Abstract
Top-down method is a type of downward construction method that slab, girders and beams are connected to slurry wall by sequentially alternating ground excavation and structure construction after the construction of cast-in-place pile. Top-down method was introduced in Korea in the middle of 1980s. Since early 2000s, about 20 top-down methods have been developed. However, the selection of top-down method adequate to apply at construction site is difficult because almost developed top-down methods excepting reinforced concrete top-down method have been patented. Also, top-down method is often avoided due to high cost, poor work conditions and low work efficiency compared with open-cut method and bottom-up method. This paper proposes a top-down method applied with the independence of slurry wall and berm. In the case study targeted for an actual construction project, the proposed method is compared with existing top-down construction method in terms of economic feasibility and work efficiency. The proposed construction method results in better quality management in PRD work, steel frame work and excavation, increased economic feasibility and reduced construction period.
