Seismic Isolation Design for Approach Spans of Suiwei Bridge in Wenchuan

2011 ◽  
Vol 71-78 ◽  
pp. 1444-1450
Author(s):  
Wen Zheng Zhu ◽  
Zhong Gen Xu
Keyword(s):  
Energy Dissipation ◽  
Seismic Isolation ◽  
Design Method ◽  
Response Spectrum ◽  
Damping Ratio ◽  
Time History ◽  
Large Earthquake ◽  
Bridge Design ◽  
Dynamic Time ◽  
Rubber Bearings

The process and thought for the approach bridge of Suiwei bridge design using the method of isolation and energy dissipation were proposed in this paper. The concept of protecting a bridge from the damaging effects of an earthquake by introducing isolating bearings to isolate it from the moving ground is an attractive one. Firstly, the sizes of the laminated rubber bearings and the dia- meters of lead plugs are calculated with static analysis. Then the internal forces of the piers and the damping ratio of the isolated bridge needed to restrict the seismic deformation to 8cm during earth- quakes with seldom intensity were calculated using the Response Spectrum Method, and the result verified with dynamic time history method demonstrates that the Response Spectrum Design Method can restrict the girder displacement to 8cm during large earthquake and reach the goal of 25 percent shock reduction. The design process can be of reference to the bridge design with isolation and energy dissipation.

A Practical Design Method for Energy Dissipation Structure

2012 ◽  
Vol 204-208 ◽  
pp. 1150-1153
Author(s):  
Min Chen ◽  
Guo Jing He ◽  
Chang Liu
Keyword(s):  
Energy Dissipation ◽  
Design Method ◽  
Damping Ratio ◽  
Time History ◽  
Structure Design ◽  
Frame Structure ◽  
Seismic Region ◽  
History Analysis ◽  
Dissipation Structure ◽  
Supplemental Damping

Energy dissipation structure is favored by designers because the earthquake energy can be dissipated by the dampers, which can avoid or reduce the damage caused by earthquake. However, the energy dissipation structure design is complex and the most domestic designers can not master it easily. In this paper, a simple and practicable design method for viscous damper dissipation structure by using the PKPM design software is proposed based on a 7-storey frame structure in highly seismic region. Firstly, lower half or one degree for the design intensity to design out an uncontrolled structure. Secondly, determine the supplemental damping ratio required for the fortification intensity via modal analysis method of PKPM software, and identify the numbers of the required dampers as well as their corresponding installation positions in line with the methods in the seismic code of China. Finally, the ETABS program is adopted to conduct the time-history analysis of the designed dissipation structure, showing that the proposed method in this paper can produce a satisfied result.

Analysis of RMS Acceleration Response Spectrum for Random Pedestrian Loads

2011 ◽  
Vol 261-263 ◽  
pp. 292-298 ◽  
Author(s):  
Jie Song ◽  
Zhi Gang Song ◽  
Yi Jie Shen
Keyword(s):  
Response Spectrum ◽  
Damping Ratio ◽  
Uniform Design ◽  
Structural Response ◽  
Time History ◽  
Step Length ◽  
Acceleration Response ◽  
Step Frequency ◽  
Time Histories ◽  
Dynamic Time

Pedestrian loads are affected by such uncertain parameters as walking step frequency, step length, dynamic load factors and phases of harmonic components, which lead to the uncertainties of structural response. A new method for calculation random response spectrum based on uniform design is introduced to reduce calculation work. A few representative samples of loads time histories are simulated using uniform design, and then the RMS acceleration response spectrums are obtained by dynamic time-history analysis of beam structures with different spans and damping ratios. The RMS acceleration response spectrums which have certain percentiles are obtained by reliability analysis based on response surface. Ultimately the general forms of RMS acceleration response spectrums are deduced from the analyses of sensitivities for damping ratio and span.

A Direct Displacement-Based Design Method Based on Chinese Code of Base Isolated Structures

2011 ◽  
Vol 255-260 ◽  
pp. 2555-2559
Author(s):  
Zhen Sun ◽  
Wei Qing Liu ◽  
Shu Guang Wang ◽  
Ding Zhou ◽  
Dong Sheng Du
Keyword(s):  
Seismic Isolation ◽  
Design Method ◽  
Response Spectrum ◽  
Base Shear ◽  
Direct Displacement Based Design ◽  
High Intensity Zone ◽  
Lead Rubber Bearings ◽  
Displacement Based ◽  
Rubber Bearings ◽  
Relationship Of

A simple and efficient direct displacement-based design (DDBD) method is introduced to base isolated (BI) structures. Assuming the vibration mode of superstructure to be the shear type and considering the BI structure to be an equivalent single degree of freedom (ESDOF) system with spring and damper at the seismic isolation layer. The acceleration response spectrum in Chinese code is converted to displacement response spectrum. Corresponding to the design displacement, the equivalent period is obtained. The relationship of the deign displacement, equivalent period, equivalent stiffness and base shear of the system can be derived from the given formulations. Then, the distribution of the base shear along the floors is obtained. This method has been applied to the design of a 12-story BI structure with lead rubber bearings in high intensity zone in Suqian city, Jiangsu province. The results show that the method is feasible for the design of BI structures.

