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1.
Summary The high amplification of the 1985 Mexico City earthquake is explained by the large number of strong and nearly continuous cycles of 2 s period motion lasting for more than 30 s. The type of damage caused by the earthquake—particularly to engineered multi-storey buildings of high flexibility is described, and methods of adding damping and stiffness elements to reduce and resist earthquake demand forces are discussed.  相似文献   

2.
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   

3.
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   

4.
The goal of this paper is to present especially the source and the type of liquefaction-related failures of those buildings which satisfied the structural codes of buildings and practices but experienced settlement, tilting and overturning in Adapazari during the Turkey earthquake of August 17, 1999. In this context, the Adapazari region is first evaluated in terms of geological setting, tectonics, seismicity and liquefaction susceptibility based on in situ and laboratory test data. In addition, the number of stories, types of buildings and their related failures have been mapped accordingly. Furthermore, laboratory model tests are conducted to enforce and/or confirm the type of building's failures with particular reference to their geometrical shape and the number of stories assuming that the models representing buildings satisfy the structural codes of buildings and practices.  相似文献   

5.
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   

6.
福建省地处台湾海峡西岸 ,1 60 4年泉州海外的 8级地震对它造成很大的破坏 ,也给我们留下了一批经过 8级大震考验的珍贵古建筑物 ,受到海内外专家的重视。作者经过实地考察 ,认真查阅历史资料 ,着重介绍了经过 1 60 4年大震考验的泉州古建筑物 ,并结合今天福建省防震减灾工作的实际情况 ,结合地质地貌 ,福建土楼等 ,较系统的展示了海峡西岸的地震地质景观。  相似文献   

7.
The earthquake closet: rendering early-warning useful   总被引:1,自引:1,他引:0  
Max Wyss 《Natural Hazards》2012,63(2):761-768
Early-warning of imminently approaching strong shaking that could have fatal consequences is a research field that has made great progress. However, its potential to save lives has a serious Achilles heel: The time for getting to safety is 5 to 10?s only, in those cities that need warnings most. Occupants of the upper floors cannot get out of their buildings and narrow streets are not a safe place in strong earthquakes. The official advice, to crawl under a table, protects from falling objects only, but not from collapsing buildings. Thus, only about 10?% of a city??s population can benefit from early-warnings, unless they have access to an earthquake protection unit that is strong enough to improve their chances of survival and not being injured by factors of 1,000 to 30,000. The purpose of this paper is to generate discussion on how to use early-warning to improve the safety for occupants of buildings exposed to strong earthquake shaking.  相似文献   

8.
The Canterbury (New Zealand) earthquake sequence of 2010–2012 caused unexpectedly extreme levels of damage and disruption, being an unparalleled event in New Zealand in terms of the damage extent. Christchurch’s heritage buildings were seriously damaged during these events, with churches especially affected in 22 February 2011 M w 6.2 earthquake. During this earthquake, a total of 84% of the heritage unreinforced stone and 81% of the clay brick masonry churches in the Canterbury region were either considered unsafe (receiving red placards) or with restricted access (yellow placards). Following the earthquakes, authorities across New Zealand are reassessing the capacity of older buildings to resist earthquakes. Current legislation requires that a building judged as earthquake prone either be strengthened by retrofitting or be demolished within a legislated number of years. Many building owners are facing the problems of owning earthquake-prone buildings and lacking the funding to upgrade. This affects both community and heritage buildings, resulting in the likely abandonment or demolition of some buildings. To address the problem of the balance between life safety and preservation in the Wellington Region, this project gathered and compared the perspectives of the general public, church communities, heritage specialists, professional engineers, and local authorities to assist in balancing the interests of these stakeholders. As a result of the findings, several recommendations have been provided that include standardizing structural assessment processes and training, feasibility of additional public funding to upgrade buildings, new signage to increase public awareness of earthquake-prone buildings, and regular communication among stakeholders to understand and resolve differences.  相似文献   

