Investigation of an improved tuned liquid column gas damper for the vertical vibration control

•Derived a theoretical model of a vertical tuned liquid column gas damper (VTLCGD).•Developed formulas of air spring stiffness and natural frequency of VTLCGD.•Validated theoretical model of VTLCGD using experimental and numerical analysis.•Significant vibration reduction effect on the human-induced vibration with VTLCGD.•Parametric studies on the spatial applicability of VTLCGD. The conventional tuned liquid column gas damper, TLCGD, as a passive control, was normally used to reduce the structures' horizontal vibration, while limited studies have been conducted on the vertical. A modified damper, i.e., vertical TLCGD (VTLCGD), was proposed to reduce the excessive vibration on the floor system induced by human walking. The theoretical model of the VTLCGD was first formulated and validated by experimental and numerical analysis considering the pressure–volume relationship. The air spring stiffness and natural frequency of the VTLCGD were derived. The liquid displacement response obtained from the model equation was validated by experimental results derived from the measured pressure. A finite element model of the floor and load model for human walking were established and the vibration reduction of the VTLCGD on the floor was numerically examined. The average vibration reduction rate could reach 43.17% and it showed a linear increase with the increasing mass of unequal liquid height in the vertical tube. An optimization concept and case study were finally proposed to further improve the reduction rate with the limited space, which provides references for the application of the VTLCGD.