With the completion of excavation last month, the main works on the 85.3km long Dahuofang water transfer tunnel in Liaoning province, China, are over and only some final inner lining work remains to be finished.
Excavation of the 8m wide bore began in September 2006, and was undertaken mostly by three TBM drives (two Robbins, one Wirth, all 8.03m diameter) while drill and blast was used for the other quarter.
The tunnel crosses 50 hills, 50 rivers and 29 faults in north west China.
Three local contractors have built the tunnel: Beijing Vibroflotation Engineering Co (BVEC) with TBM1, a Robbins shield; China Railway Tunnel Group (CRTG) with TBM2, the Wirth machine; and, Liaoning Water Conservancy Bureau (LWCB) with the other Robbins TBM. Each did almost a fifth of the overall tunnel.
In total, the tunnelling work on the project was undertaken through seven contracts, three for the TBMs and four for drill and blast work.
Two of the latter contracts were undertaken by China railway 13th Bureau Co, totalling 13.6km, and the others by Sino Hydro Engineering Bureau 6th and LWCB.
The construction work also required the excavation of 14 intermediate adits and two at the portals. The adit lengths varies from 278m to 2.6km, some of the shorter ones as steep slopes, and the shorter tunnels had cross sections of 5m by 5m while the longer went up to 6.6m by 6m.
The client agency is the Department of water Resources of Liaoning Province, and construction management was done by the Liaoning Runzhong Water Supply Co.
The tunnel was designed by the Design and Research Institute of Water Resources and Hydropower Group of the Water Conservancy Ministry of China for Liaoning Province.
The US$750M, gravity flow tunnel will convey water from the Hunjiang basin to the Dahuofang reservoir, boosting supplies for seven industrial cities – Shenyang, Fushun, Liaoyang, Anshan, Panjin, Yingkou and Dalian.
At Dahuofang
