MODULARIZED TOP-DOWN CONSTRUCTION TECHNIQUE USING SUSPENDED POUR FORMS (MODULARIZED RC SYSTEM DOWNWARD, MRSD)

摘要

Propping systems utilizing permanent slabs have been used for many decades around the world to resist lateral soil loads on piled perimeter walls or diaphragm perimeter walls during basement excavation. In the top-down construction technique, when the excavation starts to break ground and the placement of the ground level slabs is complete, upward construction of the superstructure while digging the basement are carried out simultaneously. However, the conventional top-down method requires slabs poured on excavated soils. This process of installing and removing temporary supports is difficult and dangerous, often resulting in a delayed excavation and construction schedule. The objective of this paper is to present an innovative deep basement top-down construction technique that eliminates conventional temporary supports through the use of hanging pour forms. The weight of the concrete that is cast for forming slabs is supported by the hanging pour forms. This technique utilizes permanent metal deck plates located on the edges of the pour forms. The many advantages of this technique over the conventional top-down method are described. This paper also describes the first project application on which the new technique was used to separate the concrete work from the excavation.