Reforzamiento de una estructura de acero de 8 pisos : análisis estructural y reforzamiento de estructura aporticada de 8 pisos en acero, mediante diagonales rigidizadoras.

Abstract

The main objective of this project is to propose a structural reinforcement based on stiffening diagonals for an 8-story structural steel building with a system of frames resistant to special moments, located in Quito city because it does not comply with the earthquake resistance criteria established in the NEC-15. Starting from an architectural configuration, a static linear and dynamic spectral analysis was carried out, with the purpose of obtaining the structural analysis and the necessary parameters to carry out an earthquake resistant review. The revision in question was based especially on: plan torsion, vibration modes, modal mass participation, minimum dynamic shear and damage limitation. Once the linear seismic analysis was carried out, it was quantitatively determined that the 8-story structural steel building does not meet the NEC-15 seismic resistance criteria. In addition, a non-linear analysis based on the Pushover methodology was carried out, which allowed evaluating the level of performance of the structure, obtaining as a result that the building does not meet the minimum performance criteria for a basic structure. To evaluate the level of performance, the building was subjected to three seismic events: occasional, design and strange earthquakes, these were scaled based on their return period and probability of exceedance from the design earthquake. Therefore, the reinforcement proposal, including stiffening diagonals to the structural system, thus turning it into a system of frames resistant to special moments with bracing. The building with reinforcement (CR) was also subjected to a static linear and dynamic spectral analysis, complying with all seismic resistant reviews. The performance level was also determined with a non-linear analysis, complying with the basic structure level. The structural reinforcement with stiffening diagonals that this document proposes not only a successful solution at a structural level but also at an economic level. In the first case, because the building (CR) increases the rigidity of the entire structure and decreases the displacements that will be reflected in the limitation of damage against seismic threats; for the second case, the cost of structural reinforcement does not exceed ten percent of the initial value of the building without reinforcement (SR).