The effect of strain rate on the Zanjan zinc tailing behavior in monotonic triaxial testing

Abstract

Tailing is an artificial waste material that is created after the extraction of a metal from mineral soils that seriously need to be investigated in various aspects, including from geotechnical engineering point of view. These silt sized materials are mostly influenced by the strain rate effects. For this, a series of triaxial testings has been perfomed on reconstituted saturated zanjan zinc tailing specimens. The tests were done under two confining pressures of 50 and 200 kPa with a relative density of 73% at four different strain rates of 0.5, 0.3, 0.1 and 0.05 mm/min. The testing results showed that as the strain rate increases 10-fold, the amount of the maximum deviator stress increases 1.90 and 1.33 times on average for CU and CD conditions, respectively. Also in both conditions, the higher the strain rate, the higher the friction angle. Moreover, the results showed that with increasing the strain rate, the values of pore water pressure decreased by 0.6 times. By reducing the strain rate 10 times, the volumetric strain increases 3 times on average. It was concluded that the strain rate has effective influence on the shear behavior of the zanjan zinc tailing.