Strengthening of unstable embankments using geogrids of basalt fiber and reinforced bars

Abstract

The article deals with the problem of stability of embankments on a strong and a weak base. On the main field-site of roadbed composed of clay soils ballast depressions (troughs, beds) are distributed. Existence of weak soils within the verges and sloping parts of embankments is experimentally established. The ongoing natural and man-made processes in the soils of embankments on a solid foundation lead to decrease in the strength characteristics of soils and slumping slope wash-outs. In view of these processes structures to strengthen unstable embankments are designed with geogrids of basalt fiber and rebar. On unstable sites of embankments the geogrid is laid after deep purification of crushed stone by rolling strips 10 m long on the shorter site and placing them behind a bar chain of ballast cleaner car. Curtailed roll is unrolled then. On a slope through every 1,5 m across and along the tracks rods are clogged, on which a geogrid is put on through cells. Rods immerse up to the depth of 1,5 - 2 m. On sites with narrower main platform by use of these materials the broadening of the main platform is made. A layer of the draining soil is poured out on a covering. The calculation procedure of anti-deformation design is given. The article gives an analysis of embankments depression on weak grounds. To the most extent depressions are common in the permafrost. Causes of long-term embankment depression - squeezing ground - are estimated. To eliminate such depressions it is need to raise permafrost level in the area of the slope sole of embankments or create a mechanical barrier. Technical solution using geogrids of basalt fiber and rebar designed as a mechanical barrier. The article sets out the conditions of application of such design.

Keywords

• embankments
• solid base
• weak base
• geogrid of basalt fiber
• reinforced bar