Influence of Wave Passage Effect on Seismic Response of Truss String Structure Co-Working with its Base Frame

2014 ◽  
Vol 533 ◽  
pp. 154-158
Author(s):  
He Peng Wang ◽  
Zhong Gen Xu ◽  
Chang Gen Deng
Keyword(s):  
Seismic Waves ◽  
Time History ◽  
Element Model ◽  
Seismic Responses ◽  
Passage Effect ◽  
History Analysis ◽  
Insertion Method ◽  
String Structure ◽  
Wave Passage ◽  
Wave Passage Effect

By inputting two groups of seismic waves with phase differences of 0.16s, 0.34s, 0.5 and 0.34s, 0.66s, 1.0s to column elements divided into four parts of lower story of finite element model with insertion method, this paper analyzed the influence of wave passage effect on seismic responses of truss string structure of Guangzhou Convention and Exhibition Centre co-working with its base frame by time history analysis method. The results show that: because of natural vibration characteristics of structure, wave traveling has some effect on seismic responses of truss string structure of Guangzhou Convention and Exhibition Centre.

Influence of Incoherence and Wave Passage Effects on Seismic Performances of Long Immersed Tunnel

2019 ◽  
Vol 16 (05) ◽  
pp. 1840012 ◽  
Author(s):  
Z. Y. Chen ◽  
S. B. Liang ◽  
C. He
Keyword(s):  
Axial Compression ◽  
Time History ◽  
Earthquake Ground Motion ◽  
Seismic Responses ◽  
Low Frequencies ◽  
Passage Effect ◽  
Immersed Tunnel ◽  
Support Excitation ◽  
Wave Passage ◽  
Wave Passage Effect

This paper conducts time history analysis to explore the influence of spatially varying earthquake ground motion (SVEGM) on seismic responses of the long immersed tunnel. Incoherence effect and wave passage effect are mainly focused here. Moreover, three coherency models are adopted to investigate the sensitivity of the computed responses to the models. The calculation results show that SVEGM enlarges seismic responses of the immersed tunnel significantly than uniform excitation. Considering wave passage effect and incoherence effect simultaneously makes the seismic responses increase more sharply than considering the latter only. The deformation of Gina gasket is barely sensitive to coherency model, while the axial compression force is sensitive to coherency model. It indicates suppressing that the fundamental mode and dominating higher-mode response are the hallmark of multi-support excitation. The great differences of three models decay with separation at low frequencies and their coherency in frequency domain are the main reasons that cause the variations of the axial compression forces.

Effects of Spatial Variable Ground Motions on the Seismic Response of Base-Isolated Building

2010 ◽  
Vol 163-167 ◽  
pp. 4422-4428
Author(s):  
Yong Qin Lei ◽  
Yong Feng Du
Keyword(s):  
Seismic Response ◽  
Ground Motion ◽  
Ground Motions ◽  
Time History ◽  
Spatial Variable ◽  
Passage Effect ◽  
History Analysis ◽  
Large Plane ◽  
Wave Passage ◽  
Wave Passage Effect

Aimed to base-isolated building with large plane dimension, the change laws of seismic response for base-isolated building under spatial variable ground motions were researched. Firstly, the artificial spatial variable earthquake time histories were generated using spectral representation method based on code response spectrum. Then the 3-D FEM modal of one based-isolated building with large plane dimension was established and the seismic response of based-isolated building under spatially ground motion was studied by nonlinear time history analysis. The mitigation effects of based-isolated building with large plane dimension were compared each other at the cases of uniform excitation, non-uniform excitation considering only wave passage effect, non-uniform excitation considering both the wave passage effect and incoherence effect, multi-component uniform excitation, multi-component non-uniform excitation considering the wave passage effect and multi-component non-uniform excitation considering both the wave passage effect and incoherence effect. The results show that the seismic response of base-isolated structure with large plane dimension under the uniform excitation is relative safety. When the base-isolated building with large plane dimension is designed by time history analysis, the spatial variability of earthquake ground motion effects can be considered.

