Vale S.A.'s Itabira complex is in the northeast of the Iron Quadrangle, in the central region of the state of Minas Gerais, Brazil. This complex explores iron ore in the open pit process and is formed for a lot of mines, and all their geotechnical structures such as waste rock stackings, tailings dams and, recently, the stackings that are being constructed with waste rock and tailings. For the piles formed by the shared disposal of waste rocks from mining and filtered tailings from iron ore processing, the characterization of the materials and the determination of the strength and critical state parameters determined the executive methodology that allowed the modelling of the safety factors required for the projects. The waste rocks and filtered tailings are mechanically disposed and divided into zones defined not only according to the geotechnical characteristics of the materials, but also the structural and operational needs of the stacking, which are divided into the confining zone and the confined zone. In the Confining Zone, compacted waste is placed, with technological control. The objective of this procedure is to assure that the structure performs better by using materials with greater resistance in the confining zone, because closer to the outer layer of the pile, are mobilized greater of the shear strength of the materials. In the confined zone, friable waste, with low competence in terms of geotechnical parameters, and mining tailings are disposed. In this zone, there is less mobilization of shear strength, and it is suitable for the disposal of such materials. In the case of tailings, the control and evaluation follow parameters defined with the Critical States Line, using the control of the compaction void ratio of the layers in the field, guaranteeing dilatant mechanical behaviours for the confinement stresses fixed in the project.