Pipe-jacking practice in complicated geological river in the Second West-to-East Gas Pipeline Project

River pipe-jacking crossing in the Second West-to-East Gas Pipeline Project is China's first large-scale and long-distance complicated geological river pipe-jacking crossing project. Due to the restrictions of geological structure, high groundwater pressure, large formation lithology change and other conditions, pipe-jacking construction is difficult. Through investigation and analysis of pipe-jacking engineering practice and construction problems in the Second West-to-East Gas Pipeline Project, China's special technical requirements for complicated geological complex river pipe-jacking are proposed. The existing pipe-jacking engineering design specifications are improved and more specific geophysical data are defined. The highly targeted pipe-jacking specifications are improved according to pipe-jacking system performance and device configuration. The construction capacity of geologically complex shafts are improved in terms of technologies and equipments. The cost estimate and management system of complicated geological river pipe-jacking project are developed based on actual conditions of the project to provide technical supports and safeguard to the subsequent river rock pipe-jacking project.