Evaluation of Seismic Vulnerability of Hospitals in the Tehran Metropolitan Area

The Tehran metropolitan area is extremely vulnerable to earthquakes due to the location of its active faults and its dense population. Assessing the probable damage of a high magnitude earthquake on buildings and facilities relies on a precise structural survey, which has an empirical basis depending on historic ground motions. The probability of damage and failure in discrete limits based on different ground motions is estimated by fragility curves. Using the most matching fragility curves for buildings in Tehran, the vulnerability of the hospitals in the capital, as one of the most critical structures in crisis management of disasters, was investigated in this study. Subsequently, the existing fragility curves, developed for Tehran and the other seismic prone countries such as Japan and the United States, were compared considering the typology of Tehran’s hospitals. Finally, the possible damages for each hospital were calculated based on the most conservative fragility curve and the most pessimistic scenario, which were used to evaluate the seismic vulnerability of hospitals and health care systems for different damage states. After zoning the damage of therapeutic areas of Tehran, it was observed that at least 2% to 10% damage occurred in all hospitals of Tehran, and none of the healthcare centers would remain structurally undamaged after a strong earthquake with the moment magnitude of 7 or more. In addition, the healthcare buildings could be prone to significant structural damage, especially in southern parts, which necessitates proactive management plans for Tehran metropolitan area.

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Building Seismic Vulnerability Study for China High Rises

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.353-356.2301 ◽

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.

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Fragility Assessment of a Container Crane under Seismic Excitation Considering Uplift and Derailment Behavior

Applied Sciences ◽

10.3390/app9214660 ◽

2019 ◽

Vol 9 (21) ◽

pp. 4660

Author(s):

Quang Huy Tran ◽

Jungwon Huh ◽

Nhu Son Doan ◽

Van Ha Mac ◽

Jin-Hee Ahn

Keyword(s):

Structural Damage ◽

Seismic Vulnerability ◽

Fragility Curves ◽

Three Dimensional ◽

Time History ◽

Element Model ◽

Seismic Excitation ◽

Damage State ◽

Limit States ◽

Container Crane

While the container crane is an important part of daily port operations, it has received little attention in comparison with other infrastructures such as buildings and bridges. Crane collapses owing to earthquakes affect the operation of the port and indirectly impact the economy. This study proposes fragility analyses for various damage levels of a container crane, thus enabling the port owner and partners to better understand the seismic vulnerability presented by container cranes. A large number of nonlinear time-history analyses were applied for a three-dimensional (3D) finite element model to quantify the vulnerability of a Korean case-study container crane considering the uplift and derailment behavior. The uncertainty of the demand and capacity of the crane structures were also considered through random variables, i.e., the elastic modulus of members, ground motion profile, and intensity. The results analyzed in the case of the Korean container crane indicated the probability of exceeding the first uplift with or without derailment before the crane reached the structure’s limit states. This implies that under low seismic excitation, the crane may be derailed without any structural damage. However, when the crane reaches the minor damage state, this condition is always coupled with a certain probability of uplift with or without derailment. Furthermore, this study proposes fragility curves developed for different structural periods to enable port stakeholders to assess the risk of their container crane.

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Seismic Investigation of Steel Pile Bents: I. Evaluation of Performance

Earthquake Spectra ◽

10.1193/1.1468243 ◽

2002 ◽

Vol 18 (1) ◽

pp. 121-142 ◽

Cited By ~ 3

Author(s):

Ayman A. Shama ◽

John B. Mander ◽

Blaise A. Blabac ◽

Stuart S. Chen

Keyword(s):

Seismic Behavior ◽

Seismic Vulnerability ◽

Fragility Curves ◽

Ground Motions ◽

Highway Bridges ◽

Companion Paper ◽

Experimental Program ◽

Evaluation Of Performance ◽

The Subject ◽

Overall Performance

The main objective of this study is to assess the seismic vulnerability of a class of highway bridges existing in certain regions of the eastern and central states, where steel H-piles extends out of the soil to support the pier cap. During severe ground motions, the overall performance of the bridge will be governed by the local performance of the pile-to-cap beam connection. The scope of work was divided into several tasks as follows: (1) a theory was developed to predict the performance of the connection under lateral loading; (2) an initial experimental program was conducted to investigate the seismic behavior of the steel bents; (3) a retrofit strategy is proposed; (4) a second experimental study was carried out to validate the proposed retrofit method; and (5) fragility curves for such structures were developed. This paper deals with the first two tasks of the study. The other three tasks are the subject of a second companion paper (Shama 2002).