9.
On May 12, 2008, an Ms 8.0 earthquake occurred on the Longmen Mountain Fault in Wenchuan County, Sichuan Province, China. Based on the reported earthquake intensity and surface displacement distributions in the affected areas, the damages to buildings in high-intensity areas were investigated. This paper focused on the buildings in Yingxiu Town, Wenchuan County. The unreasonable structural design and structural type were found to be the main reason for the damages of buildings. The geological environment problems of the residential area were also discussed. This research would provide valuable reference for scientific earthquake-resistance design and reconstruction after earthquake disaster.  相似文献   

10.
The structural response of buildings subjected to seismic loads is affected by local site conditions and the interaction between the structure and the supporting soil media. Seismic centrifuge model tests were conducted on two layered clay soil profiles at 80 g field to investigate soil-structure interaction and dynamic response of foundation. Several earthquake-like shaking events were applied to the models using an electro-hydraulic shaking table to simulate linear and nonlinear soil behavior. Results showed that the foundation input motion was significantly amplified in both models, especially for weak earthquake motions. Seismic soil-structure interaction was found to have an important effect on structure response by increasing the amplification of foundation input motion. A 3D finite difference numerical model was also developed to simulate the response of centrifuge model tests and study the parameters that affect the characteristics of earthquake at the base of the structure. The results indicated that the stiffness and stratification of the soil profiles had a significant effect on modifying the foundation input motion.  相似文献   

11.
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   

12.
Endeavors to realistically model physical processes responsible for earthquake occurrence and sustained large uncertainties in the results have lead to the application of techniques like artificial neural network for estimation of rate/probability of earthquake occurrence in future. The earthquake occurrence in India has been re-visited and artificial neural networks have been applied to learn the cyclic behavior of seismicity in the independent seismogenic sources to predict their future trends. As a prerequisite, the whole country has been divided into 24 seismogenic sources for which the seismicity cycles were studied. Their cyclic behavior has been captured in form of four stages of earthquake occurrence and the future trends have been predicted using ANN. To validate the trained ANN model, testing has been carried out in two ways: first, by giving the samples that are not used in training (NT) and second, by giving the total samples (T). As a method of testing, standard errors and correlation coefficients between the network output patterns and observed patterns of the testing sample given were considered. The outcome of the ANN is used to interpret the future seismicity of each of the 24 seismogenic zones in terms of various stages of the future seismicity cycles.  相似文献   

13.
隔震技术     
通过对地震的应力分析,建筑物抗震设计应该考虑对结构体系的地震反应进行控制。夹层橡胶垫隔震技术采用减震调整结构应力特性,使地震作用对上部结构产生的影响显著减小,因此夹层橡胶垫隔震技术是一项比较理想的控制地震反应的技术。  相似文献   

14.
Overview of Taiwan Earthquake Loss Estimation System   总被引:2,自引:1,他引:2  
The National Science Council (NSC) of Taiwan started the HAZ-Taiwan project in 1998 to promote researches on seismic hazard analysis, structural damage assessment, and socio-economic loss estimation. The associated application software, “Taiwan Earthquake Loss Estimation System (TELES)”, integrates various inventory data and analysis modules to fulfill three objectives. First, it helps to obtain reliable estimates of seismic hazards and losses soon after occurrence of large earthquakes. Second, it helps to simulate earthquake scenarios and to provide useful estimates for local governments or public services to propose their seismic disaster mitigation plans. Third, it helps to provide catastrophic risk management tools, such as proposing the seismic insurance policy for residential buildings. This paper focuses on the development and application of analysis modules used in early loss estimation system. These modules include assessments of ground motion intensity, soil liquefaction potential, building damage and casualty.  相似文献   

