High Damping Rubber Bearings (HDRBs)

Technical information seismic isolators

BIT’s HDRBs, manufactured by DOSHIN RUBBER, are steel laminated rubber bearings made on specially formulated high damping rubber compounds.

The rubber compounds used for the production of BIT’s HDRBs are characterized by a dynamic shear modulus G variable from 0,6 to 1,3 MPa and an equivalent viscous damping coefficient (at shear strain, y=1) varying from 10 to 20%.

The non-linear behavior of the compounds means at low strains the modulus is higher, allowing only slight movement due to forces such as wind. The steel lamination ensures a high compression stiffness to support the vertical load.

Three different rubber compound are available as standard:

  • soft compound (S), with a low modulus (G=0,6 MPa)
  • normal compound (N), with a medium modulus (G=0,9 MPa)
  • hard compound (H), with a high modulus (G=1,3 MPa)


BIT can develop alternative rubber compounds to satisfy different design requirements and can design seismic isolators to all international standards.

Technical information

TAG: | | |
see also...