基于复杂网络的建筑物强震下抗毁性估计模型

城市所处的地震危险性环境和城市建筑物的易损性是影响复杂网络建筑物强震环境下抗毁能力的关键因素。由于现阶段对建筑物抗震抗毁能力的评定仍存在一定困难,对建筑物震害程度测评只能通过强震之后建筑物受破坏的程度进行评估,且评估结果不够精准,因此提出基于复杂网络的建筑物抗震能力的评估方法。考虑到地震中的危险性因素,以地面峰值加速度为参数对强震环境下复杂网络建筑物抗毁性进行测评和分析,在此基础上提出对复杂网络下建筑物的防震抗毁能力进行评估的相对建筑物抗震性能指数,并结合建筑物抗震能力评估标准确定其抗震能力水平;再进行仿真实验加以测量,并结合震害经验,证实该方法的有效性。     

基于BP神经网络模型的多层砖房震害预测方法

针对传统的基于地震烈度的建筑物震害预测方法的不足,本文以地震动峰值加速度作为建筑物震害预测的地震动指标,结合几次大地震中多层砖房的震害实例,提出了一种基于BP神经网络模型的建筑物震害预测方法,模型的输入为反映结构抗震性能的各类物理参数,输出为给定地震动峰值加速度下建筑物破坏状态的概率。研究表明:基于BP网络模型的多层砖房的震害预测结果与震害实例的实际情况比较吻合,本文的思路和方法可推广于其他不同类型的建筑结构的震害预测。     

Building vulnerability assessment and damage scenarios in Celano (Italy) using a quick survey data-based methodology

A procedure for assessing the seismic vulnerability of residential buildings is presented along with the results of its application in an Italian town in Abruzzo (Celano Aq). This procedure is part of a methodological proposal which includes specific studies on expected seismic inputs and site effects analyses. The procedure is based on a simplified collection of data, such as typological features and factors concerning the seismic behaviour of buildings, and provides an estimate of seismic vulnerability and an expected damage forecast using fragility curves. The instruments and methods used for the Celano project are an updated and improved version of those applied to previous vulnerability investigations. This paper demonstrates how this procedure can meet the objectives of the integrated methodology proposed. In fact, the information that can be obtained using this procedure—state of vulnerability, risk analyses and GIS presentations of damage scenarios—could be used in urban planning to reduce seismical risk.     

Vulnerability Analysis in Earthquake Loss Estimate

The adobes in Costa Rica have almost the same vulnerability as the old civil houses in China, which represent vulnerability in the worst case. On the other hand, the high quality buildings in Costa Rica have the same vulnerability as the reinforced concrete buildings in China due to the adoption of state-of-art techniques in design and construction, which represent the vulnerability of the best case. The macroeconomic vulnerability defined by Chen et al. falls in the middle of the two extreme cases of the inventory studied because the total macroscopic loss is the sum of losses of different types of buildings and facilities. Therefore the macroeconomic vulnerability must be greater than that of the best case and less than that of the worst. The use of macroscopic vulnerability in earthquake loss estimate is easy, simple and feasible. The vulnerability plots are preliminary in nature and should be refined with additional earthquake loss data.     

地震损失预测评估中的易损性分析

代表着地震易损性中最坏情形的哥斯达黎加土坯房和中国老旧民房有着几乎相同的易损性,而表示地震易损性中最好情形的哥斯达黎加高质量楼房和中国钢筋混泥土结构楼房,由于采用了现代设计和建筑技术,也有着相同的易损性。陈Ｙｏｎｇ等提出的宏观经济易损性位于常规易损性分类清单中的这两种极端情况之间,因为宏观经济损失是各种建筑设施损失的总和,故宏观经济易损性差于最好的建筑情况,而优于最坏的情况。采用宏观经济易损性的地     

Application of neural networks in natural periods identification and simulation of prefabricated buildings response

The paper deals with an application of neural networks for detection of natural periods of vibrations of prefabricated, medium height buildings. The neural network technique is also used to simulate the dynamic response at selected floor of one of the analysed buildings subject to seismic loading induced by explosives in a nearby quarry. Both the training and testing patterns were formulated on the basis of measurements performed on actual structures. The results of neural network identification of natural periods of the considered buildings obtained with different soil, geometrical and stiffness parameters are compared with the results of experiments. The application of back-propagation neural networks enables us to identify the natural periods of the buildings with accuracy quite satisfactory for engineering practice. The experimental and generated data of vibration displacements are compared and much clearer comparison is given on the phase plane: displacements versus velocities. It was stated that a good generalization takes place both with respect to displacements and velocities.     

