Mitigation of Lateral Spreading Effects on Bridge Piles Using Tire-Derived Aggregate

This study focuses on evaluating the feasibility of using a layer of tire-derived aggregate (TDA) placed upslope from a bridge foundation system to absorb ground deformations associated with lateral spreading effects of the downslope movement of a surficial crust and reduce stresses imposed on the bridge foundation. In addition to being a compressible material, TDA has comparable shear strength to granular soils and has high permeability to provide drainage of excess pore water pressures. Four quasi-static lateral compression tests were performed to quantify the deformation response of steel and concrete piles within TDA layers for different spacings between the pile and a moveable wall. The results indicate that a TDA layer installed next to a fixed-base pile will absorb horizontal displacements at the pile head location of up to nearly two pile diameters in magnitude for the steel and concrete piles while limiting shear forces induced in the pile to 25% of the applied wall loads and preventing pile yielding. In addition to presenting information on the pile deformation response for different TDA spacings, p–y curves for the steel and concrete piles in TDA and the lateral compression curves of the different TDA layers were quantified so that the results from this study could be extended to field design cases for piles with different geometries and end boundary conditions.