COMBINED FOUNDATION OF A HIGH-RISE BUILDING COMPLEX ON SAND: ANALYSIS AND OBSERVATION

摘要

The building complex of the Beisheim Center at the Potsdamer Platz in Berlin has recently been completed. Different building parts had to be founded partially on the existing tunnel structures and partially on a system of piled-raft and raft foundations. The combined foundation was designed so as to minimize sectional forces due to the different foundation stiffnesses that were the unknowns in the analysis. Based on pile load tests the nonlinear stiffness of piles has been determined. For the design, both foundation components have been first decoupled and analysed separately. Subsequently, the interaction effects have been estimated by a simplified procedure. The pile configuration has been optimized by considering its effects on the superstructure. The performance of the combined foundations has been checked by comparing computed deformations with actual measurements at relevant points. Parallel to this, the system has been analysed by a 3D finite element model. The concept and the key design items of the combined foundation are presented, and a comparison is made between the estimated deformations and the measurements. The methodology for the analysis of building response to train induced vibrations is outlined.