Experimental study on vertical performance of multidimensional earthquake isolation and mitigation devices for long-span reticulated structures

The earthquake excitation is a complicated multidimensional motion, which will cause the damage or even collapse of structures. Consequently, some measures to prevent structure failure must be taken under multidimensional excitations, especially for long-span reticulated structures and high-rise buildings. Many earthquake isolation or mitigation devices have been manufactured to reduce the horizontal dynamic responses of structures, but there are few reports concerning the device isolating and mitigating earthquake actions both in horizontal and vertical directions simultaneously. In this paper, a new multidimensional earthquake isolation and mitigation device for long-span reticulated structures is developed and tested under different cases. Effects of excitation frequency and amplitude on vertical properties of this device are studied. Then, the modified equivalent standard solid model is proposed to describe the vertical properties of the device. Experimental and numerical studies show that this device has good capability of energy dissipation in vertical direction.