STABILITY ANALYSIS OF STRIP FOOTING ON REINFORCED SAND SLOPES

RAFI’ M. SULAIMAN AL-NE’AIMI

doi:10.26682/sjuod.2018.21.2.1

RAFI’ M. SULAIMAN AL-NE’AIMI College of Engineering, University of Duhok, Kurdistan Region-Iraq

DOI: https://doi.org/10.26682/sjuod.2018.21.2.1

Keywords: Reinforced sand slope;, Strip footing;, geogrid reinforcement;, Limit- equilibrium analysis;

Abstract

This paper presents a total of 55 runs using Slide v6 software computer program to study the stability of axially loaded strip footing located near the crest of sand slope model without or with geogrid reinforcement. The model represents an application of reinforced earth technique for foundations located on sloped embankments that behave as supports for retaining walls or bridge abutments. The parameters investigated were slope inclination , footing distance from edge of the slope b, length and number of geogrid layers and N, type of geogrid reinforcement in terms of its structure, polymer type, yield elongation % and strength, vertical spacing between geogrid layers and depth of embedment of footing .

The limit equilibrium analysis results show that (i) Slide v6 software program is efficient to study unreinforced or reinforced slope stability problems both for research or design purposes, (ii) Use of geogrid reinforcement would increase both slope stability and safety. The major benefit was obtained when reinforcing layers number N equal to four each of length 10B where (B = width of footing), (iii) SS30 geogrid is more effective for reinforcing slopes than TT045 type due to its higher pullout strength and other properties such as structure, shape, rib profile and grid junction tensile strength that affecting soil/grid interlock, and (iv) the optimum depth of the upper most layer of reinforcement was u = 0.5B whereas the optimum vertical spacing of the reinforcement layers lies in the range of 0.50B - 0.75B.

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