Reinforcement of earth structures using scrap tires

This research was aimed at providing geotechnical information on the design and construction procedures related to the use of scrap tires in gravity retaining structures and reinforced fills. If layers of tires, side by side, are filled with soil and tied together to make a mat or a chain, and then placed in successive layers, the resulting structure can be used as a retaining wall or reinforced fill and can provide a practical alternative for the use of this waste. The research also investigated the chemical quality of effluent water emanating from buried tire waste.;The shear resistance of a soil-geotextile interface may be a fraction of the shear resistance of the soil itself. If the reinforcement function is accomplished with tire mats filled with soil, the shearing resistance between the soil and the reinforcement is primarily due to the shear resistance of the soil itself. If the tires are cut to remove the sidewalls, the placement of the soil in the tires is facilitated. A higher degree of compaction is therefore obtained and the shear resistance of the interface between the reinforcement and the soil corresponds to the shear strength of the soil. Earth structures using tires filled with soil have more flexibility than conventional structures and are able to withstand large differential settlements. The flexibility of the resulted material implies that it can be used to support earth fills on compressible ground.;An important feature of the investigations was a large number of field pull-out tests on different configurations of tire mats. These tests provided valuable data on the interaction between the different soils and the tire reinforcement. This behaviour is necessary for the design of tire reinforced structures. Also, three large plate loading tests were performed on the surface of the completed test fill to assess the load deformation behaviour of this composite material.;To evaluate any toxic effects of buried used tires on the surrounding groundwater, a drainage system was installed below the embankment and the effluent collected in three wells. Samples were periodically collected and analysed for chemical quality. Additional tests on water quality were performed in laboratory test columns in which tire chips were embedded in sand or clay to provide a conservative estimate.;Some organic compounds can be leached out of the tire reinforced structure placed above the water table. Laboratory batch tests performed on tire chips embedded in sand provided evidence of an increase in solution of certain metal elements of which some exceed their respective drinking water standards. (Abstract shortened by UMI.)...