Italian Contractor, CMC di Ravenna has completed an impressive 1km of tunnel in the first month of construction on the $31M Lot V of the Shanxi Wanjiazhai Yellow River Diversion project in China.
Having been awarded notice to proceed in April 2000, CMC started boring the 13.5km long tunnel at the end of November 2000 using a 4.9m diameter Robbins TBM.
Originally purchased from Robbins in 1993 by the client, the Shanxi Wanjiazhai Yellow River Diversion Project Corporation, the TBM was to be used for the excavation of tunnel 5 on Lot II of the huge scheme, a job that was eventually never undertaken. After almost seven years in storage the corporation sold the TBM to CMC for the execution of Lot V. The machine has been extensively refurbished, having been equipped with 6×160 kW double speed electric motors and thirty-four 17in. hard rock disc cutters.
The tunnel is being excavated through limestone and dolomitic limestone formations with karstic cavities expected. Honeycomb lining is being erected comprising 250mm thick hexagonal segments leaving a 4.1m id. Segment alignment is guaranteed using dowels and guiding bars.
CMC has experience in the area having successfully completed 21km of 6.2m diameter hard rock bored tunnel in the River Diversion Project main line and also being a major partner in the Wan Long JV which is carrying out TBM boring of Lots II & III. The engineer is The Northern Company of Water Conservancy & Hydropower of B6 Branch office for YRDP, also supervising the TBM works on the main line.
The tunnel outlet portal is located 10km north west of Taiyuan City, the provincial capital, and runs in a westerly direction to intercept and divert water from the Fen River Valley near the town Gujiao to a treatment plant located near Taiyuan city. Construction is set for completion in 26 months.
The Yellow River Diversion Scheme, designed by the Tianjing Design Institute, will alleviate the regions’ chronic need for water for domestic and industrial use.
