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1.
Mehani Youcef Benouar Djilali Bechtoula Hakim Kibboua Abderrahmane 《Natural Hazards》2011,59(1):529-551
Algeria is a country with a high seismic activity. During the last decade, many destructive earthquakes occurred, particularly
in the northern part, causing enormous losses in human lives, buildings, and equipments. In order to reduce this risk in the
capital and avoid serious damages to the strategic existing buildings, the government decided to invest in seismic upgrade,
strengthening, and retrofitting of these buildings. To do so, seismic vulnerability study of this category of buildings has
been considered. Structural analysis is performed based on a site investigation (inspection of the building, collecting data,
materials characteristics, general conditions of the building, etc.) and existing drawings (architectural plans, structural
design, etc.). The aim of these seismic vulnerability studies is to develop guidelines and a methodology for rehabilitation
of existing buildings. This paper presents the methodology followed in our study and summarizes the vulnerability assessment
and strengthening of one of the strategic buildings according to the new Algerian Seismic Design Code RPA 99/version 2003.
As a direct application of this methodology, both static equivalent method and nonlinear dynamic analysis are performed and
presented in this paper. 相似文献
2.
Northern Algeria has experienced many destructive earthquakes throughout its history. The largest recent events occurred in El Asnam on October 10, 1980 (moment magnitude; Mw = 7.3), in Constantine on October 27, 1985 (surface-wave magnitude; Ms = 6.0), and in Zemmouri–Boumerdes on May 21, 2003 (Mw = 6.8). Because of the high population density and industrialization in these regions, the earthquakes had disastrous consequences and hence highlighted the vulnerability of Algeria to seismic events. To reduce seismic risk in Constantine, the capital city of East Algeria, we present a seismic risk scenario for this city, focusing on the vulnerability of the key historic areas of Coudia, Bellevue–Ciloc, and the Old City. This scenario allows us to assess the maximum ground acceleration using empirical attenuation laws, based on the following considerations: (a) the 1985 Constantine seismic event as an earthquake reference; (b) site effects related to regional geology; (c) damage to buildings, and (d) seismic vulnerability. This study shows the map of peak ground acceleration taking into account the effects of site lithology (Avib). We observe the strongest vibrations along the two rivers “Boumerzoug and Rhumel” and also, we note that the EC8 gives a good estimate acceleration in the image of the three studied areas (Bellevue–Ciloc, Coudia, and Old Town). By correlating with the geology, we observe an acceleration of 0.13 g in the neritic limestone of the rock (Old Town) something that fits with the value obtained 0.14 g (PGA) without taking into consideration the lithology. Moreover, according to the Algerian Earthquake Engineering Code (2003) (RPA), the Wilaya of Constantine is classified in the zone IIa (medium seismicity) with an acceleration data of 0.25 g. This study integrates geographic information system (GIS) data into risk models.
相似文献3.
Northern Algeria has experienced many destructive earthquakes throughout its history. The largest recent events occurred in El Asnam on October 10, 1980 (moment magnitude; Mw = 7.3), in Constantine on October 27, 1985 (surface-wave magnitude; Ms = 6.0), and in Zemmouri–Boumerdes on May 21, 2003 (Mw = 6.8). Because of the high population density and industrialization in these regions, the earthquakes had disastrous consequences and hence highlighted the vulnerability of Algeria to seismic events. To reduce seismic risk in Constantine, the capital city of East Algeria, we present a seismic risk scenario for this city, focusing on the vulnerability of the key historic areas of Coudia, Bellevue–Ciloc, and the Old City. This scenario allows us to assess the maximum ground acceleration using empirical attenuation laws, based on the following considerations: (a) the 1985 Constantine seismic event as an earthquake reference; (b) site effects related to regional geology; (c) damage to buildings, and (d) seismic vulnerability. This study shows the map of peak ground acceleration taking into account the effects of site lithology (Avib). We observe the strongest vibrations along the two rivers “Boumerzoug and Rhumel” and also, we note that the EC8 gives a good estimate acceleration in the image of the three studied areas (Bellevue–Ciloc, Coudia, and Old Town). By correlating with the geology, we observe an acceleration of 0.13 g in the neritic limestone of the rock (Old Town) something that fits with the value obtained 0.14 g (PGA) without taking into consideration the lithology. Moreover, according to the Algerian Earthquake Engineering Code (2003) (RPA), the Wilaya of Constantine is classified in the zone IIa (medium seismicity) with an acceleration data of 0.25 g. This study integrates geographic information system (GIS) data into risk models. 相似文献
4.
