This paper proposes a slotting construction strategy to avoid shear behavior of multistory masonry buildings. The aspect ratio of masonry piers increases via slotting between spandrels and piers, so that the limit state of piers under an earthquake may be altered from shear to rocking. Rocking piers with a structural concrete column (SCC) form a self-centering earthquake-resistant system. The in-plane lateral rocking behavior of masonry piers subjected to an axial force is predicted, and an experimental study is conducted on two full-scale masonry piers with an SCC, which consist of a slotting pier and an original pier. Meanwhile, a comparison of the rocking modes of masonry piers with an SCC and without an SCC was conducted in the paper. Experimental verification indicates that the slotting strategy achieves a change of failure modes from shear to rocking, and this resistant system with an SCC incorporates the self-centering and high energy dissipation properties. For the slotting pier, a lateral story drift ratio of 2.5% and a high displacement ductility of approximately 9.7 are obtained in the test, although the lateral strength decreased by 22.3% after slotting. The predicted lateral strength of the rocking pier with an SCC has a margin of error of 5.3%.

Axial compression ratio of Walls in UnreinforcedMasonry Structures is studied based on a 7-story concrete small block building and a 7-story common brick building with FEM. Factors that influence the axial compression ratio are analyzed. The axial compression ratio of walls in unreinforced masonry structures is compared with that of walls in concrete shear wall structures and reinforced masonry structures. Besides, Characteristic value of axial compression ratio is calculated. The results shows that axial compression ratio ranges from 0.06 to 0.50 and is associated with story number material, load, wall width and plane layout of structures etc. Characteristic value of axial compression ratio ranges from 0.04 to 0.30 which is about 60 percent of its design value. Keywords-unreinforced masonry structures; axial compressive stress; axial compression ratio; seismic walls; characteristic value1928 978-1-4577-0290-7/11/$26.00 ©2011 IEEE

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In order to study the influence of different design response spectra on the internal force of the isolated structure, the response spectra of the “Code for Seismic Design of Buildings” (Abbreviated as SD), the response spectra of “Design Standards for Seismic Isolation of Buildings” (draft for comments)(Abbreviated as ID) and the response spectra based on pseudo acceleration calibration(Abbreviated as PA) are analyzed. Compared with SD response spectra, ID response spectra adopts the (1/T) attenuation mode in the long period, which reduces the value of the earthquake influence coefficient in the long period of the response spectrum. At the same time, there is no overshoot phenomenon in ID response spectra. This paper presents the response spectrum basic on structural elastic displacement. PA response spectra considers the influence of different sites on the long-period structure, and adds the characteristic period corresponding to different sites. The calculation shows that compared with the calculation result of SD response spectra, the floor shear force calculated by ID is reduced, and the reduction ratio is between 31% and 36%. Compared with the floor shear force obtained by using PA response spectra, the reduction ratio is between 19% and 29%.

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