Behavior of Vertically Confined Square Footing on Reinforced Sand under Centric Inclined Loading

Abstract

This study presents the behavior of vertically confined square footing on geogrid-reinforced sand under centric inclined loading through a series of experimental tests. The load was applied at 5°, 10° and 20° angles of inclination with the vertical. The tests were conducted on surface footing, footing with confiner and footing with confiner and horizontal reinforcement configurations subjected to inclined loading. Parametric variations like depth of the confiner (d=1B, 1.5B, 2B), number of geogrid layers (N; varies with variation in depth of confiner), and spacing between horizontal reinforcements (Y=0.25B, 0.5B, 0.75B, 1B) have been investigated at the top surface dimension of confiner (D) as 1.0B, 1.5B and 2.0B (where B is the width of the model footing). Results show that combined effect of confiner and horizontal reinforcement increases the ultimate bearing capacity of footing significantly compared to only confiner for all angle of inclinations. It can also be observed that load bearing capacities decrease with increase in angles of inclination and record the minimum improvement at 20° angle of inclination. Improvement in bearing capacities and reduction in settlement of footing analyzed in terms of bearing capacity ratio (BCR) and settlement reduction factor (SRF) are compared for all footing configurations. To summarize, the test results showed that confiner along with reinforcement can be considered as an economic ground improvement technique for shallow foundations to counter against heavily inclined loading.

Keywords

• centric inclined loading
• load intensity
• settlement
• geogrid
• sand
• square footing