Preloaded Damping Spring ISOSISM PDS

The ISOSISM® PDS (Preloaded Damping Spring) combines the benefits of a viscous fluid damper and a prestressed hydraulic spring. In normal operating conditions, the ISOSISM® PDS acts as a fixed point. During an earthquake, it dissipates energy and then returns the structure to its initial position.
The ISOSISM® PDS can be installed along the longitudinal or transverse axis of the deck. Its ends are equipped with a sliding material to accommodate the thermal expansion of the structure.
It conforms to EN 15129 and can be supplied with the CE marking.

The preload force F₀ of the ISOSISM® PDS must be greater than the forces to be withstood during service condition, such as thermal variations, braking and wind. It must be less than the seismic forces.

The ISOSISM® PDS offers a number of benefits:

·        Three major functions combined in a single device (fixed point, damper and spring).

·        High reliability: the device is placed under stress only in the event of an earthquake.

·        Compact design.

·        High efficiency.

·        No maintenance required.

ISOSISM® PDS devices are widely used to perform the longitudinal fixed point of bridge decks.

They are particularly suitable for railway bridges.

Railway Brige in Ethiopia