Design of Foundations of High-Rise Buildings Report 2022

Design of Foundations of High-Rise Buildings 1
DESIGN OF FOUNDATIONS OF HIGH-RISE BUILDINGS
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Design of Foundations of High-Rise Buildings 2
Table of Contents
1. Introduction............................................................................................................ 3
2. Background............................................................................................................ 5
3. Factors influencing design of high-rise buildings foundations............................................6
3.1. Design forces/loads.............................................................................................. 6
3.2. Soil types.......................................................................................................... 8
3.3. Level of water table........................................................................................... 12
3.4. Ground contamination........................................................................................ 12
3.5. Type of adjoining structures.................................................................................13
4. Common types of foundations for high-rise buildings....................................................13
4.1. Raft foundation................................................................................................. 13
4.2. Pile foundations................................................................................................ 14
4.3. Piled raft foundation.......................................................................................... 17
5. Design approaches.................................................................................................. 20
5.1. Ultimate limit state (ULS) design approach..............................................................20
5.2. Serviceability limit state (SLS) design approach........................................................21
6. Foundation design process....................................................................................... 22
7. Design issues......................................................................................................... 26
8. Challenges in design of foundations of high-rise buildings..............................................27
9. Case study............................................................................................................ 29
10. Conclusions....................................................................................................... 34
References............................................................................................................. 36

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1. Introduction
This report presents analysis of different aspects of design of foundations of high-rise buildings.
The key characteristics of high-rise buildings are: they have several numbers of storeys that
necessitate use of mechanical vertical transportation system (such as lifts or elevators for
occupants to reach their destination), their height have consequential effect on evacuation, and
their total height cannot be fully reached by available fire-fighting equipment. These buildings
are typically considered to have more than seven storeys or a height greater than 23 meters. The
high-rise buildings have become very common in many cities across the world due to rapid
urbanization, industrial development and urban population growth. Public and private developers
have preferred high-rise buildings because they maximize land use especially in urban areas.
These buildings are usually designed for multiple uses – office, mixed-use, residential and hotel
(Figure 1 below shows uses of 100 tallest buildings in the world) and therefore have to withstand
a wide range of lateral and vertical forces. The forces must be supported by strong foundations,
which distribute the forces to the ground. Therefore the stability and safety of high-rise buildings
largely depend on their foundations.

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Figure 1: Uses of 100 tallest buildings in the world (Kayvani, 2015)
Foundation is the lowest part of the building that transmits all loads of the building to the
ground (Poulos, 2017). The foundation connects the building with the ground and is in direct
contact with soil. The main functions of foundations of high-rise buildings include: ensuring
even distribution of the load, minimizing the load intensity, providing a level surface on which
the superstructure is constructed, providing lateral stability of the building, anchoring the
building against natural forces like earthquakes, protecting the building against undermining, and
protecting the building against ground moisture and soil movements (Ajdukiewicz, et al.,
2017). Design of foundations is very essential for any building (Nangan, et al., 2017), but it
is more critical for high-rise buildings because of the height of these buildings, the numerous
forces acting on them and their large number of occupants. These buildings are exposed to both
dynamic loads and static loads (Hallebrand & Jakobsson, 2016). The design of foundations
of high-rise buildings entails determining the most suitable type and size of foundation and its
materials. Therefore a properly designed foundation of a high-rise building improves the
structural integrity, stability, safety and durability of the building.
The main purpose of this report is to provide the suitable criteria for the design of
adequate foundations of high-rise buildings. The other sections of this report are: background,
factors influencing the design of foundations of high-rise buildings, common types of
foundations for high-rise buildings, design approaches, foundation design process, design issues,
challenges in the design of foundations of high-rise buildings, case study and conclusion.

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earthquake. High-rise buildings are more vulnerable to earthquakes because of their excessive
heights, low structural damping, and use of lightweight materials for inner partition walls and the
super structure (Jayasinghe & Weerasuriya, 2014), hence their foundations should be
designed by considering seismic forces. Water/fluid pressure is proportional to liquid density and
increases linearly with depth. Earth/soil pressure is imposed on the substructure of the high-rise
building, including its foundation. Examples of vertical loads are: dead loads, live/imposed
loads, snow loads and other special loads (erection loads, impact, fatigue, foundation movement,
vibration and elastic axial shortening).
Figure 3: Wind load acting on a high-rise building (Daemei, et al., 2019)
The design forces are essential for the design of foundations of high-rise buildings
because they are all distributed to the ground via the foundation, as shown in Figure 4 below.
Engineers, architects and designers are using new design concepts, advanced designing methods
and tools, and new trends to reduce design loads (Sharma, et al., 2017), which also reduces
the size and cost of foundations of high-rise buildings. One such technique is use of spiral
forming and curved façade to reduce wind load, like it is the case for Shanghai Tower (Zhaoa,
et al., 2011). It is important to create 3D models of high-rise buildings during design stage so

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as to accurately predict design loads that will be supported by the foundation. This helps in
determining the most suitable type, size and construction materials of foundations of the high-
rise building.
Figure 4: Distribution of deign loads (Mishra, 2015)
Therefore appropriate methods should be used to estimate all types of loads acting on the
building from all directions, including live loads and dead loads (both the gravity loads and uplift
loads). Some of the factors that influence the quantity of design loads of the building are: type of
building structure, location of the building, material of construction, and number of floors. These
loads are the ones that act on the foundation hence should be considered as a key factor when
designing foundations of high-rise buildings.
3.2. Soil types
The type of soil can either break or make the foundation of a high-rise building. This is
because the interaction between the soil and the building affects the dynamic characteristics of
high-rise buildings (Li, et al., 2014). Some soils tend to deform when subjected to loadings and
with temperature variations. This deformation can cause settlement of the foundation thus
affecting the stability of the building. Loam, gravel, sand and rock are foundation-friendly soils