Inelastic Spectrum Method Applied to Evaluate Seismic Safety of Bridge Structures

2011 ◽  
Vol 243-249 ◽  
pp. 4056-4060
Author(s):  
Gao Hang Cui ◽  
Xiao Li Zhu ◽  
Xia Xin Tao
Keyword(s):  
Evaluation Method ◽  
Seismic Resistance ◽  
Bridge Structure ◽  
Seismic Safety ◽  
Capacity Curves ◽  
Inelastic Demand ◽  
History Analysis ◽  
Seismic Design Code ◽  
Bridge Structures ◽  
Available Information

For the past few years, Push-over analytical method was regarded as a new evaluation method for seismic resistance capacity of structure in some advanced countries. More available information can be obtained from Push-over analysis than from elastic static, even elastic dynamic analysis and the method is easy to be operated. The elastic spectrum from the Highway Engineering Seismic Design Code (JTJ 004-89) was improved in order to take the inelastic effect into account. The inelastic demand spectra were derived by means of Vidic's strength reduction factors. By comparing capacity curves of bridge structure with the demand elastic spectrum, the earthquake resistance of bridge structure can be estimated. Furthermore, it is applied to evaluate seismic resistance capacity of a real bridge example in this paper. The results show that Pushover method can replace inelastic dynamic history analysis method in some cases.

scholarly journals EVALUASI KINERJA STRUKTUR JEMBATAN PELENGKUNG AKIBAT BEBAN GEMPA DENGAN ANALISIS RIWAYAT WAKTU

2020 ◽  
Vol 6 (2) ◽  
pp. 151-156
Author(s):  
Widya Apriani ◽  
Reni Suryanita ◽  
Fadrizal Lubis
Keyword(s):  
Compressive Force ◽  
Time History ◽  
Time History Analysis ◽  
Bridge Structure ◽  
Analysis Method ◽  
Arch Bridge ◽  
Loma Prieta Earthquake ◽  
History Analysis ◽  
Bridge Structures ◽  
Second Period

The behavior of the arch bridge structure has its own peculiarities in distributing loading. The curved shape of the structure allows the structure's own weight to be transferred to the foundation as the normal compressive force without bending. the load is transferred through the semicircular structure to the abutments on either side. The curved (semicircular) design will naturally shift the load received by the floor of the bridge vehicle towards the abutment which keeps both sides of the bridge from moving sideways. Earthquake is a dominant horizontal cyclic loading of a structure. The performance of bridge structures due to the effects of earthquake loading is an important aspect that needs to be taken into account in designing and evaluating the bridge structure. The method used in this study is time history analysis. This article aims to evaluate the performance of arch bridge structures due to earthquake loads by using time-history analysis method. The results of the structure performance show that. The performance of the bridge due to the loading of the Loma prieta earthquake is generated from the period scale that has been analyzed with the 10 second period of the first earthquake for each result. Based on the results of Midas analysis, the strongest location where the damage occurs is in the middle of the bridge road. At the coordinates of 19 the largest displacement is at joint 268 of 1.177169 mm and for U2 of 0.0194 mm and U3 of 31.763771 mm.

scholarly journals Comparative Study on the Analysis Methods for the Seismic Resistance of Bridge Structure

2019 ◽  
Vol 267 ◽  
pp. 04014
Author(s):  
Danling Wang
Keyword(s):  
Comparative Study ◽  
Response Spectrum ◽  
Time History ◽  
Time History Analysis ◽  
Seismic Resistance ◽  
Bridge Structure ◽  
Response Spectrum Method ◽  
Spectrum Method ◽  
Analysis Methods ◽  
History Analysis

As a kind of destructive natural disasters, earthquake can cause serious damage to the bridges of lifeline projects, which will bring great difficulties to the rescue and relief work. The bridge structure is complex, and people pay increasingly more attention to the research on its seismic resistance. It is very important for designers and researchers to adopt an appropriate analysis method in seismic resistance analysis. This paper briefly summarizes the hazards caused by earthquakes to long-span bridges, and introduces the calculation principles of response spectrum method and time history analysis in detail. Through the comparative study of the two commonly used seismic resistance analysis methods for bridges, it summarizes the advantages and disadvantages and the application scope of each method, providing reference for selecting suitable design methods for seismic resistance design. Lastly, it describes the future research trends of response spectrum method and time history analysis.

