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Structural Engineering
Tower construction methods
The Burj Khalifa Tower utilised the latest
advancements in construction techniques
and materials technology. The walls were
formed using Doka’s SKE 100 automatic
self-climbing formwork system.
The circular nose columns were
formed with circular steel forms, and
the floor slabs were poured on MevaDec
panel formwork.
Wall reinforcement was prefabricated
on the ground in 8 m sections to allow
for fast placement. Three primary tower
cranes were located adjacent to the central
core, with each continuing to various
heights as required. High-speed, highcapacity
construction hoists were utilised
to transport workers and materials to
the required heights. A specialised GPS
monitoring system was developed to
monitor the verticality of the structure,
due to the limitations of conventional
surveying techniques.
The construction sequence for the
structure had the central core and slabs
being cast first, in three sections. The
wing walls and slabs followed behind,
and the wing nose columns and slabs
followed behind these (Fig 14). Concrete
was distributed to each wing utilising
concrete booms which were attached to
the jump form system.
One of the most challenging
construction issues was ensuring the
pumpability of the tower concrete to
reach the world record heights of the
tower, which necessitated that concrete be
pumped well over 600 m in a single stage.
High performance concrete is utilised for
the tower, with high modullus concrete
specified for the columns and walls. The
concrete mix was designed to provide low
permeability / high durability concrete.
A horizontal pumping trial was
conducted prior to the start of the
superstructure construction in order to
ensure the pumpability of the concrete
mixes (Fig 15). This trial involved the use
of a long pipe with several 180 0 bends to
simulate the pressure loss in pumping to
heights over 600 m in a single stage.
The final pumping system utilised
on-site Putzmeister pumps, including
two of the largest in the world, capable
of reaching concrete pumping pressures
up to 350 bars through a high pressure
150 mm pipeline.
Fig 14: Tower construction sequence.
28 · THE SINGAPORE ENGINEER Jun 2010