scholarly journals Seismic Fragility of Tall Concrete Wall Structures in Malaysia under Far-Field Earthquakes

2019 ◽  
Vol 13 (1) ◽  
pp. 140-146
Author(s):  
Siti Aisyah ◽  
Mohammadreza Vafaei ◽  
Sophia C. Alih ◽  
Kotaiba Aljwim
Keyword(s):  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Tall Buildings ◽  
Seismic Fragility ◽  
Far Field ◽  
Concrete Wall ◽  
Concrete Walls ◽  
Existing Structures ◽  
Wall Structures ◽  
Story Drift

Introduction: In recent years, the seismic vulnerability of structures in Malaysia has attracted the attention of researchers mainly because the majority of existing structures have not been designed for seismic actions. In this study, seismic vulnerability of tall concrete wall buildings has been investigated through the development of seismic fragility curves. Methods: Two 25-story tall buildings with similar plans but with the different number of parking levels were analyzed through the incremental dynamic analysis. The tall buildings were excited by 15 far-field earthquakes, and their inter-story drift demands and capacities were estimated. Nonlinear response of beams and columns was simulated through the lumped plasticity model. The inelastic response of concrete walls was taken into account through the use of distributed plasticity fibre-based elements. Results and Conclusion: The obtained results indicated that the probability of exceeding minor damage to the tall concrete wall buildings located in the Kuala Lumpur city was around 55%. However, the probability of collapse of these structures in the same city was less than 15%.

Building Seismic Vulnerability Study for China High Rises

2013 ◽  
Vol 353-356 ◽  
pp. 2301-2304
Author(s):  
Fan Wu ◽  
Ming Wang ◽  
Xin Yuan Yang
Keyword(s):  
Ground Motion ◽  
Structural Damage ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Response Spectrum ◽  
Earthquake Ground Motion ◽  
Published Data ◽  
Rapid Urbanization ◽  
High Rise ◽  
Story Drift

High-rise buildings, as a result of rapid urbanization in China, become one of popular structure kind. However, there have been few seismic vulnerability studies on high-rise buildings, and few fragility curves have been developed for the buildings. Based on the published data of more than 50 high rises and super high rises, the structural information such as building heights, mode periods, locations and sites, the maximum design story drift ratios, are collected and analyzed. The vulnerability analysis for high rises uses response spectrum displacement as seismic ground motion input, since the structures have comparatively long natural period. Using statistics and regression analysis, the relationship between the maximum story drift ratio and response spectrum displacement is established. Based on height groups and earthquake design codes, the fragility curves of different performance levels can be developed. These curves can provide good loss estimation of high rise structural damage under earthquake ground motion.

scholarly journals Seismic Fragility Analysis of Mid-Story Isolation Buildings

2021 ◽  
Keyword(s):  
Fragility Curves ◽  
Ground Motions ◽  
Near Field ◽  
Fragility Analysis ◽  
Seismic Fragility ◽  
Plastic State ◽  
Far Field ◽  
Analysis Method ◽  
Isolation System ◽  
Isolation Layer

Abstract. Seismic fragility analysis is essential for seismic risk assessment of structures. This study focuses on the damage probability assessment of the mid-story isolation buildings with different locations of the isolation system. To this end, the performance-based fragility analysis method of the mid-story isolation system is proposed, adopting the maximum story drifts of structures above and below the isolation layer and displacement of the isolation layer as performance indicators. Then, the entire process of the mid-story isolation system, from the initial elastic state to the elastic-plastic state, then to the limit state, is simulated on the basis of the incremental dynamic analysis method. Seismic fragility curves are obtained for mid-story isolation buildings with different locations of the isolation layer, each with fragility curves for near-field and far-field ground motions, respectively. The results indicate that the seismic fragility probability subjected to the near-field ground motions is much greater than those subjected to the far-field ground motions. In addition, with the increase of the location of the isolation layer, the dominant components for the failure of mid-story isolated structures change from superstructure and isolation system to substructure and isolation system.

Seismic Fragility Analysis of Hill Buildings with Uneven Ground Column Heights

2014 ◽  
Vol 638-640 ◽  
pp. 1848-1853
Author(s):  
Lin Qing Huang ◽  
Li Ping Wang ◽  
Chao Lie Ning
Keyword(s):  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Slope Angle ◽  
Seismic Fragility ◽  
Exceedance Probability ◽  
Considerable Influence ◽  
Analysis Method ◽  
Ground Acceleration ◽  
Mountainous Regions ◽  
The Hill

The hill buildings sited on slopes have been widely constructed in mountainous regions. In order to estimate the seismic vulnerability of the hill buildings with uneven ground column heights under the effect of potential earthquakes, the exceedance probabilities of the hill buildings sited on different angle slopes in peak ground acceleration (PGA) are calculated and compared by using the incremental dynamic analysis method. The fragility curves show the slope angle has considerable influence on the seismic performance. Specifically, the exceedance probability increases with the increasing of the slope angle at the same performance level.