5.
We performed a seismic vulnerability assessment of the city of Constantine (Algeria) using the Risk-UE and datamining-based methods [association rule learning (ARL)]. The ARL method consists in establishing relationships between building attributes (number of stories or building age) and the vulnerability classes of the European Macro-seismic Scale, EMS98. This approach avoids the costly process of drawing up an inventory of building characteristics in the field, which often discourages the assessment of seismic risk initiatives in weak to moderate seismic-prone regions. We showed that the accuracy of the assessment is independent of the subset used for the learning phase leading to development of the Constantine vulnerability proxy. Considering only two attributes, the vulnerability assignment is equal to about 75%, reaching 99% if material is added to the attributes considered. Comparison of Risk-UE and ARL results revealed a reliable assessment of vulnerability, the differences having only a slight impact on the probability of exceeding the damage level computed by EMS98 or Risk-UE in Constantine. The results of this study suggest that the ARL-based vulnerability proxy is efficient and could be applied to the rest of Algeria. 相似文献
6.
The expected fraction of buildings lost in the event of an earthquake of a given intensity can be considered as a useful indicator of the seismic vulnerability of a small urban nucleus and can be used for the evaluation of seismic risk on a regional scale. This work describes a procedure for quantifying this indicator through data obtained from the buildings which constitute the nucleus during rapid on-site surveys. The knowledge on which the procedure is based is that given by the observed vulnerability of old Italian centres. 相似文献
7.
Djillali Benouar 《Natural Hazards》1996,13(2):119-131
This paper presents the evaluation of seismic hazard at the site of Algiers (capital of Algeria). In order to implement earthquake-resistant design codes, it is usually necessary to know the maximum dynamic load which a particular structure might experience during its economic life, or alternatively, the most probable return period of a specified design load. The evaluation of the seismic hazard at the site, based on peak ground motion acceleration and using Cornell's method and Benouar's earthquake Maghreb catalogue, in terms of return period, probability of exceedance of PGA, design ground motion and a response spectrum, is carried out for the City of Algiers and its surroundings. The response spectrum for Algiers presented in this paper is the first one realized in Algeria using revised Algerian data. 相似文献
8.
Seismic risk assessment of buildings in urban areas: a case study for Denizli,Turkey 总被引：3，自引：2，他引：1
This study aims to carry out a seismic risk assessment for a typical mid-size city based on building inventory from a field
study. Contributions were made to existing loss estimation methods for buildings. In particular, a procedure was introduced
to estimate the seismic quality of buildings using a scoring scheme for the effective parameters in seismic behavior. Denizli,
a typical mid-size city in Turkey, was used as a case study. The building inventory was conducted by trained observers in
a selected region of Denizli that had the potential to be damaged from expected future earthquakes according to geological
and geotechnical studies. Parameters that are known to have some effect on the seismic performance of the buildings during
past earthquakes were collected during the inventory studies. The inventory includes data of about 3,466 buildings on 4,226
parcels. The evaluation of inventory data provided information about the distribution of building stock according to structural
system, construction year, and vertical and plan irregularities. The inventory data and the proposed procedure were used to
assess the building damage, and to determine casualty and shelter needs during the M6.3 and 7.0 scenario earthquakes, representing
the most probable and maximum earthquakes in Denizli, respectively. The damage assessment and loss studies showed that significant
casualties and economic losses can be expected in future earthquakes. Seismic risk assessment of reinforced concrete buildings
also revealed the priorities among building groups. The vulnerability in decreasing order is: (1) buildings with 6 or more
stories, (2) pre-1975 constructed buildings, and (3) buildings with 3–5 stories. The future studies for evaluating and reducing
seismic risk for buildings should follow this priority order. All data of inventory, damage, and loss estimates were assembled
in a Geographical Information System (GIS) database. 相似文献
9.
