Straightening of Low-Damage Steel Buildings With Residual Displacements

Abstract eng:
The residual interstory drift ratio (RISDR) of a three story 2-D steel frame building structure is studied under the same ground motions records applied twice. The records were chosen such that during the first shake the residual drift was close to 1%. Before the second shake the building is fitted with tension-only braces to encourage dynamic re-straightening. The tension-only braces are steel rods which yield in tension and carry no force in compression. It is shown that increasing the story strength of the structure by adding tension-only braces can straighten the structure. However, over-straightening may also occur causing significant residual drifts in the opposite direction. Increasing brace stiffness while maintaining the same strength causes the residual interstory drift ratio (RISDR) of the structure to first decrease and then increase slightly. At high brace stiffnesses the RISDR becomes almost constant and independent of stiffness. For the particular case studied, the optimal increase of story strength and stiffness was 35% and 10% respectively for the shaking considered. With the addition of a brace with these characteristics, instead of the second shake approximately doubling the residual displacement, it reduces by about 100%, effectively straightening the structure.

• Export as: BibTeX | MARC | MARCXML | DC | EndNote | NLM | RefWorks
• Add to your basket