Application of Open Caisson as Work Pit in Pipe-pushing Construction of Long Distance Pipeline

An open caisson was used as work pit for pipeline crossing at the sixth bid section of the gas transmission trunk line of the Guangdong LNG station and pipeline project, which is located at the region of urban pipeline network and water network. Pipe-pushing operation and welding operation were performed in the open caisson. Taking this project as an example, this paper illustrates the process principle, technical parameters, constructional procedure, key technical points as well as safety and environmental protection, analyses the abnormity in the course of caisson sinking, and puts forward the prevention and treatment methods.