scholarly journals Research on Seismic Vulnerability of Continuous Beam Bridges Based on Incremental Dynamic Analysis Method

2020 ◽  
Vol 198 ◽  
pp. 02026
Author(s):  
Peizhi Wang
Keyword(s):  
Seismic Performance ◽  
Seismic Design ◽  
Seismic Vulnerability ◽  
Analysis Method ◽  
Limit States ◽  
Limit Values ◽  
Vulnerability Curve ◽  
Displacement Ductility ◽  
Girder Bridges ◽  
Multi Stage

The seismic vulnerability of highway continuous girder bridges is analyzed to provide theoretical basis for the study of multi-stage fortification and seismic design of such bridges. Based on the concept of performance seismic design, five performance levels of structures are determined, and the displacement ductility ratio of piers is taken as the performance quantitative index to calculate the damage limit values of bridges in different limit states. On this basis, IDA analysis method is used to calculate 20 subjects. Based on the reliability theory, logarithmic regression fitting analysis is carried out to obtain the seismic vulnerability curve. The theoretical vulnerability curve is indicated that the bridge has good comprehensive seismic performance. Under 0.3 g ground motion, the probability of minor damage, moderate damage and serious damage are 57.9%, 44.7% and 3.6% respectively. The comprehensive seismic performance of bridges and the probability of exceeding the damage status at all levels are reflected in the results, the guiding significance to analysis of the seismic performance of the entire traffic and the formulation of emergency rescue plans.

Development of a Kind of Multi-Defense Seismic Spherical Bearing

2011 ◽  
Vol 255-260 ◽  
pp. 972-976
Author(s):  
Tian Bo Peng ◽  
Xun Tao Yu ◽  
Zhen Nan Wang
Keyword(s):  
Mechanical Properties ◽  
Seismic Performance ◽  
Seismic Design ◽  
Working Mechanism ◽  
Traffic Conditions ◽  
Girder Bridges ◽  
Spherical Bearing ◽  
Design Requirements

For continuous girder bridges, each bearing has different function requirements under normal traffic conditions and under earthquakes of different intensity levels. To meet the requirements of the three-level seismic design for continuous girder bridges presented in this paper, a new kind of multi-defense seismic spherical bearing is developed and its configuration and working mechanism are introduced in this paper. Then the results of mechanical properties test of the bearing are presented and it’s shown that the design requirements are all satisfied and the seismic performance of the bearing is effective and reliable.

scholarly journals Strengthening Methods of the Existing Reinforced Concrete School Buildings in Medina, Saudi Arabia

2019 ◽  
pp. 1-14
Author(s):  
Mohamed Laissy ◽  
Mohammed Ismaeila
Keyword(s):  
Saudi Arabia ◽  
Reinforced Concrete ◽  
Seismic Performance ◽  
Seismic Vulnerability ◽  
Seismic Analysis ◽  
Shear Walls ◽  
School Buildings ◽  
Analysis Method ◽  
Analysis And Design ◽  
Current Design

Nowadays, evaluation of the seismic performance of existing buildings has received great attention. This paper was carried out to study the effect of strengthening the existing reinforced concrete (RC) school buildings in Medina, Saudi Arabia through assessing the seismic performance and retrofitting where seismic analysis and design were done using equivalent static analysis method according to Saudi Building Code (SBC 301) and SAP2000 software. A Typical five-story RC school building designed according to the SBC301 has been investigated in a comparative study to determine the suitable strengthening methods such as RC shear walls and steel X-bracing methods. The results revealed that the current design of RC school buildings located in Medina was unsafe, inadequate, and unsatisfied to mitigate seismic loads. Moreover, adding steel X-bracing and RC shear walls represent a suitable strategy to reduce their seismic vulnerability.

