Contribuição à interpretação de provas de carga em estacas, realizadas pelo método bidirecional

Abstract

In this research, static load tests performed by the bidirectional method were analyzed to evaluate two new procedures for: (i) construction of the load-settlement curve equivalent to the conventional load test and (ii) interpretation of the loadsettlement curve for bearing capacity determination. The proposed construction of the equivalent curve consists in the use of the total loads and displacements (upward + downward) of each load stage. Thus, the equivalent curve is constructed as the test evolves, allowing an evaluation of the pile behavior at each stage, including the proximity of failure, without the need to extrapolate one of the loading segments. In relation to the stiffiness of the initial part of the equivalent load-settlement curve constructed by the current proposal, there is a considerable difference, for bored pile, in relation to Silva’s (1983) proposal. The new proposal for the definition of the bearing capacity from the load-settlement curve, is the application of a geometric rule similar to that of the oedometrer consolidation test (and can be applied to both conventional tests or the equivalent curve obtained from bidirectional tests). The results obtained by this proposal and by previous methods, such as Lopes (1979) and the Brazilian standard NBR6122, are compared.