Underground—EMEA—Germany—Tunneling
Construction of the Pforzheim Tunnel: DSI supplies Ground Support
Products for the Karlsruhe-Muehlacker Train Section
Built in 1860, the double track Pforzheim Tunnel on the train section between Karlsruhe and Muehlacker no longer meets modern
performance requirements and is in urgent need of repair. As a rehabilitation would have been too complex, a new, double track
tunnel is now being built parallel to the existing tunnel. The new tunnel runs to the west of the existing structure at a maximum
distance of 26m. The old tunnel will be shut down and backfilled once the new structure has been completed.
With a track distance of 4m instead of the
previous 3.64m, the new, 909m long tube
fulfills current safety regulations and has
a modern escape and rescue concept.
Furthermore, the new tunnel will have an
invert that prevents the ingress of ground
water. The new tunnel has a maximum cover
of 40m and an excavated cross section of
130m². Since the precut is hard to access
from the Pforzheim side, the tunnel is being
continuously excavated from the town of
Ispringen.
The tunnel is being advanced in accordance
with the New Austrian Tunneling Method
(NATM). Due to the special geological
requirements and due to the existing buildings
near the tunnel, a road header is being
used. Advancement is progressing with
calotte driving followed by bench and invert
excavation.
As the in-situ soil consists of shell limestone
– i.e. unconsolidated soil – along the first
300m, an excavator is used for advancement
in this area. In the other areas in which rock
and bedrock prevail, the tunnel is excavated
using a rotary cutter. During advancement, the
tunnel is first stabilized using a shotcrete lining.
Afterwards, a cast-in-place concrete lining is
installed.
To stabilize excavation work, DSI Underground
Austria supplied DYWI ® Drill Hollow Bar
Anchors and Self-Drilling Spiles in addition
to other products. The self-drilling ground
support products are a sound and efficient
alternative to time-consuming cased drilling
installation methods and products. For the
drainage work around the excavation, DSI
also supplied the proven AT – 76-DR Drainage
System.
Owner
DB Netz AG, Germany
Contractor
Baresel GmbH, Germany
Engineering
WBI GmbH, Germany
DSI Unit
DSI Underground GmbH, Austria
DSI Scope
Production, supply
DSI Products
DYWI ® Drill Hollow Bar Anchors and
Self-Drilling Spiles, AT – 76-DR Drainage
System
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