Deriving vulnerability curves using Italian earthquake damage data

The concerted effort to collect earthquake damage data in Italy over the past 30 years has led to the development of an extensive database from which vulnerability predictions for the Italian building stock can be derived. A methodology to derive empirical vulnerability curves with the aforementioned data is presented herein and the resulting curves have been directly compared with mechanics-based vulnerability curves. However, it has been found that a valid comparison between the empirical and analytical vulnerability curves is not possible mainly due to a number of shortcomings in the database of surveyed buildings. A detailed discussion of the difficulties in deriving vulnerability curves from the current observed damage database is thus also presented.     

A fast approach to regional earthquake hazard evaluation based on population statistical data

In the prediction process of large-scale earthquake damage occurred in urban and rural regions,new models and approaches,which are different from traditional ones,should be adopted to rapidly predict earthquake damage. This article utilizes sampled population and buildings data that is easily available from the statistical database to conduct vulnerability analysis of buildings on the basis of earthquake damage of existing urban buildings in an analogical way,so as to provide a relation model between population data and disaster losses. In virtue of this model,the average vulnerability matrix of buildings of different structures in Fujian Province is established,the matrix adjustment coefficient of different decades is developed in accordance with the economic conditions,and the rapid evaluation system is set up as well. The result shows: this evaluation model,based on the population statistical data has merits as small investment,automatic data prediction,regular updates,as well as the advantage of easy accessibility.     

On the vulnerability assessment of monumental buildings

In all European countries the will to conserve the building heritage is very strong. Unfortunately, large areas in Europe are characterised by a high level of seismic hazard and the vulnerability of ancient masonry structures is often relevant. The large number of monumental buildings in urban areas requires facing the problem with a methodology that can be applied at territorial scale, with simplified models which need little easily obtainable, data. Within the Risk-UE project, a new methodology has been stated for the seismic vulnerability assessment of monumental buildings, which considers two different approaches: a macroseismic model, to be used with macroseismic intensity hazard maps, and a mechanical based model, to be applied when the hazard is provided in terms of peak ground accelerations and spectral values. Both models can be used with data of different reliability and depth. This paper illustrates the theoretical basis and defines the parameters of the two models. An application to an important church is presented.     

Damage to residential buildings in Hveragerði during the 2008 Ölfus Earthquake: simulated and surveyed results

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.     

Damage data analysis and vulnerability estimation following the August 14, 2003 Lefkada Island, Greece, Earthquake

Earthquake damage data is of vital importance both as an indicator of the likely performance of buildings in future earthquakes, as well as for the calibration of existing theoretical-analytical models regarding building vulnerability. The analysis of damage data collected shortly after the August 14, 2003 Lefkada Island, Greece earthquake revealed the higher vulnerability of masonry buildings vis-à-vis all other building typologies on the island. However, promising means in strengthening the existing masonry stock emerge, when considering the improved performance of buildings of a dual-system of stone-masonry and timber frame – a construction practice uniquely adopted in the island. Based on the parameterless seismic intensity scale (psi) proposed by Spence et al. (1991) a set of preliminary vulnerability curves for the typologies of the island’s buildings are proposed.     

