200

All dimensions in inches

FIGURE 35.11 ADAS device (Whittaker et al. 1991).

Story shear, kip

- Frame before upgrade

----Upgraded frame with ADAS

Story shear, kip

- Frame before upgrade

----Upgraded frame with ADAS

FIGURE 35.13 Comparison of computed results for Wells Fargo Bank Building — envelope of response values in X direction (Perry et al. 1993).

stable and that all criteria were met. In addition to the introduction of the bracing and ADAS dampers, several interior columns and a shear wall were strengthened.

An alternative passive damper utilizing the principles of metallic yielding is the unbonded brace (Shiba et al. 1998; Wada et al. 2000). These braces consist of a central steel core that provides energy dissipation in both tension and compression. In order to prevent buckling, the brace is encased in a concrete-filled steel tube or a fiber-reinforced concrete sheathing. Special coatings are used to reduce friction between the steel core and surrounding concrete. Despite its recent development, a number of applications of the unbonded brace have already appeared in Japan and the United States.

0 0

Post a comment