Seismic Economic Loss Research Articles

Influence of acceleration-sensitive non-structural element classification on seismic loss estimation of a case-study building in Italy

This study focuses on quantifying the impact of implementing a recently proposed seismic classification procedure for acceleration-sensitive non-structural elements on the seismic economic losses of a three-storey case-study building in Italy. The seismic classification procedure for acceleration-sensitive non-structural elements is based on the performance observed during qualification shake table tests at predefined levels of seismic intensity according to the Italian seismic hazard map. A procedure based on updating the available component fragility functions of acceleration-sensitive non-structural elements is used to link the seismic classification procedure to seismic loss estimation of a case-study school building to quantify the effect of applying the seismic classification procedure for acceleration-sensitive non-structural elements in terms of losses. The case-study building is analysed for six different sites in Italy, considering four structural seismic retrofit strategies, and five levels of non-structural seismic classification. The results demonstrate that the expected annual loss for the building decreases as the seismic qualification performance (or class level) of the acceleration-sensitive non-structural elements increases. This study paves the way for more extensive studies that could help quantify the economic benefits of implementing the seismic classification procedure for non-structural elements at a regional level.

Estimation of economic loss by earthquakes in Taiwan Region

Earthquakes in the Taiwan region have caused significant economic losses. We develop a model to assess seismic economic losses in the Taiwan region using the records of economic losses caused by historical earthquakes. Unlike existing models, we introduce Gross National Income Per Capita (GNIPC) as a parameter that responds to the influence of socio-economic development. The results show that our model can accurately estimate the earthquake economic losses in Taiwan region. The difference between the results of this model and those of existing models is evident, indicating differences between the Taiwan region and mainland China regarding geological background, seismic tectonics, and social resistance to earthquakes. The prediction results also imply that the society significantly underestimates the seismic economic losses in the Taiwan region. Our model can help the Taiwan region in disaster prevention and preparedness, contingency planning, allocation of relief resources, and post-disaster socio-economic recovery.

Failure Probability and Economic Loss Assessment of a High-Rise Frame Structure under Synthetic Multi-Dimensional Long-Period Ground Motions

Multiple research studies and seismic data analyses have shown that multi-directional long-period ground motion affects crucial and intricate large-scale structures like oil storage containers, long-span bridges, and high-rise buildings. Seismic damage data show a 3–55% chance of long-period ground motion. To clarify, the chance of occurrence is 3% in hard soil and 83% in soft soil. Due of the above characteristics, the aseismic engineering field requires a realistic stochastic model that accounts for long-period multi-directional ground motion. A weighted average seismic amplification coefficient selected NGA database multi-directional long-period ground motion recordings for this study. Due to the significant low-frequency component in the long-period ground motion, this research uses empirical mode decomposition (EMD) to efficiently decompose it into a composite structure with high- and low-frequency components. Given the above, further investigation is needed on the evolutionary power spectrum density (EPSD) functions of high- and low-frequency components. Analyzing the recorded data will reveal these functions and their corresponding parameters. Proper orthogonal decomposition (POD) is needed to simulate samples of high- and low-frequency components in different directions. These samples can be combined to illustrate multi-directional long-period ground motion. Representative samples exhibit the seismic characteristics of long-period multi-directional ground motion, as shown by numerical examples. This proves the method’s engineering accuracy and usefulness. Moreover, this study used incremental dynamic analysis (IDA) to apply seismic vulnerability theory. This study investigated whether long-period ground motions in both x and multi-directional directions could enhance the seismic response of a high-rise frame structure. By using this method, a comprehensive seismic economic loss rate curve was created, making economic loss assessment clearer. This study shows that multi-directional impacts should be included when studying seismic events and calculating structure economic damages.

