On July 16, after more than ten years of construction, China Railway Tunnel Group Co, Ltd participated in the Hanjiang-to-Weihe River Water Diversion Project, a major national water conservancy project. China Railway No.5 Engineering Group Co., Ltd officially supplied water to Xi'an. The good wish of the Hanjiang River to cross the Qinling Mountains and moisten the Guanzhong area became a reality.
The Hanjiang-to-Weihe River Water Diversion Project is one of the 172 major water-saving and water-supply projects determined by the State Council, consisting of water diversion projects and water transmission and distribution projects, with a total investment of about 51.6 billion yuan. The project spans the Yangtze River and the Yellow River basins. It transfers water from the Hanjiang River Basin in Yangxian and Foping counties of Hanzhong City in southern Shaanxi to the Weihe River Basin in Guanzhong, which can meet the needs of four key cities such as Xi'an, Xianyang, Weinan, and Yangling, five new towns in Xixian New Area, 11 districts and counties such as Chang'an District, Lintong District, Xingping City and Fuping County on both sides of the Weihe River, as well as Weibei Industrial Park. The total water-receiving area is 1.4 million square kilometers, benefiting 14.11 million people. The Qinling Water Diversion Tunnel, the main part of the Hanjiwei Water Diversion Project, is 98.3 kilometers long, with a design flow of 70 cubic meters per second and a longitudinal slope of 1/2500. It is the first time in human history to penetrate the Qinling Mountains from the bottom, with a maximum buried depth of 2050 meters, the deepest in the world in the same type of project.
Located deep in the mountains of Ningshan County, Shaanxi Province, the Lingnan TBM section of the Qinling Water Diversion Tunnel from the Hanjiang River to the Weihe River, which China Railway Tunnel Group constructed, includes a main tunnel 18.3 kilometers long and branch tunnels No.3 and No.4 with a total length of 9.6 kilometers. The main tunnel has high strength of surrounding rock, high quartz content, high temperature and humidity, intense rock burst, strong water inflow (maximum water inflow up to 46,000 cubic meters per day), long-distance single-head construction, which is the most challenging construction section of the whole project, the most frequent rock burst and the highest strength of surrounding rock. The length of the No.0 exploration test tunnel project of the Qinling tunnel crossing the Hanjiang River to the Weihe River constructed by China Railway No.5 Engineering Group is 7416 meters, including two parts of the branch tunnel and the main tunnel. The construction is faced with a series of difficulties and challenges, such as a small section of the diversion tunnel, a long tunnel, abundant groundwater, complex geology, ventilation, transportation, and long reverse slope drainage in the tunnel.
