Case Study
Elastic Foundation Bearing for
Steigs Power Plant, Mels (CH)

Vibration isolation protects thehydroelectric power plant and nearby
residential buildings from vibrations

Residents no longer feel vibrations
or noise

Remeasurements conirm theexcellent impact of the Sylomer®
bearings and compliance with therequired limit values

Elastic Machine Foundation Bearing forProtection against Vibrations and Noise

Description of the project The Getzner solution
Special requirements for vibration
isolation

Elastic bearing achieves excellent
structure-borne noise insulation

ince mid-2014, the Steigs hydroelectric power plant in Mels has
been supplying enough hydroelectric
power to satisfy the annual needs of3500 homes. Two residential homes
in the immediate vicinity presented aparticular challenge to the plant's
owners during the construction of thenew underground power station building from 2013 to 2014. As the hydroelectric plant generates vibrations
and subsequently sound radiation
during operation, various conditions
for protecting these homes – as well
as a planned residential complex forthe former power station site – had tobe observed. Like the hydroelectric
power plant, the two homes locatedjust 50 metres away also stand on arocky subsoil, which favours thetransfer of vibrations. In order toprevent vibrations from being transferred through this rocky subsoil
when the plant is in operation, theentire foundation within the power
plant was elastically decoupled using
Sylomer® materials.

TS"This project enabled us to demonstrate our many years of experience and comprehensive materialexpertise."
Helmut Bertsch,
Getzner Project Manager.

o protect the power plant and theneighbouring domestic properties
against vibrations, the entire power
plant foundation block, loor and sidesurfaces were fully elastically decoupled using Sylomer®. Approximately
170 m2 of different types of Sylomer®
material at a thickness of 25 mm wasused.
The materials were chosen based on
the loads resulting from the foundation and generator, with the maximum

permissible foundation movement
around the pressure pipeline also
being a deciding factor. Moreover, theelastic bearing was required to exhibit excellent long-term creep behaviour; exceptional properties thatmaterials from Getzner possess inabundance.
As Getzner has access to a comprehensive and detailed range of material data, it was possible for technicalexpert Dr Hansjörg Schmid to forecast the vibration propagation andsecondary airborne noise levels in
the adjacent family homes.

Elastic decoupling of thepower plant

Full-surface foundation bearing
on Sylomer®

Feedback
Effectiveness impresses client andneighbours
In order to ensure correct installationof the Sylomer® mats, the installation
work was supervised on-site byGetzner employees and a inal inspection was performed after completion. While this not only had quality assurance beneits, it also prevents
any reduction in the effectiveness ofthe vibration protection due to installation errors, such as the risk ofstructure-borne noise bridges. Test
measurements carried out after com-missioning the system have clearly
conirmed that the speciied limit
values are being adhered to. "Theactual values are considerably smaller than originally calculated," explains Dr Hansjörg Schmid. "The residents' impressions also tally with thetest measurements performed," headds. The level difference achieved
with the elastically mounted machinefoundation lies between 20–45 decibels. The system has also demonstrated the predicted natural frequency of 20 Hz.

What does the client have to say
about the project?
"The measurements taken while theplant was in operation have shownthat the transfer of structure-borne
noise has been reduced to a minimum
using the highly elastic Sylomer®
materials. The residents of theneighbouring domestic properties nolonger notice any disruptive vibrations, and the same is true for the
newly constructed power plant. We
can highly recommend the products
used here for other projects."
Ralph Egeter,
St. Gallisch-Appenzellische Kraftwerke AG
Head of Power Projects

Level difference measurement
for a foundation elastically mounted on Sylomer®
Measured on 22/05/2014
Level difference (dB)

f0(z)
50

"The collaboration with Getzner went
very smoothly. The technical support
and consultation services provided
were always prompt and highly proicient, and the installation of theSylomer® bearings was supervised
and analysed by experienced Getzner
employees".

40

Tobias Rüesch,Rüesch Engineering AG

30

20X direction (longitudinal
axis of turbine room)
Y direction (at right-angle)
Z direction (perpendicular)
Natural frequencyof foundation (vertical)

1000Frequency (Hz)100200300

Facts and igures at a glance
Key facts for Steigs (Mels) power plant
Developer:
Vibration isolation:
Forecast calculations:
Opening:
Construction period:
Solution:
Material used:
Project support:

Kraftwerk Stoffel AG
Getzner Werkstoffe GmbH, Bürs, Vorarlberg
Dr Hansjörg Schmid,
Engineering ofice for technical physics, Hall in Tirol
June 2014
2013–2014
Full-surface bearing of loor and wall structures
Sylomer®, approx. 170 m2
Consultation, supervision and inspection of installation work

Technical data for Steigs (Mels) power plant
151.2 m3468 kW
Pelton 6-jet, manufactured by Andritz
377 metric tons (elastically mounted)
20 metric tons
24 metric tons
4.6 metric tons

Further reading
Case Study: Hydroelectric power plants, Kempten (DE),
Case Study: Rettenbach hydroelectric power plant, Sölden (AT),
Case Study: Central & Park Panorama Towers Arnulfpark,
Munich (DE)

AUSTRIA — Bürs GERMANY — Berlin — Munich — Stuttgart FRANCE — Lyon
JAPAN — Tokyo INDIA — Pune CHINA — Beijing USA — Charlotte

Construction references (extract)— Europaallee, Site H, full-surface
bearings for buildings, Zürich (CH)— Saninichuou Newspaper, elastic
bearing of a rotary printing press,
Shimane (JP)— Elastic bearing of a Gypsum mill,
Salvador de Bahia (BR)— Elastic bearing of a hydroelectric
power plant, Tobeläckerli, Buchs (CH)
— Decoupling a compressing plant,
Lingen (DE)JORDAN — Amman
www.getzner.com

CS KS en © Copyright by Getzner Werkstoffe GmbH | 08-2015

Net head:
Output:
Turbine:Foundation mass:
Turbine:Generator:
Pressure pipeline: