Design-Construction of Circular Roof for Underground Reservoir Using Precast Concrete Beams

摘要

style="text-align: left;">The main structure of this $2 million circular roof for an underground reservoir in Tokyo, japan, uses ten precast, post-tensioned T-beams. The roof carries a load of 4 7.2 kN/m2 (0.86 kips per sq ft) on top  of a vertical shaft 28.2 m (92 ft 6 in.) in diameter and 55.2 m (181 ft) deep. This project is located in a very high seismic zone. This article presents the design features, special considerations and  construction highlights of the project along with a description of the fabrication, assembly and erection of the precast beams.  >References style="text-align: left;">1. Akihiko, Kurashima, "Underground River of Tokyo Project (First Period) of Constructing Kanda River - Ring Road Route No. 7," Underground Reservoir, River Journal, Japan River Association, 1997, pp. 51-61. style="text-align: left;">2. Ryouji, Hiroki, et al., "Construction of Shaft Covering Work Using PC Beams," Proceedings of Ninth Symposium on Development of Prestressed Concrete, PC Technology Association, 1997, pp.  699-702.