Abd, Akram Hasan (2017) Geosynthetic-reinforced and unreinforced soil slopes subject to cracks and seismic action : stability assessment and engineered slopes. PhD thesis, University of Warwick.

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Abstract

The main purpose of this thesis is on one hand to enhance the current predictive capabilities of the stability of soil slopes and on the other hand, to improve the design practice to stabilise natural slopes showing signs of distress and make the design of engineered slopes more affordable. To achieve the first objective an analytical method achieved by the upper bound theorem of limit analysis and the pseudo-static approach is derived for the assessment of the stability of slopes manifesting vertical cracks and subject to seismic action. The method is validated by numerical limit analyses and displacement-based finite-element analyses with strength reduction technique. Employing this method slope stability charts to assess the stability factor for fissured slopes subject to both horizontal and vertical accelerations for any combination of c, φ, and slope inclination are produced.

To achieve the second objective limit analysis was employed to derive a semi-analytical method to extend the applicability of current method to design the slope reinforcement for frictional backfills to cohesive frictional backfills. Design charts providing the amount of reinforcement needed as a function of cohesion, tensile strength, angle of shearing resistance and slope inclination are obtained. From the results, it emerges that accounting for the presence of cohesion allows significant savings to be made, and that cracks are often significantly detrimental to slope stability so they cannot be overlooked in the design calculations of the reinforcement. Also, a new numerical method to determine multi-linear profiles of optimal shapes for reinforced slopes in frictional backfills is presented. The method is based on the limit analysis upper bound method together with genetic algorithms and provides an optimal profile for a prescribed average slope inclination, backfill strength properties and desired number of layers to be used. Several stability charts illustrating the savings on the required amount of reinforcement are provided for the benefit of designers.

Item Type:	Thesis (PhD)
Subjects:	T Technology > TA Engineering (General). Civil engineering (General)
Library of Congress Subject Headings (LCSH):	Landslides -- Forecasting, Slopes (Soil mechanics) -- Stability, Geosynthetics, Soil mechanics -- Mathematical models, Geotechnical engineering -- Mathematical models
Official Date:	July 2017
Dates:	Date Event July 2017 Submitted
Institution:	University of Warwick
Theses Department:	School of Engineering
Thesis Type:	PhD
Publication Status:	Unpublished
Supervisor(s)/Advisor:	Utili, Stefano ; Mottram, J. Toby (James Toby), 1958-
Sponsors:	Higher Committee for Education Development in Iraq
Format of File:	pdf
Extent:	xxiv, 216 leaves : illustrations, charts
Language:	eng

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