scholarly journals SEISMIC FRAGILITY ASSESSMENT AND RETROFIT OF A GOVERNMENT HOSPITAL BUILDING IN CHITTAGONG, BANGLADESH

2018 ◽  
Vol 30 (1) ◽  
Author(s):  
Md. AbulHasan ◽  
Md. Abdur Rahman Bhuiyan
Keyword(s):  
Ground Motion ◽  
Return Period ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Response Spectrum ◽  
Seismic Fragility ◽  
Earthquake Ground Motion ◽  
Type I ◽  
Type Ii ◽  
Ground Motion Records

Chittagong Medical College Hospital (CMCH) is one of the most important government hospitals in Bangladesh. It is located in the heart of Chittagong city, the only port city of Bangladesh. Bangladesh National Building Code (BNBC) is the only official document, which has been used since 1993 as guidelines for seismic design of buildings. As per the guidelines of BNBC, the CMCH building was designed for an earthquake ground motion having a return period of 200 years. However, the revised version of BNBC has suggested that the building structures shall be designed for an earthquake ground motion having a return period of 2475 years. It is mentioned that a single seismic performance objective, the life safety, of the building is considered in both versions of BNBC. Considering the significant importance of CMCH building in providing the emergency facilities during and after the earthquake, it is indispensable to evaluate its seismic vulnerability for the two types of earthquake ground motion records having return period of 200 (Type-I) and 2475 (Type-II) years. In this regard, this paper deals with the seismic vulnerability assessment of the existing ancillary building (AB) of CMCH. The seismic vulnerability of building is usually expressed in the form of fragility curves, which display the conditional probability that the structural demand (structural response) caused by various levels of ground shaking exceeds the structural capacity defined by a damage state. The analytical method based on elastic response spectrum analyses results is used in evaluating the seismic fragility curves of the building. To the end, 3-D finite element model of the building subjected to 18 ground motion records having PGA of 0.325g to 0.785g has been used in theresponse spectrum analysis in order to evaluate its inter-story-drift ratio (IDR), an engineeringdemand parameter (EDP) for developing fragility curves. The analytical results have shown thatstructural deficiencies exist in the existing ancillary building (AB) for the Type-II earthquakeground motion record, which requires the building to be retrofitted to ensure that the existingancillary building (AB) becomes functional during and after the Type-II earthquake groundmotion record.

scholarly journals Seismic fragility curves based on the probability density evolution method

2017 ◽  
Vol 39 (2) ◽  
pp. 177-189
Author(s):  
Thuat-Cong Dang ◽  
Thien-Phu Le ◽  
Pascal Ray
Keyword(s):  
Probability Density ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Fragility Curve ◽  
Seismic Fragility ◽  
Cumulative Probability ◽  
Density Evolution ◽  
Probability Density Evolution Method ◽  
Log Normal ◽  
Probability Density Evolution

A seismic fragility curve that shows the probability of failure of a structure in function of a seismic intensity, for example peak ground acceleration (PGA), is a powerful tool for the evaluation of the seismic vulnerability of the structures in nuclear engineering and civil engineering. The common assumption of existing approaches is that the fragility curve is a cumulative probability log-normal function. In this paper, we propose a new technique for construction of seismic fragility curves by numerical simulation using the Probability Density Evolution Method (PDEM). From the joint probability density function between structural response and random variables of a system and/or excitations, seismic fragility curves can be derived without the log-normal assumption. The validation of the proposed technique is performed on two numerical examples.

Seismic fragility assessment of multi-span concrete highway bridges in British Columbia considering soil–structure interaction

2021 ◽  
Vol 48 (1) ◽  
pp. 39-51 ◽  
Author(s):  
A.H.M. Muntasir Billah ◽  
M. Shahria Alam
Keyword(s):  
British Columbia ◽  
Soil Structure ◽  
Seismic Vulnerability ◽  
Structural Characteristics ◽  
Fragility Curves ◽  
Highway Bridges ◽  
System Level ◽  
Soil Structure Interaction ◽  
Seismic Fragility ◽  
Structure Interaction

Fragility curve is an effective tool for identifying the potential seismic risk and consequences during and after an earthquake. Recent seismic events have shown that bridges are highly sensitive and vulnerable during earthquakes. There has been limited research to evaluate the seismic vulnerability of the existing bridges in British Columbia (BC), which could help in the decision-making process for seismic upgrade. This study focuses on developing seismic fragility curves for typical multi-span continuous concrete girder bridges in BC. Ground motions compatible with the seismic hazard were used as input excitations for vulnerability assessment. Uncertainties in material and geometric properties were considered to represent the bridges with similar structural characteristics and construction period. The fragility of the bridge is largely attributable to the fragilities of the columns, and to a lesser extent, the abutment and bearing components. The results of this study show that, although not very significant, the soil–structure interaction has some effect on the component fragility where this effect is not very significant at the bridge system level.

