Volume 34, N. 3

September-December 2011

Acquired Knowledge on the Behavior of Deep Foundations Vertically and Horizontally Loaded in the Soil of Brasília


Volume 34, N. 3, September-December 2011 | PDF (6 downloads)


This paper presents and discusses a limited set of results from an extensive testing program which has been carried out since 1995 at the University of Brasília Experimental Research site. This site is underlain by the typical tropical, unsaturated and collapsible soil deposit of the Federal District, which has been thoroughly studied via an on going program of laboratory and in situ geotechnical tests. In this specific location, several isolated deep foundations were constructed and vertically and horizontally loaded with distinct soil moisture conditions. These foundations, and the soil deposit, do represent typical conditions that occur in other areas of the region, and have therefore been simulated under semi controlled conditions. Since 1995, a large number of research theses were involved with this particular theme, and for the first time some of their main results have been condensed and discussed in the same publication within a logical framework. The knowledge in terms of the observed site behavior, its hypothetical explanation, and some theoretically or empirically derived design variables are shown herein. General conclusions in terms of the vertical and horizontal design values are given together with experimental observations on attained displacements under distinct load levels. The influence of specific external factors on the results is studied; for instance the dissimilar behavior of piles constructed with different methods, or the influence of the weather seasons on the bearing capacity values. From this overall set of data one can have an insight into the complex physical mechanisms involved with the performance, and the difficult simulation, of deep foundations founded in tropical non-classical soils. It is a collection of results with value for researchers and practitioners at both regional and national levels.

Keywords: tropical soil, deep foundation, experimental load test, bearing capacity, displacement, acquired experience, design values,

Submitted on April 14, 2010.
Final Acceptance on September 08, 2010.
Discussion open until April 30, 2012.