Closure to 'Floor Vibration Control as a Serviceability Requirement in Design Standards and Practices: Review' by Chaimaa Jaafari and Jamshid Mohammadi

摘要

The authors are grateful to the discusser for encouraging words on their paper and for providing valuable comments. Indeed, the subject of tuned mass dampers (TMD) and multituned mass dampers (MTMD), which is brought up by the discusser, represents a very important topic in floor vibration control. This subject requires more in-depth study and research in an effort to provide some practical approaches and a roadmap that can be used by practicing structural engineers in their decision-making and design for floor vibration control. The current state of the art on TMD and MTMD, for the most part, provides applications in vibration control that are not specific to floor vibrations. The discusser, very appropriately, makes references to examples of these applications. Specific to floor systems, the type of application and the floor system may result in a rather complicated problem where multiple vibration modes play an important role. If the application requires the use of some type of damper, MTMD systems may be a more appropriate choice to address the presence of frequency contents that trigger vibration problems. The frequency content is certainly an important consideration in selecting an appropriate control system. As indicated in Table 12 of the paper, the significance of passive and active floor vibration control systems is largely affected by the frequency. Floors that contain lower frequencies, more appropriately, require active damping systems, which, in turn, require a higher cost. Of course, the main driving factor in cases with low frequencies is the application. Certain types of applications (such as floors supporting extremely sensitive equipment) call for costly vibration control systems. In any case, it is imperative to look for other alternatives for vibration control before resorting to using TMD or MTMD systems.