DFI Magazine November/December 2020 - 92

Australia's current Canley Vale Rail Station
(credit: Envisage Consulting Pty)

Lift shafts, other proposed accessibility upgrades at the
Fairfield City station (credit: Envisage Consulting Pty)

Australian Projects

German Case Study

As part of national policy frameworks to
improve public transport accessibility,
implementation of the Disability Inclusion
Action Plan 2018 - 2022 from the
Government of New South Wales (NSW)
in Australia presents a very remarkable
example. In NSW, the public transport
network is progressively being upgraded
through the Transport Access Program,
with more than 450 projects underway or
having been completed. That includes
upgrades to train stations that provide lift
access for the first time. These two planned
interventions that Ischebeck is assisting
with are expected to commence in late
2020. They involve Banksia Railway
Station in Sydney, Australia, and Canley
Vale Station in Fairfield City, Australia.

On November 23, 2015, the City of Bonn
(former capital of Germany) inaugurated an
upgraded Stadthaus-Haltestelle (City Hall
station) after 13 months of construction works.
The upgrade to the light rail station was
commissioned to guarantee barrier-free
access from the neighboring streets to the
platforms, and from the platforms to the
City Hall building. Dorsch Gruppe BDC
provided the design, which was constructed
by Neidhardt Grundbau. Ischebeck
delivered the hollow bars and assisted both
companies with their phases. The scope of
the intervention comprised:

Micropile layout for the lift shafts at
Bonn's City Hall station
(credit Dorsch Gruppe BDC)

92 * DEEP FOUNDATIONS * NOV/DEC 2020

* Two 44 yd (40 m) long, 5 yd (4.8 m)
wide raised platforms
* Two 24 yd (22 m) long platform
canopies for roof-like protection
* Two lift shafts
* Twelve masts for overhead lines

For the lift shafts, four vertical micropiles
(labeled 5 to 8 in the image) were used, as
well as two racked micropiles (1 and 2),
with an inclination of 30° to vertical, and
two racked micropiles (3 and 4), with an
inclination of 14° to vertical. The micropiles
were designed to resist a maximum axial
force of 59 Kip (260 kN).
Due to unfavorable ground conditions
and the extreme space restrictions to work
around the continuous operation of the
light rails, an integrated micropiling
solution was implemented. That is, several
groups of Ischebeck TITAN self-drilling
micropiles were used to transmit the
structural loads to the subsoil for all of the
civil engineering structures (lift shafts,
overhead masts and canopy supports).
The total construction costs for the
upgrade amounted to 5.4 million Euro
(about $6.38 million). Since this type of
intervention represents a large economic
investment, special attention was paid to the
foundation's serviceability in the long term.
The load-bearing capacity of the structural
elements needed to be guaranteed during
the complete service life. In the case of the
micropiles, this means that effective corrosion protection of the steel, load-bearing
elements (the hollow bars) had to be ensured.
For the self-drilling micropiles used,
permanent corrosion protection (100 years)
was provided by the encapsulation in grout.
That is, based on research, crack widths
controlled to less than 0.04 in (0.1 mm) can
be considered self-healing, so the cement
grout is considered acceptable as an
impermeable protective encapsulation if a
crack does not exceed that value.
DFI Magazine November/December 2020

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