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Bearing capacity of strip foundations reinforced with geogrid sheets by using upper bound finite‐element limit analysis
Author(s) -
Kumar Jyant,
Sahoo Jagdish Prasad
Publication year - 2013
Publication title -
international journal for numerical and analytical methods in geomechanics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.419
H-Index - 91
eISSN - 1096-9853
pISSN - 0363-9061
DOI - 10.1002/nag.2189
Subject(s) - geogrid , bearing capacity , limit analysis , reinforcement , finite element method , geotechnical engineering , cohesion (chemistry) , soil water , upper and lower bounds , mechanically stabilized earth , shear (geology) , structural engineering , materials science , mathematics , engineering , geology , composite material , physics , mathematical analysis , quantum mechanics , soil science
SUMMARY By using the upper bound finite‐elements limit analysis, with an inclusion of single and two horizontal layers of reinforcements, the ultimate bearing capacity has been computed for a rigid strip footing placed over (i) fully granular, (ii) cohesive‐frictional, and (iii) fully cohesive soils. It is assumed that (i) the reinforcements are structurally strong so that no axial tension failure can occur, (ii) the reinforcement sheets have negligible resistance to bending, and (iii) the shear failure can take place between the reinforcement and soil mass. It is expected that the different approximations on which the analysis has been based would generally remain applicable for reinforcements in the form of geogrid sheets. A method has been proposed to incorporate the effect of the reinforcement in the analysis. The efficiency factors, η c and η γ , to be multiplied with N c and N γ , for finding the bearing capacity of reinforced foundations, have been established. The results have been obtained (i) for different values of ϕ in case of fully granular and cohesive‐frictional soils, and (ii) for different rates at which the cohesion increases with depth for a fully cohesive soil. The optimum positions of the reinforcements' layers have also been determined. The effect of the reinforcements' length on the results has also been analyzed. As compared to cohesive soils, the granular soils, especially with higher values of ϕ , cause a much greater increase in the bearing capacity. The results compare reasonably well with the available theoretical and experimental data from literature. Copyright © 2013 John Wiley & Sons, Ltd.