Kohei Kurita

Development of Adaptive Roof Structure by Variable Geometry Truss

Moveable structure has been used for drawbridge and all-weather stadium with retractable roof. These structures move on the rail or turn around the hinge, and these behaviours are monotony and simplicity. However, near future, the shape of construction changes variously as harmonising with surroundings. In order to realize new constructions, we found VGT (Variable Geometry Truss) developed for foldable parabolic antennas of artificial satellites in space. In this study, the VGT structure was applied to the variable roofs of large hemisphere dome as ground construction. First, the roof design and motion was analyzed by computer simulation. Next, a reduced model of roof was made to investigate the structural characteristics and dynamic motion. As result of experiments for reduced model, the configuration of each roof was able to change smoothly from closing to opening, and also the roof was adept shape to any missions. Regardless of shape, the roof structure was confirmed to be dynamic stability.

Present Circumstances of an Automated Construction System for High-Rise Reinforced Concrete Buildings

An automated construction system has been developed to reduce the total cost of high-rise reinforced concrete building construction. It has been already applied to three condominium construction projects in Japan and one office building construction project in Singapore since 1995. Application of this system ensures good quality, improves the working and environmental conditions, reduces the construction period, manpower, and wastage, and improves overall productivity. Through these applications, the authors have improved and adapted the system to suit various conditions.

Development of Adaptive Structure by Variable Geometry Truss (Application of Movable Monument in Expo 2005)

This paper describes the large-scale movable monument exhibited at the International Expo 2005, Aichi, Japan, as the first application of an adaptive structure using a VGT mechanism. This monument is composed of three identical movable towers comprising four truss members combined by VGT at joints. The VGT is an adaptive truss with an extensible actuator, so the monuments shape can be changed variably by controlling the length of each of its extensible actuators. In the application of the VGT to the movable monument, security against accidents was examined and authorization for the structures design was acquired. Further, the control systems safety mechanism, management and operation manual were studied and approved. During the 185 days of the Expo, the monument was operated continuously for about 13 hours a day, and there was not a single breakdown or accident. Continuous safe and excellent performance was achieved, and the monument received high appraisal from promoters and many attendees.