scholarly journals Dynamic Characteristics and Seismic Response Analysis of Self-Anchored Suspension Bridge

2012 ◽  
Vol 5 ◽  
pp. 183-188
Author(s):  
Lian Zhen Zhang ◽  
Tian Liang Chen

Self-anchored suspension bridge is widely used in Chinese City bridge engineering for the past few years. Because the anchorage system of main cable has been changed from anchorage blocks to the ends of the girder, its’ dynamic mechanics behavior is greatly distinguished with the traditional earth anchored suspension bridge. This paper studies the dynamic characteristics and seismic response of one large-span self-anchored suspension bridge which is located in China/Shenyang city. Using a spatial dynamic analysis finite element mode, the dynamic characteristics are calculated out. An artificial seismic wave is adopted as the ground motion input which is fitted with acceleration response spectrum according to the Chinese bridge anti-seismic design code. Time-integration method is used to get the seismic time-history response. Geometry nonlinear effect is considered during the time-history analysis. At last, the dynamic characteristics and the behavior of earthquake response of this type bridge structure are discussed clearly. The research results can be used as the reference of seismic response analysis and anti-seismic design for the same type of bridge.

Author(s):  
Satoru Kai ◽  
Tomoyoshi Watakabe ◽  
Naoaki Kaneko ◽  
Kunihiro Tochiki ◽  
Makoto Moriizumi ◽  
...  

The piping in a nuclear power plant is laid across multiple floors of a single building or two buildings, which are supported at many points. As the piping is excited by multiple-inputs from the supporting points during an earthquake, seismic response analysis by multiple excitations is needed to obtain the exact seismic response of the piping. However, few experiments involving such multiple excitation have been performed to verify the validity of multiple excitation analysis. Therefore, analysis of the seismic design of piping in Japan is performed by the enveloped Floor Response Spectrum (FRS), which covers all floor response spectra at all supporting points. The piping response estimated by enveloped FRS is conservative in most cases compared with the actual seismic response by multiple excitations. To perform rational seismic design and evaluation, it is important to investigate the seismic response by multiple excitations and to verify the validity of the analytical method by multiple excitation test. This paper reports the validation results of the multiple-excitation analysis of piping compared with the results of the multiple excitations shaking test using triple uni-axial shaking table and a 3-dimensional piping model (89.1mm diameter and 5.5mm thickness). Three directional moments from the analysis and the shaking test were compared on the validation. As the result, it is confirmed that the analysis by multiple time history excitation corresponds with the test result.


Author(s):  
Michael O’Leary ◽  
William Godfrey

A partially buried fixed-base finite element model of a typical safety-related nuclear structure is analyzed for earthquake loads by the time history method, the response spectrum method, and the equivalent static load method. The spectra-consistent artificial time histories are generated with seed time histories in accordance with Standard Review Plan 3.7.1: Seismic Design Parameters [1] with target spectra based on Regulatory Guide 1.60: Design Response Spectra for Seismic Design of Nuclear Power Plants [2]. The response spectrum analyses are performed with the same target spectra used in generating the artificial time histories. The equivalent static loads are based on the nodal zero period accelerations from the fixed-base time history analyses. The seismic responses in a column in the structure are combined using algebraic sum, square root of the sum of the squares (SRSS), and the 100-40-40 rule in accordance with Regulatory Guide 1.92: Combining modal responses and spatial components in seismic response analysis [3]. The equivalent static load method is applied according to ASCE 4-15: Seismic Analysis of Safety-Related Nuclear Structures [4]. The resulting design forces and required reinforcement for a column in the structure are compared for each method along with the corresponding computational demand.


2012 ◽  
Vol 517 ◽  
pp. 824-831
Author(s):  
Yun Xiao ◽  
Jun Qing Lei ◽  
Zhong San Li

By response spectrum method, superposition method based elastic time-history analysis and nonlinear time-history analysis of Newmark-β based linear increasing acceleration method, the finite element models of frame piers 21#~29# of the Ziya River Bridge on Tianjin to Baoding railway are established, and an assistant program code is generated to analyze seismic response of the frame pier. Results indicate that the vibration modes of frame piers are scattered. Only a few modes would be aroused in a narrow band spectrum. And the seismic response obtained by the response spectrum method is generally 10%~20% smaller than which obtained by the elastic time-history analysis. Under seismic excitations along the longitudinal direction, the ratio of displacement difference between two columns to the maximum value is generally liner increased with the increasing of the girder deviation from the centre of the pier beam. And the plastic hinge yielding would occur both at the bottom and the top of pier columns under excitations of the transversal direction. As a result, taking more than 30 vibration modes into account is suggested in a seismic response analysis or design calculation for frame piers. A time-history analysis is recommended as well. The evaluation of earthquake resistant capability of the transversal direction should consider both the bottom and top of the columns, and the anti-seismic capability design of the longitudinal direction is one of the key points for frame piers in the ductility design.


2012 ◽  
Vol 166-169 ◽  
pp. 2138-2142
Author(s):  
Hui Min Wang ◽  
Liang Cao ◽  
Ji Yao ◽  
Zhi Liang Wang

For the complex features in the form of a flat L-shaped reinforced concrete frame structure, the three dimensional FEM model of the structure was established in this paper, and the dynamic characteristics of the structure was analyzed, the participation equivalent mass of every mode’s order was obtained. Seismic response analysis for the structure was carried out with modal decomposition spectrum method and time history analysis method, the weak layer of the structure was pointed out and the reference for the structural design was provided.


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