{"id":3211,"date":"2019-12-10T10:48:25","date_gmt":"2019-12-10T10:48:25","guid":{"rendered":"http:\/\/www.reinforcedearth.com.hk\/?post_type=avada_portfolio&p=3211"},"modified":"2022-01-12T11:06:26","modified_gmt":"2022-01-12T11:06:26","slug":"tortolas-tailing-dam","status":"publish","type":"avada_portfolio","link":"https:\/\/www.reinforcedearth.com.hk\/reinforced-earth\/tortolas-tailing-dam\/","title":{"rendered":"Reinforced Earth\u00ae Walls for Las T\u00f3rtolas Tailings Dam"},"content":{"rendered":"

Reinforced Earth\u00ae Retaining Walls for Raised Tailings Dam Wall at Los Bronces Copper Mine, Chile<\/span><\/p><\/h1><\/div>

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In October 2007 Anglo American approved an investment of US$2.4 billion to expand its Los Bronces<\/a>\u00a0open cut copper and molybdenum mine, high in the Andes Mountains of Chile. The expansion includes new grinding facilities in the Confluencia sector, a flotation plant at Las T\u00f3rtolas (Colina) and new piping and pumping stations. When completed in 2017, copper production will almost double to 400,000 tonnes, making Los Bronces the fifth largest copper mine in the world. Much of the additional water required with the expanded production will come from raising the Las T\u00f3rtolas tailings dam located approximately 42 km west of the mine. Anglo American reports that recycling water in the dam will reduce the quantity of fresh water used per tonne of copper produced by around 40%. It was not possible to create the tailings dam embankment near the Ladera Este Pump Station. Vertical retaining walls were necessary to protect the station located immediately downstream of the existing dam embankment. Furthermore, Anglo American wanted the dam to be raised in stages to match their expansion plans.\u00a0The challenge was to design and construct vertical protective walls, in stages, in a very limited space. The walls also had to be designed to prevent seepage of water from the tailings reservoir. Reinforced Earth\u00ae<\/a> retaining walls were selected for the construction<\/a> of both the upstream and downstream walls of the raised dam. Stage 1, completed in May 2014, is almost 14 metres high. To mitigate costs and to limit disruption to its current operations, Anglo wanted the footprint of Stage 1 to be kept to the absolute minimum whilst allowing the raising of the dam by another 8 metres in height in Stage 2. Tierra Armada Chile<\/a>\u00a0detailed 4730m\u00b2 of parallel retaining walls for Stage 1 using its TerraPlus\u00ae modular, precast concrete facing panels in a back-to-back configuration with GeoStrap\u00ae polymeric soil reinforcement. The Stage 1 downstream wall was designed and detailed as a TerraLink\u00ae<\/a> retaining wall so that the Geostrap\u00ae reinforcements in the 7,500 m2 Stage 2 downstream wall could be effectively linked to Stage 1. When completed the downstream walls in both stages act as one composite retaining wall almost 22 m high. Tierra Armada engineers carried out finite element modelling using FLAC 2D to confirm that the configuration as designed would perform adequately. An impermeable membrane seal was attached to the facing panels in the upstream wall to contain the tailings water. Special features<\/p>\n