Nichtlinearer Nachweis von unbewehrten Mauerwerksbauten unter Erdbebeneinwirkung
- Nonlinear seismic safety verification of unreinforced masonry buildings
Gellert, Christoph; Meskouris, Konstantin (Thesis advisor)
1. Aufl.. - Aachen : Klinkenberg (2010, 2011)
Dissertation / PhD Thesis
In: Mitteilungen des Lehrstuhls für Baustatik und Baudynamik, Fakultät für Bauingenieur- und Vermessungswesen, Rheinisch-Westfälische Technische Hochschule Aachen 19 = 10/2
Page(s)/Article-Nr.: VII, 157 S. : Ill., graph. Darst., Kt.
Zugl.: Aachen, Techn. Hochsch., Diss., 2010
Due to their specific material behavior, unreinforced masonry buildings are highly earthquake prone. The standard procedures for seismic safety verification of masonry buildings according to the German Seismic Building Code DIN 4149 are traditionally based on a linear design concept. This approach involves major difficulties, even for buildings which have already proven their stability in past earthquakes. With the upcoming introduction of the new German Seismic Building Code DIN EN 1998, replacing the existing DIN 4149, seismic safety verification based on a new generation of innovative nonlinear design concepts, taking into account nonlinear bearing reserves, will henceforth be possible. In order to develop a capable procedure for unreinforced masonry buildings, different procedures to seismic safety verification are introduced and compared. Taking into account typical German architecture, a new displacement-based verification procedure is introduced based on nonlinear cyclic capacity curves of single masonry shear walls. Besides the elaboration of an appropriate modeling strategy, especially a new analytical approach to determine the bilinear approximation of single shear wall capacity curves is derived. The herewith presented bilinear approach for unreinforced masonry shear walls relies on the evaluation of several experimental results of cyclic shear wall tests. The determined values for the end deformation have already been included into the national annex of DIN EN 1998 and are meanwhile available for nonlinear verification with deformation-based procedures. The introduced verification procedure and its application to two different typical residential buildings have been successfully verified by the national building authorities, opening new opportunities for unreinforced masonry constructions in Germany. Different approaches to comprise the global nonlinear bearing reserves are discussed and evaluated by means of linear and nonlinear calculations carried out on 12 different ground floors with overall 252 building variants. Therefore, verification procedures of present and future codes are applied as well as the herewith introduced displacement-based verification procedure in combination with the new bilinear approximation. The calculations focus on the nonlinear interaction between shear walls and slabs which decisively affects the nonlinear bearing capacity of unreinforced masonry buildings. Thus, additional studies with a detailed three-dimensional model are carried out to derive simplified rules regarding these interaction effects.