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1.
A number of high-profile seismic events have occurred in recent years, with a wide variation in the resulting economic damage and loss of life. This variation has been attributed in part to the stringency of seismic building codes implemented in different regions. Using the HAZUS Earthquake Model, a benefit?Ccost analysis was performed on varying levels of standard buildings codes for Haiti and Puerto Rico. The methodology computes expected loss assuming a Poisson event process with lognormally distributed event magnitude and idealized damage?Cmagnitude response functions. The event frequency and magnitude distributions are estimated from the historical record, while the damage functions are fit using HAZUS simulation results for events with systematically varying magnitudes and different seismic code levels. To validate the approach, a single-event analysis was conducted using alternative building codes and mean magnitude earthquakes. A probabilistic analysis was then used to evaluate the long-term expected value for alternative levels of building codes. To account for the relationship between lives saved and economic loss, the implicit cost of saving a life is computed for each code option. It was found that in the two areas studied, the expected loss of life was reduced the most by use of high seismic building code levels, but lower levels of seismic building code were more cost-effective when considering only building damages and the costs for code implementation. The methodology presented is meant to provide a basic framework for the future development of an economic-behavioral model for code adoption. 相似文献
2.
Earthquake disaster risk assessment and evaluation for Turkey 总被引：3，自引：0，他引：3
Kasım Armağan Korkmaz 《Environmental Geology》2009,57(2):307-320
Turkey is the one country in which 90% of the buildings are subject to the risk of earthquake disaster. Recent earthquakes
revealed that Turkey’s present residential reinforced-concrete constructions are insufficient in earthquake resistance. Many
of the buildings which collapsed or were severely damaged have been rehabilitated by applying simple methods, whose adequacy
is questionable. As in Japan and the United States, Turkey’s earthquake assessment studies have increased, especially after
earthquakes in 1999, In US, several methodologies and standards, such as Hazard-US (HAZUS) and Applied Technology Council
(ATC) 13-20-21 and 156, provide comprehensive earthquake loss estimation methodology for post-earthquake assessment. This
paper provides post-earthquake assessment and disaster management for Turkey. The main aim of the post-earthquake assessment
discussed is to evaluate loss and estimate damage through disaster management approach. Classification criteria for damage
are essential to determine the situation after an earthquake in both the short and long terms. The methodology includes probabilistic-based
analysis, which considers the magnitude of Ms ≥ 5.0 earthquakes between 1900 and 2005, for determining the probabilistic seismic
hazard for Turkey. 相似文献
3.
4.
Reconnaissance observations are presented on the building damage caused by the May 19, 2011, Kütahya–Simav earthquake in Western Turkey as well as an overview of strong ground motion data recorded during the earthquake is given. According to Disaster and Emergency Management Presidency of Turkey, the magnitude of the earthquake is 5.7 in local magnitude scale. Although the earthquake can be regarded as a moderate event when considering its magnitude and strong motion recordings, it caused excessive structural damage to buildings in Simav district and several villages in the near vicinity. During the field investigation, different types of structural damage were observed mainly in the reinforced concrete frame buildings with infill walls and masonry buildings with various types of construction materials. Observed damage resulted from several deficiencies in structural and non-structural components of the buildings. Poor construction materials and workmanship, non-conforming earthquake-resistant design and construction techniques and non-ductile detailing are the main reasons for such an extensive damage, as observed in many past earthquakes in Turkey. 相似文献
5.
Rocco Custer Kazuyoshi Nishijima 《Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards》2018,12(1):1-13
In natural hazard risk assessment situations are encountered where information on the portfolio of exposure is only available in a spatially aggregated form, hindering a precise risk assessment. Recourse might be found in the spatial disaggregation of the portfolio of exposure to the resolution of the hazard model. Given the uncertainty inherent to any disaggregation, it is argued that the disaggregation should be performed probabilistically. In this paper, a methodology for probabilistic disaggregation of spatially aggregated values is presented. The methodology is exemplified with the disaggregation of a portfolio of buildings in two communes in Switzerland and the results are compared to sample observations. The relevance of probabilistic disaggregation uncertainty in natural hazard risk assessment is illustrated with the example of a simple flood risk assessment. 相似文献
6.