Study on Dynamic Characteristics of Long Span Continuous Bridge from Construction to Completion Constructed by Cantilever Method Based on Perspective of Earthquake Resistance

2011 ◽  
Vol 368-373 ◽  
pp. 988-992
Author(s):  
Yu Guo Zheng ◽  
Wan Cheng Yuan
Keyword(s):  
Performance Analysis ◽  
Seismic Performance ◽  
Seismic Design ◽  
Dynamic Characteristics ◽  
Earthquake Resistance ◽  
Thin Wall ◽  
Girder Bridges ◽  
Long Span ◽  
Column Type ◽  
Different Types

Based on the perspective of earthquake resistance, the dynamic characteristics from construction to completion is analyzed and compared with each other for three typical long span continuous girder bridges with different types of piers constructed by balanced cantilever method, the vase-type solid pier, the thin-wall type hollow pier and the double-column type solid pier. The variation law of the dynamic characteristics along with the construction stages is obtained and the comparison law of the dynamic characteristics is obtained among the three bridges. It shows in a great degree that the seismic performance analysis and the seismic design nowadays, which are only based on the 1st period and mode in the completion state of the bridge, are not reasonable very much. The seismic performance analysis and the seismic design should consider all construction stages for the bridge constructed by the balanced cantilever method.

Discussion on the Seismic Design Analysis Method of Masonry Building

2010 ◽  
Vol 163-167 ◽  
pp. 3952-3957
Author(s):  
Xiao Song Ren ◽  
Yu Fei Tao
Keyword(s):  
Shear Strength ◽  
Seismic Performance ◽  
Seismic Design ◽  
Design Analysis ◽  
Masonry Building ◽  
Analysis Method ◽  
Seismic Capacity ◽  
Major Earthquake ◽  
Moderate Earthquake ◽  
Seismic Design Code

The main seismic objective in China is defined as “no failure under minor earthquake, repairable damage under moderate earthquake and no collapse under major earthquake”. Both strength and deformation are important to evaluate the seismic performance. For masonry building, only the shear strength check under minor earthquake is stipulated in the current Chinese seismic design code. Due to the poor ductility of masonry building, the seismic design analysis method may not guarantee the collapse-resistant capacity under major earthquake. For the achievement of the seismic objective, the demand of ductility is discussed. A typical severely damaged masonry building by the 5.12 Wenchuan Earthquake of 2008 is presented for the analysis of the through X-shape crack on the load-bearing wall. In order to enhance the collapse-resistant capacity, the authors suggest more shear strength margin to take the influence of structural ductility into consideration. The feasible way can be easily realized as a target to raise the limitation for the shear strength check parameter under minor earthquake and to keep uniform seismic capacity in two directions. The investigated building is also illustrated here as an example to process the shear strength check for better seismic performance by the authors’ suggestion.

SEISMIC CAPACITY OF MEDIUM SIZE CONTINUOUS BRIDGES WITH LEAD-RUBBER BEARINGS

2019 ◽  
Vol 3 (Special Issue on First SACEE'19) ◽  
pp. 199-206
Author(s):  
Bertha Olmos ◽  
José Jara ◽  
José Luis Fabián
Keyword(s):  
Seismic Performance ◽  
Seismic Vulnerability ◽  
Base Isolation ◽  
Elastic Behaviour ◽  
Medium Size ◽  
Nonlinear Behaviour ◽  
Seismic Capacity ◽  
Damage Scenarios ◽  
Isolation Systems ◽  
Rubber Bearings

This paper investigates the effects of the nonlinear behaviour of isolation pads on the seismic capacity of bridges to identify the parameters of base isolation systems that can be used to improve seismic performance of bridges. A parametric study was conducted by designing a set of bridges for three different soil types and varying the number of spans, span lengths, and pier heights. The seismic responses (acceleration, displacement and pier seismic forces) were evaluated for two structural models. The first model corresponded to the bridges supported on elastomeric bearings with linear elastic behaviour and the second model simulated a base isolated bridge that accounts for the nonlinear behaviour of the system. The seismic demand was represented with a group of twelve real accelerograms recorded on the subduction zone on the Pacific Coast of Mexico. The nonlinear responses under different damage scenarios for the bridges included in the presented study were estimated. These results allow determining the seismic capacity of the bridges with and without base isolation. Results show clearly the importance of considering the nonlinear behaviour on the seismic performance of bridges and the influence of base isolation on the seismic vulnerability of medium size bridges.

