Performance assessment of a railway turnout geotextile
Many railways have been making increasing use of the heavier mass per unit area geotextiles, bringing into question the financial viability of their use. In order to assess the viability of turnout geotextiles, two closely spaced turnouts, positioned on an embankment constructed of compacted clay at Rosser, near Winnipeg, were rehabilitated in September 1981. Under one turnout, a Turn Out Pack System (TOPS) geotextile of variable mass per unit area (550–1100 g/m2 (16–32 oz/yd2)) was used; with the other, no geotextile was used. The ballast was a metamorphic granodioritic gneiss known locally as Kenora granite. This article summarizes the findings of excavations made to assess the performance of the geotextile. The assessment excavations were made in August 1984 after an average of 13.6 × 106 gross tonnes (15 × 106 gross tons) per year per track of traffic. The results clearly show the damage penalty to the ballast from fouling caused at the nongeotextile locations. Key words: railways, ballast, subballast, geotextile, fouling, pumping, fines, equivalent opening size (EOS).