TECCO slope stabilization system - Geobrugg AG

TECCO ®
slope stabilization system
Slope stabilization, Weisenbach-Langenbrand B 462 / Germany
Photo documentation / March 2010

Slope stabilization / Photo documentation / March 2010
TECCO ®
slope stabilization
Weisenbach-Langenbrand / Germany
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Object: Slope 2.10, Weisenbach-Langenbrand in the
Murgtal region, alongside the B 462 road
Building promoter: Federal Republic of Germany, represented by the
Karlsruhe Regional Council, Construction Offi ce
Mitte (Central), Germany
Geotechnical investigations,
planning, construction
supervision: Ingenieurgruppe Geotechnik GbR, Kirchzarten,
Germany
Contractor: Sachtleben Mining Services GmbH, Wolfach,
Germany
Implementation: October/November 2009
Slope stabilization: TECCO ® -mesh covering in combination with nails
Max. slope height: H = approx. 15 m
Subsoil: Granite
Area: 2‘000 m2 Slope gradient: α = 80 degrees
Mesh: TECCO ® -system G65/3 mm
Erosion control mat: TECMAT
Spike plates: TECCO ® -system G65/3 mm
Nails: GEWI D = 32 mm
Nail length: L = 6 m / 3 m
Nail grid: a = b = 3 m
As part of the general geotechnical mapping of rock slopes along the B 462 in the
Rastatt district, the slope at Weisenbach-Langenbrand was evaluated as being a
high-risk area for rockfalls and avalanches. The rock is made of a fi ssured granite
known as Forbach granite. The side-cut for the road formed a slope up to 15 m
high and with an average inclination of around 80°. Protection was provided in the
form of a light protruding rockfall protection net. The rockfall catchment area in
relation to the road is less than 2 m. There was nothing to limit the rockfall catchment
area. Fissures in the fault structure undercut the slope at an angle of around
30°. Bodies of rock can thus come away from the slope and slide down the fault.
In March 2007, a rockfall occurred in which a body of rock came loose from the
upper section of the slope, broke through the fl imsy net and landed on the road.
The TECCO ® slope stabilization system was recommended as a protective measure.
The rock nails (GEWI 32 mm) are 6 m long in the fi eld and 3 m long at the edges. A
nail grid of 3 x 3 m was proposed, with the nails being inserted in slope troughs
where possible. This can lead to variations in the grid. In addition to the boundary
ropes, vertical and horizontal lateral ropes were envisaged, which were also designed
for insertion into slope troughs in order to obtain the maximum possible mesh
tension. A one-meter-high rockfall interception apron was installed at the head of
the slope. An erosion control mat was laid over the sediment layer at the top end
of the slope. The old net had previously been removed and the slope cleared.

Incised slope of heavily fi ssured Forbach
granite; high risk of rockfalls and
avalanches
Investigation of the slope by geologists/
the road construction authorities
Testing the nail tension
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Slope stabilization / Photo documentation / March 2010
Cost-effective insertion of the nails
from a drilling platform with a drilling
mount fi xed to the side
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Installation of TECCO ® -mesh, ropes and
spike plates
Elevated support at the top of the slope
edge with rear anchoring of the GEWI /
eyes
Erosion control mat in the sediment
zone above the slope edge
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Slope stabilization / Photo documentation / March 2010
Horizontal and vertical ropes, mounted
in gullies using TECCO ® , ensure that the
whole of the unstable slope is under
tension
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Traffi c on the B 462 protected from
rockfall
The integrated nature of the solution
also preserves the plant cover and
allows nature to thrive. The TECCO ®
mesh that is laid guarantees that plant
cover can be kept short at no great
effort or expense. In the future, no
more large woody plants – whose roots
would further loosen the rock – will be
able to establish themselves.
Source: Karlsruhe Regional Council,
Construction Offi ce Mitte (Central),
Germany
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Geobrugg protects people and infrastructure from the
forces of nature
It is the task of our engineers (and partners) to analyze the problem
together with you in detail and then, together with local consultants,
to present solutions. Painstaking planning is not the only
thing you can expect from us, however; since we have our own
production plants on three continents, we can offer not only short
delivery paths and times, but also optimal local customer service.
With a view towards a trouble-free execution, we deliver preassembled
and clearly identifi ed system components right to the construction
site. There we provide support, if desired, including technical
support – from installation right on up until acceptance of the structure.
A company of the BRUGG Group
Rockfall barriers
Rockfall drapes
Slope stabilization
Mudfl ow barriers
Avalanche structures
Protective structures for mines
Special applications
Geobrugg AG
Geohazard Solutions
Aachstrasse 11 • CH-8590 Romanshorn
Tel. +41 71 466 81 55 • Fax +41 71 466 81 50
www.geobrugg.com • info@geobrugg.com
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