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1.
Damage scenarios for Basel (Switzerland) are presented, based on a microzonation study and on the distribution of buildings in the different districts of the city. Two reference scenarios are assumed, corresponding to an event with an intensity between VII and VIII and a return period of 475 years, and an event that simulates the 1356 Basel earthquake with an intensity of IX in the city. The overall building damage in the different districts ranges between 8 and 20% for the intensity VII–VIII scenario, while for the intensity IX scenario values range from 31 to 56%. The variation in building vulnerability class within the city and the variability of local ground conditions affect the overall damage significantly, so that their influence on earthquake damage can accumulate or cancel for single districts. 相似文献
2.
The main purpose of this study is to obtain the damage scenario for residential buildings in the occurrence of a destructive earthquake (M = 7+) in the city area of Catania, Eastern Sicily, and to illustrate the comparative performance of two alternative methods used for this purpose. The methods are representative of two different approaches to estimating the seismic vulnerability of structures, i.e., an empirical approach based on statistical score assignments (widely used in Italy and other countries) and a more recent, mechanical approach that uses displacement limit states associated with well-defined thresholds of structural damage. A special concern for seismic vulnerability in Catania is caused by the fact that earthquake design norms were enforced in its municipal area only since 1981. We emphasise some typical problems encountered in earthquake scenario work, such as the difficulty of assembling a reliable building inventory, and the uncertainties inherent in the vulnerability assessments through different probabilistic assumptions. Different criteria for the representation of damage are applied and discussed. It is shown that the main scenarios obtained by the two methods are in reasonable agreement, provided a suitable percentile level for damage is chosen in the statistical score assignment approach. 相似文献
3.
Earthquake Damage Scenarios of the Building Stock of Potenza (Southern Italy) Including Site Effects 总被引：3，自引：0，他引：3
Mauro Dolce Angelo Masi Maria Marino Marco Vona 《Bulletin of Earthquake Engineering》2003,1(1):115-140
Damage scenarios relevant to the building stock of the town of Potenza, Southern Italy, are presented. A procedure for the
preparation of scenarios has been purposely set up. In the first step, the inventory of the building stock has been made.
Location and characteristics of buildings have been obtained from a survey carried out after the 1990 Potenza earthquake and
further updated in 1999. In the second step, the absolute vulnerability of the buildings has been evaluated. A hybrid technique
has been used, where typological analyses and expert judgement are combined together. Beyond the classes of vulnerability
A, B and C of the MSK scale, the class D of EMS98 scale, for the less vulnerable buildings, has been considered. The third
step has been the selection of the reference earthquakes by including also local amplification effects. Two events with 50
and 475 years return periods have been chosen as representative, respectively, of a damaging and of a destructive seismic
event expected in Potenza. The sites that may exhibit important amplification effects have been identified using the first
level method of the TC4 Manual. Damage scenarios of dwelling buildings have been prepared in the fourth step and reported
in a GIS. They are relevant to the selected reference earthquakes, taking into account or not site effects. The generally
low vulnerability of buildings results in a limited number of damaged buildings for the lower intensity earthquake, and of
collapsed buildings, for the higher intensity earthquake. The influence of site effects on the damage distribution is significant.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
4.
This study analyses the performance of residential buildings in the town of Hveragerði in South Iceland during the 29 May 2008 Mw 6.3 Ölfus Earthquake. The earthquake occurred very close to the town, approximately 3–4 km from it. Ground shaking caused by the earthquake was recorded by a dense strong-motion array in the town. The array provided high-quality three-component ground acceleration data which is used to quantify a hazard scenario. In addition, surveys conducted in the town in the aftermath of the earthquake have provided information on macroseismic intensity at various locations in the town. Detailed information regarding the building stock in the town is collected, and their seismic vulnerability models are created by using building damage data obtained from the June 2000 South Iceland earthquakes. Damage to buildings are then simulated by using the scenario hazard and vulnerability models. Damage estimates were also obtained by conducting a survey. Simulated damage based on the scenario macroseismic intensity is found to be similar to damage estimated from survey data. The buildings performed very well during the earthquake—damage suffered was only 5 % of the insured value on the average. Correlation between actual damage and recorded ground-motion parameters is found to be statistically insignificant. No significant correlation of damage was observed, even with macroseismic intensity. Whereas significant correlation was observed between peak ground velocity and macroseismic intensity, neither of them appear to be good indicators of damage to buildings in the study area. This lack of correlation is partly due to good seismic capacity of buildings and partly due to the ordinal nature of macroseismic intensity scale. Consistent with experience from many past earthquakes, the survey results indicate that seismic risk in South Iceland is not so much due to collapse of buildings but rather due to damage to non-structural components and building contents. 相似文献
5.
