scholarly journals Seismic Effectiveness of Multiple Seismic Measures on a Continuous Girder Bridge

2020 ◽  
Vol 10 (2) ◽  
pp. 624 ◽  
Author(s):  
Yumin Zhang ◽  
Yun Shi ◽  
Dengke Liu
Keyword(s):  
Time History ◽  
Bending Moment ◽  
Large Earthquake ◽  
Economic Losses ◽  
Bridge Structure ◽  
Expansion Joint ◽  
Maximum Reduction ◽  
Joint Application ◽  
Safety Research ◽  
Joint Displacement

Seismic hazards, such as bridge pounding, unseating, collapse, etc., cause significant economic losses and affect traffic and safety. Research on seismic measures, such as limiting and unseating prevention devices for the bridge, can effectively prevent damage to the bearings, such as excessive displacement, the pounding of the beam end, etc., in an earthquake. In this paper, the dynamic time-history analysis method was used to study the mechanical behaviors of the bridge structure, such as its seismic performance, structural displacement, pier bending moment, etc. We found that different combinations of seismic measures can effectively reduce the displacement at the bridge expansion joint and bearings. The joint application of an expansion device, restrainer, and unseating prevention devices shows the best limiting effect on bridge displacement and expansion joint displacement. The maximum reduction of bridge expansion joint displacement reaches 48% and is within the allowable deformation range of an expansion device in a large earthquake, and the maximum reduction of bearing displacement reaches 34%, which only slightly exceeds the shear deformation of the bearing. The expansion device, restrainer, and unseating prevention devices have smaller internal forces in this case than other cases, without damage. In contrast to the previous studies on single seismic measures of unseating restrainers, this study investigates the combination of multiple seismic measures and earthquakes of various magnitude. It reveals the catastrophe process of the bridge structure and the cooperation law of seismic measures in an earthquake.

scholarly journals Analytical Method for Geometric Nonlinear Problems Based on Offshore Derricks

Mathematics ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 610
Author(s):  
Chunbao Li ◽  
Hui Cao ◽  
Mengxin Han ◽  
Pengju Qin ◽  
Xiaohui Liu
Keyword(s):  
Analytical Method ◽  
Bending Moment ◽  
Nonlinear Problems ◽  
Weather Conditions ◽  
Order Effect ◽  
Practical Calculation ◽  
Geometrically Nonlinear ◽  
Uniform Load ◽  
Safety Research ◽  
Calculation Results

The marine derrick sometimes operates under extreme weather conditions, especially wind; therefore, the buckling analysis of the components in the derrick is one of the critical contents of engineering safety research. This paper aimed to study the local stability of marine derrick and propose an analytical method for geometrically nonlinear problems. The rod in the derrick is simplified as a compression rod with simply supported ends, which is subjected to transverse uniform load. Considering the second-order effect, the differential equations were used to establish the deflection, rotation angle, and bending moment equations of the derrick rod under the lateral uniform load. This method was defined as a geometrically nonlinear analytical method. Moreover, the deflection deformation and stability of the derrick members were analyzed, and the practical calculation formula was obtained. The Ansys analysis results were compared with the calculation results in this paper.

Vulnerability-Based Design of Sliding Concave Bearings for the Seismic Isolation of Steel Storage Tanks

2016 ◽  
Author(s):  
Hoang Nam Phan ◽  
Fabrizio Paolacci ◽  
Silvia Alessandri ◽  
Phuong Hoa Hoang
Keyword(s):  
Liquid Steel ◽  
Seismic Isolation ◽  
Failure Modes ◽  
Fragility Curves ◽  
Time History ◽  
Probability Of Failure ◽  
Design Parameters ◽  
Economic Losses ◽  
Storage Tanks ◽  
Isolation System

Liquid steel storage tanks are strategic structures for industrial facilities and have been widely used both in nuclear and non-nuclear power plants. Typical damage to tanks occurred during past earthquakes such as cracking at the bottom plate, elastic or elastoplastic buckling of the tank wall, failure of the ground anchorage system, and sloshing damage around the roof, etc. Due to their potential and substantial economic losses as well as environmental hazards, implementations of seismic isolation and energy dissipation systems have been recently extended to liquid storage tanks. Although the benefits of seismic isolation systems have been well known in reducing seismic demands of tanks; however, these benefits have been rarely investigated in literature in terms of reduction in the probability of failure. In this paper, A vulnerability-based design approach of a sliding concave bearing system for an existing elevated liquid steel storage tank is presented by evaluating the probability of exceeding specific limit states. Firstly, nonlinear time history analyses of a three-dimensional stick model for the examined case study are performed using a set of ground motion records. Fragility curves of different failure modes of the tank are then obtained by the well-known cloud method. In the following, a seismic isolation system based on concave sliding bearings is proposed. The effectiveness of the isolation system in mitigating the seismic response of the tank is investigated by means of fragility curves. Finally, an optimization of design parameters for sliding concave bearings is determined based on the reduction of the tank vulnerability or the probability of failure.