TIME-HISTORY ANALYSIS RESULTS OF RC FRAMES FOR DIFFERENT GROUND ACCELERATIONS

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Hak Sub Kwon ◽  
Kyung Jae Shin ◽  
Sung Hyun Park ◽  
Gi Yo Min ◽  
Joon Sub Lee
Keyword(s):  
Nonlinear Dynamic Analysis ◽  
Time History ◽  
Time History Analysis ◽  
Seismic Resistance ◽  
School Buildings ◽  
Building Structures ◽  
History Analysis ◽  
Seismic Design Code ◽  
Earthquake Load ◽  
Resistance Performance

Recent earthquake in Japan has increased the interest in seismic-resistance performance of building structures in Korea. Earthquake damages not only collapsed the buildings but also caused huge loss of both human lives and property. Therefore, the school buildings, which are often used as an emergency shelter during an earthquake, should be evaluated of their seismic-resistance performance. This study used a nonlinear dynamic analysis program, OpenSees, to perform nonlinear static and dynamic analyses for the seismic-resistance evaluation of school buildings, which were not designed for an earthquake load. Actual earthquake waves were normalized to make them similar to design acceleration spectrum as specified by current seismic design code KBC 2009. Three actual ground accelerations (i.e., El Centro 1940, Kobe 1995 and Northridge 1994) were used to carry out time-history analysis in order to evaluate the overall behavior of the structure and local nonlinear deformation at the element level. The analysis result shows that the old school building not designed for an earthquake may be damaged seriously by an earthquake load of the magnitude equivalent to current design spectrum standard.

Dynamic P-Δ Effect on Probabilistic Residual Displacement of Bridge Structures

2013 ◽  
Vol 405-408 ◽  
pp. 1678-1681
Author(s):  
Bo Yu ◽  
Di Liu ◽  
Lu Feng Yang
Keyword(s):  
Time History ◽  
Dynamic Responses ◽  
Nonlinear Time History Analysis ◽  
Stability Factor ◽  
Bridge Structure ◽  
Residual Displacement ◽  
Sdof System ◽  
History Analysis ◽  
Bridge Structures ◽  
Nonlinear Time History

Residual displacement has been identified as one of the most important parameter to assess the reparability and usability of bridge structures after strong earthquake, which is significantly impacted by the P-Δ effect. In this study, the influence of the P-Δ effect on the probabilistic characteristics of residual displacement of bridge structure was quantificationally investigated based on a series of nonlinear time-history analysis. The bridge structure was idealized as the single-degree-of-freedom (SDOF) system and the hysteretic behaviour was represented by the improved Bouc-Wen model. The statistic analysis was implemented based on the inelastic dynamic responses of the SDOF system under 69 selected earthquake records. The results show that the P-Δ effect has significant impact on the residual displacement, especially for systems with large stability factor and/or small post-yield stiffness ratio and yield strength.

scholarly journals Record-to-record variability and code-compatible seismic safety-checking with limited number of records

2021 ◽  
Author(s):  
Fatemeh Jalayer ◽  
Hossein Ebrahimian ◽  
Andrea Miano
Keyword(s):  
Seismic Hazard ◽  
Linear Time ◽  
Time History ◽  
Time History Analysis ◽  
Seismic Safety ◽  
Hazard Curve ◽  
History Analysis ◽  
Non Linear ◽  
Seismic Hazard Curve ◽  
Cloud Analysis