《International Geology Review》2012,54(5):424-440
In the past, efforts to prevent catastrophic losses from natural hazards have largely been undertaken by individual property owners based on site—specific evaluations of risks to particular buildings. Public efforts to assess community vulnerability and encourage mitigation have focused on either aggregating site—specific estimates or adopting standards based upon broad assumptions about regional risks. This paper develops an alternative, intermediate—scale approach to regional risk assessment and the evaluation of community mitigation policies. Properties are grouped into types with similar land uses and levels of hazard, and hypothetical community mitigation strategies for protecting these properties are modeled like investment portfolios. The portfolios consist of investments in mitigation against the risk to a community posed by a specific natural hazard. and are defined by a community's mitigation budget and the proportion of the budget invested in locations of each type. The usefulness of this approach is demonstrated through an integrated assessment of earthquake—induced lateral—spread ground failure risk in the Watsonville, California area. Data from the magnitude 6.9 Loma Prieta earthquake of 1989 are used to model lateral—spread ground failure susceptibility. Earth science and economic data are combined and analyzed in a Geographic Information System (CIS). The portfolio model is then used to evaluate the benefits of mitigating the risk in different locations. Two mitigation policies, one that prioritizes mitigation by land use type and the other by hazard zone, are compared with a status quo policy of doing no further mitigation beyond that which already exists. The portfolio representing the hazard zone rule yields a higher expected return than the land use portfolio does; however, the hazard zone portfolio experiences a higher standard deviation. Therefore, neither portfolio is clearly preferred. The two mitigation policies both reduce expected losses and increase overall expected community wealth compared to the status quo policy. 相似文献
7.
Within the framework of the performance based earthquake engineering, site specific earthquake spectra for Van province has been obtained. It is noteworthy that, in probabilistic seismic hazard assessment, as a first stage data from geological studies and records from the instrumental period were compiled to make a seismic source characterization for the study region. The probabilistic seismic hazard curves were developed based on selected appropriate attenuation relationships, at rock sites, with a probability of exceedance 2, 10 and 50% in 50 yrs period. The obtained results are compared with the spectral responses proposed for seismic evaluation and retrofit of building structure in Turkish Earthquake Code (2007), section 7. The acceleration response spectrums obtained from probabilistic seismic hazard analysis are matched to adjust earthquake accelerograms recorded during the 2011 Van earthquakes by using SeismoMatch v2.0 software. The aim of this procedure is to obtain a set of reasonable earthquake input motions for the seismic evaluation of existing buildings. 相似文献
8.
In this paper, we build an event-based seismic hazard assessment and financial analysis model for Hi-Tech Fabs in Taiwan. As we know, the low occurrence rate, tremendous loss and high uncertainty are characteristics of earthquake disasters. To handle the above issues, the model integrates knowledge from many fields including earth science, seismology, geology, risk management, structural engineering, the insurance profession, financial engineering and facility management. The portfolio of data from the site survey indicates that the model can be used to calculate the event losses (including buildings, contents and business interruption losses); furthermore the average annual loss and loss exceeding probabilities also can be calculated. The total earthquake risk cost, which includes earthquake insurance premiums, average annual retained loss and equivalent annual retrofit cost, is defined as an indicator for selection of optimal risk management strategies. 相似文献
9.
