Análise experimental e numérica do comportamento de sapata estaqueada em solo tropical

Abstract

This research investigated the behavior of foundations embedded in tropical soil of Uberlândia, consisting of piled footing and their isolated elements of footing and pile, subjected static axial compressive load by means of slow loading tests (SML). For this purpose, the piles were mechanically bored by dry method (L = 4 m; d = 25 cm) and circular footings, 1 m diameter and 20 cm thickness. To better evaluate the behavior of these test foundations in tropical collapsible soil, they were subjected to loading test in natural water content soil condition and under previous inundation. The piles, single pile and of the piled footing, were instrumented in depth to evaluate the distribution, load sharing and load transfer along the length of the piles. For a better understanding of some phenomena difficult to explain with the experimental model, axisymmetric numerical models in Finite Elements (FEM) of the test foundations were created, which were previously calibrated with the results of the loading tests carried out in the Experimental Field of Foundations and Soil Mechanics at FECIV-UFU. Based on the results and analyses of this research, it was found that the footing promoted a 30% to 40% gain in the capacity of the pile, in comparison to the single pile, even in inundated condition, showing that the combined system presents advantages over the sum of its elements working in isolated form. The analysis of load transfer demonstrates that the piles constructed in the soil resist in large part by shaft friction, in addition the footing, when coupled to the pile, promotes the increase in resistance performance by shaft resistance. The analysis of load transfer demonstrates that the piles constructed in the soil resist in large part by shaft friction, in addition the footing, when coupled to the pile, promotes the increase in resistance performance by shaft resistance. In all cases analyzed, the soil inundation affected the capacity of the foundations, emphasizing the collapsible behavior of the local soil, which is recognized as problematic.