Abstract: The Soil Mixing Wall (SMW) method has the advantages of short construction period, good waterproof, small impact on the surrounding environment and the hot rolled steel beams can be reused. It has been widely used in the deep excavation engineering where, the soft soil is widely distributed, such as Shanghai, Tianjin, Shenzhen and so on. The typical strata at Hongdao area shows that a thick layer of marine soft soil overlies the bedrock. The SMW method has not previously applied in this area. The investigation focuses on the key installation issues of the SMW application in the soft area based on deep excavation engineering in Hongdao coastal soil and rock composite stratum. The paper proposes the corresponding countermeasures to ensure the quality of the SMW column which can provide experience to similar projects and contribute to marine-rock strata deep excavation construction and development of coastal urbans.

Key words: Deep Excavation, SMW Method, Soft Soil, Soil-Rock Stratum