Sustainable application of waste tire chips and geogrid for improving load carrying capacity of granular soils

The objective of the present study is to explore the viability of using waste tire chips and combined waste tire chips, geogrid reinforcement for improving load-carrying capacity of sand. Under this study, series of laboratory model footing tests were conducted to study pressure settlement behaviour of Tire chip Reinforced Sand (TRS). In first phase, tests were conducted on TRS underlying poorly graded sand by varying parameters such as tire chip content, reinforcement depth of TRS Zone, relative density of TRS. In the second phase, tests were conducted on Geogrid Reinforced Sand (GRS) and results were compared with TRS, and subsequently in third phase, combined behaviour of TRS and GRS was studied. Results indicated that addition of tire chips significantly increases bearing capacity at low strains (s/B = 2-5%) as well as at high strains (s/B = 10-20%). Bearing Capacity Ratio (BCR) as high as 4.65 and 10.36 was observed at low and high strains respectively. Performance of TRS was found better than GRS at all strain levels. The BCR can be further increased to 11 if TRS is used in conjunction with GRS. Therefore, recommended technique has an advantage of enabling shallow foundations in situations that either demand use of deep foundations or costly ground improvement techniques thus providing economy in construction as well as safe disposals of large stockpiles of waste tires.