SEISMIC-SAFE BUILDINGS

CONSTRUCTION METHODS

What are seismic-safe buildings?

Seismic-safe buildings have features that reduce earthquake damage. Some of these features strengthen a building. Others allow the building to move, or shield the building from the energy of seismic waves. In earthquake-prone areas, most tall, steel-frame buildings may have one or more of the seismic-safe features shown here.

1. Base-Isolators—

Base-Isolators

The idea behind base isolation is to isolate the movement of a structure from the movement of the ground. To do this, engineers anchor the foundation to the ground, but separate a building from the foundation using flexible pads that absorb an earthquake's energy. This allows the structure to slide back and forth on its foundation. This way, despite the shaking of the ground, the building stays in one place.

2. Dampers--

Dampers work like the shock absorbers in

a car to absorb some of the

energy of seismic waves

3. Shear Walls and Cross Braces—

Shear walls transfers some of a quake’s

energy from roof’s and floors to the Cross Braces

building’s foundation.

Shear Wall

Cross braces are steel braces placed between

stories to stiffen a building’s frame and

absorb energy during an earthquake.

4. Tension Ties—

These devices firmly “tie” the floors and

ceiling of a building to the walls.

Tension ties absorb and scatter earthquake

energy and thus reduce damage.

5. Flexible Pipes—

Water and gas pipes have flexible joints. Flexible Pipes

Flexible pipes bend as energy passes through

Them, greatly reducing damage.

Buildings are safer, but what is the cost?

Seismic-safe buildings save lives and reduce damage. Despite these benefits, the technologies have drawbacks. Seismic-safe features, such as cross braces, may reduce the amount of usable space in a building. It is also expensive to add seismic-safe features to an existing building. Communities must make trade-offs between the benefits and the costs of seismic-safe buildings.