Parallel Link Type Seismic Isolator for Tower Crane

Abstract

A new type seismic isolator system for the tower crane is presented. The isolator system is composed of two components. One is an isolator for the mast of the crane using a cubic four bar links, springs, dampers and stoppers. The other is the elastic stay, which connects a stay supported type tower crane to the structure under construction. The natural period and the damping coefficient of the tower crane can be turned by adjusting spring constant, damping coefficient of dampers and the stiffness of stays. Numerical simulations for a self-stand tower crane and a stay supported type tower crane with the presented seismic isolator system and these without seismic isolator are carried out. The shaking table exciting test for a self-stand tower crane model with the presented seismic isolator is also carried out. As the results, the simulation results and the experimental results demonstrate that the presented isolator system is effective to decrease seismic inertia force.