PERMEABLE SYNTHETIC FABRIC MEMBRANES 1. THEIR USE IN THE STRENTHENING OF SOILS

This article describes some of the uses these fabrics are put to in soil "strengthening". They are frequently incorporated at subgrade level for temporary road construction or for gaining access over very poor ground conditions. Their dominant function in this case is to separate the soft subgrade from the subbase and thus prevent contamination of the subbase (i.e. the subgrade working its way up under repeated traffic loads) leading to its failure. For the fabric to give any significant reinforcing action to the pavement (i.e. an increase in its bearing capacity) large deformation of the soil-fabric system must generally be accepted. These large deflections make the use of fabrics unacceptable for permanent pavements under normal conditions, although they would be of use with weak soils such as low density sands and very soft clays. The load distributing properties of the fabric can be of value for temporary pavements or for permanent pavements during construction where local soft-spots occur in a subgrade. In these cases, the soil-fabric system deforms locally and the fabric redistributes load onto the surrounding area thereby limiting local deflection and thus limiting local pavement failure and reducing differential settlements. Similar separation and reinforcing benefits occur when the fabric is placed under mass fill, e.g. embankments built on soft foundations. In view of the wide-ranging types of fabrics available with greatly different properties, it is not surprising they have also been considered and used as an alternative to steel or aluminum in reinforced earth. Some woven fabrics have strengths, extension moduli, break strains and creep properties similar to steel mesh; while some non-woven have relatively low strengths and extension moduli less than soil. The choice of fabric for a given purpose must consider the environment and conditions in which it will be used. Basically, there are cases where large strains must be accepted as unresistable in the soil mass, and for these extensible fabrics, e.g. non-woven, might be ideal. Where strains in the soil mass must be contained or restricted, the use of a stiffer woven fabric is applicable. The need for a fabric to provide a drainage path or act as a filter in addition to separation and reinforcement will sometimes occur and for this a different type of fabric will be required.

  • Availability:
  • Corporate Authors:

    Foundation Publications Limited

    7 Ongar Road
    Brentwood CM15 9AU, Essex,   England 
  • Authors:
    • HOARE, D J
  • Publication Date: 1978-7

Media Info

  • Features: Figures; Photos; References;
  • Pagination: p. 33-36
  • Serial:
    • GROUND ENGINEERING
    • Volume: 11
    • Issue Number: 5
    • Publisher: EMAP CONSTRUCT LIMITED
    • ISSN: 0017-4653

Subject/Index Terms

Filing Info

  • Accession Number: 00184597
  • Record Type: Publication
  • Source Agency: Ground Engineering
  • Files: TRIS
  • Created Date: Feb 3 1979 12:00AM