Making a building earthquake-resistant adds about 25 to 50 percent to building costs.
Methods currently used include reinforcing concrete walls and pillars, digging deep foundations and adding special joints that ease internal stress when
buildings start to shake and sway.
Earthquake resistant technology has been around for a long time. As early as 1891, it was suggested that buildings should be placed on rolling logs to absorb the horizontal movements of quakes before they reach the building. In the early 20th century, buildings were built with super thick pillars and limits were placed on heights. In 1928 “base-isolated pillars” were proposed that included deformable membranes between the foundations and the superstructure intended to absorb the quakes energy and slow oscillations.
High rise buildings can be built with an elastic architecture that allows them to flex horizontally when the ground shifts. Earthquake resistant technology introduced in 1983 enabled concrete buildings and roads to be built atop layers of shock-absorbing rubber-bearing isolators and metal dampers. When an earthquake occurs the pads sway instead of the building. Most new buildings have this technology. Dissipation units are built into a building’s structural skeleton. They are hydraulic cylinders that elongate and contract as the building sways.
The most modern earthquake-resistant high-rises, using the latest base-isolation technology, rest on 30 layered rubber-bearing isolators, with 99 lead dampers below them. High-rise towers are strengthened with “super pillars” in the four corners and “supercrossbeams” at 10-floor intervals. Floors holding valuable computer systems have their own separate base-isolated floors. Buildings on softer soils need special braces because the building can resonate with the quake and vibrate apart.
Sapping the motion of energy.” [Source: James Glanz and Norimitsu Onishi, New York Times, March 11, 2011]
NONE OF THESE SOLUTIONS IS ACTIVE, THEY ALL FUNCTION AS SHOCK DAMPERS AND PASSIVE REACTION SYSTEMS.