scholarly journals The Stress-related related Damping Ratio of Box Girder with Corrugated Steel Web

2014 ◽  
Vol 8 (1) ◽  
pp. 301-306
Author(s):  
Pengfei Li ◽  
Baodong Liu ◽  
Bo Li ◽  
Minghzhe Yang
Keyword(s):  
Seismic Response ◽  
Response Spectrum ◽  
Damping Ratio ◽  
Seismic Intensity ◽  
Response Analysis ◽  
Seismic Response Analysis ◽  
Box Girder ◽  
Simply Supported ◽  
Corrugated Steel Web ◽  
Girder Bridge

In this paper, the stress-related damping ratio formula of box girder with corrugated steel webs is introduced. Using response spectrum method, an iterative algorithm is proposed to calculate the seismic response and the stress-related damping ratio under different seismic intensities. Based on a simply supported composite box girder bridge with corrugated steel webs, the stress-related damping ratios are calculated under different seismic intensities through iteration. The analysis and comparison show that the stress-related damping ratio increased with the seismic intensity, which is smaller than 0.05 under the lower seismic fortification intensity, and larger than 0.05 under the higher seismic intensity. Different damping ratios should be considered under different seismic intensities for the seismic response analysis of the bridge.

scholarly journals Study on the influence of seafloor soft soil layer on seismic ground motion

2020 ◽  
Author(s):  
Jingyan Lan ◽  
Juan Liu ◽  
Xing Song
Keyword(s):  
Seismic Response ◽  
Ground Motion ◽  
Sea Water ◽  
Response Spectrum ◽  
Soft Soil ◽  
Free Field ◽  
Soil Layer ◽  
Response Analysis ◽  
Peak Acceleration ◽  
Seismic Response Analysis

Abstract. In the complex medium system of sea area, the overlying sea water and the surface soft soil have a significant impact on the seafloor ground motion, which brings great seismic risk to the safety of offshore engineering structures. In this paper, four sets of typical free field models are constructed and established, which are land model, land model with surface soft soil, sea model and sea model with surface soft soil. The dynamic finite difference method is used to carry out two-dimensional seismic response analysis of typical free field based on the input forms about P and SV wave. By comparing the seismic response analysis results of four groups of calculation models, the effects of overlying seawater and soft soil on peak acceleration and acceleration response spectrum are studied. The results show that when SV wave is input, the peak acceleration and response spectrum of the surface of soft soil on the surface and the seabed surface can be amplified, while the overlying sea water can significantly reduce the ground motion. When P wave is used, the effect of overlying seawater and soft soil on peak acceleration and response spectrum of surface and seabed can be ignored. The peak acceleration decreases first and then increases from the bottom to the surface, and the difference of peak acceleration calculated by four free field models is not obvious. The results show that the overlying sea water and the surface soft soil layer have little effect on the peak acceleration of ground motion below the surface.

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
Keyword(s):  
Seismic Response ◽  
Seismic Design ◽  
Dynamic Characteristics ◽  
Response Spectrum ◽  
Time History ◽  
Suspension Bridge ◽  
Bridge Engineering ◽  
Response Analysis ◽  
Seismic Response Analysis ◽  
Seismic Design Code

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.

Effect of Pile-Soil Action on Seismic Resistance of Prestressed Continuous Box-Girder Bridge with Changed Sections

2012 ◽  
Vol 238 ◽  
pp. 743-747 ◽  
Author(s):  
Feng Lan Li ◽  
Shi Min Zhang ◽  
Shi Ming Liu
Keyword(s):  
Seismic Response ◽  
Seismic Design ◽  
Prestressed Concrete ◽  
Numerical Models ◽  
Response Spectrum ◽  
Seismic Resistance ◽  
Highway Bridge ◽  
Box Girder ◽  
Internal Forces ◽  
Girder Bridge

Combined with the design of a bridge with prestressed concrete continuous box-girder, and in accordance with the Chinese guidelines of seismic design for highway bridge, the numerical models with and without considering the pile-soil action were built using Midas Civil software. The response spectrum method was used to analyze the seismic response of the bridge under E1 and E2 seismic actions. The vibration characteristics such as frequency, period and mode as well as the internal forces and displacements of piers are discussed in view of the effect of the pile-soil action.

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