基于灰关联与人工神经网络综合评价模型的多层砖房震害预测

结合几次大地震中多层砖房的实际震害资料,基于灰关联识别方法,解析了各影响因子对多层砖房抗震性能的影响程度。以反映结构抗震性能的各类物理参数作为输入数据,以给定地震动峰值加速度下建筑物破坏状态的概率作为输出数据,采用8-6-5层结构,建立了基于BP人工神经网络的非线性模型,并对震害样本进行了训练。结果表明:利用灰关联分析,可得出各因子对多层砖房抗震性能影响程度的大小排序,有利于实际的工程抗震设计;基于BP人工神经网络模型的多层砖房的震害预测结果与震害实例的实际情况比较吻合,其思路和方法可推广于其他不同类型的建筑结构的震害预测。     

城市典型建筑的地震损失预测方法I：结构易损性分析

地震作用下结构的易损性分析是地震灾害损失预测方法的重要组成部分。本文针对多层砌体房屋结构、排架结构和多层钢筋混凝土结构等3种城市典型建筑，首先给出了该类单体建筑的地震结构易损性分析方法，然后对群体建筑的地震易损性分析方法，以及群体建筑的易损性分类方法进行了探讨，为城市典型建筑的地震灾害损失预测和评估提供参考，并为宁波市抗震防灾规划的地震损失预测提供基础。     

Framework for the derivation of analytical fragility curves and life cycle cost analysis for non-seismically designed buildings

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.     

Evaluation of displacement‐based vulnerability assessment methodology using observed damage data from Christchurch

On 22 February 2011, Christchurch City experienced a destructive magnitude (Mw) 6.2 aftershock following the main event of magnitude (Mw) 7.1 on the 4 September 2010. Severe damage was inflicted on the building stock, particularly within the central business district (CBD) of Christchurch. The strong motion stations around the CBD region and extensive building damage survey information from the Christchurch City Council provided a unique opportunity to calibrate a theoretical regional vulnerability assessment model developed and refined to be applicable for New Zealand (NZ) buildings. In this study, data from the building safety evaluation survey conducted by Christchurch City Council are synthesised and processed to extract details on building typologies in the CBD region and the colour tagging assigned to each building depending on the degree of damage. A displacement‐based framework is used to carry out vulnerability assessment for Christchurch buildings to estimate damage sustained under the recorded ground motions in the February event. As the damage survey indicators were ‘colour tags’, a mapping scheme has been explored to link the observed colour tagging damage statistics with ‘drift‐based damage limit states’ adopted in the theoretical approach. A sensitivity analysis is carried out to calibrate the mapping scheme, which can provide estimates of proportions of buildings likely to fall in different colour regimes when used in conjunction with the proposed vulnerability assessment methodology. It is shown that the methodology is reasonably robust, thereby increasing the confidence in using this approach to predict seismic vulnerability of building stock in NZ. Copyright © 2014 John Wiley & Sons, Ltd.     

An inventory of buildings in the city of Tunis and an assessment of their vulnerability

Tunis is a densely populated city. Its building stock was constructed without any seismic design code and mostly over soft soils. These facts make a seismic risk assessment of the city necessary. To prepare a large-scale vulnerability assessment of the buildings of Tunis, the following methodology was employed: (1) a collection of data based on a rapid visual screening procedure was gathered using an inventory form. These data were composed of files and information placed at the disposal of the authors by the municipality of Tunis. The data also contained information gathered by surveys carried out by engineering departments and information gathered from building owners. (2) A classification of building typologies was carried out considering construction material, structural system, age, height, function and state of maintenance. A measure of seismic vulnerability was assigned to each typology considering the first two parameters. (3) A large-scale vulnerability assessment using two methods was conducted for buildings for which few data were available. Vulnerability methods inspired by the EMS98 concepts and the Italian GNDT concepts were modified and applied to pilot-scale buildings located in the downtown zone (Habib Bourguiba Avenue) and in the old zone (Medina). The data analysis, through the application of the two methods, suggests that the vulnerability of buildings surveyed in Tunis is significant and risk mitigation efforts are necessary.     

