An innovative design of three-dimensional vibration-damping support based on modular cylindrical helical springs

This paper presents an innovative design of a three-dimensional vibration mitigation bearing (3DVM) by paralleling modular cylindrical helical springs and laminated lead-rubber bearings to mitigate vertical and horizontal seismic vibrations of building structures. The study is conducted for fundamental components and the integrated bearing to elucidate the design principles and working mechanisms of the 3DVM bearing. The mechanical properties of the modular cylindrical helical springs and the 3DVM bearing are tested. Multi-parameter optimization is numerically performed to yield an optimal design. The results show that the present 3DVM bearing is capable of bidirectional decoupling control of horizontal and vertical motions along with stable hysteretic energy dissipation. Specifically, the vertical mechanical performance is attributed to the modular cylindrical helical springs and can achieve an ultimate bearing capacity of 556 kN, which corresponds to a displacement of 45.64 mm. The horizontal energy dissipation is primarily provided by the lead-rubber component. At a shear displacement of 30 mm, the equivalent horizontal damping ratio reaches 10.94%. The ultimate shear displacement can attain 48.75 mm, and the horizontal response exhibits minimal dependence on the loading frequency and the number of cycles.