California to Build San Vicente PipelineThe San Diego County Water Authority officially launched on 21st July, 2005 at a groundbreaking ceremony the construction on the San Vicente Pipeline project, a 17,454 m-long 2.62 m-inner diameter pipeline connecting the San Vicente reservoir in Lakeside to the water authority's second aqueduct west of Interstate 15. This pipeline will be built in a tunnel at a depth ranging from 15 to 180 m below the surface.The pipeline is part of the USD834 million Emergency Storage Project designed to ensure in the future the reliability of San Diego County's water supply. The pipeline will increase the amount of water available within the county for use during emergencies. A drought or major earthquake could cut off the county's supply of imported water for up to six months and some communities could stay without water for three to four days. Imported water meets up to 90% of San Diego County's water needs. The tunnel is comprised of six reaches, which are designated so by differing geologic conditions. When completed, the six reaches will combine to form one long tunnel. There will be six headings broken up as follows: Reach 6 will be excavated with a main beam TBM, then the machine will be backed out and put into service to mine Reach 1, Reach 5 will be mined in two directions from a shaft in the centre of the reach, 75% of Reach 4 will be mined by commissioning a digger in the finished Reach 5 tunnel and begin excavation, while the other 25% of Reach 4, all of Reach 3, and all of Reach 2 will be mined by commissioning a digger in a central shaft. The excavated diameter of Reaches 1 and 6 will be 3,535 mm, Reaches 2, 3 and 4 will be 3,718 mm, Reach 5E will be 3,566 mm and Reach 5W will be 3,992 mm. The geology is as follows: Reach 1 and 6 - Hard granitic rock (207-345 MPa), Reach 2 - Fine grained cemented conglomerate (34.5 MPa with 138-207 MPa cobbles), Reach 3 - Hard granitic rock (207-345 MPa), Reach 4 - Uncemented to cemented conglomerate (0-34.5 MPa with cobbles and boulders up to 1.5 m in diameter, with most in the range of 10-50 cm diameter), Reach 5 - Hard granitic rock (207-345 MPa, highly weathered granitic rock, and conglomerate below the water table).Reaches 1 and 6 are 1,341 m and 1,195 m in length respectively and will be mined with a main beam TBM, Reach 2 is 2,880 m to be mined with a digger shield TBM, Reach 3 consists of 167 m of hard rock that will be drilled and blasted and one of the diggers will be pushed through, Reach 4 (conglomerate) spans 10,271 m and will be mined with a digger, Reach 5 is 1,585 m, of which 1,219 m will be drilled and blasted and 366 m will be mined in soft ground with a tunnel excavator.One refurbished Robbins main beam gripper TBM and two new digger shields of Construction and Tunneling Services (CTS) will be employed together with one refurbished Atlas Copco Rocket Boomer 282 with two booms and 1838 hammers for the tunnel and two ATD3800 Airtracks with PR123 air hammers for shaft sinking. Visit www.robbinstbm.com, www.ctstbm.com and www.atlascopco.comReaches 1 and 6 will be unlined with rock bolts where necessary, Reaches 2, 3 and 4 will be supported with precast concrete segments. There will be six trapezoidal segments per lining ring. The maker of the segment moulds is CBE and the producer of the segments is the Traylor Shea Ghazi JV. The drill and blast section of Reach 5 will be supported with epoxy grouted rock bolts and, if necessary, 5 cm of shotcrete. Soft ground (conglomerate under the water table) will be supported with steel fibre-reinforced shotcrete, steel ribs and, if necessary, pipe umbrellas. Visit www.cbe-tunnels.comThe mucking-out from Reaches 1, 2, 3, 4 and 6 will be with locomotives and muck boxes (wagons), mucking-out for Reach 5 will be with Wagner ST-3.5 LHDs for the first 366 m, then with a Schaeff ITC 112 tunnel excavator and Dux DT12 trucks for the remainder of the drive. Locomotives will be Clayton Equipment, Balco and Brookville, all owned by the JV. Rolling stock was designed and fabricated by the JV. Visit www.atlascopco.com/ure, www.schaeff-cmt.com, www.duxmachinery.com, www.clayton-equipment.co.uk, www.irwincar.com and http://brookvilleequipment.com/index.htmOther underground structures in the scheme include three shafts and one portal. One shaft will be 9 m in diameter and 33.5 m deep, another will be a 18 m by 9 m oval shaft that is 21 m deep and the third shaft will be 11 m in diameter and 23 m deep. The start date for tunnelling will be November 2005 and scheduled completion is 30th November, 2008. Click us/47 for more. Visit www.sdcwa.org/infra/esp-sanvicente.phtml and www.sdcwa.org/infra/pdf/ESPspring05.pdf 35/05.