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Authors
Abstract(s)
O contínuo crescimento do setor da construção civil, juntamente com a urbanização ascendente e a busca pelo máximo aproveitamento das áreas urbanas, traz consigo efeitos não tão frequentes em edificações de menor porte, como o efeito da Interação Solo-Estrutura (ISE), o qual pode ser analisado por meio métodos analíticos, através de cálculos manuais, ou através da implementação de programas computacionais
que buscam encontrar resultados mais próximos aos encontrados em campo, resultando em edificações mais seguras, previsíveis e econômicas. Este estudo buscou analisar criticamente a influência de parâmetros de um solo argiloso no comportamento da ISE. Utilizando o programa computacional RFEM, foi possível analisar os resultados obtidos por meio do Método dos Elementos Finitos (MEF) e pelo método de Winkler
para determinação dos recalques e efeitos da ISE na estrutura, considerando a profundidade do substrato rígido. A pesquisa levou em consideração recomendações das normas europeias, bem como dos anexos nacionais impostos à Portugal. Verificou-se que a proximidade da camada rígida em relação à cota de assentamento da fundação resulta em menor influência da ISE. Bem como, conforme o substrato rígido se apresentava a uma maior profundidade a ISE tendia a uma estabilização, sendo que as maiores oscilações na ISE foram encontradas quando o impenetrável se encontrava nos primeiros 10 metros abaixo da cota de assentamento. Os parâmetros do solo como ângulo de atrito, coesão, nível do lençol freático e peso
específico não apresentaram relação direta com a ISE, mas influenciaram na capacidade de carga do solo. Já o módulo de elasticidade, o módulo de cisalhamento e o coeficiente de Poisson apresentaram relação direta com os recalques, influenciando nos efeitos da ISE de forma mais pronunciada. Constatou-se que,
quando o impenetrável se encontrava nos primeiro metros, os bulbos de tensões das sapatas eram mais nítidos, e não cruzavam com os bulbos das demais sapatas de modo atenuante, sendo assim os efeitos de grupo oriundos dos bulbos foram menores quando o impenetrável estava mais próximo da cota de assentamento. Também verificou-se que, quando mais proximo, o solo apresentava uma maior concentração
de tensões circundando as sapatas, trazendo risco de ruptura do solo por puncionamento.
Observou-se um comportamento atípico em dois pilares periféricos, houve uma redução de carga quando o substrato impenetrável se aproximou da cota de assentamento, diferente do esperado pela ISE, resultado atrelado à menor inércias destes pilares, estar voltada para os pilares mais carregados, o que resultou em um engaste da viga nos pilares inferior ao encontrado no direção paralela ao maior comprimento do pilar, também a alta sensibilidade destes pilares por terem apresentados efeitos mais baixos devido à ISE (inferiores a 4%), favoreceu para que ocorresse este efeito atípico.
The continuous growth of the civil construction sector, along with upward urbanization and the pursuit of maximum utilization of urban areas, brings with it effects not so common in smaller buildings, such as the Soil-Structure Interaction (SSI) effect, which can be analyzed through analytical methods, either via manual calculations or through the implementation of computer programs seeking to find results closer to reality, resulting in safer, more predictable, and economical buildings. This study aimed to critically analyze the influence of parameters of a clayey soil on the behavior of SSI. Using the RFEM computational program, it was possible to analyze the results obtained through the Finite Element Method (FEM) and the Winkler method for determining the settlements and effects of SSI on the structure, considering the depth of the rigid substrate. The research took into account recommendations from European standards, as well as national annexes imposed on Portugal. It was found that the proximity of the rigid layer to the foundation's settlement level results in a lesser influence of SSI. Moreover, as the rigid substrate was at greater depths, SSI tended towards stabilization, with the greatest oscillations in SSI found when the impenetrable layer was within the first 10 meters below the settlement level. Soil parameters such as friction angle, cohesion, water table level, and specific weight showed no direct relationship with SSI but influenced the soil's load-bearing capacity. On the other hand, the modulus of elasticity, shear modulus, and Poisson's ratio showed a direct relationship with settlements, influencing the effects of SSI more pronouncedly. It was observed that when the impenetrable layer was within the first meters, the stress bulbs of the footings were more distinct and did not intersect with the bulbs of other pillars in an attenuating manner, thus, the group effects originating from the bulbs were smaller when the impenetrable layer was closer to the settlement level. It was also observed that, when closer, the soil exhibited a higher concentration of stresses surrounding the footings, posing a risk of soil rupture due to punching. An atypical behavior was observed in two peripheral pillars, where there was a reduction in load when the impenetrable substrate approached the settlement level, contrary to what was expected by SSI, a result linked to the lower inertias of these pillars, being oriented towards the most heavily loaded pillars, resulting in a restraint in the bottom beam compared to that found in the direction parallel to the pillar's longest length; also, the high sensitivity of these pillars due to their lower effects caused by SSI (less than 4%) favored the occurrence of this atypical effect.
The continuous growth of the civil construction sector, along with upward urbanization and the pursuit of maximum utilization of urban areas, brings with it effects not so common in smaller buildings, such as the Soil-Structure Interaction (SSI) effect, which can be analyzed through analytical methods, either via manual calculations or through the implementation of computer programs seeking to find results closer to reality, resulting in safer, more predictable, and economical buildings. This study aimed to critically analyze the influence of parameters of a clayey soil on the behavior of SSI. Using the RFEM computational program, it was possible to analyze the results obtained through the Finite Element Method (FEM) and the Winkler method for determining the settlements and effects of SSI on the structure, considering the depth of the rigid substrate. The research took into account recommendations from European standards, as well as national annexes imposed on Portugal. It was found that the proximity of the rigid layer to the foundation's settlement level results in a lesser influence of SSI. Moreover, as the rigid substrate was at greater depths, SSI tended towards stabilization, with the greatest oscillations in SSI found when the impenetrable layer was within the first 10 meters below the settlement level. Soil parameters such as friction angle, cohesion, water table level, and specific weight showed no direct relationship with SSI but influenced the soil's load-bearing capacity. On the other hand, the modulus of elasticity, shear modulus, and Poisson's ratio showed a direct relationship with settlements, influencing the effects of SSI more pronouncedly. It was observed that when the impenetrable layer was within the first meters, the stress bulbs of the footings were more distinct and did not intersect with the bulbs of other pillars in an attenuating manner, thus, the group effects originating from the bulbs were smaller when the impenetrable layer was closer to the settlement level. It was also observed that, when closer, the soil exhibited a higher concentration of stresses surrounding the footings, posing a risk of soil rupture due to punching. An atypical behavior was observed in two peripheral pillars, where there was a reduction in load when the impenetrable substrate approached the settlement level, contrary to what was expected by SSI, a result linked to the lower inertias of these pillars, being oriented towards the most heavily loaded pillars, resulting in a restraint in the bottom beam compared to that found in the direction parallel to the pillar's longest length; also, the high sensitivity of these pillars due to their lower effects caused by SSI (less than 4%) favored the occurrence of this atypical effect.
Description
Mestrado de dupla diplomação com a UTFPR - Universidade Tecnológica Federal do Paraná
Keywords
RFEM Winkler Finite element method (FEM)