Por: David Ojeda Farfán, Malena Arrieta Quiroz, Efraín Flores Quispe, Minera Las Bambas.

Abstract

The occurrence of slope slides in open pits is very frequent in mining operations. Therefore, these undesired events jeopardize the integrity of people, equipment and in some cases put the operational viability of the mining business at risk. Therefore, determining an early warning system for rock and soil slides is vital for risk management and risk reduction within an organization. 

The Ferrobamba mining deposit is one of the deposits in which mining activities are currently being carried out and whose reserves represent 100% of the production of Minera Las Bambas in the next 10 years, due to its progress and development, there are 112 instabilities in the entire Ferrobamba pit during the 7 years of operation. 

In this paper we will use as representative samples 3 significant landslide events that occurred in the Ferrobamba pit, which are detailed below: 

ν Instability #83: Partial sliding of 6 benches from level 3870 to level 3780. The sliding material was retained on the lower benches of level 3750 and level 3720 with no damage to equipment or people. The event was identified by three systems and two geotechnical monitoring equipment (Radars, Prisms, INSAR images). 

ν Instability #105: Large scale slope slide located on the west wall of the ore production pit and an access ramp to the north sector of phase 05. The event was identified by different geotechnical monitoring systems (Radars, Prisms, INSAR images and Inclinometers). 

ν Instability #112: The sliding zone affects 5 benches from level 3915 to level 3990 with an area of 600 square meters and a volume of 30,000.00 cubic meters. The sector has a dirty limestone lithology and a break by the multi-bench wedge type structure. The event was identified by 2 radars: IBIS FM01 and FM02. 

This paper shows how early identification of sectors with geotechnical risk (landslides) was achieved with the application of geotechnical tools and the accuracy of the new early warning model to issue alert levels used by the geotechnical monitoring equipment at Minera Las Bambas.