Introduction Gijs de Jongh

Can we introduce you to: Gijs de Jongh

As of 4 march our new college Gijs de Jongh has started at Geobest B.V. Gijs has recently graduatied from The Hague university of applied sciences on the subject: Vibration forecast with Plaxis 2D.

The aim of this research was to investigate the possibility of creating an accurate vibration forecast for the driving-in of sheet pile walls using a computational Plaxis 2D model. In order to compare the calculated vibrations from Plaxis 2D with other models and measured vibrations, a suitable validation project was sought, and two empirical vibration forecasts (CUR166 and IFCO) were used as comparison. Through an iterative process, the Plaxis 2D model was systematically optimized. The research, conducted at IFCO Funderingsexpertise B.V., only considered structures shallow foundations and did not account for the occurrence of water surcharges.

The study revealed that the soil in the Plaxis 2D model is best modeled using the Hardening Soil – Small Strain model. The axisymmetric model is most suitable for representing geometric damping of the subsoil during the driving-in of sheet pile walls. Due to the use of the axisymmetric model, it is not possible to model the sheet pile as a plate because it becomes dimensionless in the middle of the model. Therefore, a volume element was chosen for modeling, with the diameter of the element selected so that the resistance closely matches that of a sheet pile under maximum load. Rayleigh damping is further applied to better represent material damping.

The image below depicts the final iteration of the Plaxis 2D model (green line). It can be observed that the calculated vibrations in the Plaxis model closely follow the measured vibrations in the reference project. This demonstrates the feasibility of creating a vibration forecast in Plaxis 2D for the driving-in of sheet pile walls.