Análisis de factibilidad de la implementación de riostras de pandeo restringido como dispositivos disipadores de energía

Abstract

Buckling restrained braces (BRBs) are devices used in buildings’ frames to provide protection against seismic events. These devices consist of a slender steel core embedded into a sturdy encasing, commonly composed of a steel tube filled with mortar. This configuration prevents buckling of the core under axial compression loads. In order to prevent an excessive shear stress transfer, it is important to allow free sliding between the core and the buckling-restraining system (steel tube filled with mortar). Because the BRBs can develop their full axial capacity in tension and compression, they are able to dissipate large amounts of energy through stable hysteresis loops. The main purpose of this thesis is to find the specific conditions under which it is feasible to implement BRBs in buildings of Cuenca, Ecuador. As a starting point, four dissipators were built in a scale of 1:14 with common materials and local technology. The four devices were subjected to axial compression tests to verify that loss of axial stiffness due to buckling effects does not occur. Finally, 5-story and 10-story steel buildings incorporating BRBs were seismically evaluated in the ETABS software using a linear static analysis procedure. The results of this study indicate that a low cost BRB, together with an appropriate number and distribution of these devices into the frames, encompass the necessary requirements for a practical use of this seismic force resisting system in Cuenca, Ecuador.