Effects of Brace Stiffness and Nonlinearity of Viscous Dampers on Seismic Performance of Structures

In the applications of supplemental dampers for seismic hazard mitigation, the supporting braces for the dampers are considered an important component for ensuring an efficient energy dissipation in the structure. Despite their importance, studies on the effects of the brace stiffness and the velocity exponent in the case of nonlinear viscous dampers are rather limited. In this paper, a numerical time-stepping method is developed for computing the seismic response of the structure with supporting braces and nonlinear viscous dampers. Using the proposed method, effects of the parameters of the nonlinear damper-brace systems are investigated, using first a single-story structure, followed by multi-story buildings. Results indicated that the design parameters for the dampers and supporting braces may be combined in numerous ways to satisfy a given set of structural performance objectives, but the brace stiffness can be minimized to achieve design efficiency in the range of velocity exponent commonly used for seismic applications of nonlinear viscous dampers. Results also indicated that for a set brace stiffness, if the dampers are optimally designed, the velocity exponent has an insignificant effect on the structural seismic performance objectives considered in this paper.

Seismic hazard microzonation of Bengkulu City, Indonesia

It has been known that Bengkulu City (Indonesia) is vulnerable to undergo seismic damage. This study is initiated by measuring horizontal to vertical spectral ratio (H/V) to sites in Bengkulu City using microtremor. The inversion analysis is performed to generate shear wave velocity profile. Hundreds of sites are investigated in this study. The results show that observed H/V is consistent with the theoretical H/V. National Earthquake Hazard Reduction Program code is adopted to classify the site class. The results also exhibit that Bengkulu City is dominated by Site Classes C and D. In general, this study could lead local government to consider seismic hazard mitigation for spatial plan.

Seismic Hazard Microzonation of Bengkulu City, Indonesia

It has been known that Bengkulu City (Indonesia) is vulnerable to undergo seismic damage. This study is initiated by measuring horizontal to vertical spectral ratio (H/V) to sites in Bengkulu City using microtremor. The inversion analysis is performed to generate shear wave velocity profile. Hundreds of sites are investigated in this study. The results show that observed H/V is consistent with the theoretical H/V. National Earthquake Hazard Reduction Program code is adopted to classify the site class. The results also exhibit that Bengkulu City is dominated by Site Classes C and D. In general, this study could lead local government to reconsider seismic hazard mitigation for spatial plan.

Seismic Hazard Microzonation of Bengkulu City, Indonesia

It has been known that Bengkulu City (Indonesia) is vulnerable to undergo seismic damage. This study is initiated by measuring horizontal to vertical spectral ratio (H/V) to sites in Bengkulu City using microtremor. The inversion analysis is performed to generate shear wave velocity profile. A total of 218 sites is investigated in this study. The results show that observed H/V is consistent with the theoretical H/V. National Earthquake Hazard Reduction Program (NEHRP) code is adopted to classify the site class. The results also exhibit that Bengkulu City is dominated by Site Classes C and D. In general, this study could lead local government to reconsider seismic hazard mitigation for spatial plan.