Lateral Pressures Behind Retaining Walls Backfilled with Tire Derived Aggregate

Tire derived aggregate (TDA) consists of tires cut into pieces typically ranging in size from 0.5 in. (12 mm) and 12 in. (305 mm) and has been used as a construction material in several states over 20 years for various applications including lightweight fill, thermal insulation, vibration attenuation, and drainage layers. A special case of use as lightweight fill is backfill for retaining walls. Over the past decade the use of TDA as backfill for retaining walls has been studied in a series of five full-scale instrumented projects. The primary goal of these projects was to measure earth pressures behind retaining walls backfilled with TDA. The data was used to make inferences relative to post-construction lateral earth pressure coefficients and to quantify potential benefits in terms of reduced lateral pressures and reduced overturning moments acting on the structures. The data supports the use of a lateral pressure coefficient, K, equal to 0.3 for TDA used as backfill for cantilever retaining walls with TDA layers up to 10 ft (3 m) thick. For a typical unit weight of TDA, ã = 50 pcf (7.9 kN/m3), the resulting equivalent fluid pressure would be 15 pcf (2.4 kPa/m). The use of the lower equivalent fluid pressure for the TDA could lower design lateral pressures on the wall stem and could result in a reduction of the resultant moment at the base of the retaining wall.

Language

  • English

Media Info

  • Media Type: DVD
  • Features: Figures; References;
  • Monograph Title: TRB 89th Annual Meeting Compendium of Papers DVD

Subject/Index Terms

Filing Info

  • Accession Number: 01157856
  • Record Type: Publication
  • Report/Paper Numbers: 10-4012
  • Files: TRIS, TRB
  • Created Date: Jan 25 2010 12:03PM