Strengthening of Steel Frames in Seismic Resistance

Abstract

Based on the balance of energy between the seismic input and the structural resistance, the basic formulation for strengthening buildings is derived. The loading effect of an earthquake can be grasped as the energy input, while the seismic resistance of an building can be considered to be the energy absorption capacity of the building.

In order to improve the seismic resistance of existing buildings, the following methods are effective;

• 1) to dispose energy absorbing structural elements in addition to existing structural skeletons

• 2) to equip an energy absorbing story with the energy absorption capacity large enough to be able to absorb the total energy input, leaving the other stories undamaged

• 3) to dispose energy absorbing elements over the building evenly, keeping the structural elements which sustain gravitational loadings elastic