Engineering Monitoring for Yangtzi River Tunnel Crossing Project of Anqing Gas Transmission Pipeline

General situation of Yangtzi River Tunnel Crossing Project for Anqing Gas Transmission Pipeline is introduced from closing structure of receiving well and sending well, geologic profile and hydrogeological environment, principle of shield-driven tunneling and influence of hydrogeological environment on construction, earth surface and barrier settlement are analyzed. Combined with engineering practice, the principle, content, method, technical key point and technical requirement for monitoring accuracy in shield-driven tunneling as well as controlling technique for formation settlement are presented. Construction practice shows that by means of engineering monitoring on shield-driven tunneling, the deformation of formation is effectively controlled for the pipeline.