Tunnelling got underway last month on Contract CW-BID1, as part of the 98km long Kunming Zhangjiuhe River Water Diversion and Water Supply Project in south-west China.
Contract CW-BID1 includes the 7.8km long Kangle tunnel and the 13.8km long Shanggongshan tunnel. The US$35M contract was awarded to the Italian contractor CMC (Cooperativa Muratori & Cementisti, Ravenna). Electrowatt Infra (with it’s Chinese Sub consultant GHIDRI) is assisting the client and supervising construction.
Work began in May 2002, with the construction of the portal and 100m of drill and blast tunnel. The main tunnels will be excavated by a 3.65m diameter double-shield Robbins TBM and lined by precast concrete segmental lining (gasketed, bolted), backfilled with pea gravel and grouted to leave an i.d. of 3m.
Installation of the TBM was completed by mid of April 2003, and excavation started two months ahead of schedule. Average daily advance rates are hoped to reach 24m/day.
The geology along the alignment includes limestone, karstic limestone and sandstone with some expected fault zones.
Kunming is the political and economic centre of Yunnan Province in the south-west of China and one of the 14 cities in China that are severely short of water.
Project completion is planned for end of 2005 when this contract, together with other water supply contracts that are currently under construction, will provide Kunming with 1.4Mm3 of water per day – providing enough water until 2020.
The total investment for the project is about US$476M. To connect the Yunlong reservoir with the water treatment plant 98km of water conveyance line (mostly tunnels) will be built. Other contracts include: the 8.2km long Pingdi tunnel near Sanqinghe; the 3.6km long Qingshuitang tunnel, the 11.2km long Changkou tunnel and the 1.5km long Huanghuipo tunnel; and the 9km long Wulaoshan tunnel.
The Japan Bank for International Co-operation is providing about US$173M in loans.