15.
Bad weather conditions usually limit the acquisition of optical remote sensing images, while all day and all weather synthetic aperture radar (SAR) shows the ability of providing timely remote sensing data for emergency response and rescue works after earthquake. Because SAR is sensitive to the surface changes caused by earthquake, the modified electromagnetic behaviour by geological disasters and the collapse of buildings can be recorded in SAR images as backscattering intensity changes. Absolute radiometric calibration was performed to SAR products to derive backscattering coefficient sigma nought from image digital number (DN). Based on change detection methods, Advanced Land Observing Satellite (ALOS) Phased Array type L-band Synthetic Aperture Radar (PALSAR) data and TerraSAR-X data acquired for the Ms 8.0 Wenchuan earthquake were used to extract earthquake damage information. This study revealed that landslides showed stronger backscattering and barrier lakes showed lower backscattering in post-earthquake 10 m ALOS PALSAR images comparing to pre-earthquake, and collapsed buildings showed lower backscattering compared to un-collapsed buildings in 1 m TerraSAR-X image. Results showed that SAR data with different spatial resolutions are useful for different earthquake damage information extraction: medium spatial resolution SAR data, e.g. 10 m ALOS PALSAR data, were efficient for secondary geological disaster extraction; high-resolution SAR data, e.g. 1 m TerraSAR-X data, with the help of ancillary GIS data or high-resolution optical data, could be used to extract building collapse information in urban areas. This study indicates that SAR remote sensing data can provide earthquake damage information at early emergency stage and assist the field surveying, further damage assessment and post-earthquake reconstruction.  相似文献   

16.
In this paper, for the first time, disk-based discontinuous deformation analysis (DDA) is applied to simulate a real landslide triggered by an earthquake. For this purpose, the kinematic behaviour of the Donghekou landslide triggered by the Wenchuan earthquake is simulated and the results obtained using disk-based DDA are compared with actual data. The comparisons show that there is a good agreement between the results obtained using disk-based DDA and observed data. The simulation results provided an understanding of the failure behaviour and temporal evolution of the landslide. This study shows that disk-based DDA is a practical numerical tool that can be used to simulate the post-failure behaviour of landslides triggered by an earthquake.  相似文献   

17.
On Tuesday, November 17, 2015 at 07:10:07 (UTC) a strong earthquake struck Lefkas Island (Ionian Sea, Western Greece) with magnitude Mw 6.4, depth of about 6 km and epicenter located 20 km southwest of Lefkas town. It was felt in Lefkas Island and the surrounding region and caused the death of two people, the injury of eight others, many earthquake environmental effects (EEE) and damage to buildings and infrastructures. Secondary EEE were observed in western Lefkas and classified as ground cracks, slope movements and liquefaction phenomena. Primary effects directly linked to surface expression of seismogenic source were not detected in the field. The maximum intensity VIIIESI 2007 was assigned to large-volume slope movements along western coastal Lefkas. Damage to buildings was mainly observed in villages located in Dragano-Athani graben arranged almost parallel to the northern segment of the Cephalonia Transform Fault Zone (Lefkas segment). Among structures constructed with no seismic provisions, the stone masonry buildings and monumental structures suffered most damage, while the traditional buildings of the area with dual structural system performed relatively well and suffered minor damage. Reinforced-concrete buildings were affected not so much by the earthquake itself but by the generation of secondary EEE. The maximum seismic intensities VIIIEMS-98 were assigned to villages located in Dragano-Athani graben due to very heavy structural damage observed on masonry buildings mainly attributed to the combination of the recorded high PGA values, the poor antiseismic design and construction of buildings and the geological and tectonic structure of the affected area.  相似文献   

18.
Macroseismic Surveys in Theory and Practice   总被引:1,自引:0,他引:1  
Cecić  Ina  Musson  Roger 《Natural Hazards》2004,31(1):39-61
Macroseismology is the part of seismology that collects and evaluates non-instrumental data on earthquakes, i.e., effects on people, objects, buildings and nature. The methods that seismologists use for collecting and evaluating the macroseismic data are often based on long (trial-and-error) experience more than on some formal procedure. Until very recently manuals or guidelines on how to do a macroseismic survey were rare and often superficial. After an earthquake is felt in some region, the data are usually collected by means of questionnaires. Field survey is an obligatory tool that complements the questionnaires in the case of a damaging earthquake. An overview of the approaches to deriving the earthquake parameters (epicentre and barycentre, epicentral intensity, magnitude, depth, source parametres) from macroseismic data, as well as a review of some existing practices is given.  相似文献   