L. G. Pujades A. H. Barbat R. González-Drigo J. Avila S. Lagomarsino 《Bulletin of Earthquake Engineering》2012,10(1):331-349
Between the late nineteenth century and the early twentieth century, Barcelona was expanded, occupying the terrains connecting
the old walled city and the nearby towns of the plateau of Barcelona. At that time, a large number of unreinforced masonry
buildings were constructed and nowadays many of them are still used as dwellings. Though built individually, these buildings
are connected to adjacent buildings, forming blocks composed of aggregates. In order to analyze the seismic behavior of isolated
buildings and aggregates, two typical central buildings and one typical corner building have been chosen. The two central
buildings and the corner building are referred as C1, C2, and E buildings. Two corner buildings and two central buildings have been connected in order to simulate a block side. This aggregate
is referred as AGG and it is composed by the following sequence of individual buildings: E-C1-C2-E. Original plans and drawings of existing buildings are then used to model these buildings. The modeled buildings have five
stories. Standard pushover analyses lead to evaluate their seismic performance by means of capacity spectra and fragility
curves. The analysis has been carried out in the parallel (Ux) and transversal (Uy) directions to the street. Then, a capacity
spectrum based method is used to analyze the seismic behavior of these buildings considered as individual buildings and as
an aggregate. Two earthquake scenarios are considered. The first one is a deterministic scenario which is based on a historical
earthquake occurred in 1,824, 25 km away from the city and the second one is a probabilistic scenario, which represents the
ground motion with a probability of occurrence of 10% in 50 years. The soil local effects have been also considered and both
scenarios have been used to assess the expected damage. Four non-null damage states are considered: slight (1), moderate (2),
severe (3) and extensive-to-collapse (4). For the type of soil where most of the buildings are, and in the Ux direction, the
four buildings show a similar behavior. The mean damage grade is 2.3 for the deterministic scenario and 2.7 for the probabilistic
one. This means that moderate to severe damage is expected in both cases; furthermore, in the case of the deterministic scenario
more than 10% of the buildings would suffer extensive-to-collapse damage and nearly 20% for the probabilistic scenario, confirming
the high vulnerability of such buildings. The differences in the expected damage are due to the significant different characteristics
of the response spectra of the earthquake scenarios in the range of the fundamental periods of the buildings. 相似文献
6.
A methodology for defining seismic scenario‐structure‐based limit state criteria for rc high‐rise wall buildings using net drift 
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下载免费PDF全文 As a result of population growth and consequent urbanization, the number of high‐rise buildings is rapidly growing worldwide resulting in increased exposure to multiple‐scenario earthquakes and associated risk. The wide range in frequency contents of possible strong ground motions can have an impact on the seismic response, vulnerability and limit states definitions of RC high‐rise wall structures. Motivated by the pressing need to derive more accurate fragility relations to be used in seismic risk assessment and mitigation of such structures, a methodology is proposed to obtain reliable, Seismic Scenario‐Structure‐Based (SSSB) definitions of limit state criteria. A 30‐story wall building, located in a multi‐seismic scenario study region, is utilized to illustrate the methodology. The building is designed following modern codes and then modeled using nonlinear fiber‐based approach. Uncertainty in ground motions is accounted for by the selection of forty real earthquake records representing two seismic scenarios. Seismic scenario‐based building local response at increasing earthquake intensities is mapped using Multi‐Record Incremental Dynamic Analyses (MRIDAs) with a new scalar intensity measure. Net Inter‐Story Drift (NISD) is selected as a global damage measure based on a parametric study involving seven buildings ranging from 20 to 50 stories. This damage measure is used to link local damage events, including shear, to global response under different seismic scenarios. While the study concludes by proposing SSSB limit state criteria for the sample building, the proposed methodology arrives at a reliable definition of limit state criteria for an inventory of RC high‐rise wall buildings under multiple earthquake scenarios. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
7.
