الفهرس 
Chapter 1 : IntroductionOnly 14 pages are availabe for public view
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Abstract
Laterally loaded piles can be classified as “active” and “passive” piles. Active piles are exposed to external lateral loads. Passive piles are exposed to lateral soil movement from an unstable layer. Piles that support bridge abutments resting on soft clay are one form of passively loaded piles. This is a complex and challenging problem in geotechnical engineering. Raked piles are known for their effectiveness in resisting active lateral loads; however, their performance under passive loading has an argument and needs more study.
In this thesis, a numerical study was conducted using PLAXIS 3D software to study the effect of using one row of raked piles (RPG) under a bridge abutment on soft clay soil and compare it with a vertical pile group (VPG). The study was conducted on two parametric studies. The first one concerns the effect of inclination angle and other factors that are affected by applying different raking angles (embankment load, construction time of embankment, and loading type). The other parametric study concerns the geometry of the piles and studies four factors (pile spacing to diameter ratio, pile diameter, pile length, and pile shape).
The main observation of using RPG is the reverse movement towards the backfill. That movement reduces the lateral displacement, bending moment for the piles, and differential settlement; however, it increases the passive pressures on the front pile, and the abutment wall has a reverse movement that may cause failure. These values vary successively with increasing raking angles. RPG produced lower lateral displacements, bending moments, and higher passive loading for the front piles compared to VPG for all studied factors. Increasing embankment load and pile spacing/diameter ratio have a significant effect on increasing lateral movement, bending moment, and lateral pressure on the piles for VPG and RPG. RPG is preferable to use with a higher embankment load. Increasing the time of construction of the embankment, pile diameter, pile length, and use of square piles have an effective effect on the piles, decrease lateral movement, and produce more resistance. Lower times for embankment construction, lower pile diameter, and lower pile length are more effective for the RPG. The type of applied loading has a significant effect while applying pure active loading; raking piles aren’t preferable to use.
Finally, it’s suggested using RPG under the bridge abutment for its effectiveness in decreasing overall lateral movement, but with a smaller raking angle suggested not to increase by about 10°, and cautions must be taken while using it.