Title: Aseismic Design of a 28-Story Reinforced Concrete Building of Cross-Shaped Plan

Author(s): Agustin A. Mazzeo

Publication: Symposium Paper

Volume: 63

Issue:

Appears on pages(s): 383-408

Keywords: building codes; computer programs; dynamic loads; dynamic structural analysis; earthquake resistant structures; earthquakes; foundations; frames; high-rise buildings; reinforced concrete; shearwalls; structural analysis; structural design.

DOI: 10.14359/6659

Date: 8/1/1980

Abstract:
This paper describes the structural earthquake design of a 28 story reinforced concrete Office Building located in Caracas, Venezuela, which is a very heavy seismic area. The structure has special features, such as its cross-shaped plan and four 'U' shaped shearwalls placed at comers of the building. It was designed to resist a total shear at the base of building of .08g, distributed over the height according to its dynamic response. Soil site properties, represented by a measured alluvial deposit 160 meters deep (525 ft.), were considered to select an appropriate response spectrum for the structural design. The structural analysis underlined the excellent behavior of the lateral load resisting system used in this structure. This system consists of longitudinal frames interacting with 'U' shearwalls. The structural system complies with limits on lateral deformations imposed by the Venezuelan Seismic Code MOP-1967 (1). The shearwalls proved to be extremely efficient in limiting lateral deformations and in resisting additional shear forces due to Code requirements in connection with torsion. The Wide column-frame analogy was used to model shearwalls, and the analysis considered full frame-shearwalls interaction, axial strainin all structural elements and infinitely rigid haunches at nodal points of frames in order to take account of the relative effect of the actual dimensions of the structural elements. The design of the shearwalls was achieved by means of ultimate strength computer interaction diagrams for combinations of axial loads and uniaxial bending moments.