This paper briefly reviews the main topics developed in the last 15 years dealing with advances on predicting earthquake scenarios for the Lisbon Region. These developments, which have been reverted into seismic scenario simulators, include the entire earthquake process, as different modules, from the seismic source to vulnerability modelling. Recent achievements in several modules are presented, describing the level of uncertainties associated with the source, attenuation, soil effect, typology classification and inventory of the building stock, and vulnerability assessment of each typology. One simplified model is shown, and results of other models are compared for two selected occurrence scenarios. The paper ends with a brief appointment on the selection of scenario types, a key point in the application of simulators, and highlights the issues where more research and development should be made to optimize the gains in knowledge and to reduce overall uncertainties. 相似文献
8.
On Chinese earthquake history — An attempt to model an incomplete data set by point process analysis 总被引：1，自引：0，他引：1
Since the 1950s, the Academia Sinica in Peking, People's Republic of China, has carried out extensive research on the Chinese earthquake history. With a historical record dating back some 3000 years, a wealth of information on Chinese earthquakes exists. Despite this monumental undertaking by the Academia Sinica, much work is still necessary to correct the existing earthquake data for historical changes in population, customs, modes of communication, and dynasties. In this paper we report on the status of our investigation of Chinese earthquake history and present some preliminary results. By applying point process analysis of earthquakes in Central China, we found suggestions of (1) lower earthquake activity at intervals of about 175 years and 375 years, and (2) higher earthquake activity at an interval of about 300 years. 相似文献
9.
A GIS-oriented procedure that may partially illuminate the consequences of a possible earthquake is presented in two main steps (seismic microzonation and vulnerability steps) along with its application in Tabriz (a city in NW Iran). First, the detailed geological, geodetical, geotechnical and geophysical parameters of the region are combined using an Analytic Hierarchy Process (AHP) and a deterministic near-field earthquake of magnitude 7 in the North Tabriz Fault is simulated. This simulation provides differing intensities of ground shaking in the different districts of Tabriz. Second, the vulnerability of buildings, human losses and basic resources for survivors is estimated in district two of the city based on damage functions and relational analyses. The results demonstrate that 69.5% of existing buildings are completely destroyed, and the rate of fatalities is approximately 33% after a nighttime scenario. Finally, the same procedure was applied to an actual earthquake (first event on the 11th of August, 2012 of the Ahar twin earthquakes) to validate the presented model based on two aspects: (1) building damages and (2) seismic intensity. 相似文献
10.
The quantification of the devastating effects of earthquakes on buildings can be achieved with the use of earthquake risk assessment. The formulation of strategies to minimise this risk is a complex task which relies on data regarding mainly the hazard, vulnerability and remaining life of the building. In this paper, the case study of Limassol municipality is presented. Initially, the building inventory and categorisation is defined followed by the selection of hazard scenarios and the development of analytical vulnerability curves. In the final part, risk assessment is performed leading to the formulation of retrofitting strategies for long term use. 相似文献
11.
Egypt and the Nile Basin 总被引：1，自引：0，他引：1
12.
An attempted use of seismic gap observations to predict a large earthquake in Oaxaca, Mexico is discussed. The observations were initially published in a scientific journal and were subsequently distorted by noncientists, who predicted a major earthquake and tsunami to take place at Pinotepa Nacional, Oaxaca on 23 April 1978. Public reactions and property losess sustained by individuals and communities were comparable to those expected from an actual earthquake. A revision of epicenter locations from the NOAA data file revealed that a number of earthquakes did occur in the alleged gap but had been excluded because their reported focal depth was in excess of 60 km. It is shown that the probability that the number of earthquakes in two consecutive time intervals of a stationary Poisson process differs by an amount which would be reported as a seismic gap is of the order of 5% or more for Oaxaca. This means that spurious seismic gaps would be observed in one out of 20 data runs. The possibility of detecting a true interval of abnormal quiescence in a random earthquake sequence appears to be fairly remote in this case. 相似文献
13.
Models capable of estimating losses in future earthquakes are of fundamental importance for emergency planners, for the insurance and reinsurance industries, and for code drafters. Constructing a loss model for a city, region or country involves compiling databases of earthquake activity, ground conditions, attenuation equations, building stock and infrastructure exposure, and vulnerability characteristics of the exposed inventory, all of which have large associated uncertainties. Many of these uncertainties can be classified as epistemic, implying—at least in theory—that they can be reduced by acquiring additional data or improved understanding of the physical processes. The effort and cost involved in refining the definition of each component of a loss model can be very large, for which reason it is useful to identify the relative impact on the calculated losses due to variations in these components. A mechanically sound displacement‐based approach to loss estimation is applied to a test case of buildings along the northern side of the Sea of Marmara in Turkey. Systematic variations of the parameters defining the demand (ground motion) and the capacity (vulnerability) are used to identify the relative impacts on the resulting losses, from which it is found that the influence of the epistemic uncertainty in the capacity is larger than that of the demand for a single earthquake scenario. Thus, the importance of earthquake loss models which allow the capacity parameters to be customized to the study area under consideration is highlighted. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
14.
