Tire-reinforced earthfill. Part 1: Construction of a test fill, performance, and retaining wall design

TLDR

Scrap tires pose a major environmental problem, occupying landfill space and presenting health and fire hazards. The study proposes using scrap tires as reinforcement for retaining walls and slopes to reduce waste. A 57 m high × 17 m wide instrumented test fill was built, employing ~10 000 whole and sidewall‑removed tires tied with polypropylene rope in both cohesionless and cohesive backfills, and subjected to plate loading, pull‑out, water‑quality, and laboratory tests. Results show that reinforced earth fills are practically feasible, with large plate load tests and field behavior confirming that negative wall friction increases active thrust when the wall is more compressible than the backfill. Recommendations for designing retaining walls with scrap tires are provided.

Abstract

The satisfactory disposal of scrap tires is a major environmental problem worldwide. This waste occupies valuable space in landfill sites, and tire stockpiles pose serious health and fire hazards. The use of scrap tires as reinforcement for construction of retaining walls and slopes is a viable method towards reduction of this waste. This paper describes the construction of a 57 m high × 17 m wide instrumented test fill, comprising both retaining wall and reinforced slope sections. Approximately 10 000 whole tires and tires with one sidewall removed, tied together with polypropylene rope, were used in both cohesionless and cohesive backfills. The testing program also included plate loading tests, field pull-out tests on tire mats, water-quality assessment in the field and laboratory, and other complementary laboratory testing. This first paper, in a series of three, demonstrates the practical feasibility of constructing reinforced earth fills using scrap tires. Results of large plate load tests and the field behaviour with particular reference to the design of the retaining wall sections are presented. The paper emphasizes the role of negative wall friction in increasing the active thrust when the retaining wall becomes more compressible than the backfill. Recommendations for the design of retaining walls using scrap tires are presented.Key words: scrap tires, earth reinforcement, retaining walls, reinforced slopes, plate load test, construction, performance.