Application of Earthquake Resistance Analysis Technique in the Design of Constructional Engineering

2013 ◽  
Vol 756-759 ◽  
pp. 4482-4486
Author(s):  
Chun Gan ◽  
Xue Song Luo
Keyword(s):  
Response Spectrum ◽  
Structural Response ◽  
Time History ◽  
Economic Losses ◽  
Element Analysis ◽  
Architectural Engineering ◽  
Analysis Technique ◽  
History Analysis ◽  
Earthquake Resistant ◽  
History Of

In recent years, frequent earthquakes have caused great casualties and economic losses in China. And in the earthquake, damage of buildings and the collapse is the main reason causing casualties. Therefore, in the design of constructional engineering, a seismicity of architectural structure is the pressing task at issue. Through time history analysis method, this paper analyzes the time history of building structural response and then it predicts the peak response of mode by response spectrum analysis. Based on this, this paper constructs a numerical simulation model for the architecture by using finite element analysis software SATWE. At the same time, this paper also calculates the structure seismic so as to determine the design of each function structure in architectural engineering design and then provides reference for the realization of earthquake-resistant building.

scholarly journals Dynamic Response Evaluation of Long-Span Reinforced Arch Bridges Subjected to Near- and Far-Field Ground Motions

2018 ◽  
Vol 8 (8) ◽  
pp. 1243 ◽  
Author(s):  
Iman Mohseni ◽  
Hamidreza Lashkariani ◽  
Junsuk Kang ◽  
Thomas Kang
Keyword(s):  
Ground Motion ◽  
Dynamic Performance ◽  
Time History ◽  
Bending Moment ◽  
Element Model ◽  
Structural Performance ◽  
Far Field ◽  
Inelastic Behavior ◽  
Earthquake Loads ◽  
Arch Bridges

This study assessed the structural performance of reinforced concrete (RC) arch bridges under strong ground motion. A detailed three-dimensional finite element model of a 400 m RC arch bridge with composite superstructure and double RC piers was developed and its behavior when subjected to strong earthquakes examined. Two sets of ground motion records were applied to simulate pulse-type near- and far-field motions. The inelastic behavior of the concrete elements was then evaluated via a seismic time history analysis. The concept of Demand to Capacity Ratios (DCR) was utilized to produce an initial estimate of the dynamic performance of the structure, emphasizing the importance of capacity distribution of force and bending moment within the RC arch and the springings and piers of the bridge. The results showed that the earthquake loads, broadly categorized as near- and far-field earthquake loads, changed a number of the bridge’s characteristics and hence its structural performance.

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.

Nonlinear Analysis of a RC Frame Structure with Semi-Interlayers Damaged during Wenchuan Earthquake

2010 ◽  
Vol 156-157 ◽  
pp. 467-472
Author(s):  
Peng Tao Yu ◽  
Jing Jiang Sun
Keyword(s):  
Nonlinear Analysis ◽  
Wenchuan Earthquake ◽  
Time History ◽  
Large Earthquake ◽  
Frame Structure ◽  
Nonlinear Time History Analysis ◽  
Frame Structures ◽  
Rc Frame ◽  
Rc Frame Structures ◽  
Nonlinear Time History

Under the excitation of large earthquake, structures enter into high nonlinear stage. Currently, Opensees, Perform-3d and Canny are used as the most popular nonlinear analysis procedures. The fiber model will be introduced firstly and the nonlinear analysis models in Canny are explained in detail. Then Canny2007 is used to conduct nonlinear time history analysis on a heavily damaged frame structure with interlayer in Dujiangyan during Wenchuan Earthquake. Analysis shows that the maximum inter-story drift appears between the interlayer and its upper layer, and the heavy damage agrees well with the results of damage investigation. By comparing the damage extent of frame structures with or without interlayer, it reveals that the seismic performance of RC frame structures without interlayer is obviously better than that of ones with interlayer.

