The Messeturm in Frankfurt is a high-rise tower founded on a compensated piled raft foundation. This type of foundation is particularly well suited for high-rise buildings constructed over soft or compressible soils, as it combines the benefits of raft and pile foundations while mitigating total and differential settlements. The concept of compensation in this context refers to the idea of balancing the applied building loads with the weight of the excavated soil, thereby reducing the net stress increase imposed on the subsoil.

 

Figure 1: View of MesseTurm Tower and arrangement of piles (Kumar et al. 2016)

 

The analysis of such foundations requires advanced numerical modelling techniques capable of capturing the complex soil–structure interaction, the construction sequence, the groundwater flow regime, and the impact of staged excavation and dewatering. In this context, PLAXIS 3D provides a comprehensive environment for modelling the full 3D geometry and construction process of a compensated pile raft system.

This example presents the 3D finite element modelling workflow for the MesseTurm foundation using PLAXIS 3D. The analysis considers the detailed geometry of the excavation pit and the raft, the excavation process along with pre-stressing of anchors, the dewatering sequence, and the pile system represented either as volume elements or through the embedded beam feature. A particular focus is given to comparing both approaches for pile modelling in terms of displacements and load transfer behaviour under serviceability and ultimate limit state loading conditions.

The objective is to demonstrate how PLAXIS 3D can be used to realistically simulate the construction process, evaluate the performance of the foundation system, and provide design insights into the mobilised pile resistances, raft settlements, and stress redistribution throughout the structure.