Construction—EMEA—Germany—Excavations
The Karlsruhe City Railway: DYWIDAG Strand Anchors ensure Stability
against hydrostatic Ground Water Pressure
Within the scope of what is called the Kombiloesung (combined solution), Karlsruhe’s center is being converted to a pedestrian zone
without any railway tracks. For this purpose, a 2.4km long, single-tube city tunnel is being built underneath Kaiser Road with a 1km
long southern branch leading towards the Congress Center. The major project also includes the construction of a new road tunnel
between Karlstor and Mendelssohn Square.
Photo reprinted courtesy of Stump Spezialtiefbau GmbH,
Germany
Since most of the subterranean stations are
located in the Upper Rhine Rift in layers that
are unstable or not watertight, impermeable
excavation enclosures consisting of diaphragm
or bored pile walls had to be built in several
sections due to the high ground water levels.
To tie back the different retaining walls,
DSI had previously supplied approximately
100t of DYWIDAG Strand Anchors. Recently,
DSI received a follow-up order from the
subcontractor Stump Spezialtiefbau GmbH.
At the Ettlinger Gate, DYWIDAG Strand
Anchors were also used to tie back the walls.
82
In total, 457 semi-permanent, 8 strand
DYWIDAG Strand Anchors with a total
length of 11,422m were installed to
stabilize the walls against ground water
pressure. DSI also supplied 572 temporary,
5-6 strand DYWIDAG Strand Anchors that
were installed at a total length of 12,511m.
Furthermore, DSI supplied 150 load cells to
monitor the forces acting on the anchors.
In this area, the high ground water levels and
several obstructions in the ground such as
steel sheet piles posed a special challenge.
Owner
KASIG - Karlsruher
Schieneninfrastruktur-Gesellschaft mbH,
Germany
Contractor
Joint Venture Stadtbahntunnel, consisting
of BeMo Tunnelling GmbH, Austria and
FCC, S.A., Spain
Subcontractor
Stump Spezialtiefbau GmbH, Germany
Consulting Engineers
Planungsgemeinschaft Stadtbahntunnel
Karlsruhe, Germany
DSI Unit
DYWIDAG-Systems International GmbH,
BU Geotechnics, Germany
DSI Scope
Production, supply
DYWIDAG Products
457 semi-permanent, 8 strand DYWIDAG Strand
Anchors, 572 temporary, 5-6 strand DYWIDAG
Strand Anchors, 150 load cells