Interference behavior of four adjacent footings on geosynthetic reinforced sand

Abstract

Bearing capacity, the supporting power of soil plays an important role in design of shallow foundation. The general scenario is to design the footing as an isolated footing. The interference and spacing effects are generally ignored while designing the footings. In recent years, several heavy axisymmetric structures are coming up very close to each other. Also uses of geosynthetic materials are mostly preferred as soil reinforcement for improving the performance of shallow foundation. The effect of interference of adjacent footing may change the behavior from serviceability point of view and therefore, a need is felt to investigate the effect of interference between closely spaced footings on reinforced soil. In the present study, the bearing capacity of four square adjacent footings on geosynthetic reinforced sand and the effect of different parameters contributing to their performance were studied using model plate load tests. The parameters included were footings placement pattern, depth of footings, type of reinforcement, and number of reinforcement layers. In each case, different center to center distance between footings were applied for the purposes of comparison among all of the results. To evaluate these effects, laboratory model plate load tests were conducted at 55% relative density of sand. It was observed that the footing placement pattern, depth of footings, type of reinforcement, and number of reinforcement layers play a significant role in bearing capacity. The bearing capacity of interfering footing increases as the spacing between footing decreases. Load responses of four footings are similar to those of the single footing at distances greater than three times the footing width.