Seismic performance of L-shaped multi-storey buildings with moment-resisting frames

Abstract

Recent earthquakes have demonstrated that buildings with irregular configuration are more vulnerable to earthquake damage. Moreover, the configuration irregularities introduce major challenges in the seismic design of building structures. One such form of irregularity is the presence of re-entrant corners and torsional irregularity that causes stress concentration due to sudden changes in stiffness and torsion amplification in buildings. Constructive research into re-entrant corner and torsion-irregular buildings is therefore needed to evaluate the seismic response demands for reducing the potential damage. The aim of the study reported in this paper is to grasp the seismic performance of L-shaped irregular buildings with moment-resisting frames through an evaluation of the irregularity effects on measured seismic response demands. The results for inter-storey drift, storey shear force, overturning moment, torsion–moment responses at the base and along the building height, top-floor displacement and torsional irregularity coefficient prove that buildings with irregularity are more vulnerable than those with a regular configuration resulting from stress concentration and coupled lateral–torsional behaviour.

Respuesta sísmica de edificios de 8 niveles de concreto armado con irregularidad en planta

“…Es decir, al reducir la excentricidad y la irregularidad en planta de la estructura, esto resulta en una disminución del periodo fundamental del modelo estructural. Por consiguiente, se evidencia que el periodo fundamental no solo es función de la altura del edificio según el método convencional, sino que también acumula una influencia significativa de la forma horizontal del edificio [30].…”

“…Se consideró el valor de R = 3.6 para evaluar la irregularidad horizontal torsional extrema para la tipología L. Esta configuración presenta esquinas entrantes y modo oscilatorio de alta frecuencia, que genera una concentración alta de esfuerzos en esquinas entrantes, debido a cambios abruptos en la rigidez y amplificaciones de la torsión. Estos factores provocan fallas en los elementos estructurales [30], [31]. La Fig.…”

“…La relación total de respuesta a la deriva de entrepisos aumenta a medida que aumenta la irregularidad de la planta. La respuesta a la deriva de entrepisos a lo largo de la altura del edificio muestra que los pisos intermedios se ven más afectados que los pisos inferiores y superiores [30]. En la Fig.…”

A moderately refined and efficient regional seismic damage simulation method considering building irregularity

“…Numerous studies (Anagnostopoulos et al, 2015;Aşıkoğlu et al, 2020;Bugeja et al, 1999;De Stefano and Pintucchi, 2008;Yiu et al, 2014) showed that for an irregular structure, the eccentricity between the center of mass and the center of rigidity is the main factor causing structural torsional deformation under ground motion excitation and as a result leading to serious damage. For example, Raheem et al(Abdel Raheem et al, 2018) analyzed the seismic response of L-shaped irregular buildings showing that buildings with irregular planar layouts have worse seismic performance compared to regular buildings; In the Wenchuan earthquake of 2008, the external-corridor type buildings widely used in classroom buildings, dormitories, and office buildings were severely damaged; In the 1985 Mexico earthquake, about 50% of buildings were damaged because of the torsional effect generated by the irregular arrangement of lateral load-resisting members directly or indirectly (Chandler, 1986;Meli and Rosenblueth, 1986) Therefore, considering the irregularity characteristic of buildings in regional seismic damage simulation has significant engineering values. Because of the high number of buildings in regions, a spatial simplified model is a feasible method to moderately consider the lateral-torsional coupling effect of irregular buildings (Ruggieri et al, 2022).…”

Seismic Behavior of Multi-Storied Rc Building With Re-Entrant Corner

“…In recent times, many buildings have been designed with irregular configurations. The irregular configuration of buildings has been one of the major issues to be addressed, for those located in earthquake-prone areas [1]. Past and recent earthquake events demonstrate that buildings with irregular configurations are more vulnerable to earthquake damage [2].…”