Enrico Quagliarini Gabriele Bernardini Chiara Wazinski Luca Spalazzi Marco D’Orazio 《Bulletin of Earthquake Engineering》2016,14(4):1071-1101
One of the most influencing elements in inhabitants’ earthquake safety definition is represented by the interactions between people and post-event environment in urban scenarios. Understanding and simulating rules for pedestrians’ motion in earthquake evacuation could be useful to inquire the risk assessment introducing the “human” factor influence: integrated “risk maps” could be realized by combining results of similar analyses with the traditional site hazard, buildings vulnerability and exposition indices. This work proposes an innovative approach based on the analysis of these interactions. Two experimentally-based activities are required: an analysis of human behaviors towards the post-earthquake environment; a relation for defining environmental modifications. Results firstly show a summary of man-environment interactions in earthquake evacuations. A possible criterion for path choice in evacuation is also numerically defined. A theoretical agent-based model is developed on these bases and summarizes phases, motion rules and man-environment interactions in earthquake pedestrians’ evacuation in urban scenarios. Secondly, quick criteria for scenario modifications involving ruins formation are proposed and evaluated: for each building, the percentages of internal and external ruins area is a function of its vulnerability and the expected earthquake Richter magnitude. Moreover, the external ruins formation criterion is validated by comparing predicted and effective values of ruins area depth in real cases. The model could be proposed as a tool for evaluating probable pedestrians’ choices in post-event scenarios, in order to reduce the interferences between the built environment and the evacuation process through interventions on buildings, urban fabric and strategies for emergency management. 相似文献
15.
Vulnerability and risk analysis of monuments in Málaga city’s historical centre (Southern Spain) 总被引：1，自引：1，他引：0
A vulnerability analysis of some historical and monumental buildings in the city of Málaga is presented in this paper. More than twenty of these monuments were severely damaged or completely destroyed due to the large earthquake (I max = VIII–IX) occurred in the Málaga region in October 1680. The vulnerability index methodology has been used in this paper. This technique is based on statistical data from seismic damage caused to Italian monuments for the past 30?years. For each building, vulnerability curves have been obtained and damage grades have been estimated. A comparison has been carried out between the expected damage grades and the damage observed from past earthquakes, in order to check the feasibility of applying this methodology to Spanish monuments. This comparison has been possible due to the fact that detailed seismic damage information exists for monuments in the city of Málaga that still exist today, which is a very uncommon case in Spain. Results show a good consistency between expected and observed damage, especially for the churches type. Two seismic scenarios have been proposed for the city centre, one deterministic and one probabilistic, where 54 historical and modern buildings have been analyzed. Both scenarios show worrying results, especially for the types of churches, chapels and towers, where expected high probabilities of suffering very heavy damage or even collapse have been obtained. It is highly recommended to take the necessary measures, in the hope of trying to avoid the possible damage that can be expected from future earthquakes. 相似文献
16.
The pirmary objective of this paper is to review inversion algorithms employed to interpret magnetotelluric data by the geophysical/electromagnetics group at Brown University. Examples are presented from a variety of tectonic regimes — the Rio Grande rift, the Colorado Plateau, and Iceland. Following a brief tutorial in which the basic relations for the inverse prrolem are developed, we discuss the detectability and resolvability of various elements of the models. The correlation between certain model parameters is stressed, a phenomena well-known to interpreters. In this paper we emphasize the importance of identifying the precise range of values for which two or more parameters are coupled — these ranges are defined by what wer term saturation limits. Generalized inverse theory is employed to arrive at optimal models which are evaluated in terms of resolution and information matrices. The degree to which models fit a given dat base can be assessed using several quantitative approaches. We have found that it is impotant not only to determine the best fitting model, but also to identify those marginal solutions which also fall within the range of uncertainty of the data. The results from our direct invverse method agree favorably with those from Monte Carlo methods. 相似文献
17.
