The Role of Fabric, Stress History, Mineralogy, and Particle Morphology on the Triaxial Behavior of Nontextbook Geomaterials

Abstract

Soil mechanics traditionally have focused on studying pure clays and clean sands. However, natural soils and other geomaterials usually do not fall into these two classes. Most geomaterials are a complex matrix of fines and coarser particles, with distinct shapes and mineralogy interacting. This paper studied iron ore tailings over a broad range of pressures and stress histories to investigate the mechanical behavior of this nontextbook geomaterial. A thorough experimental program was conducted, and aspects of the stress–strain response, yielding, hardening, and critical state were evaluated. The state boundary surface of iron ore tailings also was investigated. The results demonstrated that the stress history of tailings affects the tailings’ behavior only at elevated stress levels. The existence of particles with distinct mineralogy in the iron ore tailings (mainly iron oxide and quartz) could have induced different breakage patterns, with an evolving particle morphology being the dominant mechanism up to the pressures achieved.