Research on Synchronous Construction Technology of Shield Tunnel and Pipe Jacking in Confined Space

The construction of urban underground municipal infrastructure is often subject to various restrictions on the ground and underground, which is also the key direction of underground engineering construction research. Combined with engineering examples, the construction scheme was optimized and studied in view of the limited urban space, complex pipeline in underground space, and numerous ownership units and existing buildings involved in the above-ground space, and the construction technology of "shield tunneling power tunnel+pipe jacking method prefabricated large-diameter concrete pipeline rear guide tunnel bidirectional synchronous construction" was creatively developed. The creative use of shield pipe jacking bidirectional double force reaction frame reduces the shutdown time of shield machine and shortens the construction period of 21 days; Efficient use of urban underground space, reduce the impact on the surrounding environment, make the cable path selection and laying more convenient and economical, saving at least 1 million yuan of construction costs. The technology has been successfully applied in a 500 kV power tunnel project of Guangzhou Southern Grand Trunk Line, and has obtained good social and economic benefits. It can provide reference for similar engineering practice, and has good promotion and application value.