LABORATORY STUDIES OF BRICKWORK WALLS TAKING INTO ACCOUNT THE INFLUENCE OF THE VERTICAL COMPONENT OF SEISMIC IMPACT

Abstract

The article presents the results of the analysis of methods for testing masonry walls for seismic effects. According to the results of the analysis, it is determined that the existing methods of testing masonry wall fragments allow for a fairly accurate determination of the effect of the seismic component, but not all of them have the ability to take into account the vertical component of the seismic load. From all the variety of previously performed studies, the optimal methods for testing masonry wall fragments were selected, and on their basis, the method described in this article was finalized. The work is part of a comprehensive study that includes numerical, laboratory, and research aimed at creating a methodology for certification and visual assessment of seismic resistance (1st and 2nd levels of the methodology for assessing seismic resistance on the example of buildings with load-bearing masonry walls). The purpose of this work was to develop a methodology for testing masonry walls for seismic effects, taking into account not only the horizontal component but also the vertical one. During the study of a masonry wall fragment for seismic effects with regard to the vertical component, the methodology for conducting the experiment was improved. The method of gradual application of the vertical and horizontal parts of the seismic load after loading with a static vertical load was used. This technique allows us to fully determine at what stages deformations occur, where exactly the crack opening begins, and at what degrees of loading. In addition, clock-type indicators were installed at the ends of the wall, which allowed recording the wall's skew from its initial position due to vertical and horizontal impacts. The proposed methodology makes it possible to test wall fragments for seismic effects, taking into account the influence of the vertical component. Tests are carried out in 2 stages: application of vertical static loads and stepwise application of loads arising from seismic impacts. The peculiarity is that not only the horizontal load, but also the corresponding vertical component of the seismic impact will be added in stages.