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Fragility Assessment of Container Crane under Seismic Excitation Considering Uplift and Derailment Behavior

10.20944/preprints201909.0151.v1 ◽

2019 ◽

Author(s):

Quang Huy Tran ◽

Jungwon Huh ◽

Nhu Son Doan ◽

Van Ha Mac ◽

Jin-Hee Ahn

Keyword(s):

Structural Damage ◽

Seismic Vulnerability ◽

Fragility Curves ◽

Three Dimensional ◽

Time History ◽

Element Model ◽

Seismic Excitation ◽

Damage State ◽

Limit States ◽

Container Crane

While the container crane is an important part of daily port operations, it has received little attention compared with other infrastructures, such as buildings and bridges. Crane collapse due to earthquake affects the operation of the port, and indirectly impacts the economy. This study proposes fragility analyses for various damage levels of the container crane that allow the port owner and partners to better understand the seismic vulnerability presented by container cranes. A large quantity of nonlinear time history analyses was applied for a three-dimensional (3D) finite element model to quantify the vulnerability of the container crane in considering the uplift and derailment behavior. The uncertainty of demand and capacity of the crane structures were also considered through random variables, i.e. elastic modulus of members, ground motion profile, and intensity. The results analyzed in the case of a Korean container crane showed that the probability of exceeding the first uplift with or without derailment is shown before the crane reaches the structure’s limit states. This means that under low seismic excitation, the crane might be derailed without any structural damage. But when the crane reaches the minor damage state, it is always coupled with a certain probability of uplift with or without derailment. This study also proposes the fragility curves developed for different structural periods to enable port stakeholders to assess the risk of their container crane.

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Structural performance of buildings during the 30 November 2018 M7.1 Anchorage, Alaska earthquake

Earthquake Spectra ◽

10.1177/87552930211043539 ◽

2021 ◽

pp. 875529302110435

Author(s):

Wael M Hassan ◽

Janise Rodgers ◽

Christopher Motter ◽

John Thornley

Keyword(s):

Structural Damage ◽

Seismic Vulnerability ◽

The United States ◽

Structural Performance ◽

Single Family ◽

Steel Buildings ◽

Test Bed ◽

Building Stock ◽

Ground Acceleration ◽

Nonstructural Components

Southcentral Alaska, the most populous region in Alaska, was violently shaken by a Mw 7.1 earthquake on 30 November 2018 at 8:29 am Alaska Standard Time. This was the largest magnitude earthquake in the United States close to a population center in over 50 years. The earthquake was 46 km deep, and the epicenter was 12 km north of Anchorage and 19 km west of Eagle River. The event affected some 400,000 residents, causing widespread damage in highways, nonstructural components, non-engineered and older buildings, and structures on poorly compacted fills. A few isolated serious injuries and partial collapses took place. Minor structural damage to code-conforming buildings was observed. A significant percentage of the structural damage was due to geotechnical failures. Building stock diversity allows use of the region as a large test bed to observe how local building practices affected earthquake damage levels. The prevailing peak ground acceleration (PGA) was 0.2–0.32 g, causing shaking intensity at most sites of 50%–60% of the ASCE 7-16 design basis earthquake acceleration. Thus, the seismic vulnerability of building stock in the region was not truly tested. Reinforced concrete buildings had minor structural damage, except in a few cases of shear wall and transfer girder shear cracking. Fiber-reinforced polymer (FRP)-retrofitted buildings performed satisfactorily. Concrete-masonry-unit (CMU) masonry buildings experienced serious structural damage in many cases, including relatively newer buildings. The earthquake caused widespread structural damage in non-engineered buildings (primarily wood and CMU masonry) that exist widely in the region, especially in Eagle River. Of these, non-engineered single-family wood buildings had the heaviest structural damage. No structural damage could be observed in steel buildings. The aftershock sequence, which included 7 M5+ and 50 M4+ events, exacerbated structural damage in all types of buildings. The present study is based on the EERI field reconnaissance mission conducted by the authors following the earthquake. Based on the observed damage and structural performance, seismic risk mitigation recommendations are suggested.

