Back Analyzed Parameters from Piled Foundations Founded on Tropical Porous Clay

This paper presents the results of numerical analyses carried out with a program exclusively developed for simulating piled raft foundations. It was developed by Zhang and it extends the use of the finite layer method to the analysis of a general loading system applied to piled raft foundations. It allows the establishment of a coupled relationship between displacements, rotations, and external loads and it furnishes displacements, moments, shears and forces within the analyzed system. The paper explores the applicability of this program by using it to simulate the behavior of experimental field loading tests carried out at the University of Brasília (UnB) experimental site. At this site, Cunha and Sales carried out several vertical loading tests on a small scale isolated raft and piles, group of piles, and piled rafts. Zhang's program was adopted to back analyze this series of experimental results, furnishing preliminary geotechnical parameters for use in future designs with this or similar soils. The analyses also highlighted the fact that it is possible to numerically simulate the complex behavior of such mixed foundation systems founded on "non classical" materials such as the Brasília porous clay.