Seismic economic loss assessment of highway girder bridges using Wenchuan earthquake as a sample

Seismic economic loss assessment of highway girder bridges using Wenchuan earthquake as a sample

Seismic Economic Loss Assessment of Highway Girder Bridges Using Wenchuan Earthquake as a Sample

Seismic Economic Loss Assessment of Highway Girder Bridges Using Wenchuan Earthquake as a Sample

Earthquake Economic Loss Assessment of Reinforced Concrete Structures Using Multiple Response Variables

For buildings that meet the requirements of current seismic design codes, damage to nonstructural components and the internal objects of buildings often become the main source of the seismic economic losses of these buildings. However, the current specifications only consider the safety of ‘no collapse under strong earthquake’ and do not consider ‘functional recoverability’. In this paper, a six-story frame building was taken as an example. Four joint performance limit states were proposed, as per FEMA 273, to establish a two-dimensional probabilistic seismic demand model that considers parameter correlations. The limit state function was established, and the two-dimensional seismic vulnerability curve was calculated. The seismic intensity–economic loss curve and the annual average economic loss established by one-dimensional and two-dimensional seismic vulnerability curves were compared. The results showed that the seismic performance of the structure was lower than expected when using only a one-dimensional seismic vulnerability curve. However, the situation was more serious under high-intensity earthquake and high-performance levels.

The use of Stick-IT model in loss assessment at the large scale

Direct economic losses represent a convenient proxy to communicate seismic risk to stakeholders both at the building and at the large-scale level. In the perspective of a performance-based approach, seismic economic losses can be calculated starting from the response of single buildings expressed in terms of engineering demand parameters such as interstory drift ratios and peak floor accelerations. This way the distribution and the extent of earthquake-induced damage can be estimated for various structural and nonstructural components and buildings content. The Stick-IT, which is a MDOF system consisting of a series of masses lumped at the story level connected by nonlinear shear link elements, has been recently proposed and calibrated to predict the response, in terms of engineering demand parameters, for infilled RC building typologies.This paper adopts the Stick-IT model within a probabilistic framework to predict the expected direct losses for a portfolio of buildings damaged and repaired in the aftermath of the L'Aquila 2009 earthquake. The predicted losses are compared with the actual repair costs showing.

Observational loss database of typological precast RC buildings damaged after the 2012 Emilia Earthquake

The Emilia Earthquake occurred in 2012 in a highly industrialized area, characterized by the presence of about one firm every 9 inhabitants. The industrial heart of the region hosts many important clusters, from the Motor Valley to Food, Wellbeing, Fashion and Health devices. The main activities are conducted in production districts with several different long-span buildings like storages, deposits, warehouses, factories and silos. Among these, those made of precast reinforced-concrete (RC) elements were heavily damaged by the seismic sequence, resulting in a huge amount of economic losses due to damage to structures, products and machineries, business interruption and casualties. In the aftermath of the earthquake, the Region defined the criteria for the request of funds for the reconstruction of the buildings, the restoration of the products, the reparation of the equipment, and the temporary relocation of the activities. Thus, a large number of documents was collected reporting a variety of information concerning the seismic damage, the structural properties of the buildings, and the economic costs.In this work, through a process of progressive selection and refinement of the data, a database of seismic economic losses of damaged precast RC buildings was created. The main principles for the creation of the repository and the categorization of the information are illustrated. Hence, the losses were statistically analysed to derive useful consequence functions based on the investigation of diversified trends of the repair costs at different damage levels. The outcomes presented in this study may be adopted to perform loss assessment evaluations to guide the decision-makers in establishing priorities of structural interventions to reduce the consequences of future earthquakes in industrial areas.

Seismic vulnerability analysis of reinforced concrete frame with infill wall considering in-plane and out-of-plane interactions

