The 15.000th ring installed in the tunnel completes three quarters of it. The final break through is planned for the end of 2010. The lining of the tunnel is done with hexagonal pre-manufactured concrete rings (so-called Tübbings) manufactured in the city of Shuozhou 15 km away. Four of these honeycomb-shaped segments are put together to form a single ring. This procedure was developed to allow fast and continuous drilling without reducing speed during the installation of tubbings.
The 25.4 km long tunnel with a diameter of 4.8 m is excavated with Robbins Double Shield TBMs. This tunnel is one of the longest tunnels world-wide drilled with a single TBM. The unusual soil conditions make for a special challenge. These cover anything from water-saturated cohesive layers of clay to highly abrasive sandstone formations and coal seams several metres strong.
Since 2000 this Double Shield TBM operates in China and has already been used for the 12 km long Lot 5, an earlier section of the Yellow River Diversion Project. ALPINE constructs this tunnel since September 2006 in cooperation with Sino-Austria Hydraulic Engineering Co. (SAHEC).
>> Description of Shanxi Project
>> Double-Shield TBM manufacturer Robbins
