Application of numerical methods to underground excavations

Iñaki García Mendive and Alejo Sfriso
Wednesday, August 31, 2016
First presented: 
ISRM International Symposium - EUROCK 2016, Turkey
Published paper
Rock Mechanics

Arenal Deeps is an Au mine located near Minas de Corrales, Uruguay, which was exploited via an open pit operation from 2004 until 2009 and underground since then, using both inclined room and pillar and transversal stoping methods. The progression of mining activities (down to ~320m BGS) has led to an ever-growing complexity in the geometry of the mine, which cannot be adequately assessed solely with empirical design methods. This work presents a case study in which empirical and numerical methods were integrated to assess the stability of a stope roof and adjoining pillar. Empirical methods enabled straightforward determination of the need to include an intermediate pillar. A 3D boundary element model indicated that stress concentration in the roof was the main driver for instability. The 2D finite element model provided a FoS for roof failure of 1.20, considered adequate given the conservative plane-strain hypothesis it entails and geomechanical uncertainty.

Feature Author

Iñaki García Mendive

Iñaki García Mendive is a geotechnical engineer in SRK’s Buenos Aires office. His specialization focuses on the characterization of rock masses, application of empirical and numerical methods for design and validation in open pit and underground operations. He has experience in the design of geotechnical projects including foundations, anchor systems, embankments, slopes and excavations (OP and UG). He has participated in investigation projects at the Soil Mechanics Laboratory of the University of Buenos Aires. He collaborated as teaching assistant in the course of Strength of Materials.

Geotechnical Engineer
SRK Buenos Aires
Alejo Oscar Sfriso

Alejo O. Sfriso is a Principal Engineer with 25 years of experience in geotechnical engineering for infrastructure and mining works. He is an expert in the application of numerical methods for geotechnical design and analysis. In addition to his activity at SRK, he is the Director of AOSA - Geotechnical Laboratory, Professor of Soil Mechanics and Geology of the University of Buenos Aires, Vice President for South America of the International Society of Soil Mechanics and Geotechnical Engineering for the period 2017 - 2021, former Professor of Geotechnics at the National University of La Plata and former President of the Argentinean Society of Geotechnical Engineering.

Principal Consultant
PhD, Civil Engineer
SRK Buenos Aires
SRK North America