Geosynthetic Encased Column: comparison between numerical and experimental results

The use of granular column is one of the ground improvement methods used for soft soils. This method improves the foundation soils mechanical properties by displacing the soft soil with the compacted granular columns. The columns have high permeability that can accelerate the excess pore water pressure produced in soft soils and increase the undrained shear strength. When it comes to very soft soils, the use of granular columns is not of interest since these soils present no significant confinement to the columns. Here comes the encased columns that receive the confinement from the encasement materials. In this study, the influence of the column installation method on the surrounding soil and the encasement effect on the granular column performance were investigated using numerical analyses and experimental tests. The results show that numerical simulations can reasonably predict the behavior of both the encased column and the surrounding soil.

Numerical Simulation of Precast Pile Caps Reinforced Concrete

This paper investigates the structural behavior of pile caps designed in precast concrete. Firstly, it is performed an introduction to the subject, indicating the advantages and disadvantages of using this element as structural solution. Secondly, some aspects related to its application in Brazil and abroad are discussed as well and finally, considerations are presented regarding the research in this area, followed by numerical analysis of two pile caps studied by Chan & Poh [3], using finite element method by Diana V 9.2 software. A load versus displacement response of a specimen is presented as the cracking panorama and nodal stress in the pile and the column. Comparison of ultimate load between experimental and numerical simulation shows that numerical model is able to represent the structural behavior.