Estimativa da eficiência do ensaio SPT através da execução da prova de carga estática sobre o amostrador / Estimation of the efficiency in SPT test through static load tests to the sampler
AUTOR(ES)
Pablo Cesar Trejo Noreña
FONTE
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia
DATA DE PUBLICAÇÃO
29/07/2011
RESUMO
The Standard Penetration Test, SPT, is one of the most used one for subsoil information in the USA and Brazil. The data obtained in this dynamic test, such as the penetration resistance index, NSPT, the soil classification and phreatic level are used by different methods to estimate the shallow and deep foundations load capacity. For the same soil, the index NSPT can be different if different equipments are used, because different SPT equipments show different efficiency levels. Having this in mind, an alternative to estimate the essay efficiency of the SPT test is using the static load test (SLT) to the sampler. This test was implemented in order to evaluate the efficiency of SPT. To do so, 13 dynamic tests and 13 static tests were performed in the experimental campus of the State University of São Paulo at Bauru (Unesp- Bauru-Brazil). To estimate the efficiency of the SPT test through the dynamic test, a data acquisition system was used to register accelerations and forces at the located section close to the sampler SPT. The dynamic test was modified so that it would be possible to use many nominal potential energy of the hammer and elevation systems. The estimation of the efficiency made through the SLT tests was based on Hamilton\ s principle. Furthermore, by comparing the dynamic and static behavior, we can get the soil-sampler interface static resistance. This resistance is calculated by using the field data through various estimation methods such as Aoki\ s (2007), De Souza\ s (2009) and Odebrecht\ s (2003). The estimates of the efficiency obtained through SLT test were found to be consistent with those obtained through the SPT modified tests. We conclude that SLT is a simple and non-expensive alternative to obtain the efficiency of SPT equipment.
ASSUNTO(S)
dynamic resistance hamilton s principle efficiency eficiência ensaio spt princípio de hamilton prova de carga estática resistência dinâmica resistência estática spt test static resistance static load test