Iran is one of the most seismically active countries of the world located on the Alpine-Himalayan earthquake belt. More than
180,000 people were killed due to earthquakes in Iran during the last five decades. Considering the fact that most Iranians
live in masonry and non-engineered houses, having a comprehensive program for decreasing the vulnerability of society holds
considerable importance. For this reason, loss estimation should be done before an earthquake strikes to prepare proper information
for designing and selection of emergency plans and the retrofitting strategies prior to occurrence of earthquake. The loss
estimation process consists of two principal steps of hazard analysis and vulnerability assessment. After identifying the
earthquake hazard, the first step is to evaluate the vulnerability of residential buildings and lifelines and also the social
and economic impacts of the earthquake scenarios. Among these, residential buildings have specific importance, because their
destruction will disturb the daily life and result in casualties. Consequently, the vulnerability assessment of the buildings
in Iran is important to identify the weak points in the built environment structure. The aim of this research is to prepare
vulnerability curves for the residential buildings of Iran to provide a proper base for estimating probable damage features
by future earthquakes. The estimation may contribute fundamentally for better seismic performance of Iranian societies. After
a brief review of the vulnerability assessment methods in Iran and other countries, through the use of the European Macroseismic
method, a model for evaluating the vulnerability of the Iranian buildings is proposed. This method allows the vulnerability
assessment for numerous sets of buildings by defining the vulnerability curves for each building type based on the damage
observations of previous earthquakes. For defining the vulnerability curves, a building typology classification is presented
in this article, which is representative of Iranian building characteristics. The hazard is described in terms of the macroseismic
intensity and the EMS-98 damage grades have been considered for classifying the physical damage to the buildings. The calculated
vulnerability indexes and vulnerability curves show that for engineered houses there is not any notable difference between
the vulnerability of Iranian and Risk-UE building types. For the non-engineered houses, the vulnerability index of brick and
steel structures is less than the corresponding values of the other unreinforced masonry buildings of Iran. The vulnerability
index of unreinforced and masonry buildings of Iran are larger than the values of the similar types in Risk-UE and so the
Iranian buildings are more vulnerable in this regard. 相似文献
10.
Intermediate-depth earthquakes in the Vrancea region occur in response to stress generation due to descending lithosphere
beneath the southeastern Carpathians. In this article, tectonic stress and seismicity are analyzed in the region on the basis
of a vast body of observations. We show a correlation between the location of intermediate-depth earthquakes and the predicted
localization of maximum shear stress in the lithosphere. A probabilistic seismic hazard assessment (PSHA) for the region is
presented in terms of various ground motion parameters on the utilization of Fourier amplitude spectra used in engineering
practice and risk assessment (peak ground acceleration, response spectra amplitude, and seismic intensity). We review the
PSHA carried out in the region, and present new PSHA results for the eastern and southern parts of Romania. Our seismic hazard
assessment is based on the information about the features of earthquake ground motion excitation, seismic wave propagation
(attenuation), and site effect in the region. Spectral models and characteristics of site-response on earthquake ground motions
are obtained from the regional ground motion data including several hundred records of small and large earthquakes. Results
of the probabilistic seismic hazard assessment are consistent with the features of observed earthquake effects in the southeastern
Carpathians and show that geological factors play an important part in the distribution of the earthquake ground motion parameters. 相似文献
11.