10.
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11.
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
12.
Youcef Bouhadad 《Natural Hazards》2014,72(3):1329-1339
Earthquakes constitute the natural hazard that is one of the main natural threats to the northern part of Algeria because of its geographical setting at the Eurasia–Africa plate boundary. Several active multi-segment reverse faults have been identified near urban areas that may rupture during characteristic earthquakes and produce earthquakes of magnitudes ≥7.0. Characteristic earthquakes are extreme seismic events characterized by long return periods, which can have great societal impact. Earthquakes in northern Algeria are destructive for two main reasons: firstly, the shallow character of the faults and secondly, the vulnerability of the building stock built essentially prior to the implementation of seismic design codes that take into account the level of the seismic hazard. That is why even moderate earthquakes are disastrous in this area. 相似文献
13.
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
14.
Chang-Guk Sun 《Environmental Earth Sciences》2012,65(7):1987-2001
A geotechnical information system (GTIS) was constructed within a spatial geographic information system (GIS) framework to
reliably predict geotechnical information and accurately estimate site effects at Gyeongju, an urban area in South Korea.
The system was built based on both collected and performed site investigation data in addition to acquired geo-knowledge data.
Seismic zoning maps were constructed using the site period (T
G) and mean shear wave velocity to a depth of 30 m (V
S30), and these maps were presented as a regional strategy to mitigate earthquake-induced risks in the study area. In particular,
the T
G distribution map indicated the susceptibility to ground motion resonance in periods ranging from 0.2 to 0.5 s and the corresponding
seismic vulnerability of buildings with two to five stories. Seismic zonation of site classification according to V
S30 values was also performed to determine the site amplification coefficients for seismic design and seismic performance evaluation
at any site and administrative subunit in the study area. In addition, we investigated the site effects according to subsurface
and surface ground irregularities at Gyeongju by seismic response analyses in time domains based on both two- and three-dimensional
spatial finite element models, which were generated using spatial interface coordinates between geotechnical subsurface layers
predicted by the GTIS. This practical study verified that spatial GIS-based geotechnical information can be a very useful
resource in determining how to best mitigate seismic hazards, particularly in urban areas. 相似文献
15.
泥石流作用下建筑物易损性评价方法分析与评价 总被引：1，自引：0，他引：1
建筑物易损度评价作为泥石流易损度评价的重要组成部分,其研究是实现城镇及居民点泥石流风险定量化和风险管理的必要环节。综述近30年来,泥石流作用下建筑物易损度研究的发展过程,并指出以统计分析方法建立的建筑物易损度曲线普适性差且力学机理不明等问题,提出数值计算和模型实验的手段获取建筑物结构易损度的机理模型。由于建筑物易损度研究问题本身的复杂性,统计分析方法仍将作为建筑物易损度研究的重要手段,力学机理明晰的研究方法则将成为今后研究的难点和热点。此外,地震、滚石、雪崩等类似灾种的易损度研究方法和成果可被借鉴到泥石流领域。针对灾害中因结构破坏引发人员伤亡的情况,建议采用时间概率和基于条件概率的事件树方法计算建筑物内人员易损度。最终形成综合结构和人员易损度研究成果的建筑物易损度评价方法。 相似文献
16.
