• 레미콘
• /
• no.1 s.70
• /
• pp.73-79
• /
• 2002

• 건축구조
• /
• v.19 no.2
• /
• pp.84-88
• /
• 2012

• Journal of Korean Association for Spatial Structures
• /
• v.11 no.2
• /
• pp.129-138
• /
• 2011

Construction methods for underground structure are classified as bottom-up, up-up, and top-down methods depending on the procedure of construction related to a superstructure. In top-down construction methods, building's main structure is built from the ground level downwards by sequentially alternating ground excavation and structure construction. In the mean time, the main structure is also used as supporting structure for earth-retaining wall, which results in the increased stability of the earth-retaining wall due to the minimized deformation in adjacent structures and surrounding grounds. In addition, the method makes it easy to secure a field for construction work in the downtown area by using each floor slabs as working spaces. However top-down construction method is often avoided since an excavation under the slab has low efficiency and difficult environment for work, and high cost compared with earth anchor method. This paper proposes a combined construction method where semi-open cut is selected as excavation work, slurry as earth -retaining wall and CWS as top-down construction method. 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, construction period and work efficiency. The proposed construction method results in increased work efficiency in the transportation of earth and sand, and steel frame erection, better quality management in PHD construction, and reduced construction period.

• Construction Engineering and Management
• /
• v.11 no.4
• /
• pp.21-25
• /
• 2010

• Journal of Korean Association for Spatial Structures
• /
• v.12 no.1
• /
• pp.20-24
• /
• 2012

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2008.05a
• /
• pp.43-46
• /
• 2008

In Top-Down construction for underground structures, the placement of slab as a horizontal supporting member against lateral earth pressure is an important process in determining construction time and cost. Usually, a reinforced concrete perimeter girder distributes concentrated lateral loads from earth retaining structures such as Cast-in-place (CIP) piles. By combining the function of the R/C perimeter girder and horizontal slabs, the Opened Slab Method is efficient for reducing construction time by elimination of time-consuming formwork for traditional perimeter girders. The structural performance of the method is also discussed in this paper.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2006.11a
• /
• pp.9-12
• /
• 2006

In recent years, construction site has developed lots of new methods and materials for Time-Cost Trade-off and improving constructability. In the case of underground construction, especially, there are many restrictions and difficulties. Shortening of the construction time in construction of underground, we use top-down method in undergroud wall. A open slab has been designed for the purpose of overcoming a weak point of former top-down method. This study based on open slab on the under ground top-down method, to more improve constructability, to introduce the effect and the performance of top-down method.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2013.11a
• /
• pp.4-7
• /
• 2013

In recent downtown high land due to an increase in the utilization of land from the property line to maximize the proximity of the construction and use of underground structures has increased. The nature of urban underground retaining structure construction safety, environmental management, and civil contrast situations, construction periodt perspective, this method is widely used in the backhand. Recent Patents DP method and the method of the DBS method than in the SPS process is deleted according to the PRD process cost savings are generated. The workability and safety study of two kinds of method, such as air speed, and considering the reduction of indirect costs in terms of economic efficiency is considered to be a superior method.

• Journal of the Architectural Institute of Korea Structure & Construction
• /
• v.35 no.6
• /
• pp.101-109
• /
• 2019

The purpose of this study is to improve a general Top-Down construction process for superstructure construction period reduction. In a general Top-Down construction sequence, the ground floor slab is set up first. Subsequently, 1st basement level construction including core walls is constructed. Initiation of the ground level superstructure gets waited until then. In this study, removable deck plate installation on the bottom of the core walls of ground level is preceding the concrete casting, therefore, ground level superstructure construction is able to get started earlier. Up to first typical floor concrete casting, total of seventy-two working(calendar) days will be resulted in a reduction from the total construction periods.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2021.05a
• /
• pp.180-180
• /
• 2021

Recently, structural damage and defect has occurred in the H-beam backfill installation part of Top-Down construction method. In order to secure structural safety and usability in the adjacent section of the backfilling method, It turns out that it is necessary to analyze by dividing into various cases. The H-beam backfill installation section is divided into the case of adding a vertical plate inside the slab, adding a shear stud, adding a reinforcing bar, changing the thickness of the pressure plate, and filling the H-beam backfill with mortar. Ansys modeling was performed and an appropriate solution was suggested by analysis.