The industrial company Julius Blum GmbH, located in Vorarlberg, Austria, is specialized in the production and distribution of furniture fittings. In 2012, building damage in the form of cracks was detected in the production hall 5 (Plant 5), in which the metal is processed by using punching presses. A geodetic survey showed that in some areas settlements had occurred since the end of the consolidation of the soil.
The BERNARD Gruppe was commissioned by the Blum company to carry out a dynamic investigation of Plant 5 and to provide advice on remediation measures.
Already in December 2012, an electronic liquid levelling system for continuous documentation of occurring settlements was installed. Subsequently, the natural frequencies of the building and the vibration transmission of the building components were determined. For this purpose the building was excited by means of an unbalance exciter and the vibrations were measured by means of geophones. In addition, the transmission of the vibrations of the punching machines to the adjacent components was measured and recorded. With the help of this input data, the building could be simulated with a finite element program and suggestions for damping measures could be made.
However, the Blum company then decided to build a new plant that would serve as a punching center – Plant 8.
In order to exclude settlement problems at Plant 8, dynamic pile tests were proposed and carried out by the BERNARD Gruppe. For this purpose, piles of different lengths were manufactured at the construction site of the future plant and dynamically loaded in order to simulate the load of the punching presses over their entire service life. The measurement results of these large-scale tests formed the basis for the dimensioning of the piles.
After completion of Plant 8, the dynamic properties (natural frequency and damping) of this production hall were also determined by means of measurement technology, and the Blum company was supported in the arrangement of the punching presses to avoid the occurrence of vibration resonances.
Meanwhile, the settlements in Plant 5 were further documented. By now, the punching machines have been moved to Plant 8 and Plant 5 has been put to a less vibration-prone use. In order to ensure that the increase in settlement now comes to a standstill, the electronic liquid levelling system will continue to be operated.
The BERNARD Gruppe was able to support the Blum company as an advisor when making important decisions and to accompany the entire process from the identification of the problem to the optimization of the machine installation in the new production hall.
Sonja Dallinger, BERNARD Gruppe
