Since its launch on 18 December last year, a Wirth TBM has bored and lined 4.1km of tunnel on the Dahuofang Reservoir Water Diversion project in the People’s Republic of China (T&TI, June, p11).
Financed by the state, the tunnel system will stretch 85km as it links the Huanren and Dahnofany reservoirs in Liaoning Province to supply the city of Shenyang. The main tunnel diameter is 8m and there will also be sixteen feeder adits.
Approximately 60km of the tunnel system will be constructed by hard rock TBM. The Ministry of Water in Beijing has divided this into three equal lots. All of the contracts have been won by Chinese contractors, a source within Wirth told T&TI that its machine was working on Lot 2, the 20km awarded to China Railway Group.
The Wirth TB803E gripper machine has a boring diameter of 8.03m. The tunnel is being driven at <0.5% gradient, with muck transport by conveyor belt manufactured by REI of France. T&TI was told that wet shotcrete is being used to create the tunnel lining. The 150m long back-up gantry was supplied by Rowa. Both gantry and TBM were pre-assembled in China (Wirth has a strategic agreement with Shenyang Heavy Machinery Group) before being transported to the jobsite that was still 2000km away.
The two other sections of tunnel are being built by Beijing Vibroflotation Engineering Co. Ltd. (BVEC)and the Bureau of Water Conservancy and Hydroelectric Power Construction of Liaoning Province (LWCB) respectively, who both opted for Robbins hard rock TBMs for their drives that were scheduled to get underway this year. The Wirth source said the total project duration was 5.5 years.