Seismic Response Analysis of Cable-Stayed Bridges

2012 ◽  
Vol 446-449 ◽  
pp. 2290-2294
Author(s):  
Wen Liang Qiu ◽  
Meng Jiang ◽  
Xing Bo Zhang
Keyword(s):  
Time History ◽  
Element Model ◽  
Response Analysis ◽  
Longitudinal Displacement ◽  
Seismic Responses ◽  
Cable Stayed Bridge ◽  
Optimum Parameters ◽  
History Analysis ◽  
Floating System ◽  
Main Bridge

For floating system cable-stayed bridge, the longitudinal displacement of stiffening girder and moments of towers are very large when strong earthquake happens. Too large displacement of stiffening girder leads to collision between girders of the main bridge and the approaches. Using spatial finite element model and time history analysis method, the seismic responses of cable-stayed bridge are studied considering the elasto-plastic effects. The results show that the displacement of stiffening girder is very large when no seismic reduction measures are adopted. The viscous dampers installed between the stiffening girder and towers can efficiently reduce seismic responses of the cable-stayed bridge. Especially, the displacement of stiffening girder can be controlled well to meet the design requirement. Using the optimum parameters of damper, the height of pier under tower and intermediate supports in side span on seismic responses are studied in detail. The longitudinal displacement of stiffening girder increases with the pier height increasing. The intermediate supports in side span are benefit for seismic reduction.

Seismic Response Reduction of Cable-Stayed Bridge with Viscous Dampers

2011 ◽  
Vol 137 ◽  
pp. 154-158
Author(s):  
Wen Liang Qiu ◽  
Meng Jiang ◽  
Xing Bo Zhang
Keyword(s):  
Seismic Waves ◽  
Time History ◽  
Longitudinal Direction ◽  
Element Model ◽  
Design Parameters ◽  
Longitudinal Displacement ◽  
Cable Stayed Bridge ◽  
History Analysis ◽  
Floating System ◽  
The Cost

For floating system cable-stayed bridge, the longitudinal displacement of girder and moments of towers are very large when strong earthquake happens. The dampers installed between girder and towers in longitudinal direction can reduce efficiently displacement of the girder and moments of the towers induced by longitudinal seismic waves. Using spatial finite element model and time history analysis method, the influences of design parameters of viscous damper on seismic responses of cable-stayed bridge are studied in detail. The results of study show that, with the damping constant increasing, the longitudinal displacement of girder and moment of tower decrease, and the forces of damper increase. With velocity exponent increasing, the longitudinal displacement of girder and moment of tower increase, and the force of damper decrease. So, when determining the design parameters of damper, the cost of dampers, difficulty of construction and seismic reduction effects should be considered together.

Seismic Performance Analysis of a Hollow Tower Structure with Three Prismatic Section

2012 ◽  
Vol 549 ◽  
pp. 879-883
Author(s):  
Lu Ping Yi ◽  
Jing Ji
Keyword(s):  
Finite Element ◽  
Seismic Performance ◽  
Seismic Waves ◽  
Lateral Displacement ◽  
Time History ◽  
Element Model ◽  
Finite Element Software ◽  
History Analysis ◽  
Tower Structure ◽  
Earthquake Action

In order to better understand seismic performance of tower body structure in a square, the symbol tower finite element model is established using the finite element software ANSYS. Modal analysis is carried out and the first 3 natural frequencies and vibration modes of marking tower are obtained. By selecting 2 group natural seismic waves and a synthetic seismic wave the seismic time-history analysis of the model is performed, the symbol tower response under the earthquake action is obtained and the maximum lateral displacement and the maximum stress of symbol tower meet the standard requirements, so mark tower under earthquake are safe. These can provide reference for the same type of engineering design.

Theoretical Analysis and Application Research on Grid String Branch Structure

2011 ◽  
Vol 243-249 ◽  
pp. 374-378
Author(s):  
Zong Yun Mo ◽  
Xiao Li Liu ◽  
Xue Feng Song
Keyword(s):  
Natural Vibration ◽  
Time History ◽  
Calculation Model ◽  
Structural Vibration ◽  
Application Research ◽  
General Law ◽  
History Analysis ◽  
String Structure ◽  
Internal Forces ◽  
Node Displacement

According to the thought of beam string structure, pre-stressing structure was presented that it was joined by rigid grid and flexible cable by pole support. It was grid string branch structure. A calculation model of string branch grid was founded. Static and dynamic characteristics of the structure that it was acted by different pre-stress value were analyzed. Through the analysis, the structure displacement and internal forces of rod are improved obviously depending on pre-stress value. The pre-stress value is larger, structure displacement and internal forces of rod are lower. Natural vibration characteristics of the structure are almost not changing, while pre-stress value is changing. When the structure is time history analysis, its response curve accords with general law of structural vibration. Node displacement response of up and bottom chord nodes are not occurred retardation effect.