EFFECTIVENESS OF SEISMIC ISOLATION FOR CABLE-STAYED BRIDGES

2006 ◽  
Vol 06 (01) ◽  
pp. 77-96 ◽  
Author(s):  
B. B. SONEJI ◽  
R. S. JANGID
Keyword(s):  
Seismic Response ◽  
Seismic Isolation ◽  
Damping Ratio ◽  
Time History ◽  
Time Interval ◽  
Lumped Mass ◽  
Pendulum System ◽  
Isolation Systems ◽  
Rubber Bearings ◽  
Cable Stayed Bridges

This paper investigates the effectiveness of elastomeric and sliding types of isolation systems for the seismic response control of cable-stayed bridges. A simplified two-dimensional lumped-mass finite-element model of the Quincy Bay-view Bridge at Illinois was developed for the investigation. The seismic isolation of cable-stayed bridges is achieved using three different isolators, namely, high damping rubber bearings (HDRB), lead rubber bearings (LRB) and friction pendulum system (FPS). Time history analysis is performed for the bridge with four different earthquake ground motions applied in the longitudinal direction using Newmark's method with linear variation of acceleration over the time interval. The seismic response of the isolated cable-stayed bridge is compared with that of the bridge with no isolation system. The results show that the isolation systems are effective for reducing the absolute acceleration of the deck and the base shear response of the tower. Further, a parametric study is performed by varying the damping ratio, yield strength and friction coefficient of HDRB, LRB and FPS to investigate the influence of these parameters on the seismic response of the bridge. From such a study, optimal values can be found for the isolators for reducing the bridge responses.

Seismic Performance of a Multi-Span RC Highway Bridge with High Damping Rubber Bearings

2013 ◽  
Vol 540 ◽  
pp. 69-78 ◽  
Author(s):  
Yong Li ◽  
Jin Jie Wang ◽  
Jing Bo Liu
Keyword(s):  
Seismic Performance ◽  
Damping Ratio ◽  
Time History ◽  
Highway Bridge ◽  
Seismic Excitations ◽  
High Damping Rubber Bearings ◽  
History Analysis ◽  
High Damping Rubber ◽  
Dynamic Time ◽  
Rubber Bearings

Based on the nonlinear dynamic time history analysis, a multi-span RC highway bridge with high damping rubber bearings was studied, to investigate the damping ratio and seismic performance of the bridge and high damping rubber bearings compared with the rubber bearings. Results show that the application of high damping rubber bearings can reduce the seismic response of substructures of the bridge under longitudinal and transversal seismic excitations to some extent. But what is more important is that high damping rubber bearings wont suffer shear and displacement failure which may happen on rubber bearings. As a result, the pounding response and residual displacement can be dispelled.

Response Law and Influencing Factors of the Soil under Action of Pile Driving Vibration Based on Midas/GTS

2013 ◽  
Vol 353-356 ◽  
pp. 979-983
Author(s):  
Dong Zhang ◽  
Jing Bo Su ◽  
Hui De Zhao ◽  
Hai Yan Wang
Keyword(s):  
Damping Ratio ◽  
Large Diameter ◽  
Time History ◽  
Pile Driving ◽  
Analysis Model ◽  
Vibration Load ◽  
History Analysis ◽  
Study Results ◽  
Propagation Law ◽  
Dynamic Time

Due to the upgrade and reconstruct of a high-piled wharf, the piling construction may cause the damage of the large diameter underground pipe of a power plant nearby. For this problem, a dynamic time-history analysis model was established using MIDAS/GTS program. Based on the analysis of the pile driving vibration and its propagation law, some parameters, such as the modulus of the soil, the Poissons ratio of soil, the action time of vibration load and the damping ratio of the soil that may have an effect on the response law of the soil, were studied. The study results not only serve as an important inference to the construction of this case, but also accumulate experience and data for other similar engineering practices.

