Earthquake resistant structures

About: Earthquake resistant structures is a research topic. Over the lifetime, 1126 publications have been published within this topic receiving 27467 citations.

Seismic Response of Curved Steel Box Girder Bridges

Abstract: The results of a comprehensive study of the seismic response of curved steel box girder bridges are presented. Multiple‐span bridges with up to five spans are analyzed. The bridge is modeled using 3‐D space frame elements and El Centro earthquake accelerogram is used as a dynamic input to calculate the maximum responses at the bridge deck and columns. Different elements of the bridge model and the seismic loading are examined, and a comparison between the response history and the response spectrum methods for analyzing curved bridges, using El Centro earthquake accelerogram, shows that the latter technique fails when vibration modes with relatively high frequencies are considered. The simultaneous application of the earthquake loadings in the three global directions is also discussed. Parametric studies are performed and the effect of the span length, radius of curvature, bridge weight, and column geometry are presented.

Seismic Design of Friction-Damped Precast Concrete Frame Structures

Abstract: This paper is on the seismic design of unbonded post-tensioned precast concrete frame structures that use friction dampers for supplemental energy dissipation. A procedure is described to determine the friction damper slip force and the area of post-tensioning steel needed in a frame to satisfy prescribed lateral strength and energy dissipation requirements. The proposed design procedure assumes that the lateral strength requirements for the frame have been obtained from a linear elastic analysis of the structure under equivalent lateral forces. Nonlinear reversed cyclic analyses of friction-damped precast concrete beam-column subassemblies and multi-story frame structures under lateral loads are conducted to evaluate the design procedure and to identify areas where improvement may be needed. The analytical results show that friction-damped precast concrete frames can achieve significant energy dissipation levels while maintaining a large level of self-centering capability due to the post-tensioning force.

Earthquake Input Energy to Two Buildings Connected by Viscous Dampers

Abstract: A frequency-domain method is developed for evaluating the earthquake input energy to two building structures connected by viscous dampers. It is shown that the earthquake input energies to respective building structures and added viscous connecting dampers can be defined as works done by the boundary forces between the subsystems on their corresponding displacements. Fourier and inverse Fourier transformations enable one to transform the earthquake input energy in time domain to that in frequency domain. The earthquake input energy in frequency domain has an advantage that, while the input energy cannot be decomposed into the term for the structural parameters and that for the parameters of input ground motions in the conventional time-domain approach, it is possible in the proposed frequency-domain approach. It is demonstrated that the proposed energy transfer function is very useful for clearer understanding of dependence of energy consumption ratios in respective buildings and connecting viscous dampers on their properties. It is concluded that the total input energy to the overall system including both buildings and connecting viscous dampers is approximately constant regardless of the quantity and location of connecting viscous dampers. This property leads to an advantageous feature that, if the energy consumption in the connecting viscous dampers increases, the input energies to the buildings can be reduced drastically.

Reliability of Concrete Frames Damaged by Earthquakes

Abstract: A methodology that permits an assessment of the reliability of concrete frames, which may have been damaged in previous earthquakes, is presented. Using Monte Carlo simulation, damage probability matrices are constructed that take into account the variability of building strength parameters in addition to the randomness of ground motions. This methodology can serve owners and public officials as a decision aid for strengthening strategies and repairs.