Numerical Investigation Into the Behavior of Circular Pad Shallow Foundations Supported by Geogrid Reinforced Sand

Abstract

This study seeks to widen the pool of knowledge on the use and characteristics of geosynthetics, specifically in the area of circular foundations supported by geosynthetic reinforced sand. The main objective of the work was to increase the awareness of circular foundation systems and thus increase the accuracy of current laboratory methods. Also, compare the results with that of previous papers on the subject and to provide new model curves to estimate the bearing capacity of circular foundations. In this respect, the foundation and the soil underneath was modeled using four nots isoparameters finite element aid, while, for geogrid reinforcement, the four nots one-dimentional finite element model was used. The sand behavior was based on demolition elasto-plastic druckerprager criteria and for the reinforcement the linear criteria was used. The paper investigates the effects of the reinforcement placing properties, soil properties, reinforcement properties, and the geometric properties of circular foundations. The results showed that; the bearing capacity ratio at a settlement level for geogrid reinforced sand is effected considerably by parameters such as: reinforcement placement, reinforcement layers, reinforcement strength, geometric properties of circular foundations, and effects of using granular soils. Based on the results achieved, a number of design curves have been developed to assist with the estimation (design) of field bearing capacity of shallow foundations supported by geogrid reinforced soil. Keeping in mind the settlement limitations in real space, the curves have been developed for normal settlement levels up to a settlement ratio of 2.5%.

Laboratory Studies on Bearing Capacity of Strip Interfering Shallow Foundations Supported by Geogrid-Reinforced Sand

“…Also the results obtained show that the pressure-settlement curves for N=3 and N=4 are very close to each other. This contribution coincides with researches performed by Akinmusuru and Akinbolade (1981), Guido et al (1985), Marandi et al (2008) reported that the increase in bearing capacity for single reinforced footing is not much tangible when the number of reinforcement layers is greater than 3 [4,11,23]. However, Das and Omar (1994) and Boushehrian and Hataf (2003) reported that for a single reinforced footing the optimized N is 4 [7,9].…”

“…The results of this research showed the effects of reinforcement layers on the bearing capacity changes and tilt over closely spaced footings. Marandi et al (2008) studied the behavior of circular foundation supported by geogridreinforced soil using finite element method [11]. The results of their research showed that the number of reinforcement layers greater than 3 does not considerably increase the bearing capacity.…”