AbstractThe Italian code requires spectrum compatibility with mean spectrum for a suite of accelerograms selected for time-history analysis. Although these requirements define minimum acceptability criteria, it is likely that code-based non-linear dynamic analysis is going to be done based on limited number of records. Performance-based safety-checking provides formal basis for addressing the record-to-record variability and the epistemic uncertainties due to limited number of records and in the estimation of the seismic hazard curve. “Cloud Analysis” is a non-linear time-history analysis procedure that employs the structural response to un-scaled ground motion records and can be directly implemented in performance-based safety-checking. This paper interprets the code-based provisions in a performance-based key and applies further restrictions to spectrum-compatible record selection aiming to implement Cloud Analysis. It is shown that, by multiplying a closed-form coefficient, code-based safety ratio could be transformed into simplified performance-based safety ratio. It is shown that, as a proof of concept, if the partial safety factors in the code are set to unity, this coefficient is going to be on average slightly larger than unity. The paper provides the basis for propagating the epistemic uncertainties due to limited sample size and in the seismic hazard curve to the performance-based safety ratio both in a rigorous and simplified manner. If epistemic uncertainties are considered, the average code-based safety checking could end up being unconservative with respect to performance-based procedures when the number of records is small. However, it is shown that performance-based safety checking is possible with no extra structural analyses.

Applicability of Modal Pushover Analysis on Bridges

2011 ◽  
Vol 255-260 ◽  
pp. 806-810
Author(s):  
Biao Wei ◽  
Qing Yuan Zeng ◽  
Wei An Liu
Keyword(s):  
Seismic Analysis ◽  
Pushover Analysis ◽  
Time History ◽  
Seismic Demand ◽  
Seismic Demands ◽  
Modal Pushover Analysis ◽  
History Analysis ◽  
Bridge Structures ◽  
Scope Of Application ◽  
Modal Pushover

Taking one irregular continuous bridge as an example, modal pushover analysis (MPA) has been conducted to judge whether it would be applicable for seismic analysis of irregular bridge structures. The bridge’s seismic demand in the transverse direction has been determined through two different methods, inelastic time history analysis (ITHA) and MPA respectively. The comparison between those two results indicates that MPA would be suitable only for bridges under elastic or slightly damaged state. Finally, some modifications are used to improve the MPA’s scope of application, and the results illustrate that the adapted MPA will be able to estimate bridges’ seismic demands to some extent.

Probabilistic Peak Displacement Analysis of Bridge Structures with P-Δ Effect

2013 ◽  
Vol 405-408 ◽  
pp. 1674-1677
Author(s):  
Bo Yu ◽  
Di Liu ◽  
Lu Feng Yang
Keyword(s):  
Time History ◽  
Dynamic Responses ◽  
Nonlinear Time History Analysis ◽  
Bridge Structure ◽  
Vibration Period ◽  
Peak Displacement ◽  
Sdof System ◽  
Bridge Structures ◽  
Performance Based Seismic Design ◽  
Nonlinear Time History

Peak displacement is one of the most important parameters for the performance based seismic design of bridge structure, while the peak displacement is often significantly impacted by the P-Δ effect. In this study, the influence of the P-Δ effect on the statistics of peak displacement of bridge structure was quantificationally investigated based on a series of nonlinear time-history analysis. The bridge structure was idealized as the single degree of freedom (SDOF) system and the hysteretic behaviour was represented by the improved Bouc-Wen model. The statistic analysis was implemented based on the inelastic dynamic responses of the SDOF system under 69 selected earthquake records. The results show that the P-Δ effect has significant impact on the mean and dispersion of peak displacement of bridge structures, especially if the normalized yield strength and the natural vibration period are small.

scholarly journals Reliability-Based Topology Optimization Using Two Alternative Inverse Optimum Safety Factor Approaches: Application to Bridge Structures

2020 ◽  
Vol 30 (3) ◽  
pp. 498-511
Author(s):  
Ghias Kharmanda ◽  
Imad R. Antypas ◽  
Alexey G. Dyachenko
Keyword(s):  
Topology Optimization ◽  
Safety Factor ◽  
Optimization Model ◽  
High Performance ◽  
Bridge Structure ◽  
Objective Performance ◽  
Bridge Structures ◽  
Alternative Approaches ◽  
Alternative Choice

