Tunnelling Well Advanced on Tizi Ouzou-Algiers Potable Water SchemeTizi Ouzou is situated at a pass that culminates at 270 metres ("tizi" means pass and "ouzou" means broom in Kabylian) but it is not completely a mountain city and even less a plain city. The city of Tizi Ouzou, which therefore means "Pass of the Brooms", is 100 km east of Algiers. It is the capital of Great Kabylia, mainly a mountainous region, and is squeezed between the Belloua massif (650 m of altitude) and the Hasnaoua massif (more than 600 m of altitude).The drinking water transfer scheme from the Taksebt dam in Tizi Ouzou to Algiers includes the construction of a treatment station, a pumping station, tunnels and a pipeline of a length of 95 km, to transfer 150 million cubic metres per year downstream the dam, mainly to Algiers. The project fulfils a double objective: improving the living conditions of the urban population in the region, by supplying clean and sufficient water and a continuous service, and contributing to the sustainable management of the water resources in the regions of Algiers and Kabylia.The owner of the project is Agence Nationale des Barrages et Transferts (ANBT), the national agency for dams and water transfers, under the Ministry of water resources. The ANBT is assisted by ENB. SNC-Lavalin, the main contractor, will operate the scheme for five renewable years. GAAT is the group of engineering companies responsible for work supervision, including Bonnard et Gardel, IBG, Stouki and CTTP Alger. Visit www.anb-dz.com, www.enb.gr, www.snc-lavalin.com, www.bg-21.com and www.ibgrombach.com Ravenna-based Cooperativa Muratori e Cementisti (CMC) has reported significant progress in the multi-tunnel (totalling 11 kilometres) for the Tizi Ouzou-Algiers water transfer project. CMC is contracted to work for the general contractor SNC-Lavalin, as tunnelling subcontractor. Visit www.cmc.coopThe first of two new Lovat RMP146SE hard rock TBMs, 3.7 m in diameter, was launched last 19th February, 2006 for the 2,800 m Tizi Ouzou tunnel and completed its drive on 6th August, 2006. This TBM completed the bore in under 24 weeks. CMC has relaunched this TBM on 5th September for the 2,600 m Naciria tunnel. To date, 166 m has been excavated. Visit www.lovat.comUsing the second TBM, CMC started tunnelling on 18th March, 2006 for the Draâ-Ben-Khedda tunnel. The second TBM broke though on 17th May after completing 1.2 km of tunnel with a primary lining of expanded prefabricated concrete segments. The second TBM was subsequently reassembled and relaunched on 18th June, 2006 at the Thenia tunnel and has bored up to now 1,664 metres of the total 3.4 kilometres. CMC is achieving a daily tunnelling rate of 24 metres.The tunnel alignments are above the water table and through hard, compacted and very compacted blackish-grey marl with an RQD typically from 75-90% and a UCS up to 70 MPa at a maximum depth above the tunnel crown of 95 metres. The secondary lining of these water transfer tunnels will be a grouted-in-place concrete pipe. Click here and dz/13. 39/06.