Estimation of seismic hazard in Gujarat region, India 总被引：1，自引：1，他引：0
Sumer Chopra Dinesh Kumar B. K. Rastogi Pallabee Choudhury R. B. S. Yadav 《Natural Hazards》2013,65(2):1157-1178
The seismic hazard in the Gujarat region has been evaluated. The scenario hazard maps showing the spatial distribution of various parameters like peak ground acceleration, characteristics site frequency and spectral acceleration for different periods have been presented. These parameters have been extracted from the simulated earthquake strong ground motions. The expected damage to buildings from future large earthquakes in Gujarat region has been estimated. It has been observed that the seismic hazard of Kachchh region is more in comparison with Saurashtra and mainland. All the cities of Kachchh can expect peak acceleration in excess of 500?cm/s2 at surface in case of future large earthquakes from major faults in Kachchh region. The cities of Saurashtra can expect accelerations of less than 200?cm/s2 at surface. The mainland Gujarat is having the lowest seismic hazard as compared with other two regions of Gujarat. The expected accelerations are less than 50?cm/s2 at most of the places. The single- and double-story buildings in Kachchh region are at highest risk as they can expect large accelerations corresponding to natural periods of such small structures. Such structures are relatively safe in mainland region. The buildings of 3?C4 stories and tall structures that exist mostly in cities of Saurashtra and mainland can expect accelerations in excess of 100?cm/s2 during a large earthquake in Kachchh region. It has been found that a total of 0.11 million buildings in Rajkot taluka of Saurashtra are vulnerable to total damage. In Kachchh region, 0.37 million buildings are vulnerable. Most vulnerable talukas are Bhuj, Anjar, Rapar, Bhachau, and Mandvi in Kachchh district and Rajkot, Junagadh, Jamnagar, Surendernagar and Porbandar in Saurashtra. In mainland region, buildings in Bharuch taluka are more vulnerable due to proximity to active Narmada-Son geo-fracture. The scenario hazard maps presented in this study for moderate as well as large earthquakes in the region may be used to augment the information available in the probabilistic seismic hazard maps of the region. 相似文献
12.
In this paper, seismic risk scenarios for Bucharest, the capital city of Romania, are proposed and assessed. Bucharest has one of the highest seismic risk levels in Europe, and this is due to a combination of relatively high seismic hazard and a building stock built mainly before the devastating Vrancea 1977 earthquake. In this study, the seismic risk of Bucharest is assessed using the most recent information regarding the characteristics of the residential building stock. The ground motion amplitudes are evaluated starting from random fields obtained by coupling a ground motion model derived for the Vrancea intermediate-depth seismic source with a spatial correlation model. The seismic risk evaluation method applied in this study is based on the well-known macroseismic method. For several structural typologies, the vulnerability parameters are evaluated based on a damage survey performed on 18,000 buildings in Bucharest after the March 1977 earthquake. Subsequently, the risk metrics are compared with those from other studies in the literature that apply a different risk assessment methodology in order to gain a better view of the uncertainties associated with a seismic risk study at city level. Finally, the impact of several Vrancea intermediate-depth earthquake scenarios is evaluated and the results show that the earthquake which has the closest epicenter to Bucharest appears to be the most damaging. 相似文献
13.
A probabilistic model is presented to obtain a realistic estimate of earthquake insurance rates for reinforced concrete buildings in Turkey. The model integrates information on seismic hazard and information on expected earthquake damage on engineering facilities in a systematic way, yielding to estimates of earthquake insurance premiums. In order to demonstrate the application of the proposed probabilistic method, earthquake insurance rates are computed for reinforced concrete buildings constructed in five cities located in different seismic zones of Turkey. The resulting rates are compared with the rates currently charged by the insurance companies. The earthquake insurance rates are observed to be sensitive to the assumptions on seismic hazard and damage probability matrices and to increase significantly with increasing violation of the code requirements. 相似文献
14.
During an earthquake, buildings which are vulnerable to seismic loads will be damaged, resulting in property loss and the potential for casualties. To reduce loss of life and injury, the relationship between earthquake-induced building failure and injury severity and distribution needs to be clarified. To this end, a methodology and a series of data collection forms were developed to collect pertinent data for post-event analysis and to provide a basis for structural triage in the field shortly following an earthquake for search and rescue purposes. The forms were developed in four steps: (1) identifying the variables which affect the outcome of an occupant in a damaged building; (2) classifying the variables into three levels of priority for data collection; (3) designing the forms; and (4) applying the forms to damaged buildings from past earthquakes. These forms represent a significant departure from existing forms in that they consider both casualties and building damage jointly in a consistent format. This paper describes the first two steps of the development process; a companion paper outlines the latter components. 相似文献
15.