19.
Andrej Gosar 《Natural Hazards》2012,62(3):1059-1079
Site effects studies using microtremor free-field measurements were performed recently in five Slovenian towns characterized by increased seismic hazard to determine resonance frequency of soft sediments. In this study, microtremor investigations were extended to the measurements inside buildings to determine their fundamental frequencies and to assess the possible occurrence of soil-structure resonance. Measurements were performed in 66 buildings, and by spectral analysis, it was possible to determine reliably fundamental frequencies (longitudinal and transverse) for 58 buildings. Residential masonry houses with two or three floors prevail, but some buildings of up to six-floor height were also surveyed. Microtremor measurements have proved to be an effective tool for assessment of fundamental frequencies of buildings. Such experimental approach is very valuable, as analytical seismic evaluation of an existing building is usually very difficult. Statistical analysis of the fundamental frequency versus number of floors (height) was performed to generalize identification of potential soil-structure resonance. The difference in average fundamental frequency is very clear between buildings with two and three floors. The average value of both horizontal components for two-floor buildings is 9.11?±?1.94?Hz, and for three-floor buildings, 7.03?±?1.46?Hz. On the other hand, the difference in frequencies between three- and four-floor buildings (average for later is 6.52?±?0.80?Hz) is very small. The average fundamental frequencies for five- and six-floor buildings are lower, 4.62?±?0.64?Hz and 5.30?±?0.70?Hz, respectively, with no statistically significant difference between both types. Most Slovenian towns are located in shallow sedimentary basins where the free-field soft covers frequencies are in the range 2?C20?Hz. On the other hand, houses with two and three floors represent the large majority of the building stock. To assess the possible occurrence of soil-structure resonance in general, an average fundamental frequency?±?one standard deviation interval is obtained for these two building heights, which gives the range 5.6?C11.1?Hz. The free-field data show that this frequency range occupies from 22?% of the surveyed area in the Kobarid basin to up to 59?% in the Bovec basin and is in between for other three basins. This leads to the conclusion that the possible occurrence of soil-structure resonance is a serious issue for typical geological situations, in which towns are located.  相似文献   

20.
The aim of this study is the comparison between the fundamental periods identified experimentally and those calculated using the formulas given in the Algerian Seismic Code (RPA 99) for vulnerability assessment and for experimental data collection of selected sample of old buildings. The results obtained for vulnerability assessment will then be extrapolated to buildings of the same typology built during the 1949 to 1954 period in the northern part of Algeria. From 1949 to 1954, the reinforced concrete constructions in Algeria were built before the first generation of the Algerian Seismic Code. These buildings being old are certainly weakened by the occupancy activities and seismic event loads. Hence, the evaluation of their vulnerability with respect to the regional seismic hazard requires the knowledge of their structure on a site capacity. The empirical formulas to calculate the fundamental period of a building are based on the Algerian Earthquake Code (RPA 99) .These formulas consider only the geometrical dimension (length, width and height) and the structural design of the buildings. The fundamental periods of vibration of twenty-two buildings, located in Algiers, calculated using the empirical formulas given in the RPA 99 are lower than those identified experimentally. A question then rises, do these tested buildings present any damage or not? As five of these buildings were tested before the 21 May 2003 earthquake, the experimental testing highlighted a decrease in the fundamental frequency which means that these buildings are damaged. Hence, for vulnerability assessment, the empirical formulas given in the Algerian Seismic Code (RPA 99) may not be appropriate for vulnerability assessment of the old buildings built during the 1949 to 1954 period.  相似文献   

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