Mitigating the uneven settlement of nearby strip footings on loose saturated sand using concrete pedestals: A model test study

Abstract

Adjacency and interference of the footings are of importance in geotechnical engineering. Researchers have studied the behavior of adjacent footings by several approaches; however, the load-deformation mechanism used for such footings under unequal and non-simultaneous surcharges has not been explored to date. In this study, two series of experiments were conducted using small-scale 1 g models to investigate the behavior of two adjacent footings under reinforced and unreinforced soil conditions. The footings were installed with different side-to-side spacing and placed on loose saturate sand. The ultimate bearing capacity, settlement, and tilting of footings were evaluated when: (1) the footings rested on unreinforced sand and (2) the soil underneath the new footing was reinforced by concrete pedestals. The results indicated that reinforcing the new footing by three concrete pedestals at a spacing to footing's width ratio (S=B) of 0 (i.e., two coherent footings) led to increasing the bearing capacity of the new footing by 67%, compared to that of the unreinforced condition. Moreover, the settlement and tilting of the old footing adjacent to the new footing decreased up to 250% and 600%, respectively, in comparison to those of the unreinforced condition.