Abstract: The accelerated development of urbanization has led to an increase in the number of deep excavation projects, which has also increased the complexity of their mechanical mechanisms, making the traditional single excavation support structure show significant limitations. Based on typical deep excavation projects in the Guiyang area, combined with the key and difficult points of the projects, an anchored soldier pile retaining wall support structure is proposed. The mechanical characteristics and suitable application aspects of this structure are explored through theoretical analysis, mechanical analysis, and case verification. The results show that: 1) within a depth range of 5m in the dual-layered stratum structure of rock-soil mixed deep excavation projects in Guiyang, the lateral earth pressure on the excavation slope is relatively small, and the soil pressure distribution pattern is nearly “inverted funnel” shaped, with abrupt changes near the rock-soil interface, forming a multi-peak distribution characteristic; 2) the anchored soldier pile retaining wall is a combined structure consisting of an upper cantilever section and a lower anchor tension section. The cantilever section bears the smaller soil pressure on the upper part, while the anchor tension section bears the larger and more complex multi-peak abrupt rock-soil pressure on the middle and lower parts. The force model is clear, safe, and efficient; 3) the top row of anchor of the soldier pile retaining wall is generally set 2.0m to 6.5m below the pile top, which can avoid the risk sources such as the comprehensive pipe network area, building basement, and pile foundation within a certain range behind the foundation pit slope. Compared to the double-row pile support structure, it saves 2.0 m to 8.0 m of temporary land use on the slope top, making it more suitable; 4) the cost of anchored soldier pile retaining wall support is about 80% to 90% of the cost of anchored sheet pile retaining wall support and 35% to 45% of the cost of double-row pile support. It is more economical. The use of anchored soldier pile anchor rod retaining wall for supporting deep excavation projects with a dual-layered stratum structure where the upper part is soft soil and the lower part is hard rock has achieved significant results. The research findings can provide reference for similar deep excavation support projects.

Key words: Deep Excavation, Anchored Retaining Wall, Soldier Pile, Cantilever Type, Mechanical Behavior