Evaluation of rockburst energy capacity for the design of rock support systems for different tunnel geometries at El Teniente copper mine

Abstract

Rockburst events have been a serious problem for many years in many mines worldwide, and in particular at El Teniente mine in Chile. El Teniente is the largest copper mine in the world, located in the Andes Cordillera where high stress levels are present due to intensing mining activity in addition to complex geology. Consequently, the study and management of the rockburst threat are necessary. In this work, the case of the Diablo Regimiento (DR) mine within El Teniente is studied. The energy capacity of dynamic support systems is determined for different tunnel geometries based on two kinetic methodologies, using data from DR. Initially, rockburst potential is determined by means of a stress analysis around different tunnel geometries through the boundary elements method. In the first methodology a yielding zone (YZ) is estimated for each excavation geometry using the finite element method FEM. The second methodology involves the definition and determination of a critical strain energy (SE) around each excavation geometry using a FEM numerical analysis. In both cases, peak particle velocity PPV is estimated by a scaling law, which is subsequently adjusted due to tunnel amplification effects. According to the results, and knowing the working energy capacity applied in DR mine, it was found that the values of energy capacity for the rock dynamic supports were better estimated by the YZ-PPV approach than by the SE approach.

Evaluation of Anti-Burst Performance in Mining Roadway Support System

“…Chen et al [ 13 ] derived the energy criteria of burst failure caused by the instability of a roadway under rockburst due to source disturbance, and proposed an evaluation method of roadway support energy under rockburst using the energy absorbed by the support system and the energy released by surrounding rocks of the roadway after the burst as the evaluation indexes. Based on the amount of rock mass yielding around the excavation (yield zone YZ-PPV criterion) and the amount of strain energy stored in the rock mass (SE-PPV criterion), Villalobos estimated the surrounding rock supporting energy capacity of six different tunnel geometries in the Diablo Regimiento Mine [ 14 ].…”