Sensitivity Analysis of Soil Treatment Systems including Surcharge and Vacuum and PVDs

In Finite element modelling (FEM) of the soil treatment systems that includes prefabricated vertical drains (PVDs), either for preliminary designation, or in the evaluation period, one the main challenges of geotechnical engineers are the correct estimation of the parameters used in the model. The main objective of these kind of soil treatment is the acceleration of the consolidation process to reinforce the weak soft clay stratum underneath. In the consolidation process the initial soil parameters changes, such as void ratio, hydraulic conductivity, swelling and compression index and so on and that is why the modelling of such reclamation process is so challenging. In previous published literature, there was no paper, especially concentrate on the sensitivity analysis. In this literature first, a case history is presented and verified, and then base on the verified model, the following parameters as: void ratio, vacuum pressure, phi and over consolidation ratio, rate of loading of the surcharge embankment, mesh size, Lambada (𝝀) and Kappa (𝜿), Hydraulic conductivity ratio and Mesh type were parametrically investigated. It was shown that, even a minute change in the quantity of some parameters can adversely affect the precision of the prediction of the model. The results of this study can be used by both field and design engineers, involved in the construction of embankments on soft ground for soil treatment systems in weak and rate-sensitive clays.

Sensitivity Analysis of Soil Treatment Systems including Surcharge and Vacuum and PVDs Keywords:

Sensitivity analysis , Clay , PVD , surcharge , Vacuum preloading , FEM