Nonlinear Analysis of Reinforced Concrete Three-Dimensional Structures

This project addresses the development of three closely related computer programs and several advanced elements for modeling the nonlinear dynamic behavior of reinforced concrete high-rise structures and their members.

The first computer program deals with the nonlinear static and dynamic analysis of two-dimensional structures and is called DRAIN-2DX. The second deals with the nonlinear static and dynamic analysis of three dimensional structures and is called DRAIN-3D and the third program deals with the nonlinear static and dynamic analysis of three dimensional buildings called DRAIN-BUILDING.

The project also addresses the development of suitable element libraries for these three programs. Several elements are already complete and some are in the final stages of development. Most of these elements are two-dimensional and thus presently work only with DRAIN-2DX. Three-dimensional beam-column elements have also been developed by the CUREe-Kajima team, and are presently awaiting implementation in the three-dimensional program DRAIN-BUlLDING. The Kajima beam-column element accounts for bending, shear and bond-slip deformations and is presently implemented in the in-house computer program. The UC Berkeley beam-column element presently accounts for bending deformations, only, and is implemented in a stand alone version. A two dimensional beam-column joint element based on an extension of the fiber concept is in the final stages of development and will be implemented in DRAIN-2DX.

Finally, the project also addresses issues related to the pre- and post-processing of the results. A set of interactive tools are proposed to facilitate the data input and the evaluation of the response of the nonlinear analysis. These tools are, presently, in the final stages of development and should be released shortly. In order to facilitate the future addition of elements by other researchers and to guide engineers in the practical use of the program a major part of the total effort was directed towards documenting the modeling and analysis procedures used in this project.