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SEISMIC HAZARD ASSESSMENT OF SCHOOL BUILDINGS IN PENINSULAR MALAYSIA

Journal of Applied Geology ◽

10.22146/jag.7267 ◽

2015 ◽

Vol 2 (3) ◽

Author(s):

K.T. Tan ◽

H. Abdul Razak

Keyword(s):

Fragility Curves ◽

Response Spectrum ◽

Ground Motions ◽

Active Faults ◽

Plate Boundary ◽

Peninsular Malaysia ◽

Soil Conditions ◽

Soil Parameters ◽

School Buildings ◽

Damage State

Peninsular Malaysia is located on the southern edge of the Eurasian Plate. However, it is close to a seismically active plate boundary, the inter-plate boundary between the Indo-Australian and Eurasian Plates. Occasionally, tremors can be felt throughout the region even when active faults are located several hundred kilometers away. Lessons learnt from past events, active earthquakes located far from the existing building can cause potential damage. Thus, fragility curves become an essential tool to estimate probability of building damage caused by seismic ground motions. In this study, the response of low-rise and mid-rise RC school buildings located in various soil conditions within Peninsular Malaysia under earthquake excitation was investigated by performing dynamic response spectrum analysis. These buildings were analysed using DIANA 9.3 structural analysis program and subjected to a range of low to high seismic ground motions to determine the performance damage state of each type of building. All structural elements were modeled using solid brick finite-element. Correspondingly, the fragility curves were developed using the log-normal distribution for structural response. The effects of various soil conditions on the response of the buildings were also investigated. The results indicated that the effect of soil parameters had a significant effect on the outcome of the fragility curves. However, the risk of these existing school buildings at a location in the northern part of Peninsular Malaysia showed the highest probability of exceeding each damage state. On the contrary, the risk of the existing school buildings at a location in the central part of Peninsular Malaysia was the lowest. Keywords: Interaction, fragility curves, soil-structure

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Fragility Analysis of Gantry Crane Subjected to Near-Field Ground Motions

Applied Sciences ◽

10.3390/app10124219 ◽

2020 ◽

Vol 10 (12) ◽

pp. 4219

Author(s):

Qihui Peng ◽

Wenming Cheng ◽

Hongyu Jia ◽

Peng Guo

Keyword(s):

Failure Probability ◽

Structural Damage ◽

Fragility Curves ◽

Damage Control ◽

Ground Motions ◽

Near Field ◽

Vertical Component ◽

Gantry Crane ◽

Fe Model ◽

Demand Model

A gantry crane located in a near-field earthquake-prone area is selected in this paper as an example, and the nonlinear finite element (FE) model is used considering the material nonlinearity including plastic hinges and the second order (P − Δ ) effect with a comprehensive consideration of the components including sill beams, support beams, legs, and trolley girders. The local displacement ratio (LDR) and deflection ratio (DR) are proposed as demand measures (DMs) of the gantry crane, which are utilized to construct a probabilistic seismic demand model (PSDM). Then, the capacity limit states for the gantry crane are defined in this study by performing pushover analysis (POA), known as serviceability, damage control, and collapse prevention, respectively. Moreover, the operating capacity of the crane during an earthquake is further investigated and quantified by operating seismic peak ground acceleration, which is defined as the maximum acceleration when the failure probability is 50%. Finally, the fragility curves and the failure probability of the gantry crane are derived by the above definitions, all of which are pioneering in the seismic design of gantry cranes subjected to near-field ground motions. Some major conclusions are drawn that the horizontal component of an earthquake has a more notable effect on the structural damage of the gantry crane compared to the vertical component, and incremental dynamic analysis can take seismic uncertainty into account and quantify the deformation of gantry crane in more detail.

