as, normalized p-y curves were constructed using the finite difference technique, with the aid of the results of the finite element analysis to provide p-multipliers that can be implemented into simple software programs to determine the straining actions on the pile, without the need to construct a complicated 3-dimensional model. Furthermore, a parametric study was conducted to study the effect of different parameters on the load-deformation beahviour as well as on the p-y curves and normalized p-y curves.
6.2 Conclusions
Based upon the numerical analysis model and construction of p-y curves using the finite difference technique, the following conclusions can be drawn:
• The numerical analysis model can accurately represent the field case study regarding the load vs. deformation curve for working loads. However, as the applied loads approach the ultimate state, the model fails to accurately simulate the site conditions due to the nonlinearity of the steel pile, which wasn’t taken into consideration.
• The soil resistance increases with depth measured downward along the pile length.
• Numerical analysis model can be used for back calculating p-y curves implementing the finite difference method.
• As the slope inclination angle decreases, the p-y curve for the pile located near the earth slope approaches the backbone curve, case of leveled ground.
The value of the p-multiplier, at a certain target depth, increases as the pile is placed farther from the crest of the slope until it tends to 1 when the pile is placed at a distance of 8D; i.e., the effect of slope diminishes at a distance of 8D and the lateral behaviour of the pile near the earth slope is similar to that of a pile placed in leveled ground.
• For various target depths, the p-multiplier ranges between (0.4-0.8) for the pile at a distance of 0D, (0.6-0.83) at a distance of 2D, (0.8-0.95) at a distance of 4D and (0.98-1) at a distance of 8D.
• The p-multiplier for the studied slope inclinations (n=0.5, 1, 2) ranges between (0.3-0.45) for the pile at a distance of 0D, (0.76-0.8) at a distance of 2D, (0.82-0.93) at a distance of 4D and (0.98-1) at a distance of 8D for a target depth of 1m.
• The modified chin method can be used to determine the ultimate capacity of piles under lateral loads.
• The factor of safety of the design loads obtained from the numerical analysis model increases as the pile is placed farther from the crest.
6.3 Future Recommendations
• For future research, it is recommended to study the effect of slope inclinations on the lateral capacity of piles embedded in cohesionless soil.
• Regarding the p-multiplier, it is recommended that researchers implement these factors in LPile software or any other p-y software program and compare the straining actions.
• The research can be extended to include the zone of failure of the slope from slope stability analysis softwares to study the effect on the lateral capacity of the pile when placed within the failure zone, or beyond it.
• Plasticity of the pile should be taken into consideration in pile modelling.