Investigation of tire chips-sand mixtures as preventive measure against liquefaction

This paper presents results of a series of element testing and model testing in which tire derived geosynthetics such as tire chips are utilized as liquefaction preventive backfill material. Undrained cyclic shear tests were conducted on tire chips and sand mixed tire chips for various percentages of mixtures, and the liquefaction potentials of the mixtures were evaluated. The best mixing percentage of tire chips was found to be close to 50% by the total volume of sand. Also, a model shaking table test on a caisson type quay wall was conducted on liquefaction prevention measures for backfill sand reinforced with tire chips. The test results have demonstrated that, despite the fact that the tire chips reinforced composite backfill has a very low relative density, there was no liquefaction in the backfill. Also, the earth pressure on the wall and its residual displacement could be substantially reduced, implying a good performance of the soil-structure system during earthquake loading.