Design and Construction of Horizontal Drains Using Large-Sized Shredded Scrap Tires

摘要

One application for recycling large (1 -m top size) shredded tires is as an economical alternative to conventional field tile, drainage pipe, and gravel drains. The objective of this research was to develop guidelines for design of horizontal drains constructed with large-sized shredded scrap tires. The compressibility and hydraulic conductivity of the shredded tires, required for horizontal drain design, were evaluated with a large-scale permeability-compression apparatus. The test results showed that these scrap tires compressed to 50% strain under a vertical stress of about 20-30 kN/m~2. The hydraulic conductivity of the tire shreds decreased with increasing vertical strain and typically ranged between about 1.5 and 7 cm/sec. A value of 2 cm/sec was selected for use in the design guidelines. A full-scale shredded tire horizontal drain was installed in a trench 1.4 m wide x 3 m deep and 20 m long to assess field performance. This prototype drain was tested and monitored over a period of about 1 year. The field test results showed that the shredded tire drain could effectively conduct flows of 0.0058 m~3/sec and that groundwater flow was diverted to the drain. Field performance of the full-scale horizontal drain and hydraulic conductivity and compressibility results from the laboratory tests were used to develop design guidelines for shredded scrap tire drains. The research results indicate that a horizontal drain constructed with large-sized shredded scrap tires provides effective drainage and lowering of the water table in low permeability soils.