Experimental study on the performance of strip footings on geocell-reinforced granular slopes

Abstract

A series of reduced scale plate load tests was conducted to evaluate the bearing capacity of a strip footing resting on granular slopes. The effect of three factors including geocell burial depth, geocell length and spacing of geocell layers were discussed and evaluated. In this regard, 18 tests were performed to investigate the behavior of one and two layered geocell-reinforced slopes as well as the unreinforced slope and plain conditions. The results suggest that in single-layered geocell-reinforced slope, the optimum burial depth of the first layer of geocell reinforcement is 0.1 times of the strip footing width, whereas at greater depth beneficial effect of the geocell will reduce. In addition, expanding the reinforcement length up to approximately three times the foundation width could effectively increase the bearing capacity, whereas extending the length beyond that does not lead to any significant improvement. Furthermore, it was observed that use of two geocell layers by considering an optimum geocell space of 0.2 times of the foundation width could enhance the bearing capacity up to 226% in comparison with the unreinforced slope, and up to 79% of the plane condition for settlement ratio of 15%. Finally, the results indicate that the efficiency of the geocell reinforcements in lessening the gap between slope and plane conditions increases as the settlement of the footing rises due to better mobilization of dilation characteristics of granular backfill material and better lateral confinement of coarse aggregates in greater strains.