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Seismic Fragilities of High-Voltage Substation Disconnect Switches

Earthquake Spectra ◽

10.1193/030118eqs049m ◽

2019 ◽

Vol 35 (4) ◽

pp. 1559-1582

Author(s):

Bai Wen ◽

Mohamed A. Moustafa ◽

Dai Junwu

Keyword(s):

Seismic Vulnerability ◽

Fragility Curves ◽

Ground Motions ◽

Incremental Dynamic Analysis ◽

Nonlinear Finite Element ◽

Power Grids ◽

Finite Element Models ◽

Severe Damage ◽

Substation Equipment ◽

Motion Characteristics

Electrical substations and vital components, e.g., disconnect switches, experienced severe damage that caused blackouts during past earthquakes. To improve the seismic resiliency of power grids and use probabilistic decision-making frameworks, comprehensive fragility data for the different substation equipment are needed. The objective of this study is to investigate the seismic performance of and develop component and system fragility curves for a critical substation component: disconnect switches. The seismic vulnerability of two common switch types was evaluated and two operational configurations were considered. Detailed nonlinear finite element models for the full switches were calibrated using previous experimental data and used to conduct incremental dynamic analysis and carry out the fragility assessment. A total of 160 triaxial ground motions representing four sets of different ground motion characteristics were used. The switches’ fragility curves were developed and presented to be readily used for new substation design, prioritizing retrofit/maintenance activities and reliability assessment of power grids.

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Comparison of ground motions estimated from prediction equations and from observed damage during the <i>M</i> = 4.6 1983 Liège earthquake (Belgium)

Natural Hazards and Earth System Science ◽

10.5194/nhess-13-1983-2013 ◽

2013 ◽

Vol 13 (8) ◽

pp. 1983-1997 ◽

Cited By ~ 1

Author(s):

D. García Moreno ◽

T. Camelbeeck

Keyword(s):

Western Europe ◽

Seismic Vulnerability ◽

Fragility Curves ◽

Ground Motions ◽

Gravitational Acceleration ◽

Prediction Equations ◽

Epicentral Area ◽

Moderate Earthquake ◽

Spectral Accelerations ◽

Observed Damage

Abstract. On 8 November 1983 an earthquake of magnitude 4.6 damaged more than 16 000 buildings in the region of Liège (Belgium). The extraordinary damage produced by this earthquake, considering its moderate magnitude, is extremely well documented, giving the opportunity to compare the consequences of a recent moderate earthquake in a typical old city of Western Europe with scenarios obtained by combining strong ground motions and vulnerability modelling. The present study compares 0.3 s spectral accelerations estimated from ground motion prediction equations typically used in Western Europe with those obtained locally by applying the statistical distribution of damaged masonry buildings to two fragility curves, one derived from the HAZUS programme of FEMA (FEMA, 1999) and another developed for high-vulnerability buildings by Lang and Bachmann (2004), and to a method proposed by Faccioli et al. (1999) relating the seismic vulnerability of buildings to the damage and ground motions. The results of this comparison reveal good agreement between maxima spectral accelerations calculated from these vulnerability and fragility curves and those predicted from attenuation law equations, suggesting peak ground accelerations for the epicentral area of the 1983 earthquake of 0.13–0.20 g (g: gravitational acceleration).

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Seismic Fragility Analysis of the Smithsonian Institute Museum Support Center

Earthquake Spectra ◽

10.1193/123115eqs193m ◽

2017 ◽

Vol 33 (1) ◽

pp. 85-108 ◽

Cited By ~ 1

Author(s):

Xin Chu ◽

James M. Ricles ◽

Shamim N. Pakzad

Keyword(s):

Structural Damage ◽

Fragility Curves ◽

Ground Motions ◽

Three Dimensional ◽

Element Model ◽

Seismic Fragility ◽

Design Basis ◽

Virginia Earthquake ◽

Smithsonian Institute ◽

Hazard Levels

This paper presents the seismic fragility assessment of the Smithsonian Institute Museum Support Center (MSC), which sustained appreciable damage during the 2011 Virginia earthquake. A three-dimensional (3-D) finite element model (FEM) for the building was created and validated using measured dynamic characteristics determined from field vibration test data. Two suites of bidirectional ground motions at different hazard levels were applied to the FEM to generate fragility curves for structural as well as nonstructural (storage cabinets) damage. The effect of brace yielding strength on structural and nonstructural damage is also investigated to provide recommendations for future retrofit. The fragility curves show that the spectral acceleration to cause structural damage to the building is not high. Due to low seismicity, however, the probability for the structure to be damaged at the design basis earthquake is small. Nevertheless, the probability for nonstructural damage is considerable, which is an important issue related to the seismic performance of the building.

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