The seismic performance of a building hinges on the seismic capacity and damage features of the reinforced concrete (RC) frame with masonry infill walls. To reasonably evaluate the seismic performance and seismic economic loss of masonry infill walls, it is necessary to consider the in-plane (IP) and out-of-plane (OOP) interactions of these walls under seismic actions, and to model the vulnerability of the infill walls and the frame. Based on the test data on masonry infill walls, this paper designs a performance indicator for infill wall in the light of IP-OOP interactions, and determines the response threshold of each damage state. With the aid of OpenSees, the authors developed and verified a reasonable modeling method for RC frames with infill walls. As per the current code in China, a 5-storey RC frame with infill walls was designed, and two three-dimensional (3D) space models were established for the structure by the proposed modeling method. One of them considers IP-OOP interactions, and the other does not. Then, the structure was subjected to incremental dynamic analyses (IDA), and different damage indicators were determined to examine the damage of the infill walls and the overall structure, producing a set of vulnerability curves. The results show that the consideration of IP-OOP interactions significantly increases the probability of seismic damages on the infill walls and the overall structure. The most prominent increase was observed in the medium to serious damage stages.

Seismic Vulnerability Assessment of Thermal Power Plants Based on Beta Function

The study on seismic vulnerability of thermal power plants is of great significance for seismic damage prevention of the electrical power system and risk analysis of seismic economic loss. This paper presented a study method for obtaining the seismic vulnerability matrix and vulnerability curve of thermal power plants based on beta function. Firstly, according to the study results of thermal power plants in American ATC-25 report, the expected values of seismic damage indexes of thermal power plants under different seismic intensities were calculated. It was assumed that the expected values of seismic damage indexes of substation and thermal power plant were the same, and the dispersion of distribution of seismic damage indexes was the same. Then, based on the actual seismic vulnerability matrix of substations obtained from statistics in Wenchuan earthquake, the seismic vulnerability matrix of thermal power plants under different seismic intensities was fitted by using the probability density function of beta distribution. Finally, the seismic vulnerability curve of the thermal power plant based on peak ground acceleration (PGA) was obtained by using the cumulative function curve of standard lognormal distribution. The calculation results show that the seismic damage ratio calculated from the seismic vulnerability matrix of thermal power plants is basically consistent with the seismic damage ratio in ATC-25 report.

Estimation of Seismic Economic Loss and Downtime of Precast Concrete Frames with “Dry” Connections

The seismic loss of buildings comes not only from the damaged structural components. Much more loss may be induced by non-structural components, the demolition loss and social impacts associated with excessive downtime. One of the main characteristics of a resilient city is that the buildings in the city should be able to recover to their pre-earthquake functionalities with minimized economic loss and downtime. For this purpose, a comparative study regarding seismic economic loss and downtime is conducted between the conventional cast-in-situ reinforced concrete frames (RCFs) and precast concrete frames (PCFs) with "dry" connections. The results show that the PCFs with prestressed tendons (PTs) can effectively reduce demolition loss given their extraordinary self-centering capacity provided by PTs. By adding web friction devices at the beam ends, the economic loss of structural components and drift-sensitive non-structural components can be effectively reduced. The downtime of PCFs is reduced at given hazard levels compared with RCF given their rapid repair speed and easy assemblage. In view of the rapid post-earthquake repair and lower earthquake loss, the PCFs are worth further investigation and application to develop resilient cities.

Rapid Seismic Economic Loss Assessment for Steel Concentrically Braced Frames Designed to Eurocode 8

AbstractThis paper presents a rapid method for calculating the expected earthquake repair costs incurred by steel concentrically braced frame structures designed to Eurocode 8. The method adopts the FEMA P‐58 performance assessment methodology which is based on the predicting Engineering Demand Parameters (EDPs), such as peak inter‐story drift and peak floor acceleration, at various seismic hazard intensity levels of interest and then using these EDPs to calculate expected damage and associated economic losses. Typically, multiple nonlinear time history analyses (NLTHA) are employed to calculate the required EDPs, however this can be computationally expensive and technically challenging. This paper proposes the use of regression equations, developed from a large number of nonlinear analyses, as an alternative to NLTHA for EDP prediction. This allows loss assessment to be carried out without the need for multiple NLTHA, a process termed rapid loss assessment. The proposed equations are applied in loss assessment for three case study CBFs. It is shown that the economic losses predicted by the rapid method compare well with results obtained from conventional NLTHA‐based assessment.

