The Mina de Águas Claras : GEWI ® Soil Nails stabilize a huge Open Pit Mine
Construction — South America — Brazil — Slope Stabilizations
The Mina de Águas Claras is an open pit mine in the Brazilian federal state of Minas Gerais in which iron ore was extracted from 1971 to 2002 . The mine is located in southeastern Brazil , only 10km to the northeast of Belo Horizonte .
Until the depletion of the iron ore reserves in 2002 , approximately 300 million tons of iron ore were extracted from Águas Claras over an area of roughly 1,000ha . After the mine was closed , the deep pit was partly filled with water , which created a large lake over the years .
Before the mine was closed , a large landslide occurred in 1992 , causing a part of the Curral Ridge to collapse . A 2008 report also detected many steep slopes that were not covered by vegetation and therefore exposed to erosion . However , the shutdown and rehabilitation of the mine area , which had been planned for the years 2003 to 2013 , were repeatedly delayed .
Since the former mine is located in the immediate vicinity of a densely populated area , the uncovered , steep slopes in the open pit mine represented a major security risk . In 2013 , the owner Vale decided to carry out stabilization measures in order to minimize the risk of landslides and to enable the future use of the entire area .
Within the scope of the project “ Cava Oeste ”, the comprehensive stabilization of the highest portion of the western pit started in August 2014 . During this project , loose soil was removed and a drainage system was installed that will prevent future erosion . Afterwards , a stepwise slope stabilization is carried out from the top down . The slopes are stabilized using high-strength steel mesh and revegetated following installation .
The passive steel mesh slope stabilization system is anchored in the stable slope strata using GEWI ® Soil Nails that act directly on the slope surface . 47,535m of 32mm Ø , GR 50 / 55 GEWI ® Soil Nails with a weight of 21t were installed to safely secure the steel mesh . Protendidos DYWIDAG supplied the soil nails complete with 7,310 nuts .
Owner Vale S / A , Brazil General Contractor BVP Engenharia , Brazil Subcontractor Joint Venture Consorcio EMPA-SEEL - Cava Oeste , consisting of EMPA S / A and SEEL Seviços Especiais de Engenharia Ltda ., both Brazil Engineering BVP Engenharia , Brazil
DSI Unit Protendidos DYWIDAG Ltda ., Brazil Protendidos DYWIDAG Scope Production , supply DYWIDAG Products 47,535m of 32mm Ø GEWI ® Soil Nails including nuts
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