Geomechanical evaluation of large excavations at the New Level Mine - El Teniente

The New Level Mine is a 130.000 tpd panel caving project set to start in 2017 at the El Teniente mine. VP-NNM CODELCO (Vice-President Office of the New Level Mine) is currently finishing a detailed engineering design of the underground mine. The evaluation considers, the design of the crusher cavern Nº1 located in the Braden Pipe, which is a waste rock chimney located in the central part of the ore body. A geo-mechanical study has been carried out to evaluate the stability of the planned infrastructure and to provide recommendations about the design of underground caverns and galleries, including support. As part of this study, empirical methods, two-dimensional and three-dimensional continuum models have been developed and applied to evaluate the influence of the high stresses and different geotechnical units, on the mechanical response of the excavation. This paper introduces general aspects of the New Mine Level underground project and discusses in particular geo-mechanical analyses and design carried out to evaluate stability and support of some of the large excavations involved in the project.