24 August 2015, 10:16
In August, BAUER Foundations Canada Inc., the Canadian subsidiary of BAUER Spezialtiefbau GmbH, acquired a major project worth about EUR 65 million to build a cut-off wall for the Diavik Diamond Mine in Canada.
The Diavik mine is operated by Diavik Diamond Mines (2012) Inc., a member of the Rio Tinto Group, and is located approximately 220 kilometers south of the Arctic Circle and 300 kilometers by air from Yellowknife, the territorial capital. The project marks a return to this subarctic site for the BAUER Group. From 2000 to 2002, BAUER Maschinen GmbH – in partnership with other companies and using a range of equipment – was involved in the construction of the water retention dikes that enabled open-pit mining of diamonds from the first three kimberlite pipes.
"It's a great story that our company is returning to Diavik almost 15 years later to take an active part in the further progression of the mine. It shows that the client has great confidence in our services," said Prof. Thomas Bauer, Chairman of the Management Board of BAUER AG.
A 26 meter deep cut-off wall is required for the 2.2 kilometer dike so that the fourth kimberlite pipe, designated A21 and located under the waters of Lac de Gras, can be open-pit mined. Bauer offered the Cutter-Soil-Mixing method (CSM), which combines cutter diaphragm walling technologies and the Mixed-in-Place method. The CSM technique is implemented through the use of trench cutters that are specially modified for this process. By using the in-situ soils, the CSM technique provides substantial logistic advantages and cost savings compared to more traditional methods.
The location of the mine presents special challenges: work can only be done between May and October because temperatures are too low during the winter months. Logistics is another major challenge, as large transports are only possible during an eight week period in the winter when the ice road to the mine is open. As a result, the project will be completed in two stages in 2016 and 2017. In 2016, the company will use two BAUER BG 30 rotary drilling rigs, three universal drilling rigs from KLEMM Bohrtechnik GmbH and cranes to complete soil improvement, perform trials, carry out curtain grouting work in the underlying rock and some other essential preliminary works for the cut-off wall. In 2017, the cut-off wall will be completed using the CSM method and jet grouting. Five BG 30 rigs will be used for this final stage of the project. These BG 30s will be specially configured to carry out three activities on this project: pre-drilling, CSM work and jet grouting therefore demonstrating the versatility of Bauer’s equipment.
Source: BAUER Aktiengesellschaft; Bauer Group