Yangtze River crossing of NG Pipeline Project from Sichuan to The East

NG Pipeline Project from Sichuan to The East has 7 crossings passing through the Yangtze River,and the total length is up to 15.3 km.By analyzing the crossing ways and considering the key points in the crossing scheme,based on different geological conditions,the crossing project is implemented with shield-driven tunneling,drilling exploding tunneling and directional drilling crossing,respectively.Among these crossings,the world record as the longest pipeline directional drilling in the Yangtze River and the largest in pipe diameter has been created in Nanjing directional drilling project;the domestic record as the largest cross section area has been borne in Zhongxian crossing project;the domestic record as the largest span in long-distance gas transmission pipeline has been set up in Anqing shield-driven tunneling project,and the ground pressure balance method crossing the sand layer is first applied;the domestic record as the continuous tunneling a 635-m'length has been put on hold in Yichang shield-driven tunneling project.The above project cases accumulate the construction experience for future similar crossing project.