The Abu Dhabi Sewerage Services Company (ADSSC) as a subsidiary of Abu Dhabi Water and Electricity Authority (ADWEA) is stepping up efforts to implement the Strategic Tunnel Enhancement Programme (STEP) during the next six years to establish a tunnel that will cater to the immediate, short and long-term needs of Abu Dhabi's wastewater and drainage issues. The outline design of the STEP project comprises two new huge pumping stations in Al Mafraq and Zakher located 70 metres underground and designed to deliver 30 cubic metres per second (1.6 million cubic metres per day) and 40 kilometres of 5.5 m-diameter tunnel up to 40 m deep with 30 km of link tunnels up to 3 m deep. There will be at least six complementary design-build contracts with the first set of documents ready for issue next October. CH2M Hill is the programme manager. The project will be tendered under a build, own, operate, transfer (BOOT) scheme. Visit www.ch2m.com 32-33/08.
International contractor Impregilo has been awarded the first of three lots of the Strategic Tunnel Enhancement Programme (STEP), value EUR167million, for construction of 15 km of segmentally-lined 6.3 m-diameter EPB tunnel and six access shafts to depths of 40-50 m, completion late-2013. The main feature of the STEP project is a 40 km lined gravity tunnel to collect wastewater on the Abu Dhabi island and mainland and convey it to the treatment plant in Al Wathba. Visit www.impregilo.it. 38/09.
Zueblin Australia of Perth has been awarded two major contracts, value EUR365 million, as part of the STEP project by Abu Dhabi Sewerage Services Company. Contract 1 is for the 35.7 km-long Link Sewer network, with diameters ranging from 200 mm to 2.8 m, and 247 manhole shafts of depths 8-20 m. Contract 2 comprises a 15.4 km-long sewer network with 95 manholes of up to 26 m-depth. Pipejacking is the favoured method. Contract duration is 39 months. For project description and history visit tunnelbuilder archive ae/16, and for contractor profile visit www.zueblin-international.com. More from Erhan Oguz or Stefan Nalbach in Perth, tel +61 (0)893259399, e-mail erhan.oguz@zueblin-international.com. 03/12.
Drake & Scull Water and Power LLC (DSWP) secured a EUR99.09 million subcontract for the design review, procurement and construction of mechanical, electrical, plumbing and instrumentation works for the Strategic Tunnel Enhancement Programme (STEP) pumping station in Abu Dhabi. Developed by Abu Dhabi Sewerage Services Company (ADSSC), STEP will be one of the longest gravity-driven wastewater tunnels in the world, designed to reduce the pressure on the current Emirate sewerage system and to expand its future capacity.
The tunnel pumping station will be located at the termination of the new deep tunnel sewer at Al Wathba area. Construction will be executed in partnership with the main design and build contractor Construtora Norberto Odebrecht. The execution of the MEP package will commence immediately after the civil works have been completed. Visit www.drakescull.com/PJSC/MediaCorporateNews.aspx?News_ID=355#NEWS_DETAIL and http://en.adssc.ae/SitePages/Home.aspx. 20/12.
Abu Dhabi Sewerage Services Company (ADSSC) awarded to Impregilo the USD200 million T-03 contract for the third and final lot of the Strategic Tunnel Enhancement Programme (STEP), a 40 km-long hydraulic tunnel in Abu Dhabi. Using gravity, the tunnel will collect wastewater and convey it to a treatment plant in Al Wathba. Under the new contract, Impregilo is to construct 10 km of the hydraulic tunnel, with a 7 m-diameter excavated section, four access shafts to depths between 60 and 80 m, and the links to the main tunnel.
For the first time in Abu Dhabi two TBM EPB for pressures up to 8 bars, will bore and simultaneously line the tunnel with prefabricated concrete segments.
The hydraulic tunnel and the access shafts will be lined with a special membrane to ensure the concrete structures are fully protected from the aggressive environment, for a minimum term of one hundred years. Click ae/16 for tunnelbuilder archive. Visit www.impregilo.it. 49/10.
Samsung C&T Engineering & Construction Group signed the T-01 contract with Abu Dhabi Sewerage Services Company worth USD270 million for the construction of Deep Tunnel Sewerage System (DTSS) in Abu Dhabi. Samsung C&T will design and build 16 km portion of a 41 km DTSS as well as four operating shafts and 3 access shafts. Click ae/16 for tunnelbuilder archive. Visit http://www.secc.co.kr/eng/html/pr/press_view.asp. 08/11.
