Comparative study on performance and index tests simulating abrasion damage of a woven geotextile

A series of modified sliding block/sandpaper tests are performed to investigate the relationship between the sliding cycles (N_s) and percentage ultimate strength reduction (PSR) of a woven geotextile. This relationship is then employed to calculate the required sliding cycles (N_req) for a similar amount of damage induced by various turbid flow conditions. To this end, relationships between PSR and various turbid flow-related parameters, such as flow velocity (V_m), particle concentration (P_c) and resistance to particle breakdown of rock minerals represented by Los Angeles percentage weight loss (A_L), obtained in a series of laboratory turbid flow chamber tests are utilised to facilitate the derivation of N_req. Results of the comparative study show that the values of N_req can be much larger than 250 for some commonly encountered turbid flow environments, such as V_m ranging between 1.5 m/s and 2.5 m/s, and P_c of several percent. It is also shown that the effect of V_m on the value of N_req is significant. For all tests using V_m = 2.5 m/s, the corresponding values of N_req are greater than the maximum value of sliding cycles (N_s = 750) recommended in current sliding block/sandpaper tests, regardless of the aggregate type and particle concentration used in this study. At present, a standardised performance test on abrasion damage of geosynthetic materials is lacking, and the index tests such as sliding block/ sandpaper may require revision to fill this gap.