Development of Innovative Pile Foundations for Seismic Isolation of the Structures Built on Swelling Clay Soils

Swelling clay soils are often located in seismic hazardous areas. It increases the risk of emergency moistening of a clay base. Using pile foundations for structures in the case of clay soils swelling causes the affect of negative friction forces. It contributes to the uneven vertical thrust of piles. For seismic isolation of pile structures, it’s necessary to develop protective measures requiring additional costs. Innovative designs of driven and filling piles were developed for swelling clay soils provided with elastic screens. In the case of using driven piles, tubular elements were used, made from a pack of the same type of old metal cord tires, in the internal holes of which special cutouts were made equal to the cross-sectional parameters of the driven pile. In the case of using filling reinforced concrete piles, the holes were first made corresponding to the outer diameter of old tires. On the inside, between the edges of old tires and the side surface of the filling pile shaft, there’s a polymer film preventing liquid concrete penetration into the cavities of recycled tires. The screens absorb the pressure and deformation of swelling clay soils, and also serve as seismic isolation during strong earthquakes. The proposed designs of piles for swelling clay soils are considered relatively cost-effective ones, as they are prepared on the basis of waste.