Realizes a comfortable office environment! Prevents walking vibration on long-span floors

Open offices with long spans and column-free spaces are prone to floor swaying problems when walking.　By installing a vibration control system TMD, a spacious and comfortable office space can be realized.

issue

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In recent years, spacious, open offices with long spans and no pillars have become popular.　Such long-span structures tend to deflect easily (resulting in lower natural frequencies), which can cause the work environment to deteriorate, such as discomfort from shaking the floor when walking or difficulty concentrating.
An office building featured a long-span floor of approximately 24 m, and floor vibration during walking was a concern.　

Figure 1.

counter-measure

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Although a structure can be made less prone to swaying by increasing the beam height, the ceiling height will be lowered.　If Yacmo's TMD vibration control system is installed at the time of design, the beam beam can be reduced and the structure can be made to sway less even in large spans, resulting in an open space with few pillars and high ceilings.
Four TMDs with a mass mass of approximately 1000 kg on each floor are installed in the girder beam in the center of the span.
　Heel excitation was performed at the center of the span to check the natural frequencies. The floor was at 11.2 Hz, and the TMD frequency was adjusted accordingly (Figure 3).

Figure 2: TMD exterior (left) and installation (right)

Table 1: TMD basic specifications

result

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　Two people walked in unison and evaluated the building using the occupant performance evaluation criteria of the Architectural Institute of Japan to confirm the vibration control effect.
In the non-vibration controlled condition, all locations were above V-90.　This was the level at which 90% of the people felt the vibration, a level that was quite disturbing and not suitable for office use.
When vibration control was applied, vibration was reduced to about half for floors A and C, and the occupant comfort rating was V-70, indicating an improvement to a good environment for office use.　Floor B, which had the highest vibration, was also reduced to about V-50, demonstrating the effectiveness of vibration control by TMD.

Figure 3.Effects of TMD Measurements during three-person resonant walking (Floor A, Floor B, Floor C)　

Related Pages

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• 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 TMD (Tuned Mass Damper)
  

Related Content

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• • Introduction of TMD Series
    
  • Resolving TMD Questions! Frequently Asked Questions Q&A
    
  • Walking vibration countermeasure for long-span floors
    
  • Points and weaknesses of TMD that you need to know in order to achieve optimal results.
    
  • Types and characteristics of measures to reduce floor sway caused by walking and machinery
    
  • Database of measured office floor vibrations caused by walking and running.
    
  • Concept of walking vibration countermeasures
    
  • Lineup of Vibration Damping Devices for Vertical Vibration (TMD) Examples