对照现行《建筑抗震设计规范》（GB50011-2001）场地类别划分方法,应用模糊数学原理,推导了场地类别的模糊二次评价方法,得出了场地类别的模糊向量和模糊特征周期,实现了场地类别划分的连续化;在此基础上,基于收集到的杭州市254个建筑场地波速钻孔实测资料,通过建立场地类别地质模型,实现了场地类别、特征周期的模糊等值线,与实测资料对比,结果表明：由该模糊等值线得出的建筑场地抗震类别与现行《建筑抗震设计规范》给出的场地类别是统一的,模糊特征周期与规范给出的特征周期基本上是吻合的,该模糊等值线对建筑抗震设计具有指导意义。 相似文献
17.
《Geomechanics and Geoengineering》2013,8(1):35-47
The need to revise the current Indonesian Seismic Hazard Map contained in Indonesian Earthquake Resistant Building Code SNI 03-1726-2002 which partially adopts the concept of UBC 1997, was driven among others by the desire to better reflect the potential larger earthquake disasters faced by the nation in the future. The much larger than maximum predicted Aceh Earthquake (M w 9.0–9.3) of 2004, followed by the destruction observed during the 2005 Nias Earthquake (M w 8.7) urgently underline to need to consider the new conceptual approach and technological shift shown in the transition of UBC 1997 to IBC 2006. This paper presents research works for developing spectral hazard maps for Indonesia. Some improvements in seismic hazard analysis were implemented using recent seismic records. Seismic sources were modeled by background, fault, and subduction zones by considering a truncated exponential model, pure characteristic model or both models. A logic tree method was performed to account for the epistemic uncertainty and several attenuation functions were selected. Maps of PGA and spectral accelerations for a short period (0.2 s) and for a 1-s period were then developed using a probabilistic approach. The maps will be proposed as a revision for the current seismic hazard map in the Indonesian Seismic Building Code. 相似文献
18.
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
19.
Al Hoceima is one of the most seismic active regions in north of Morocco. It is demonstrated by the large seismic episodes reported in seismic catalogs and research studies. However, seismic risk is relatively high due to vulnerable buildings that are either old or don’t respect seismic standards. Our aim is to present a study about seismic risk and seismic scenarios for the city of Al Hoceima. The seismic vulnerability of the existing residential buildings was evaluated using the vulnerability index method (Risk-UE). It was chosen to be adapted and applied to the Moroccan constructions for its practicality and simple methodology. A visual inspection of 1102 buildings was carried out to assess the vulnerability factors. As for seismic hazard, it was evaluated in terms of macroseismic intensity for two scenarios (a deterministic and probabilistic scenario). The maps of seismic risk are represented by direct damage on buildings, damage to population and economic cost. According to the results, the main vulnerability index of the city is equal to 0.49 and the seismic risk is estimated as Slight (main damage grade equal to 0.9 for the deterministic scenario and 0.7 for the probabilistic scenario). However, Moderate to heavy damage is expected in areas located in the newer extensions, in both the east and west of the city. Important economic losses and damage to the population are expected in these areas as well. The maps elaborated can be a potential guide to the decision making in the field of seismic risk prevention and mitigation strategies in Al Hoceima. 相似文献
20.
建筑物的地震安全性是城市规划和建设过程首先要回答的问题。我国城市地震安全性评价的方法理论多针对地上建筑物,而对地下空间的地震安全性研究较为薄弱,严重滞后于城市发展对地下空间的需求。活断层是诱发地震、导致建筑物破坏的的直接因素。考虑到空间关系上,地下空间与断层之间的交互关系为相交或相离。因此,本文将地下空间分为两类:与断层相交的地下空间称为跨断层地下空间,远离断层的地下空间称为远离断层地下空间。本文尝试将断裂带同震地表破裂、地震峰值加速度、地震烈度等地表地震安全性评价考量的要素与地下空间埋藏深度建立联系,并在此基础上总结基于震害统计的地下空间地震安全性评价方法。最后,本文选取地下空间利用需求较高的深圳和北京地区为实例进行介绍。 相似文献