scholarly journals Experimental Study on the Behavior of Existing Reinforced Concrete Multi-Column Piers under Earthquake Loading

2021 ◽  
Vol 11 (6) ◽  
pp. 2652
Author(s):  
Jung Han Kim ◽  
Ick-Hyun Kim ◽  
Jin Ho Lee
Keyword(s):  
Seismic Performance ◽  
Seismic Design ◽  
Bridge Piers ◽  
Scale Model ◽  
Inertia Force ◽  
Small Scale ◽  
Lap Splice ◽  
Existing Structures ◽  
Seismic Design Code ◽  
Seismic Force

When a seismic force acts on bridges, the pier can be damaged by the horizontal inertia force of the superstructure. To prevent this failure, criteria for seismic reinforcement details have been developed in many design codes. However, in moderate seismicity regions, many existing bridges were constructed without considering seismic detail because the detailed seismic design code was only applied recently. These existing structures should be retrofitted by evaluating their seismic performance. Even if the seismic design criteria are not applied, it cannot be concluded that the structure does not have adequate seismic performance. In particular, the performance of a lap-spliced reinforcement bar at a construction joint applied by past practices cannot be easily evaluated analytically. Therefore, experimental tests on the bridge piers considering a non-seismic detail of existing structures need to be performed to evaluate the seismic performance. For this reason, six small scale specimens according to existing bridge piers were constructed and seismic performances were evaluated experimentally. The three types of reinforcement detail were adjusted, including a lap-splice for construction joints. Quasi-static loading tests were performed for three types of scale model with two-column piers in both the longitudinal and transverse directions. From the test results, the effect on the failure mechanism of the lap-splice and transverse reinforcement ratio were investigated. The difference in failure characteristics according to the loading direction was investigated by the location of plastic hinges. Finally, the seismic capacity related to the displacement ductility factor and the absorbed energy by hysteresis behavior for each test were obtained and discussed.

scholarly journals Experimental Investigation into the Seismic Performance of Prefabricated Reinforced Masonry Shear Walls with Vertical Joint Connections

2021 ◽  
Vol 11 (10) ◽  
pp. 4421
Author(s):  
Zhiming Zhang ◽  
Fenglai Wang
Keyword(s):  
Seismic Performance ◽  
Cross Sections ◽  
Shear Walls ◽  
Construction Method ◽  
Shear Capacity ◽  
Initial Stiffness ◽  
Equivalent Viscous Damping ◽  
Displacement Ductility ◽  
Reinforced Masonry ◽  
Cracking Performance

In this study, four single-story reinforced masonry shear walls (RMSWs) (two prefabricated and two cast-in-place) under reversed cyclic loading were tested to evaluate their seismic performance. The aim of the study was to evaluate the shear behavior of RMSWs with flanges at the wall ends as well as the effect of construction method. The test results showed that all specimens had a similar failure mode with diagonal cracking. However, the crack distribution was strongly influenced by the construction method. The lateral capacity of the prefabricated walls was 12% and 27% higher than that of the corresponding cast-in-place walls with respect to the rectangular and T-shaped cross sections. The prefabricated walls showed better post-cracking performance than did the cast-in-place wall. The secant stiffness of all the walls decreased rapidly to approximately 63% of the initial stiffness when the first major diagonal crack was observed. The idealized equivalent elastic-plastic system showed that the prefabricated walls had a greater displacement ductility of 3.2–4.8 than that of the cast-in-place walls with a displacement ductility value of 2.3–2.7. This proved that the vertical joints in prefabricated RMSWs enhanced the seismic performance of walls in shear capacity and ductility. In addition, the equivalent viscous damping of the specimens ranged from 0.13 to 0.26 for prefabricated and cast-in-place walls, respectively.