Earthquake damages are assessed based on a holistic approach using structural as well as non-structural factors to model earthquake
damage distributions with Decision Tree Techniques, using the Answer Tree program and the damage data from recent major earthquakes
in Turkey. The damage dataset consists of approximately 9,400 buildings that were surveyed to evaluate the factors affecting
building damage after Erzincan [1992], Dinar [1995], and Kocaeli [1999] earthquakes. The earthquake damage is defined as the
dependent variable, while earthquake magnitude (M), intensity (I) in the city, peak ground acceleration (PGA) in each city,
epicenter distance (ED), building types (BT), number of storeys (NS), presence of soft storey (SS), building position (BP)
on the site, and site conditions (SC) are independent variables in the proposed model. The damage level (DL) was classified
with respect to red, yellow, and green codes. The main purpose was (1) to identify the factors controlling building damage
during earthquakes; (b) to determine the most significant factor; (c) to evaluate the effects of different factors for different
earthquakes; (d) to develop damage distribution models for different subgroups based on the Decision Tree Techniques.
相似文献
| Atilla AnsalEmail: |
16.
Applying the HAZUS-MH software tool to assess seismic risk in downtown Ottawa,Canada 总被引：3，自引：3，他引：0
The aim of this paper is to present earthquake loss estimations for a portion of downtown Ottawa, Canada, using the HAZUS-MH
(Hazards United States Multi-Hazard) software tool. The assessment is performed for a scenario earthquake of moment magnitude
6.5, at an epicentral distance of 15 km, occurring during business hours. A level 2 HAZUS-MH analysis was performed where
the building inventory, microzonation studies, and site-specific ground motion hazard maps (2% exceedence probability in 50 years)
were all improved based on local information. All collected data were assembled into a set of standard geodatabases that are
compatible with the HAZUS-MH software using a GIS-specific procedure. The results indicate that the greatest losses are expected
in unreinforced masonry buildings and commercial buildings. Sensitivity studies show that soil classes, the vulnerability
of schools, and the spatial scale of loss estimations are also important factors to take into account. 相似文献
17.
Assessment of seismic vulnerability of urban areas provides fundamental information for activities of planning and management of emergencies. The main difficulty encountered when extending vulnerability evaluations to urban contexts is the definition of a framework of assessment appropriate for the specific characteristics of the site and providing reliable results with a reasonable duration of surveys and post-processing of data. The paper proposes a new procedure merging different typologies of information recognized on the territories investigated and for this reason called “hybrid.” Knowledge of historical events influencing urban evolution and analysis of recurrent building technologies are used to evaluate the vulnerability indexes of buildings and building stocks. On the other hand, a vulnerability model is calibrated by means of experimental and numerical investigations on prototype buildings representative of the most recurrent typologies. In the final framework, the vulnerability index, calculated through simplified assessment forms, is linked to the seismic intensity expressed by the peak ground acceleration and associated with an index of damage expressing the economical loss. The procedure has been tested on the urban center of Lampedusa island (Italy) providing as the output vulnerability index maps, vulnerability curves, critical PGA maps, and estimation of the economical damage associated with different earthquake scenarios. The application of the procedure can be suitably repeated for medium-to-small urban areas, typically recurring in the Mediterranean by carrying out each time a recalibration of the vulnerability model.
相似文献18.
