BIOTECHNICAL STABILIZATION OF STEEPENED SLOPES

The use of tensile inclusions makes it possible to repair slope failures or to construct steepened slopes along highway rights-of-way. Live cut brush layers can be used in place of or with synthetic fabrics or polymeric geogrids for this purpose. This approach, which is termed biotechnical stabilization or soil bioengineering, entails the use of living vegetation (primarily cut, woody plant material) that is purposely arranged and imbedded in the ground to prevent surficial erosion and to arrest shallow mass movement. In the case of brush layering, the live cut stems and branches provide immediate reinforcement; secondary stabilization occurs as a result of adventitious rooting along the length of buried stems. Imbedded brush layers also act as horizontal drains and wicks that favorably modify the hydrologic regime in the slope. The basic principles of biotechnical stabilization are described. Guidelines are presented for analyzing the surficial, internal, and global stability of brush layer-reinforced fills. A case study is reviewed in which live brush-layer inclusions were used to stabilize steep slopes along a roadway. A brush-layer buttress fill was used to repair an unstable cut slope along a highway in Massachusetts. Several repair alternatives were considered in this case. Scenic and environmental considerations with stability analyses eventually dictated the use of a composite, drained rock, and earthen brush-layer fill. The rock section was placed at the bottom to intercept critical failure surfaces that passed through the toe of the slope. Biotechnical stabilization resulted in a satisfactory and cost-effective solution; the treated slope has remained stable, and it blends in naturally with its surroundings.

Language

  • English

Media Info

  • Features: Figures; Photos; References;
  • Pagination: p. 23-29
  • Monograph Title: Mechanically stabilized backfill and properties of geosynthetics and geocomposites
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00712986
  • Record Type: Publication
  • ISBN: 0309061105
  • Files: TRIS, TRB
  • Created Date: Oct 12 1995 12:00AM