NEHRP Clearinghouse

Single and Multiple Tuned Liquid Column Dampers for Seismic Applications.
Sadek, F.; Mohraz, B.; Lew, H. S.
November 1996, 43 p.
Identifying Number(s)
The optimum parameters of single and multiple tuned liquid column dampers (TLCD) for reducing the response of structures to seismic loads are presented. A deterministic analysis is carried out using 72 earthquake ground motion records to determine the optimum tuning ratio, tube width to liquid length ratio, and head loss coefficient corresponding to a given mass ratio for single tuned liquid column dampers (STLCD). A similar analysis is performed to determine the optimum central tuning ratio, tuning bandwidth, and grouping of dampers for multiple tuned liquid column dampers (MTLCD). The optimum parameters are used to compute the response of several single-degree-of-freedom structures and one multi-degree-of-freedom structure with single and multiple TLCDs to different earthquake excitations. The solution from an analysis using TLCDs is compared with that using tuned mass dampers where it is found that both devices result in comparable reductions in the response. Design examples using STLCDs and MTLCDs in a simple bridge model and in a ten-story structure are presented to illustrate how the parameters are selected and demonstrate the performance of the devices under different ground excitations.
Dynamic response; Earthquake resistance; Liquid column dampers; Design analysis; Passive systems; Ground motion; Dynamic structural analysis; Loads (Forces); Tuning; Structural vibration; Performance evaluation; Earthquake engineering; Vibration damping; Acceleration; Energy absorption; Structural response; Seismic effects; Degrees of freedom; Energy dissipation