Experimental assessment of geotextile serviceability lifetime as ballasted railway filter focusing on clogging phenomenon

Abstract

Abstract In this research, the main goal is investigation of the clogging phenomenon of geotextile, as a separator material between the ballast and subgrade of railway track. Firstly, a Slurry Pumping Simulator Apparatus (SPSA) has been developed. Using SPSA, the performance of geotextile filter is assessed subjecting to different conditions of silt slurry pumping. For this purpose, the slurry density (soil over water weight ratio), slurry pumping frequency and geotextile Apparent Opening Size (AOS) have ranged between 1 15 t o 1 2 , 3 to 10 Hz and 0.06 to 0.2 mm, respectively. Also, slurry pumping pressure has chosen as 97, 117 and 141 kPa. In this regard, the ratio of slurry passing flow rate in proportion to water passing flow rate through geotextile, was considered as a determinative parameter. The results indicated that increase in slurry density and decrease in AOS cause geotextile clogging time reduce while the variation of slurry pumping pressure does not remarkably influence that. Furthermore, an equation was derived for the ratio of slurry passing flow rate in proportion to water passing flow rate through geotextile in which the examined parameters varied. Eventually, a numerical example was solved using the proposed equation.