Avaliação da Resposta Sísmica de um Edifício Pórtico Considerando a Interação SoloEstrutura

This research evaluates the seismic response of a portal frame building considering the effects of soil-structure interaction using the model of the Russian standard SNIP 2.02.05-87 and measuring the influence with respect to the rigid base model; for this purpose, a 5-story building with a structural system of mainly reinforced concrete portal frames with a combined footing foundation on S2 soil was considered as a sample. The methodology used in this study was applied, non-experimental and descriptive. Among the main results found, it is highlighted the increase of 11.56% of the floor distortions in the X direction, an increase of up to 22.88% in the Y direction; regarding the behavior of the foundation, a considerable decrease of up to 92.65% of the settlements was obtained in footing Z-6, regarding the pressure stresses of the foundation, there was an increase of up to 71.73% in footing Z-6 and a decrease of up to 20.08% in footing Z-2. These results indicate a significant influence when evaluating the soil-structure interaction model of the Russian standard SNIP 2.02.05-87 with respect to the embedded foundation model.En la presente investigación evalúa la respuesta sísmica de un edificio aporticado considerando los efectos de interacción suelo estructura mediante el modelo de la norma rusa SNIP 2.02.05-87 y medir la influencia respecto al modelo de base rígida; para ello de considero como muestra un edifico de 5 niveles de sistema estructural principalmente de pórticos de concreto armado con una cimentación de zapatas combinada asentado en un suelo S2. La metodología utilizada en el presente estudio de tipo aplicada, no experimental y descriptiva. Entre los principales resultados encontrados se destaca el incremento de las distorsiones de entrepiso en un 11.56% en la dirección X, un incremento de hasta el 22.88% en la dirección Y; en cuanto al comportamiento de la cimentación se obtuvo una disminución considerable de los asentamientos de hasta el 92.65% en la zapata Z-6, en cuanto a los esfuerzos de presión de la cimentación se tuvo un aumento de hasta el 71.73% en la zapata Z-6 y disminución de hasta el 20.08% en la zapata Z-2. Estos resultados nos indican una influencia significativa al evaluar el modelo de interacción suelo estructura de la norma rusa SNIP 2.02.05-87 respecto al modelo de base empotrada.Na presente investigação avalia-se a resposta sísmica de um edifício com pórtico, considerando os efeitos da interação solo-estrutura utilizando o modelo da norma russa SNIP 2.02.05-87 e medindo a influência em relação ao modelo de base rígida; Para isso, considero como amostra um edifício de 5 níveis com um sistema estrutural maioritariamente de pórticos de betão armado com uma fundação combinada assente num solo S2. A metodologia utilizada neste estudo é aplicada, não experimental e descritiva. Dentre os principais resultados encontrados, destaca-se o aumento das distorções do mezanino em 11,56% na direção X, aumento de até 22,88% na direção Y; Quanto ao comportamento da fundação, obteve-se uma diminuição considerável nos recalques de até 92,65% na sapata Z-6, em termos das tensões de pressão da fundação obteve-se um aumento de até 71,73% na sapata Z. -6 e queda de até 20,08% na base Z-2. Estes resultados indicam uma influência significativa na avaliação do modelo de interação solo-estrutura da norma russa SNIP 2.02.05-87 em relação ao modelo base incorporado

Evaluation of Soil-Structure Interaction on the Seismic Response of Liquid Storage Tanks under Earthquake Ground Motions

Soil-structure interaction (SSI) could affect the seismic response of structures. Since liquid storage tanks are vital structures and must continue their operation under severe earthquakes, their seismic behavior should be studied. Accordingly, the seismic response of two types of steel liquid storage tanks (namely, broad and slender, with aspect ratios of height to radius equal to 0.6 and 1.85) founded on half-space soil is scrutinized under different earthquake ground motions. For a better comparison, the six considered ground motions are classified, based on their pulse-like characteristics, into two groups, named far and near fault ground motions. To model the liquid storage tanks, the simplified mass-spring model is used and the liquid is modeled as two lumped masses known as sloshing and impulsive, and the interaction of fluid and structure is considered using two coupled springs and dashpots. The SSI effect, also, is considered using a coupled spring and dashpot. Additionally, four types of soils are used to consider a wide variety of soil properties. To this end, after deriving the equations of motion, MATLAB programming is employed to obtain the time history responses. Results show that although the SSI effect leads to a decrease in the impulsive displacement, overturning moment, and normalized base shear, the sloshing (or convective) displacement is not affected by such effects due to its long period