Deep Cement Mixing (DCM) Method for Reclamation of Tung Chung East Reclamation – Construction Aspects

Deep Cement Mixing (DCM) is an effective soil improvement technique widely used in geotechnical engineering. This technique involves the use of cement slurry to create cylindrical columns in the soil. These columns help to improve the strength, stiffness, and stability of the soil. DCM has been successfully applied in various projects, including marine infrastructure development. In the advanced work for Tung Chung New Town Extension (TCNTE) project, as a non-dredged construction scheme, deep cement mixing (DCM) method for ground improvement was used to strengthen very soft to soft marine sediment of clay to silty-clay materials in the project area for supporting seawalls and overlying fill material for ground formation. During the project, various types of DCM method and equipment were used according to the construction stage, purpose and site restraints in both marine and land work front. Different challenges were encountered and handled during the project such as low water, works near the noise sensitive area, severe barges interference by site congestion, low headroom and many others. Through the entire project, more than 6.2 million m3 of volume of DCM was installed successfully which sets the record of world largest DCM application for a single contract.