The August 17, 1999 Kocaeli earthquake ruptured the earths surface along 145 km and produced a magnitude of Mw=7.4. As expected for such an event Modified Mercalli intensities of typically IX and X in the vicinity of the fault were determined. Yet the observed accelerations at the five near-fault sites remained amazingly small with horizontal PGA values of 0.14 g to 0.4 g. We attempt to resolve the enigma by modeling surface ground motion with a finite-difference algorithm, utilizing two different rupture and slip histories derived from the strong-motion observations and translate the computed horizontal motion in intensity values. We can show that (a) in a given simple crustal velocity model different slip distributions result in significantly different ground motion distributions in the vicinity of the fault even though both slip distributions fit the observed accelerometer data quite well. (b) Both slip distributions project high ground motion into areas adjacent to the fault where no accelerometer was located. (c) Both slip distributions are not fully compatible with observed intensity observations around the fault, although this could be partly attributed to the lack of knowledge regarding to the crustal structure. In the light of our results it would thus be misleading if the few strong-motion observations around the Kocaeli earthquake fault were taken as typical or representative for the entire area and for potential future events. 相似文献
18.
The initial subevent of the 1994 Northridge, California, earthquake: Is earthquake size predictable? 总被引：1，自引：0，他引：1
We examine the initial subevent (ISE) of the M 6.7, 1994 Northridge, California, earthquake in order to discriminate between two end-member rupture initiation models: the preslip and cascade models. Final earthquake size may be predictable from an ISE's seismic signature in the preslip model but not in the cascade model. In the cascade model ISEs are simply small earthquakes that can be described as purely dynamic ruptures. In this model a large earthquake is triggered by smaller earthquakes; there is no size scaling between triggering and triggered events and a variety of stress transfer mechanisms are possible. Alternatively, in the preslip model, a large earthquake nucleates as an aseismically slipping patch in which the patch dimension grows and scales with the earthquake's ultimate size; the byproduct of this loading process is the ISE. In this model, the duration of the ISE signal scales with the ultimate size of the earthquake, suggesting that nucleation and earthquake size are determined by a more predictable, measurable, and organized process. To distinguish between these two end-member models we use short period seismograms recorded by the Southern California Seismic Network. We address questions regarding the similarity in hypocenter locations and focal mechanisms of the ISE and the mainshock. We also compare the ISE's waveform characteristics to those of small earthquakes and to the beginnings of earthquakes with a range of magnitudes. We find that the focal mechanisms of the ISE and mainshock are indistinguishable, and both events may have nucleated on and ruptured the same fault plane. These results satisfy the requirements for both models and thus do not discriminate between them. However, further tests show the ISE's waveform characteristics are similar to those of typical small earthquakes in the vicinity and more importantly, do not scale with the mainshock magnitude. These results are more consistent with the cascade model. 相似文献
19.
房屋建筑的地震易损性是地震损失评估和地震巨灾风险模型的基础。作为房屋建筑的重要组成部分,各类非结构构件的损失在现有的易损性模型中并未得到足够重视。本文以一栋典型钢筋混凝土框架结构教学楼为对象,通过将房屋建筑中的各类构件划分为具有不同地震损伤特性和损失后果的易损性组,考察建筑内的损失分布和非结构损失对房屋建筑地震易损性的影响。分析结果表明:由于许多非结构构件在中小地震作用下即可能发生较严重的破坏,房屋建筑在中小地震下的易损性主要受非结构损失控制;随着地震动强度等级的不断提高,结构损伤渐趋严重,结构损失对整体建筑易损性的影响不断增大;在结构进入震后不可修状态之前,建筑不同楼层的损失分布是评估建筑地震损失时不可忽略的因素。 相似文献
20.
W. D. Ortlepp 《Pure and Applied Geophysics》1992,139(3-4):677-695
Mining of a highly-stressed remnant in a deep South African gold mine was accompanied by considerable seismic activity and some significant rockbursts. The larger seismic events were registered some 60 km away at a WSSN station and several shear ruptures corresponding to these events were encountered during mining operations.A careful study based on detailed exploration of two of these ruptures proved them to be the source of two of the larger rockbursts.Certain striking features revealed by a scanning electron microscopic study of some of the fresh cataclastic rock-flour forming part of the comminuted filling of these ruptures provide strong evidence of violent shock rebound phenomena in the faulting process. This interpretation could provide useful insight into earthquake source mechanisms and also has practical significance in the understanding of mine rockbursts. 相似文献