Volume 40, N. 2

May-August 2017

Behavioral Evaluation of Small-Diameter Defective and Intact Bored Piles Subjected to Axial Compression

Article

Volume 40, N. 2, May-August 2017 | DOWNLOAD PDF (15 downloads)

Abstract

Foundation engineering has continually sought to understand the behavior of piles subjected to loads and their influence on the overall structural behavior. Recently, more load tests are being performed in construction due to the recommendations of the NBR6122/2010 Brazilian code. The available literature offers few reports on pile behavior in a faulty foundation. Therefore, the present study assessed the behavior of a single pile with and without a defect: 5 m long, small-diameter (ϕ = 0.25 m) bored piles were embedded in diabase soil (porous, lateritic and unsaturated) at Experimental Site II (Unicamp). The piles behavior were compared by laboratory tests, numerical analysis using the finite element software LCPC Cesar v.4.07 and experimental results from slow maintained load (SML) tests. Strain gauge instruments were installed at the top and tip of each pile. As predicted by the numerical analyses, when subjected to the first stage of the pile load test, the defective region of the pile failed structurally; however, the pile was still able to resist or “absorb” loading. Factors related to the loading ratio of the foundation, the total and differential displacements and the rotation of the top block were examined. The results obtained in the two analyses (numerical and in situ) were satisfactory and showed significant agreement, providing greater understanding of the complex behavior of this foundation system.

Keywords: Defective pile, Bored pile, Load test, Instrumented piles,


Submitted on October 08, 2016.
Final Acceptance on May 05, 2017.
Discussion open until September 29, 2017.
DOI: 10.28927/SR.402109