High-Rise Buildings on Compressible Soil

Research on the Structural Behavior and Substantiation of the Mitigating Measures

Master thesis (2020)

Authors

G.P. Woestenburg Civil Engineering & Geosciences

Contributors

R. Nijsse Applied Mechanics - CEG (supervisor 1)
K.C. Terwel Applied Mechanics - CEG (supervisor 2)
M. Korff Geo-engineering - CEG (supervisor 2)
Dennis Snijders Royal HaskoningDHV (supervisor 2)
Faculty
Civil Engineering & Geosciences
Copyright: © 2020 Geert Woestenburg
Structural Behavior High-Rise Buildings Compressible Soil
More Info
expand_more

Published Date

30-04-2020

Language

English

Reuse Rights

Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.

Faculty

Civil Engineering & Geosciences

Abstract

Cities like Amsterdam and Rotterdam are located on top of a compressible clay layer. Most of the buildings in these cities are founded on the foundation layer above the compressible layer. Therefore this compressible layer can induce problems when the soil pressure increases significantly due to the weight of the high-rise buildings. This deformation can cause inclination of the floors, damage to the structural and non-structural elements of the building. Therefore the structural design of a building must appropriately be designed to respond or resist these deformations.

The deformation, which causes the problems in the building itself, is the differential deformation (sagging). This is unequal deformation over the entire plot of the building. The uniform deformation of the building does not induce problems in the structure itself, but it can damage the adjacent buildings because the soil under these buildings will deform (hogging). The construction sequence decreases the problem for the higher levels because the deformation of the compressible layer start occurring during construction, and these levels are constructed horizontally independent on the amount of deformation of the
soil.

For this research, the following mitigating measures are considered: changing the construction sequence; increase the length of the foundation pile; application of a camber; increase the stiffness of the foundation slab; increase the stiffness of the superstructure; application of a jack-down system.

The primary factors which are affecting the applicability of the mitigating measures are the amount of settlement, the soil structure, and the time-dependent behavior. By a significant settlement of the soil, the mitigating measures of applying a camber and increasing the stiffness of the structure are not possible or less favorable. The soil structure determines if increasing the length of the foundation piles is possible, this mitigating measure put the foundation piles in the second foundation layer, which is situated under the compressible layer. With this measure, the problem of the compressible layer is solved, but it is an expensive mitigating measure. Adjusting the construction sequence depends on the time-dependent behavior of the settlement. It can be an option when the settlement happens mostly during construction. When the settlement of the soil takes longer than the construction time, the jack-down system can be applied to adjust the structure when needed, even when the building is finished.

The application of the jack-down system is definitely worth considering when a high-rise building is built on compressible soil. The other mitigating measures can be applied too, however, only under very specific conditions. This makes the jack-down system the most favorable mitigating measure.