scholarly journals Vulnerability Analysis of Ancient Timber Architecture by Considering the Correlation of Different Failure Modes

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Junhong Huan ◽  
Donghui Ma ◽  
Wei Wang
Keyword(s):  
Ming Dynasty ◽  
Seismic Vulnerability ◽  
Failure Modes ◽  
Fragility Curves ◽  
Lower Boundary ◽  
Seismic Fragility ◽  
Occurrence Probability ◽  
Joint Distribution Function ◽  
First Order ◽  
Innovative Method

The paper proposes an innovative method of analyzing the seismic fragility of ancient timber architecture. The method is based on the Copulas, in which correlation between different failure modes is considered. This method is applied to assess the vulnerability of ancient timber architecture in Ming dynasty. The assessment includes four steps. In the first step, the incremental dynamic analysis is employed to establish seismic vulnerability curves of different failure modes for the structure. After that, Copula joint distribution function is used to analyze the correlation among different failure modes. In the third step, fragility curves considering correlation among different failure modes are established. In the last step, the fragility curves are compared with those obtained by first-order bound method. The results show that seismic vulnerability of ancient timber architecture based on the Copulas is greater than that of any single failure modes. Moreover, the occurrence probability ranges between the upper and lower boundaries of the first-order bound method, but is close to the lower boundary.

Improved time-dependent seismic fragility estimates for deteriorating RC bridge substructures exposed to chloride attack

2020 ◽  
pp. 136943322095681
Author(s):  
Fengkun Cui ◽  
Huihui Li ◽  
Xu Dong ◽  
Baoqun Wang ◽  
Jin Li ◽  
...  
Keyword(s):  
Service Life ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Back Propagation ◽  
Steel Corrosion ◽  
Time Dependent ◽  
Seismic Fragility ◽  
Exceedance Probability ◽  
Seismic Capacity ◽  
Bridge Substructures

RC bridge substructures exposed to chloride environments inevitably suffer from corrosion of reinforcement embodied in concrete. This deterioration issue leads to the loss of reinforcement areas and a reduction in seismic capacity of reinforced concrete (RC) bridge substructures. To quantify the effect of steel corrosion on seismic fragility estimates, this paper proposes an improved time-dependent seismic fragility framework by taking into account the increase in the corrosion rate after concrete cracking and the reduction in seismic capacity of RC bridge substructures during the service life. Additionally, an analytical method based on a back propagation artificial neural network (BP-ANN) is proposed to provide probabilistic capacity estimates of deteriorating RC substructures. A three-span T-shaped girder bridge is selected as a case study bridge to provide improved time-dependent seismic fragility estimates that consider uncertainties in the material properties, geometric parameters, deterioration process and ground motions. The obtained fragility curves show that there is a nonlinear increase in the exceedance probability of deteriorating RC bridge substructures for different damage states during the service life. In addition, time-dependent seismic fragility analysis shows that the cases of considering only the effect of an increase in seismic demand or the reduction in seismic capacity as well as neither of them may lead to a significant underestimation of the seismic vulnerability of deteriorating RC bridge substructures.

scholarly journals Seismic Fragility Evaluation of Simply Supported Aqueduct Accounting for Water Stop’s Leakage Risk

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1404
Author(s):  
Zhihua Xiong ◽  
Chen Liu ◽  
Aijun Zhang ◽  
Houda Zhu ◽  
Jiawen Li
Keyword(s):  
Seismic Vulnerability ◽  
Mechanical Performance ◽  
Numerical Study ◽  
Numerical Models ◽  
Fragility Curves ◽  
Concrete Strength ◽  
Latin Hypercube Sampling ◽  
Seismic Fragility ◽  
Lumped Mass ◽  
Water Transportation

Due to the demands of booming Chinese cities and the increase in urban residents, the safety of aqueduct water transportation structures is noteworthy. A lot of old aqueducts were built in the 1990s and even earlier in the last century and may become vulnerable to potential earthquakes. This paper deals with an evaluation of an aqueduct’s seismic vulnerability accounting for leakage risk. Based on the Hua Shigou aqueduct in Ningxia, a probabilistic investigation was carried out to obtain the seismic fragility using Latin hypercube sampling. In the numerical study, the superstructure and substructure of the aqueduct were modeled as beam elements, and the lumped mass method was adopted to simulate the fluid–structure interaction. The rubber water stop’s mechanical performance was studied, and its damage states were proposed. Parametric numerical models were then subjected to a set of ground motions according to incremental dynamic analysis (IDA), which contained probabilistic parameters such as water, concrete strength, and bearing performance degradation. Both the system and component levels of the old aqueduct’s seismic fragility curves were obtained. It was found that the probability of the water stop’s leakage risk is significantly elevated with the increase in ground motion.

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