Ground and structure
Seismic isolator
hospitalemergency centerschoolhigh-rise buildingbridge
It is a flexible support, usually made of layers of rubber and steel, placed between the foundation and the building. It usually works together with dampers that absorb part of the earthquake’s energy.
What it solves
It separates the building from the shaking ground, so the structure moves more slowly and with less force. It protects lives and also what is inside, which is key for hospitals in a seismic country like Costa Rica.
Today
Decide on it from the first sketch, because it requires a free gap around the building so it can move, and flexible connections in pipes, cables and entrances.
Common mistake
Filling or building inside the perimeter gap, which locks the building against the ground and cancels the isolation.
Tomorrow
With sensors, each isolator can record the earthquakes it receives and signal when it should be inspected. If its cost falls with regional manufacturing, it could reach hospitals, schools and homes.
Fact A 2025 Costa Rican university thesis modeled a ten-story concrete building. With isolators the seismic force at the base fell by more than 60% and the cost of materials rose by 24%.
Where it comes from
- 1Achaemenid Persia Pasargadae, Iran, around 550 BC
The tomb of Cyrus the Great rests on a two-layer base. The upper one, of polished stones without mortar, can slide over the lower one during an earthquake. - 2New Zealand engineering Wellington, New Zealand, 1974 to 1982
In 1974 the lead-core rubber and steel bearing was invented. A public building completed in 1982 was the first in the world to use it. - 3Public hospital Cartago, Costa Rica, 21st century
The design of the new Cartago hospital includes seismic isolators to reduce the risk from the nearby fault.
Appears in the routes
See also
Also in Ground and structure
Diagrams and texts by LDB Arquitectura. They are shared under the CC BY 4.0 license, which allows them to be used and adapted with credit to the source.