Abstract
Geotechnical monitoring plays an important role in the detection of operational safety issues in the slopes of open pits. Currently, monitoring companies offer several solutions involving robust technologies that boast highly reliable data and the ability to control risky conditions. The monitoring data must be processed and analysed so as to allow the results to be used for several purposes, thereby providing information that can be used to manage operational actions and optimize mining plans or engineering projects. In this work we analysed monitoring data (pore pressure and displacement) and its correlation with the tension and displacement of the mass of an established failure slope calculated using the finite element method. To optimize the back-analysis, a Python language routine was developed using input data (point coordinates, parameter matrix, and critical section) to use software with the rock mass parameters (cohesion, friction angle, Young's modulus, and Poisson's ratio). For the back-analysis, the Mohr-Coulomb criterion was applied with the shear strength reduction technique to obtain the strength reduction factor. The results were consistent with both the measured displacements and the maximum deformation contours, revealing the possible failure mechanism, allowing the strength parameters to be calibrated according to the slope failure conditions, and providing information about the contribution of each variable (parameter) to the slope failure in the study area.
Highlights
The extraction of minerals by open pit mining is widely practised throughout the world
The date corresponds to a period of 24 hours, which initially did not show a tendency towards imminent failure until 03/11/17
The analysis showed that seven series had displacement values similar to those measured in the area at the moment of collapse (Tables VI and VII)
Summary
The extraction of minerals by open pit mining is widely practised throughout the world. Large mines with very high and steep slopes are designed to allow economic gains. Such designs can promote high-risk situations, such as disastrous instabilities, with critical social, economic, and environmental consequences, especially in events culminating in the loss of human life. A balance between operational security and mining economics must be sought. In this context, geotechnical studies play an important role. Excavation activities modify the initial stresses on the rock mass. In an effort to re-equilibrate, these stresses can cause instability, thereby enhancing the possibility of slope failures on the bench scale, inter-ramp scale, and/or mine scale. Geotechnicians must consider (mainly during the operational phase) a variety of factors that can contribute to instabilities, such as increases in shear stresses with the removal of lateral support (resulting in erosion, falling blocks, and subsidence), changes in the groundwater level and corresponding increases in pore pressure, overloading of slopes, rainfall, external vibrations, and natural stress relief mechanisms with movements/displacements of the slope
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
