Scale Effects of Footings on Geocell Reinforced Sand Using Large-Scale Tests

Abstract

The scale effect on bearing capacity of shallow footings supported by unreinforced granular soils has been evaluated extensively. However, the subject has not been addressed for shallow footings on geocell-reinforced granular soils. In this study, load-settlement characteristic of large square footings is investigated by performing large-scale loading tests on unreinforced and geocell-reinforced granular soils. The effects of footing width (B), soil relative density of soil (Dr), and reinforcement depth (u) have been investigated. The test results show that the scale effects exist in geocell-reinforced soils, like unreinforced soils, and the behavior of small-scale models of footings cannot be directly related to the behavior of full-scale footings due to the difference between initial conditions of tests and the initial state of mean stresses in the soil beneath the footings having different dimensions. Large footings create higher mean stresses in the soil, resulting in low soil friction angle and initial conditions of the test approach to the critical state lines. The results of tests indicate that model experiments should be conducted on low-density soil for better prediction of the behavior of full-scale footings, otherwise, the predicted behavior of full-scale footings does not seem conservative.

Response of Square Footing on Geocell-Reinforced Sand Bed Under Static and Repeated Loads

“…However, the scale effect can be reduced by carefully controlling the test parameters [35]. The particle size of foundation soil, size of model footing and geocell size contribute to the scale effect in model tests on sand [32,36,37]. In case of prototype footing, the width of the footing (B) is usually very large in comparison to mean particle size (d 50 ) of the soil.…”

“…Results of a study on load-settlement characteristic of large square footings (150 to 600 mm) investigated by performing large-scale loading tests on unreinforced and geocell-reinforced (d/B = 1.66 to 0.416, h/B = 1 to 0.25, u/B = 0.33 to 0.083, tensile strength of geocell material = 15 kN/m) granular soils have shown that the effect of footing width on scale effect has the same trend at 65% relative density for both unreinforced and reinforced conditions [37]. This indicates that the model footing size has a much more dominant role than geocell parameters in the scale effect of the tests conducted.…”

Performance of Circular Footing on Expansive Soil Bed Reinforced with Geocells of Chevron Pattern

“…Indraratna et al [33] performed large scale cubical triaxial tests to evaluate the behavior of sub ballast with and without reinforcement under cyclic loading. Shadmand et al [34] investigated load settlement characteristics of large square footing through large scale loading test on unreinforced and geocell reinforced granular soil and reported that scale effect exist for geocell reinforced soils like unreinforced soils. The behaviour of small scale footing models cannot be directly related to that of the full scale footing.…”

Behavior of Eccentrically Inclined Loaded Ring Footings Resting on Granular Soil

“…About 120 laboratory test results have been reported regarding the ultimate bearing capacity of a strip footing subject to eccentrically-inclined load as a reduction factor [15]. There are many papers about the application of analytical and numerical approaches in the modeling of shallow footings subject to general loading [16][17][18][19][20][21][22][23][24].…”