Evaluación del desempeño sísmico de un edificio industrial auxiliar filtrante diseñado según la norma NCH2369 2023.
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Date
2024
Journal Title
Journal ISSN
Volume Title
Publisher
Universidad de Concepción
Abstract
Chile a lo largo del tiempo ha experimentado gran actividad sísmica, lo que ha hecho necesaria la creación de códigos de diseño sísmico avanzados en el país de tal forma de minimizar los riesgos asociados a estos eventos naturales. Uno de estos códigos corresponde a la norma NCh2369 “Diseño sísmico de estructuras e instalaciones industriales” que surge en el año 2003, la cual tiene como objetivo primordial la protección de la vida y la continuidad de operación en la industria dotando a las estructuras de una considerable sobrerresistencia y una ductilidad moderada. Dentro de este contexto, los arriostramientos y los pernos de anclaje desempeñan un papel esencial como elementos que disipan energía, actuando como fusibles sísmicos.
Luego del terremoto de Maule en el año 2010, se identificaron falencias en la norma, lo que, sumado al avance del conocimientos y mejores herramientas de análisis, impulsó una actualización de la normativa. Esta actualización, concretada en el año 2023, incorpora nuevas formas espectrales provenientes de un análisis formal de la amenaza sísmica, límites más exigentes de compacidad local y la aplicación de cargas sísmicas amplificadas por 0.71R1≥1.0 como un criterio unificado para diseñar los miembros que no tienen como objetivo disipar energía.
El objetivo principal de este trabajo consiste en evaluar el desempeño sísmico de un edificio industrial “Auxiliar Filtrante” perteneciente al rubro de la minería, el cual está estructurado en base a marcos arriostrados concéntricamente (MAC). Para esto, el edificio fue diseñado según las disposiciones de la norma NCh2369 2023 para luego realizar un análisis no lineal tiempo-historia en dos niveles de demanda sísmica, uno asociado al espectro objetivo a nivel de diseño y el otro asociado al espectro objetivo a nivel máximo, considerando la no linealidad de pernos de anclaje y arriostramientos.
Del diseño resultaron perfiles más robustos para las columnas sísmicas debido al criterio de diseño de cargas sísmicas amplificadas. Los arriostramientos tienen límites de compacidad local más estrictos, por lo que se utilizaron perfiles tubulares que tienen mayor holgura con respecto a esta restricción. Las vigas que soportan de equipos quedan controladas principalmente por serviciabilidad dado los estrictos límites de deflexiones impuestos por los proveedores de estos equipos. Los pernos de anclaje se diseñan considerando el anclaje más solicitado, práctica común en el diseño industrial. Del análisis no lineal se evidencia que la estructura trabaja en su rango de sobrerresistencia utilizando muy poco de ductilidad a través de los elementos definidos como fusibles sísmicos.
Throughout time, Chile has experienced significant seismic activity, necessitating the development of advanced seismic design codes in the country to minimize the risks associated with these natural events. One of these codes is the NCh2369 standard, "Seismic Design of Industrial Structures and Installations," established in 2003. Its primary objective is the protection of life and the continuity of operations in the industry by endowing structures with considerable overstrength and moderate ductility. Within this context, bracings and anchor bolts play an essential role as energy dissipation elements, acting as seismic fuses. Following the Maule earthquake in 2010, deficiencies in the standard were identified. Coupled with advancements in knowledge and improved analysis tools, this spurred an update of the regulations. This update, finalized in 2023, incorporates new spectral shapes derived from a formal analysis of seismic threat, stricter local compactness limits, and the application of seismic loads amplified by 0.71R1≥1.0 as a unified criterion for designing members not intended for energy dissipation. The main objective of this study is to evaluate the seismic performance of an industrial building, "Auxiliar Filtrante," belonging to the mining industry, structured based on concentrically braced frames (CBFs). For this purpose, the building was designed according to the provisions of the NCh2369 2023 standard, followed by a nonlinear time-history analysis at two levels of seismic demand: one associated with the target spectrum at the design level and the other associated with the target spectrum at the maximum level, considering the nonlinearity of anchor bolts and bracings. The design resulted in sturdier profiles for seismic columns due to the amplified seismic load design criterion. Bracings have stricter local compactness limits, leading to the use of tubular profiles that provide greater flexibility concerning this restriction. Beams supporting equipment are primarily controlled by serviceability due to the strict deflection limits imposed by equipment suppliers. Anchor bolts are designed considering the most demanding anchorage, a common practice in industrial design. Nonlinear analysis shows that the structure operates within its overstrength range, utilizing minimal ductility through elements defined as seismic fuses, namely, vertical bracings and anchor bolts.
Throughout time, Chile has experienced significant seismic activity, necessitating the development of advanced seismic design codes in the country to minimize the risks associated with these natural events. One of these codes is the NCh2369 standard, "Seismic Design of Industrial Structures and Installations," established in 2003. Its primary objective is the protection of life and the continuity of operations in the industry by endowing structures with considerable overstrength and moderate ductility. Within this context, bracings and anchor bolts play an essential role as energy dissipation elements, acting as seismic fuses. Following the Maule earthquake in 2010, deficiencies in the standard were identified. Coupled with advancements in knowledge and improved analysis tools, this spurred an update of the regulations. This update, finalized in 2023, incorporates new spectral shapes derived from a formal analysis of seismic threat, stricter local compactness limits, and the application of seismic loads amplified by 0.71R1≥1.0 as a unified criterion for designing members not intended for energy dissipation. The main objective of this study is to evaluate the seismic performance of an industrial building, "Auxiliar Filtrante," belonging to the mining industry, structured based on concentrically braced frames (CBFs). For this purpose, the building was designed according to the provisions of the NCh2369 2023 standard, followed by a nonlinear time-history analysis at two levels of seismic demand: one associated with the target spectrum at the design level and the other associated with the target spectrum at the maximum level, considering the nonlinearity of anchor bolts and bracings. The design resulted in sturdier profiles for seismic columns due to the amplified seismic load design criterion. Bracings have stricter local compactness limits, leading to the use of tubular profiles that provide greater flexibility concerning this restriction. Beams supporting equipment are primarily controlled by serviceability due to the strict deflection limits imposed by equipment suppliers. Anchor bolts are designed considering the most demanding anchorage, a common practice in industrial design. Nonlinear analysis shows that the structure operates within its overstrength range, utilizing minimal ductility through elements defined as seismic fuses, namely, vertical bracings and anchor bolts.
Description
Tesis para optar al título de Ingeniero/a Civil
Keywords
Diseño sismorresistente, Pernos para anclaje de rocas