Análise do comportamento estrutural de blocos de concreto armado sobre estacas como fundação para aerogerador onshore

Abstract

The growth of the wind energy industry in Brazil has demanded projects of big size foundations, which in most cases are pile caps. These structural elements spend close to 300 cubic meters of concrete and 20 tons of steel in its construction. In this context, a deepest structural analysis about this kind of wind turbine foundations should contribute to improvement of projects in this sector, that are of great relevance for the development of the Brazilian energy matrix. In that way, this work proposes to analyze the structural behavior of reinforced concrete pile caps, as onshore wind turbine foundations, using numerical models. In order to do, eight finite elements models were constructed, with the aid of the ANSYS V17 and SAP2000 V17 softwares. It was adopted as variables: the finite element type used for modeling the pile cap and piles (solid or shell); the soil representation (spring or semi-infinite space); and, the consideration or not of the soil under the pile cap base. All the materials constitutive models were considered as with linear elastic behavior. The interest results were: pile´s reaction; division of loading between soil and piles; pile cap´s displacement; radial normal stress and bending moments in the pile cap; and, the increase of vertical stresses in the soil. The models designed in solid elements and plate elements demonstrated good compatibility between the found values. In some models, the numerical analysis showed results against the structural safety of the foundation when the soil under the pile cap is not considered.