Introduction. The Deterministic Topology Optimization model provides a single solution for a given design space, while the Reliability-Based Topology Optimization model provides several reliability-based topology layouts with high-performance levels. The objective of this work is to develop two strategies that can provide the designer with two categories of resulting topologies. Materials and Methods. Two alternative approaches based on the Inverse Optimum Safety Factor are developed: the first one is called the Objective-Based IOSF Approach and the second one is called Performance-Based IOSF Approach. When dealing with bridge structures, the uncertainty on the input parameters (boundary conditions, material properties, geometry, etc.) and also output parameters (compliance, etc.) should not be ignored. The sensitivity analysis is the fundamental idea of both developed approaches, identifies the role of each parameter on the structural performance. In addition, the optimization domain choice is important when eliminating material that should not affect the structure functioning. Results. Two numerical examples on a 2D bridge structure are presented to demonstrate the efficiency of the developed approaches. When considering a certain reliability level, the Reliability-Based Topology Optimization leads to two different configurations relative to the Deterministic Topology Optimization one. When increasing the reliability levels, the quantity of materials decreases that leads to an increase in the number of holes in the structures. Discussion and Conclusion. In addition to their simplified implementation, the developed alternative approaches can be considered as two generative tools to produce two different categories (families) of solutions where an alternative choice between two functions (objective/performance) is presented.

Development of an Evaluation Method for Seismic Isolation Systems of Nuclear Power Facilities: Part 2 — Application of CCFS Method to the Multiply Supported Systems

2014 ◽  
Author(s):  
Koichi Tai ◽  
Keisuke Sasajima ◽  
Shunsuke Fukushima ◽  
Noriyuki Takamura ◽  
Shigenobu Onishi
Keyword(s):  
Power Plant ◽  
Nuclear Power ◽  
Seismic Isolation ◽  
Evaluation Method ◽  
Time History ◽  
Piping System ◽  
History Analysis ◽  
Piping Systems ◽  
Isolation Systems ◽  
Seismic Isolation Systems

This paper provides a part of series of “Development of an Evaluation Method for Seismic Isolation Systems of Nuclear Power Facilities”. Paper is focused on the seismic evaluation method of the multiply supported systems, as the one of the design methodology adopted in the equipment and piping system of the seismic isolated nuclear power plant in Japan. Many of the piping systems are multiply supported over different floor levels in the reactor building, and some of the piping systems are carried over to the adjacent building. Although Independent Support Motion (ISM) method has been widely applied in such a multiply supported seismic design of nuclear power plant, it is noted that the shortcoming of ignoring correlations between each excitations is frequently misleaded to the over-estimated design. Application of Cross-oscillator, Cross-Floor response Spectrum (CCFS) method, proposed by A. Asfura and A. D. Kiureghian[1] shall be considered to be the excellent solution to the problems as mentioned above. So, we have introduced the algorithm of CCFS method to the FEM program. The seismic responses of the benchmark model of multiply supported piping system are evaluated under various combination methods of ISM and CCFS, comparing to the exact solutions of Time History analysis method. As the result, it is demonstrated that the CCFS method shows excellent agreement to the responses of Time History analysis, and the CCFS method shall be one of the effective and practical design method of multiply supported systems.

Consideration of the vertical load from a tsunami on bridge structures

2021 ◽  
pp. 86-92
Author(s):  
Anton D. Yakovlev
Keyword(s):  
Natural Disaster ◽  
Russian Federation ◽  
Computer Modelling ◽  
Significant Part ◽  
Transport Infrastructure ◽  
Bridge Structure ◽  
Vertical Load ◽  
Tsunami Waves ◽  
Bridge Structures ◽  
The Russian Federation

A significant part of the territory of the Russian Federation is exposed to various natural disasters. One of the most destructive are tsunami waves. At the same time, for the development of these territories, there is a need for the development of transport infrastructure, which implies, among other things, the design of bridges. To ensure the reliability of bridges in the event of tsunami, it is necessary to fully take into account the possible impacts from these waves. In Russia, there is a document to determine the load from the tsunami. But, despite the existence of this document, the issue of taking into account the loads from the tsunami on various structures remains relevant. In particular, there are no clear guidelines for accounting for vertical loads from tsunami waves on bridge structures. With the help of the studies carried out on computer modelling of the wave roll-up on the bridge structure, this article proves the need to take into account the vertical loads from the tsunami, and also proposes a method for determining its numerical values. This study can complement the basic methodology for determining the loads from tsunami waves on bridge structures and help designers fully account for this dangerous natural disaster.

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