Top-down Construction Method using basement beam systems instead of Shoring systems to support diaphragm walls

Abstract

Nowadays, one of the most popular solutions for underground constructions is the Bottom-up method using the Shoring-Kingpost system [1]–[3]. This kind of excavation methodology is easy to manipulate and install the steel components; generate good ventilation and illumination during construction stage. However, its disadvantages are the long construction time and a high construction cost. This paper proposes an appropriate underdround excavation methodology in which the reinforced concrete (RC) beams of the underground structures are combined with the vertical Kingpost steels to generate a support structure during the construction phase. This support structure is also retained during the service-life of the structure. Results from calculations and comparisons reveal that this method is feasible and brings great benefits such as: saving construction costs and construction time, as well as providing good ventilation and illumination for construction.

Keywords: Top-down; bottom-up; excavation; underground; Shoring-Kingpost; beam systems.