System-wide seismic vulnerability of aging multiple-span multiple-girder bridges in low-to-moderate seismic hazard regions

2021 ◽  
Vol 37 (1_suppl) ◽  
pp. 1626-1651
Author(s):  
John E Lens M.EERI ◽  
Mandar M Dewoolkar ◽  
Eric M Hernandez M.EERI
Keyword(s):  
United States ◽  
Seismic Hazard ◽  
Cross Sections ◽  
Seismic Vulnerability ◽  
Time History ◽  
The United States ◽  
National Database ◽  
Eastern United States ◽  
Girder Bridges ◽  
The Status

This article describes the approach, methods, and findings of a quantitative analysis of the seismic vulnerability in low-to-moderate seismic hazard regions of the Central and Eastern United States for system-wide assessment of typical multiple span bridges built in the 1950s through the 1960s. There is no national database on the status of seismic vulnerability of bridges, and thus no means to estimate the system-wide damage and retrofit costs for bridges. The study involved 380 nonlinear analyses using actual time-history records matched to four representative low-to-medium hazard target spectra corresponding with peak ground accelerations from approximately 0.06 to 0.3 g. Ground motions were obtained from soft and stiff site seismic classification locations and applied to models of four typical multiple-girder with concrete bent bridges. Multiple-girder bridges are the largest single category, comprising 55% of all multiple span bridges in the United States. Aging and deterioration effects were accounted for using reduced cross-sections representing fully spalled conditions and compared with pristine condition results. The research results indicate that there is an overall low likelihood of significant seismic damage to these typical bridges in such regions, with the caveat that certain bridge features such as more extensive deterioration, large skews, and varied bent heights require bridge-specific analysis. The analysis also excludes potential damage resulting from liquefaction, flow-spreading, or abutment slumping due to weak foundation or abutment soils.

Development of a preliminary seismic risk screening tool for existing buildings in Canada

2018 ◽  
Vol 45 (9) ◽  
pp. 717-727 ◽  
Author(s):  
Reza Fathi-Fazl ◽  
Eric Jacques ◽  
Zhen Cai ◽  
Bessam Kadhom ◽  
Bassem Saassouh ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Seismic Performance ◽  
Seismic Design ◽  
Seismic Risk ◽  
Screening Tool ◽  
Existing Buildings ◽  
Seismic Risk Assessment ◽  
Risk Screening ◽  
Categorization System ◽  
Remaining Time

This paper presents a preliminary seismic risk screening tool to identify buildings whose superior structural and non-structural seismic performance in regions of low seismicity can be assessed based on several key attributes. The tool is designed to exempt buildings from detailed seismic risk assessment if key exemption criteria are met. The exemption criteria are based on: a seismic categorization system linked to anticipated building damage and seismicity; whether or not the building was designed using modern seismic design provisions; and the remaining time that the building will be occupied. The tool also provides a second list of criteria, which if satisfied, will automatically trigger further detailed seismic risk assessment. The decisions rendered by the tool regarding the expected seismic performance of a building are evaluated against the next level of seismic risk screening tool to ensure the consistency. A flowchart is presented to facilitate adoption of the tool by practicing engineers and other end-users.

Analysis on Seismic Performance of Beam and Plate Converter Floor

2014 ◽  
Vol 580-583 ◽  
pp. 1551-1554
Author(s):  
Gen Tian Zhao ◽  
Xu Ting Kou
Keyword(s):  
Seismic Performance ◽  
Seismic Design ◽  
Structure Calculation ◽  
High Rise ◽  
High Rise Building ◽  
Design Requirements

With the project case, the seismic performance of girder transfer floor member and the plate transfer floor member were discussed. Contrast calculation was carried out in girder transfer floor member and the plate transfer floor member with SATWE method to analyze its reasonable and unreasonable places. Based on overall structure calculation of a high rise building, the seismic design requirements for buildings applying thick transferring plate have been presented. The conclusion is that the seismic performance of girder transfer floor member is more advantageous and affordable, more convenient and more economical in ingredients.

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