Assessment of seismic vulnerability of urban areas provides fundamental information for activities of planning and management of emergencies. The main difficulty encountered when extending vulnerability evaluations to urban contexts is the definition of a framework of assessment appropriate for the specific characteristics of the site and providing reliable results with a reasonable duration of surveys and post-processing of data. The paper proposes a new procedure merging different typologies of information recognized on the territories investigated and for this reason called “hybrid.” Knowledge of historical events influencing urban evolution and analysis of recurrent building technologies are used to evaluate the vulnerability indexes of buildings and building stocks. On the other hand, a vulnerability model is calibrated by means of experimental and numerical investigations on prototype buildings representative of the most recurrent typologies. In the final framework, the vulnerability index, calculated through simplified assessment forms, is linked to the seismic intensity expressed by the peak ground acceleration and associated with an index of damage expressing the economical loss. The procedure has been tested on the urban center of Lampedusa island (Italy) providing as the output vulnerability index maps, vulnerability curves, critical PGA maps, and estimation of the economical damage associated with different earthquake scenarios. The application of the procedure can be suitably repeated for medium-to-small urban areas, typically recurring in the Mediterranean by carrying out each time a recalibration of the vulnerability model. 相似文献
19.
Shafiq Ur Rehman Muhammad Khalid Asif Ali Abd El-aziz Khairy Abd El-Aal 《Arabian Journal of Geosciences》2013,6(9):3481-3492
Gwadar City is located at the coastline of Pakistan. The city is currently in a phase of development, which is expected to become a future economic hub for Pakistan. This has led us to choose Gwadar for seismic hazard evaluation. Seismic hazard analysis for Gwadar is carried out using deterministic and probabilistic seismic hazard analysis techniques. The present study will help in sustainable development of a future large city and economic hub for Pakistan on ways of coping from a major threat of earthquake hazard. In deterministic seismic hazard analysis, line sources were identified close to Gwadar. Based on the analysis of maximum magnitude and closest distance (worse conditions), Makran subduction zone was identified out of all the line sources with earthquake potential of 8.2 at a distance of 30 km. This yielded a peak ground acceleration value of 0.38 g for Gwadar City. In second phase, probabilistic seismic hazard analysis technique with the area source modeling was adopted to acquire results at different return periods. For this purpose, seismic data were collected from the Pakistan Meteorological Department and International Seismological Center (2010) databases for development of a comprehensive data catalog. The a and b values were obtained using regression analysis for each source zone, and probabilistic analysis yielded the results of 0.34 g for a return period of 500 years. As per building codes of Pakistan, areas or cities with ground acceleration greater than 0.32 g are considered in seismic zone 4, and both deterministic and probabilistic hazard analysis place the city in seismic zone 4. These values correspond to rock site with shear wave velocity of 760 m/s. 相似文献
20.
This paper highlights the seismic microzonation carried out for a nuclear power plant site. Nuclear power plants are considered to be one of the most important and critical structures designed to withstand all natural disasters. Seismic microzonation is a process of demarcating a region into individual areas having different levels of various seismic hazards. This will help in identifying regions having high seismic hazard which is vital for engineering design and land-use planning. The main objective of this paper is to carry out the seismic microzonation of a nuclear power plant site situated in the east coast of South India, based on the spatial distribution of the hazard index value. The hazard index represents the consolidated effect of all major earthquake hazards and hazard influencing parameters. The present work will provide new directions for assessing the seismic hazards of new power plant sites in the country. Major seismic hazards considered for the evaluation of the hazard index are (1) intensity of ground shaking at bedrock, (2) site amplification, (3) liquefaction potential and (4) the predominant frequency of the earthquake motion at the surface. The intensity of ground shaking in terms of peak horizontal acceleration (PHA) was estimated for the study area using both deterministic and probabilistic approaches with logic tree methodology. The site characterization of the study area has been carried out using the multichannel analysis of surface waves test and available borehole data. One-dimensional ground response analysis was carried out at major locations within the study area for evaluating PHA and spectral accelerations at the ground surface. Based on the standard penetration test data, deterministic as well as probabilistic liquefaction hazard analysis has been carried out for the entire study area. Finally, all the major earthquake hazards estimated above, and other significant parameters representing local geology were integrated using the analytic hierarchy process and hazard index map for the study area was prepared. Maps showing the spatial variation of seismic hazards (intensity of ground shaking, liquefaction potential and predominant frequency) and hazard index are presented in this work. 相似文献