Earthquake Resistant Design of Tilt-Up Buildings with Segmented Walls: Fid-Bau Portal

Earthquake Resistant Design of Tilt-Up Buildings with Segmented Walls

Chou, Sheila Hsiao-Fen / Anderson, James C.

Recent trends in the design of tilt-up wall buildings has been toward the use of segmented wall panels that are connected by welded plates at two or three locations over the height of the panel. It has also been suggested that in seismic regions panels should be connected in pairs or at most in groups of three. In both conditions, chord steel at the top if the panel is provided. The purpose of this study is to evaluate the effects of strong ground motions having pulse type displacement characteristics on this type of tilt-up wall construction. In order to investigate the seismic behavior, three dimensional, linear and nonlinear models of a prototype building are developed within the constraints of the computer program, SAP2000. Nonlinear elements are incorporated for the connections of the glulam beams and purlins to the wall panels and the nonlinear behavior of the diaphragm is modeled using a Hrennikoff model of the continuum. A third building model was developed having cast-in-place connections (pilasters) between the panels. This modeling permitted a comparison between the traditional pilaster construction and the more modem segmented wall construction. In addition, the effects of dense nailing and sparse nailing in the diaphragm are considered. Results of these analyses indicate that the use of segmented panels in tilt-up wall construction is a viable procedure for buildings located in seismic regions. However, it is important that tests be conducted on the various connections used to tie the components of this system together and that their strength and ductility in the post yield region be determined. Based on the results of these tests some additional strengthening of critical connections may be required to provide the necessary strength and ductility.