The geotextiles for RRR method

FR Grid / RRR method

  • Geotextile product
  • Certified product by Railway Technical Research Institute

Outline

Highly durable, sheet type reinforcement for embankment with high-strength vinylon fiber

FR Grid is a geotextile coated with a high-strength vinylon fiber grid. It was developed for the RRR-B construction method (reinforced embankment method), in which the slope can be constructed vertically using the embankment reinforced by geotextile and the rigid wall surface.

Protect the safe operation of railways with geotextiles

The RRR method is a reinforced soil method developed by Railway Technical Research Institute.
A geotextile reinforced embankment is constructed in advance, and a cast-in-place concrete wall surface shall be constructed after the embankment and foundation ground have stabilized. It is possible to construct a concrete integrated wall with excellent safety. This method has many achievements in Shinkansen, conventional lines and private railways.

Characteristics

  • Highly strong and suitable for embankment reinforcement
  • Excellent weather resistance, chemical resistance, cold resistance and heat resistance
  • Excellent resistance to damage during construction
  • It maintains sufficient strength against momentary loads during earthquakes and repeated train loads

Application

  • As sheet type reinforcement for reinforced embankment method (RRR-B method)

 

Standard / specification

Standard / specification

Product No.  Material
(base cloth)
Weight
(g/m2)
Mesh
(mm)
Width of string of warp direction
(mm/strand)
Width×Length
(m)
FR-30W Vinylon 320 21×15 3 2×50
FR-60W Vinylon 600 23×15 7 2×50
  • *The mesh size indicate “warp x weft”

Design value

Product No. Ta Taj Tai Tae Ks
Quality control strength
(kN/m)
Firm design strength
(kN/m)
Temporary design strength
(kN/m)
Seismic design strength
(kN/m)
Spring value for wall stress calculation
(kN/m)
FR-30W 41 20 35 35 490
FR-60W 81 40 69 69 980
  • * The above figures are the results of a certification test conducted by the Railway Technical Research Institute.
  • * Reduction coefficients αj, αi, and αe are values for the product warranty value Ta.
  • * Ks is a 5% strain value (calculated from the tensile test in the air)

Main materials

Member for RRR method

Standard type welded wire mesh Fixing pin
Drainage sheet Drainage bag

 

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