In recent years, despite the rapid development of society, the frequent occurrence of earthquakes in recent years has made us attach great importance to vibration isolation and shock absorption. The ability of the vibration isolator is well demonstrated, especially for bridge maintenance.
The following is an introduction to the impact of the vibration isolator on the mechanical performance of the bridge during an earthquake. Everyone should know: For long-span continuous beam bridge structures, the seismic inertial force of the superstructure is relatively large under the action of earthquakes, and most of the seismic inertial force in the longitudinal direction of the superstructure is borne by the fixed piers. How to effectively reduce the seismic force on fixed piers is the key to the seismic design of bridges.
The vibration isolation design can keep the lower key components in an elastic state. The basic principle of vibration isolation is to use the flexibility of the spring isolator to extend the period of the structural system and reduce the seismic response of the structure, thereby creating the superior performance of the vibration isolation friction pendulum bearing in terms of seismic resistance.
The friction pendulum support of the vibration isolator mainly includes limited sliding bolts, a spherical sliding groove made of stainless steel, a sliding block coated with Teflon material, and a cover plate used to connect to the upper structure. The friction pendulum support makes the superstructure undergo a single pendulum movement through the movement of the spherical sliding surface. The period and stiffness of the seismic isolation system are controlled by selecting the appropriate radius of curvature of the sliding surface, and the damping is controlled by the coefficient of dynamic friction. Before the sliding-limit bolts are sheared, the friction pendulum isolation support does not slide, and the seismic-isolated bridge structure under its support is the same as the ordinary bridge structure; when the sliding-limit bolts are sheared by an earthquake, the friction pendulum isolation support is displaced.
Practice has proved that the vibration isolator is a vibration isolation device with good mechanical properties. It can effectively reduce the seismic force and is of great significance to the construction and development of bridges and the development of society.