Solving traffic vibration problems in detached houses!
A floor swaying problem caused by traffic vibration occurred in a detached house. The home builder installed intervening columns to solve the problem, but this resulted in an increase in vibration levels. Yacmo used the AMD vibration control device to solve the problem, and the client was able to experience the high vibration control effect in a small space.
issue
In buildings facing a main street, the floor of the building may vibrate due to traffic vibrations generated by passing vehicles, causing discomfort and other problems that may deteriorate the living environment.
In a certain detached house, there was also a complaint of unpleasant vibration when a vehicle passed by on the floor of a second-floor living room facing the main street.
The building is a steel-framed, three-story structure facing a long straight road where traffic is heavy and vehicles tend to speed. When a large vehicle passed by, a tremor with a vibration level of 65 dB was generated at the second-floor room floor (Figure 1). (Figure 1)
This is the level at which many people notice vibration and shoji screens, etc., rattle and shake. In addition, an evaluation based on the Occupant Performance Evaluation Guidelines (2004 edition) showed that the vibration was about V-50. This is a level of vibration that is perceived by about 50% of people, and is of a magnitude that would be somewhat disturbing in a quiet general house.
Figure 1: Location of the subject building
The problematic room had a garage downstairs, which was a large pillarless space, causing vibration near the center. Therefore, measures were taken in advance by the home builder to add columns in the center of the span.
However, although the floor stiffness increased, the vibration level increased from 65 dB to 69 dB. This is thought to be due to the fact that while the location of the additional columns was constrained to the ground, increasing the rigidity, the contact points with the ground increased and the transmitted vibration increased.
Figure 2: Image of second-floor floor beam sub-floor plan and added column locations
counter-measure
Since prior measurements had confirmed that floor vibration during vehicle passage was caused by resonance, we took measures with vibration control equipment, which is the most effective solution to the vibration problem caused by resonance.
In the measures taken,
- Make the device small enough to be installed indoors in a house
- provide the highest possible vibration control performance
Based on the above, we decided to install an active mass damper (hereafter AMD) that suppresses vibration with power (Table 1, Figure 3). the AMD control software was optimally tuned to the measured vibration characteristics of the floor.
Table 1.AMD device (YAMD-0050) basic specifications
Table 1.AMD device (YAMD-0050) basic specifications
(※Similar showroom exhibit)
result
By implementing vibration control with AMD equipment, we were able to reduce the vibration size of the floor, where vibration had been a problem, by about half. The occupant could feel less vibration, and the occupant could improve the comfort of the building.
Figure 6.Effects of FM Floor acceleration when vehicle passes
Related Pages
- added. This report compares AMD (Active Mass Damper) and TMD (Tuned Mass Damper), which are commonly used as vibration countermeasures for building floors, in terms of features, cost, and ease of maintenance. Please use this report when considering vibration countermeasures.
- Product Information AMD (Active Mass Damper)
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