Seismic Vulnerability Analysis of FRP Retrofitting Industrial Buildings

2015 ◽  
Vol 724 ◽  
pp. 353-357
Author(s):  
Jian Zhu ◽  
Ping Tan ◽  
Pei Ju Chang
Keyword(s):  
Seismic Vulnerability ◽  
Response Spectrum ◽  
Time History ◽  
Seismic Intensity ◽  
Fiber Reinforced Polymers ◽  
Infill Wall ◽  
Intensity Index ◽  
Industrial Buildings ◽  
Dynamic Time ◽  
Masonry Infill Wall

This study focus on derivation of such vulnerability curves using Fiber Reinforced Polymers technologies retrofitted conventional RC industrial frames with masonry infill wall. A set of stochastic earthquake waves which compatible with the response spectrum of China seismic code are created. Dynamic time history analysis is used to compute the random sample of structures. Stochastic damage scatter diagrams based different seismic intensity index are obtained. Seismic vulnerability of FRP-reinforced RC industrial frames is lower than unreinforced frames obviously, and seismic capability of frames using FRP technologies is enhanced especially under major earthquake.

Stiffness Design for Specified Nonexceedance Probability of Seismic Response

1998 ◽  
Vol 14 (1) ◽  
pp. 165-188 ◽  
Author(s):  
Yutaka Nakamura ◽  
Tsuneyoshi Nakamura
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Seismic Response ◽  
Amplification Factor ◽  
Design Method ◽  
Response Spectrum ◽  
Time History ◽  
Stiffness Design ◽  
The Mean ◽  
Shear Building

A direct procedure is presented for generating a response spectrum for an arbitrary nonexceedance probability from a prescribed design mean response spectrum. An amplification factor is derived to estimate the maximum response values of an MDOF system for a nonexceedance probability from the mean maximum ones. An efficient stiffness design method for a shear building is developed with the use of its fundamental frequency and translational eigenvector as parameters for adjusting the nonexceedance probability of the seismic drifts to the specified value. The validity and accuracy of the proposed method are demonstrated by a Monte Carlo simulation together with time-history analyses.

Development of an Evaluation Method for Seismic Isolation Systems of Nuclear Power Facilities: Part 3 — Seismic Response of Crossover Piping for Seismic Isolation System

2014 ◽  
Author(s):  
Akihito Otani ◽  
Teruyoshi Otoyo ◽  
Hideo Hirai ◽  
Hirohide Iiizumi ◽  
Hiroshi Shimizu ◽  
...  
Keyword(s):  
Seismic Response ◽  
Nuclear Power ◽  
Seismic Isolation ◽  
Evaluation Method ◽  
Response Spectrum ◽  
Time History ◽  
Response Analysis ◽  
Isolation System ◽  
Isolation Systems ◽  
Seismic Isolation Systems

This paper, which is part of the series entitled “Development of an Evaluation Method for Seismic Isolation Systems of Nuclear Power Facilities”, shows the linear seismic response of crossover piping installed in a seismically isolated plant. The crossover piping, supported by both isolated and non-isolated buildings, deforms with large relative displacement between the two buildings and the seismic response of the crossover piping is caused by two different seismic excitations from the buildings. A flexible and robust structure is needed for the high-pressure crossover piping. In this study, shaking tests on a 1/10 scale piping model and FEM analyses were performed to investigate the seismic response of the crossover piping which was excited and deformed by two different seismic motions under isolated and non-isolated conditions. Specifically, as linear response analysis of the crossover piping, modal time-history analysis and response spectrum analysis with multiple excitations were carried out and the applicability of the analyses was confirmed. Moreover, the seismic response of actual crossover piping was estimated and the feasibility was evaluated.

Seven Mega Floor MSCSS Modal Analysis

2013 ◽  
Vol 353-356 ◽  
pp. 2210-2215
Author(s):  
Jun Jun Wang ◽  
Lu Lu Yi
Keyword(s):  
Modal Analysis ◽  
Response Spectrum ◽  
Time History ◽  
Response Analysis ◽  
Superposition Method ◽  
Response Spectrum Analysis ◽  
Mode Superposition Method ◽  
History Analysis ◽  
Basic Performance ◽  
Dynamic Time

Modal analysis is also known as dynamic analysis for mode-superposition method. In the seismic response analysis of linear structural systems, it is one of the most commonly used and the most effective ways. Through the modal analysis of building structure, we can get some basic performance parameters of the structure. These parameters can help us make qualitative judgments for the respond of a structure first, and can help us judge whether they meet demands for conceptual design. Modal analysis is also the basis of other dynamic response analysis, including dynamic time history analysis and response spectrum analysis.

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