Using viscoelastic materials to mitigate earthquake-induced pounding between adjacent frames with unequal height considering soil-structure interactions

Abstract

The effectiveness of viscoelastic (VE) material with different mechanical properties in reducing the pounding between neighboring buildings, considering soil-structure interactions (SSI), is investigated in this paper. The analytical investigation is carried out based on the viscoelastic pounding force analytical method. Adjacent buildings/frames with unequal-story-height, including a 9-storey and a 3-storey reinforced concrete structure, and three types of soil, including soft soil, medium soil, and dense soil, are considered in this study. Pounding force, the amplification of the acceleration and inter-story drift of the adjacent buildings subjected to earthquakes are numerically investigated to evaluate mitigating performance of the VE material. The influence of the constitutive parameters of the VE material on the effectiveness in reducing structural response of the adjacent buildings are discussed in detail. It is confirmed from the conducted numerical studies that seismic response of buildings, especially acceleration of collision floors, could be amplified considerably due to collisions. But impact force as well as acceleration of the structures can be reduced significantly by VE material for all types of soil. The performance of VE material on reducing pounding force and seismic response of structures are influenced by separation gap size and properties of VE material significantly. The minimum gap to avoid pounding is 1.22 m, 1.25 m, 1.29 m and 1.29 m for soft soil, medium soil, dense soil and fixed-base case respectively for all considered earthquake records. The pounding force increased firstly and decreased with the increasing of the gap size. Pounding force was increased with the increasing of equivalent elastic modulus, but the indentation was reduced simultaneously by higher equivalent elastic modulus. Larger pounding force were induced between collision floors covered by VE material with larger R1, but limited influence on pounding force can be found for R2.