Interpretação de deformação e recalque na fase de montagem de estrutura de concreto com fundação em estaca cravada / Strain and settlement interpretation in the assembly of a concrete structure supported by driven piles
AUTOR(ES)
Luiz Russo Neto
DATA DE PUBLICAÇÃO
2005
RESUMO
Although encouraged by several authors and by the Brazilian Foundation Code, reports of actual column loads measurement in natural scale are not frequent in our technical literature, especially in the case of buildings supported by deep foundations. Results of load and settlement measurements at 20 contiguous columns of a structure built in pre-cast reinforced concrete and supported by driven piles are presented. Settlements were measured by means of optical level and a range of values between 1.1 to 4.3 mm were observed. Settlement under constant load were observed under variable creep rates from 0.8 to 3.2 mm/log t. Loads over columns were indirectly evaluated through column length variation, using a demountable mechanical extensometer. The methodology for interpretation of measurements made with the mechanical extensometer is described, considering corrections due to the variation of environmental conditions and to the concretes rheology; this methodology leads to a good agreement between measured values and those supplied by conventional structural design. The collected data is back analysed taking into account the soil structure interaction. The superstructure was modelled as a spatial frame supported by springs with the same rigidity of the pile foundation element. The equivalent spring parameter for each column support has considered the settlement group effect for all piles embedded in soil, using the numerical integration of Mindlin s equations. Results of this back analysis show a high variability, reflecting the high degree of variability of local subsoil conditions. Therefore, one can conclude that predictions, in order to be reliable, must consider these soil variations
ASSUNTO(S)
creep fluência fundação profunda settlement field instrumentation instrumentação de campo recalque estrutura de concreto pré-moldado soil structure interaction concrete pre-cast structure interação solo estrutura deep foundation
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