Behavior of Instrumented Omega Pile in Porous Soil

Abstract

Results obtained from in-situ load tests carried out on omega displacement piles sunk in a porous, lateritic and unsaturated soil deposit, are analyzed in this paper. Three slow-maintained load tests were performed on deep instrumented piles with a diameter of 0.37 m and around 12 m long. The soil deposit consists of a superficial, silty clay “porous” layer 6 m thick. Under this layer there is a lateritic stratum 10 m thick, geotechnically consisting of a residual clayey silt. The results of the field load tests yielded a maximum pile load (average for the tests) of 1428 kN, which is twice as high as corresponding experimental values from standard bored piles with similar geometric conditions. Numerical finite element analyses, were performed in order to back-analyze the geotechnical soil parameters for a post-execution pile condition. The results permitted a better understanding of the improvement of the subsoil given the intrinsic execution characteristics of this particular pile. It was also possible to note that omega displacement piles have great potential to become an economically viable solution in tropical soils, given the enhanced behavior of such piles when compared to alternative techniques.