ABSTRACT
The deep cement mixing pile composite foundation reinforcement technology of immersed tube tunnel has the advantages of obtaining high-strength foundation reinforcement in a short period, small structure settlement, less spoil, superior seismic performance, and small impact on the surrounding environment. The deep cement mixing pile, as the treatment method of immersed tube tunnel foundation, is the first large-scale application in Shenzhen-Zhongshan Link and is a successful practice of exploring and accumulating the application of deep cement mixing pile in the industry. The deep cement mixing pile composite foundation of the immersed tunnel in Shenzhen-Zhongshan Link faces three challenges: the reasonable layout of DCM piles, the quality of DCM piles in the floating mud layer, and the coordination of longitudinal deformation of the pile foundation. Through the numerical analysis of the DCM pile action mechanism and relevant process tests, the feasibility of deep cement mixing pile composite foundation reinforcement technology for deep and medium channel immersed tunnels is evaluated in this project. At the same time, the typical demonstration function of the Shenzhen-Zhongshan Link will influence and drive the new development of the composite foundation reinforcement technology of deep cement mixing piles for immersed tunnels.