城市典型建筑的地震损失预测方法Ⅰ: 结构易损性分析

地震作用下结构的易损性分析是地震灾害损失预测方法的重要组成部分。本文针对多层砌体房屋结构、排架结构和多层钢筋混凝土结构等3种城市典型建筑,首先给出了该类单体建筑的地震结构易损性分析方法,然后对群体建筑的地震易损性分析方法,以及群体建筑的易损性分类方法进行了探讨,为城市典型建筑的地震灾害损失预测和评估提供参考,并为宁波市抗震防灾规划的地震损失预测提供基础。     

Estimating building exposure and impact to volcanic hazards in Icod de los Vinos,Tenerife (Canary Islands)

Principal and subsidiary building structure characteristics and their distribution have been inventoried in Icod, Tenerife (Canary Islands) and used to evaluate the vulnerability of individual buildings to three volcanic hazards: tephra fallout, volcanogenic earthquakes and pyroclastic flows. The procedures described in this paper represent a methodological framework for a comprehensive survey of all the buildings at risk in the area around the Teide volcano in Tenerife. Such a methodology would need to be implemented for the completion of a comprehensive risk assessment for the populations under threat of explosive eruptions in this area. The information presented in the paper is a sample of the necessary data required for the impact estimation and risk assessment exercises that would need to be carried out by emergency managers, local authorities and those responsible for recovery and repair in the event of a volcanic eruption. The data shows there are micro variations in building stock characteristics that would influence the likely impact of an eruption in the area. As an example of the use of this methodology for vulnerability assessment, we have applied a deterministic simulation model of a volcanic eruption from Teide volcano and its associated ash fallout which, when combined with the vulnerability data collected, allows us to obtain the vulnerability map of the studied area. This map is obtained by performing spatial analysis with a Geographical Information System (GIS). This vulnerability analysis is included in the framework of an automatic information system specifically developed for hazard assessment and risk management on Tenerife, but which can be also applied to other volcanic areas. The work presented is part of the EU-funded EXPLORIS project (Explosive Eruption Risk and Decision Support for EU Populations Threatened by Volcanoes, EVR1-2001-00047).     

Macroseismic and mechanical models for the vulnerability and damage assessment of current buildings

The European Commission funded the RISK-UE project in 1999 with the aim of providing an advanced approach to earthquake risk scenarios for European towns and regions. In the framework of Risk-UE project, two methods were proposed, originally derived and calibrated by the authors, for the vulnerability assessment of current buildings and for the evaluation of earthquake risk scenarios: a macroseismic model, to be used with macroseismic intensity hazard maps, and a mechanical based model, to be applied when the hazard is provided in terms of peak ground accelerations and spectral values. The vulnerability of the buildings is defined by vulnerability curves, within the macroseismic method, and in terms of capacity curves, within the mechanical method. In this paper, the development of both vulnerability and capacity curves is presented with reference to an assumed typological classification system; moreover, their cross-validation is presented. The parameters of the two methods and the steps for their operative implementation are provided in the paper.     

Application of artificial neural networks in optimal tuning of tuned mass dampers implemented in high-rise buildings subjected to wind load

High-rise buildings are usually considered as flexible structures with low inherent damping. Therefore, these kinds of buildings are susceptible to wind-induced vibration. Tuned Mass Damper (TMD) can be used as an effective device to mitigate excessive vibrations. In this study, Artificial Neural Networks is used to find optimal mechanical properties of TMD for high-rise buildings subjected to wind load. The patterns obtained from structural analysis of different multi degree of freedom (MDF) systems are used for training neural networks. In order to obtain these patterns, structural models of some systems with 10 to 80 degrees-of-freedoms are built in MATLAB/SIMULINK program. Finally, the optimal properties of TMD are determined based on the objective of maximum displacement response reduction. The Auto-Regressive model is used to simulate the wind load. In this way, the uncertainties related to wind loading can be taken into account in neural network’s outputs. After training the neural network, it becomes possible to set the frequency and TMD mass ratio as inputs and get the optimal TMD frequency and damping ratio as outputs. As a case study, a benchmark 76-story office building is considered and the presented procedure is used to obtain optimal characteristics of the TMD for the building.