Tire-chip reinforced foundation as liquefaction countermeasure for residential buildings

To prevent vibration-induced and liquefaction-induced damage to residential buildings during earthquakes, a low-cost technique has been developed and described here. It utilizes a mixture of tire chips and gravel as the horizontal reinforcing inclusion under the foundation of residential houses. The horizontal reinforcing inclusion refers to a layer of tire chips and gravel which is placed horizontally beneath the foundation. This mixture of tire chips and gravel provides sufficient bearing capacity to the foundation. In this research, a series of small-scale 1 g model shaking table tests was performed to evaluate the effectiveness of the technique. In addition, cyclic undrained triaxial tests were performed to evaluate the liquefaction susceptibility of tire chip-gravel mixtures. The results of the model tests indicated that when the thickness of the reinforced layer is 10 cm (2 m in prototype) and the gravel fraction (percentage by volume of gravel in the mixture) is 50%, the technique yields the best performance. The element tests also indicated that the gravel fraction plays an important role. A gravel fraction of 50–60% by volume was found to be the best mixing percentage, at which the rise in excess pore water pressure could be significantly restrained without compromising the stiffness of the reinforcing inclusion.