Analysis of Structural Properties and Seismic Performance of a Temple

2012 ◽  
Vol 535-537 ◽  
pp. 2007-2011
Author(s):  
Da Feng Gao ◽  
Lei Wang ◽  
Peng Fei Li
Keyword(s):  
Safety Margin ◽  
Time History ◽  
Element Model ◽  
Shear Capacity ◽  
Timber Structure ◽  
Spring Element ◽  
History Analysis ◽  
The Ancient Chinese ◽  
The Temple ◽  
Column Base

In order to further study the seismic mechanism of ancient timber structure, the wooden structure of the temple was taken as the research object, and the reasonable mechanical model was established by applying semi-rigid spring element to simulate mortise-tenon joint, tou-kung and column base. The test of the compressive, bent and the shear capacity all met requirements by analyzing the model under the static load, and the average safety margin of the structure is 86.7%. The first six inherent frequencies and vibration shapes were obtained by analysing the finite element model using the method of Block Lanczos, With full transient analysis, considered the model in the El-Centro wave, Taft wave and Lanzhou artificial wave excitation under the three earthquake time history analysis, and got the model acceleration time history curves, the results show that the ancient Chinese timber structure has better aseismic performance. The above-mentioned methods and corresponding conclusions could provide the reference for maintenance and protection of ancient Chinese timber structure.

Dynamic Response Characteristics of Underground Powerhouse Caverns for Sandaowan Hydropower Station

2011 ◽  
Vol 382 ◽  
pp. 80-83 ◽  
Author(s):  
Zhen Zhong Shen ◽  
Hua Chun Ren
Keyword(s):  
Seismic Waves ◽  
Low Frequency ◽  
Time History ◽  
Element Model ◽  
Frequency Characteristics ◽  
Dynamic Responses ◽  
Principal Stresses ◽  
Underground Powerhouse ◽  
Response Characteristics ◽  
Set Up

According to the practical situation, the 3-D finite element model of Sandaowan underground powerhouse caverns on Taolai River is set up for analyzing the behaviors under earthquake action. Based on static stress field of the surrounding rock mass, and with the selection of appropriate seismic waves for dynamic time-history analysis method, the dynamic responses of underground powerhouse caverns are analyzed. It is shown that the time-history waveform of dynamic displacement of given points has a very similar variation regularity with that of acceleration, and the wave phases of both are almost synchronous. The dynamic displacements and principal stresses of the given points on rock walls are with the vibration of low-frequency characteristics, the acceleration response is with the vibration of high-frequency characteristics.

Characteristic Analysis of 3.11 Seismic Waves

2013 ◽  
Vol 838-841 ◽  
pp. 1484-1491
Author(s):  
Guo Ping Chen ◽  
Xiang Liang Ning ◽  
Hong Feng Guo ◽  
Han Yu Zhou
Keyword(s):  
Seismic Waves ◽  
Response Spectrum ◽  
Time History ◽  
Predominant Frequency ◽  
Characteristic Analysis ◽  
History Analysis ◽  
Spectral Components ◽  
Spectrum Distribution ◽  
Spectrum Characteristics ◽  
Basic Characteristics

33 records of Japanese earthquake are extracted in this paper (referred to as 3.11 seismic waves in the article).Then, through studying the basic characteristics, spectrum characteristics and anisotropic of 3.11 seismic waves, as well as the similarities and differences of the response spectrum of 3.11 seismic waves contrasting with the response spectrum of the code. The results show that: a) 3.11 seismic waves have rich spectral components almost near the predominant frequency and its energy mainly concentrate in 0.1~10Hz.b) By analyzing the spectrum distribution of the seismic waves, its destruction strength on different structures can be evaluated. c) Damaging strength of horizontal seismic waves is much larger than the vertical seismic waves. Serious damage to the structure can be caused by the horizontal seismic waves’ excellence spectrum components focusing on the frequency of the structure in the engineering. Vertical seismic waves have greater damage to the structures’ periods between 0.02s to 1s, but much smaller to other structures. d) it can effectively assess the damaging strength on the structure,in time history analysis ,when make 3.11 seismic waves as the input earthquake waves.

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