High Damping Rubber Bearing (HDRB)
Base isolation technology is a solution for significant projects in high-intensity seismic regions such as Iran country due to the simplicity of its application, notable improvement of the structural seismic response, and long term economic benefit in that areas. The established and accepted technology of base isolation has been widely used in bridges and structures all over the world. Seismic (or base) isolation offers remarkable advantages compare to the conventional protection methods by reducing the earthquake-induced forces transmitted into a structure. Base isolation functions mainly based on increasing the structural natural period and reducing the transmitted earthquake-induced forces. Such a capability is significantly important for the buildings such as hospitals, emergency centers, museums, and advanced technology factories that need to have immediate occupancy seismic performance. It is worth pointing out that despite the need for more structural damping, seismic isolators are not basically absorbing the earthquake energy. Actually, they are providing an interface that causes the reflection of earthquake energy into the ground.
The interface of a base isolation that separates the superstructure (i.e., seismic isolated part) from the lower part of the structure requires the following characteristics:
- Low horizontal stiffness at design displacement;
- High vertical stiffness;
- Supporting the compression load of the structure weight over long term;
- Large horizontal displacement capacity during the design earthquake and supporting the vertical load simultaneously;
- Appropriate level of damping;
- Re-centering the structure after an earthquake;
- Damping and stable stiffness properties over long term;
- High initial horizontal stiffness to support wind excitations;
- Re-functioning after the design earthquake.
KOHRANG High damping rubber bearings work on the principles of base isolation and are simple, cost-effective, and maintenance-free and have the capability to support the design earthquake loads without significant damage. They are similar to natural rubber bearings (i.e., regular reinforced elastomeric bearings) with steel connection plates. The difference is the used elastomer material, which has a special composition and ability to dissipate seismic energy by generation of deformation and heat. The specific rubber layers of them provide the isolation and re-center the bearing after an earthquake event.
KOHRANG Lastic Company designs, manufactures, tests, and supplies high damping rubber bearings to meet all international standards specifications such as; BS, EN, AASHTO, DIN, and ISO. The KOHRANG high damping rubber bearings are adaptable, effective, and safe.
