An investigation on relations between dissipated energy and dynamic compressive strength of Kemi-peridotite at high strain rates

Abstract

Dynamic properties of rocks are essential for planning sustainable engineering structures in regions prone to dynamic loading as well as effective fragment size distributions during quarrying activities. Due to the vast application of dynamic rock properties, several studies have been conducted on the context. However, studies on relations between dissipated energy and dynamic compressive strength are scanty. The aim of the study is to investigate relations between dynamic compressive strength and dissipated energy during fragmentation of Kemi-peridotites at high strain rates. To achieve this, cored specimen was prepared according to recommendations of the International Society for Rock Mechanics and fractured using the split Hopkinson’s pressure bar. Results indicate that the dissipated energy during rock fracture generally increases at high dynamic compressive stress. However, the regression square of dissipated energy and dynamic compressive strength plots suggest poor relations between both variables. Further evaluation of measured strain at maximum dynamic compressive stress indicates that strain in specimen continued significantly after maximum dynamic compressive stress was attained. However, evaluations on relations between dissipated energy and strain indicates that energy dissipation continued along a significant portion of the measured strain during rock fracture at high strain rates. Visual evaluation of broken fragments also indicates good relations between dissipated energy and fragmentation results of Kemi-peridotites at high strain rates. Based on study findings, dissipated energy provides improved indices for evaluating strain and fragment size distribution while dynamic compressive stress provides indices on maximum stress required for rock failure.