Análise da eficiência de fundações ramificadas

Abstract

Study of foundations in engineering is very relevant since these elements form the basis of virtually any building. Piles are foundation elements that use, in many cases, basically lateral friction as a mechanism for transferring loads, which depends on the surface contact area between the structure and the soil. Branched natural systems have large surface areas, such as tree’s roots, that use its branched geometry as an anchor system to increase its ability to withstand requests, like self weight and wind loads. This research presents a branched structure model based on fractal geometry, that may be used as an alternative solution for foundations. The aim of this research is to compare the performance of branched foundation models against standard stake ones. The performance of each model will be discussed for its load capacity, stress levels and displacements. In addition to that, analyse the efficiency related to increasing the number of branches in the structures, the impact due the adoption of different branching angles and the efficiency related to other branched model generation parameters. The model was simulated using PLAXIS, a software capable of modeling the non-linear soil behavior and the interface between soil and structure. The results of the simulations evidence that a branched structure compared to a standard pile with same volume presents higher carrying capacity and lower maximum displacements, showing that this structures are more efficient in both aspects. On the other hand, the rate of increase of load capacity comparing different branched models declines for structures with higher number of branches. The same behavior is observed for the reduction of displacements analysis. Simulating structures with different branch angles shows that, until a certain point, the higher the branching angles the higher the load capacity, however, angles higher than 60◦ showed a decrease in its load capacity. In general lines, the study suggests the concept of an optimum design model for a branched structure in both parameters, number of branch orders and branch angle, proposing the existence of an optimized structure, capable of increase the soil-foundation mechanical resistance properties without using a very complex geometry. The efficiency of this structural systems was also verified through a study with an adapted branched model that has no branch angle (inspired by torpedo stakes), by using laboratory tests and computational analysis, whose results corroborate the efficiency of using branched geometries in optimizing the resistance of foundation systems. The studies showed that branched structures have a good potential to be used as a solution for edification foundation systems.