The Review about a New Type of Bridge Structure — Semi–Integral Abutment Jointless Bridge

2011 ◽  
Vol 368-373 ◽  
pp. 72-75
Author(s):  
Tian Li Wang ◽  
Qing Ning Li ◽  
Da Lin Hu
Keyword(s):  
Life Cycle ◽  
Temperature Effect ◽  
Mechanical Performance ◽  
Bridge Structure ◽  
Expansion Joint ◽  
Integral Abutment ◽  
Life Cycle Design ◽  
Weak Part ◽  
New Type ◽  
Jointless Bridge

It was well known that expansion joint of a bridge was a weak part of structure, it led to early structure destroy and reduced the bridge life. Basing on Life-Cycle Design of bridge structure , a new type of optimum bridge structure --- Semi–Integral Abutment Jointless Bridge was put forward. Firstly the new bridge structure was defined and its performance was described. Then several problems that included temperature effect, the interaction of structure-soil etc were discussed about the application of the new bridge structure. Finally the conclusion is the Semi–Integral Abutment Jointless Bridge is a kind of durable bridge structure that has rational mechanical performance and great practical value.

Time History Analysis of Steel Tall Buildings

2014 ◽  
Vol 1025-1026 ◽  
pp. 918-921 ◽  
Author(s):  
Yong Chul Kim ◽  
Sung Won Yoon
Keyword(s):  
Wind Direction ◽  
Time History ◽  
Tall Buildings ◽  
Bending Moment ◽  
Ground Level ◽  
Structural Systems ◽  
Loading Conditions ◽  
Normal Stresses ◽  
History Analysis ◽  
Principal Axes

The results of wind tunnel experiments were used to conduct time history analyses of three conventional square cross-section tall buildings with different structural systems. The primary purpose of the study was the direct comparison of the effects of the wind loads on the steel tall buildings. Time history analyses were conducted by applying local wind forces to the center of each floor. The results showed that, although the bending moments in the ground-level column on the two principal axes were different, the peak normal stresses were almost the same regardless of the structural systems. Similar observations were made regarding the tip displacements. Furthermore, analyses for the various loading conditions revealed that the contribution of the bending moment in the across-wind direction was the largest, followed by that in the along-wind direction. The ratio of the peak normal stresses for different loading conditions were observed to be almost the same regardless of the structural systems.

scholarly journals A simple method for determining seismic demands on gravity load frames

2017 ◽  
Vol 44 (8) ◽  
pp. 661-673 ◽  
Author(s):  
J. Beauchamp ◽  
P. Paultre ◽  
P. Léger
Keyword(s):  
Response Spectrum ◽  
Time History ◽  
Bending Moment ◽  
New Method ◽  
Simple Method ◽  
Seismic Demands ◽  
Gravity Load ◽  
Comparison Results ◽  
Seismic Force ◽  
Nonlinear Time History

This paper presents a simple method based on modal response spectrum analysis to compute internal forces in structural elements belonging to gravity framing not part of the seismic force resisting system (SFRS). It is required that demands on these gravity load resisting system (GLRS) be determined according to the design displacement profile of the SFRS. The proposed new method uses the fact that if the linear stiffness properties of the GLRS not part of the SFRS have negligible values compared to those of the SFRS, only the latter will provide lateral resistance. Displacements of the GLRS then correspond to those of the SFRS alone. The new method is illustrated by computing the seismic responses of a symmetric and an asymmetric multi-storey reinforced concrete building. These results are compared to those obtained from the application of the simplified analysis method proposed in the Canadian standard for the design of concrete structures. Nonlinear time history analyses are also performed to provide a benchmark for comparison. Results show that the new method can predict shear and bending moment in all members at once with ease. Therefore, this new simplified method can effectively be used to predict seismic forces in elements not considered part of the SFRS.

Vibration Analysis of Bridge Structure under Moving Train Load and Earthquake Action

2014 ◽  
Vol 501-504 ◽  
pp. 1266-1269 ◽  
Author(s):  
Bei Bei Fan ◽  
Yuan Zhang ◽  
Dong Hua Ruan
Keyword(s):  
Dynamic Response ◽  
Time History ◽  
Dynamic Effect ◽  
Bridge Structure ◽  
Steel Truss Bridge ◽  
History Analysis ◽  
Steel Truss ◽  
Earthquake Action ◽  
Truss Bridge ◽  
Moving Train

In this paper, vibration of a steel truss bridge under moving train and earthquake action is analyzed. The following conclusions are drawn by modal analysis and time-history analysis. 1) Lateral dynamic response of this structure is more obvious under earthquake action and lateral dynamic effect of train running load; 2) seismic response in the directions different from train load is small, and dynamic response becomes larger obviously when they are considered together.

Sign in / Sign up

Export Citation Format

Share Document