Multiple Sloped Wall Tuned Liquid Dampers for Vibration Control of Structure Excited by Near and Far-Fault Earthquakes

The floor plan, geometric requirements, and space constraints create unavoidable problems when installing regular-shaped tuned liquid dampers (TLDs). The present study numerically investigates a special shape TLD with sloped walls to verify its vibration control efficiency under harmonic and seismic excitations. Due to the sloping walls, a higher amount of liquid participates in sloshing, which generates a higher sloshing force.

The numerical modeling of the structure-TLD system is done by combining the finite element model for liquid sloshing and the spring-mass model for the structural response. The seismic performance of the structure-TLD system is investigated under a set of near- and far-field natural earthquake records.

Even though all earthquake records are scaled to a fixed magnitude (i.e. PGA = 0.2 g), the high-energy pulse present in near-fault earthquakes causes a significantly higher structural response compared to far-fault records. Due to the transmission of higher structural response to the TLD tank, the sloshing-induced base shear force under near-fault ground motions is observed to be much higher.

Even with a higher hydrodynamic base shear, the % reduction in the structural response is lower under near-fault earthquakes. However, with a lower sloshing force, a higher % reduction is observed for far-fault earthquakes.