Evaluación de desempeño sísmico de edificio de soporto colector de polvo diseñado según NCh2369:2023.
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Date
2024
Journal Title
Journal ISSN
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Publisher
Universidad de Concepción
Abstract
Los terremotos han sido una constante en la historia de Chile, que con el pasar del tiempo, han pasado a formar parte de la identidad colectiva de los chilenos. Para abordar estos eventos sísmicos desde la ingeniería civil, se aplican normas sismorresistentes como la NCh2369 "Diseño sísmico de estructuras e instalaciones industriales", cuya primera edición fue oficializada en 2003. La filosofía del diseño industrial chileno se fundamenta en la sobrerresistencia y una ductilidad moderada, con la esperanza de no tener que utilizarla en absoluto. Dentro de este contexto, los fusibles sísmicos desempeñan un papel esencial como elementos disipadores de energía. Después del terremoto de Maule 2010, se identificaron falencias en la norma, lo que, sumado a nuevos conocimientos y herramientas de análisis, impulsó una actualización de la normativa. Esta actualización incorpora nuevas formas espectrales, que provienen de un análisis formal de la amenaza sísmica, cambios de los límites de compacidad, y la aplicación de cargas sísmicas reducidas amplificadas por 0.7R1≥1.0, como un criterio unificado para diseñar los miembros que no tienen como objetivo disipar energía.
El objetivo principal de este trabajo es evaluar el desempeño sísmico del Edificio de Soporte para Colector de Polvo constituido en base a marco arriostrados y marcos resistentes a momento. Para lograr esto primero se diseñó de acuerdo con las disposiciones de la actualización de la NCh2369 y posteriormente se realizó un análisis no lineal de tiempo-historia considerando la no linealidad de los arriostramientos y vigas en marcos de momento, para dos escenarios de demanda sísmica: nivel de diseño (SDI) y nivel de sismo máximo probable (SMP).
El diseño lineal resultó con una significativa sobrerresistencia, la cual se logra con un factor R=2. Las diagonales se conformaron por perfiles tipo cajón HSS, debido a que cumplen de mejor manera con los nuevos límites de compacidad. Por otro lado, la configuración de los pernos de anclaje quedó controlada por un solo anclaje, práctica común en el diseño industrial, lo que deja sobredimensionado al resto de los anclajes. En el análisis no lineal, la estructura trabajó en su rango de sobrerresistencia, utilizando muy poca ductilidad. Las columnas sísmicas presentaron factores de utilización elevados y podrían implicar la necesidad de incorporar rótulas plásticas en la modelación. En trabajos futuros se debe estudiar el efecto de la plastificación de pernos de anclaje en la disipación de energía para bases empotradas.
Earthquakes have been a constant in the history of Chile, which over time have become part of the collective identity of Chileans. To address these seismic events from civil engineering, seismic standards are applied such as NCh 2369 "Seismic design of industrial structures and facilities", whose first edition was made official in 2003. The philosophy of Chilean industrial design is based on over-resistance and ductility moderately, hoping not to have to use it at all. Within this context, seismic fuses play an essential role as energy-dissipating elements. After the 2010 Maule Earthquake, shortcomings in the regulation were identified, which, added to new knowledge and analysis tools, prompted an update of the regulations. This update incorporates new spectral shapes derived from a formal analysis of seismic hazards, as well as changes to compactness limits and the application of reduced seismic loads amplified by 0.7R1≥1.0, serving as a unified criterion for designing members not intended for energy dissipation. The main objective of this work is to evaluate the seismic performance of the Dust Collector Support Building made up of braced frames and moment-resistant frames. To achieve this, it was first designed in accordance with the provisions of the NCh2369 update and subsequently a non-linear time-history analysis was carried out considering the non-linearity of the bracing and beams in moment frames, for two seismic demand scenarios: design level (SDI) and probable maximum earthquake level (SMP). The linear design resulted in significant overstrength, achieved with a factor R=2. The diagonals were made of HSS profiles because they better comply with the new compactness limits. On the other hand, the configuration of the anchor bolts was controlled by a single anchor, a common practice in industrial design, which leaves the rest of the anchors oversized. In the nonlinear analysis, the structure worked in its overstrength range, using very little ductility. The seismic columns presented high utilization factors and could imply the need to incorporate plastic hinges in the modeling. In future work, the effect of plasticizing anchor bolts on energy dissipation for embedded bases should be studied.
Earthquakes have been a constant in the history of Chile, which over time have become part of the collective identity of Chileans. To address these seismic events from civil engineering, seismic standards are applied such as NCh 2369 "Seismic design of industrial structures and facilities", whose first edition was made official in 2003. The philosophy of Chilean industrial design is based on over-resistance and ductility moderately, hoping not to have to use it at all. Within this context, seismic fuses play an essential role as energy-dissipating elements. After the 2010 Maule Earthquake, shortcomings in the regulation were identified, which, added to new knowledge and analysis tools, prompted an update of the regulations. This update incorporates new spectral shapes derived from a formal analysis of seismic hazards, as well as changes to compactness limits and the application of reduced seismic loads amplified by 0.7R1≥1.0, serving as a unified criterion for designing members not intended for energy dissipation. The main objective of this work is to evaluate the seismic performance of the Dust Collector Support Building made up of braced frames and moment-resistant frames. To achieve this, it was first designed in accordance with the provisions of the NCh2369 update and subsequently a non-linear time-history analysis was carried out considering the non-linearity of the bracing and beams in moment frames, for two seismic demand scenarios: design level (SDI) and probable maximum earthquake level (SMP). The linear design resulted in significant overstrength, achieved with a factor R=2. The diagonals were made of HSS profiles because they better comply with the new compactness limits. On the other hand, the configuration of the anchor bolts was controlled by a single anchor, a common practice in industrial design, which leaves the rest of the anchors oversized. In the nonlinear analysis, the structure worked in its overstrength range, using very little ductility. The seismic columns presented high utilization factors and could imply the need to incorporate plastic hinges in the modeling. In future work, the effect of plasticizing anchor bolts on energy dissipation for embedded bases should be studied.
Description
Tesis para optar al título profesional de Ingeniero/a Civil
Keywords
Sismos, Terremotos Chile Zona Sur 2010, Edificios Efectos sísmicos Chile