Seismic economic losses in mid-rise steel buildings with conventional and emerging lateral force resisting systems

This paper investigates the seismic loss performances of mid-rise steel buildings adopting different lateral force resisting systems. The considered lateral force resisting systems include a moment resisting frame, a buckling restrained braced frame, and a frame consisting of re-centering non-buckling braces, which are denoted as MRF, BRBF, and RNBF, respectively. MRF and BRBF were designed following the equivalent lateral force procedure. The re-centering non-buckling braces in RNBF were intentionally designed to enable the system to have the same elastic inter-story strengths and stiffness values as BRBF. Incremental dynamic analyses (IDA) were performed for the three considered systems and the IDA result database were converted into their respective vulnerability functions. This research establishes economic loss performance pyramids based on the critical quantities identified from the vulnerability functions. Taking the volume of the economic loss performance pyramid as a measure, the authors compared the respective advantages and limitations of the considered systems in mitigating seismic economic losses.

Indirect seismic economic loss assessment and recovery evaluation using nighttime light images – application for Wenchuan earthquake

Abstract. Indirect seismic economic loss not only impacts regional economic recovery policies but is also related to economic assistance at the national level. Due to cross-regional economic activities and the difficulty of obtaining data, it is difficult for the indirect economic loss survey to cover all economic activities. However, nighttime light in an area can reflect the economic activity of the region. This article focuses on the indirect economic losses caused by the 2008 Wenchuan earthquake and evaluation of the progress of restoration and reconstruction based on nighttime light images. First, the functional relationship between GDP and nighttime light parameters is established based on pre-earthquake data. Next, the indirect loss of the earthquake is evaluated by the nighttime light attenuation in the disaster area after the earthquake. Then, the capacity recovery, which is characterized by the brightness recovery process of the light area, is evaluated. Lastly, the process of light expansion in the disaster area is analyzed to evaluate the speed and efficiency of economic expansion.

A Multi-Step Approach to Assess the Lifecycle Economic Impact of Seismic Risk on Optimal Energy Retrofit

Most European buildings built before 1980s were constructed without any design concern for energy efficiency and environmental sustainability. In addition to this issue, over the last decades, the essential need of safer buildings has progressively attracted the interest of scientific community and government institutions. However, the strong interaction between energy and structural aspects in building retrofit design has never been handled via robust and reliable approaches. The present study explores this knowledge gap by introducing a novel multi-step approach that addresses the retrofit of existing buildings by integrating energy, structural and economic aspects. To this end, a multi-stage energy optimization is carried out by implementing a genetic algorithm and a smart research strategy. Thus, the cost-optimal energy retrofit solution is identified and the impact of the expected economic losses due to seismic damage is assessed throughout the building lifecycle. The methodology is applied to a multi-story residential building, considering the effects of two different building locations, namely Milan and Norcia. These latter are characterized by similar climatic conditions but by a different level of seismic risk, which is higher for Norcia. The outcomes show that the estimated seismic economic losses associated with the energy retrofit solutions are strongly affected by the building location. Thus, the selection of the optimal energy retrofit measures should be related to the building structural behavior in order to achieve reliable economic and sustainability benefits.

Evolution of earthquake losses in Portuguese residential building stock

The evolution of the expected earthquake losses in different Portuguese regions was studied in order to determine whether the natural regeneration of buildings could contribute to the mitigation of seismic risk, although the building exposure has increased over time in most analysed regions. To achieve this goal, five inter-related risk indicators were estimated, based on the Portuguese censuses’ surveys of residential buildings and inhabitants obtained in two different moments in time: 2001 and 2011. The FEMA (2008) approach was used to estimate the risk indicators, i.e., the Annualized Economic and Human earthquake Losses, either in absolute terms or normalised by building and population exposure. This study offers a perspective of the seismic risk in the Portuguese mainland, provides a comparison of risk levels between different epochs, and analyses the obtained results in order to compare the risk among Portuguese regions. It is important to mention that the comparison of economic losses based on the building stocks surveyed in 2001 and in 2011 took into account the Portuguese inflation rate in that time interval. The main findings of the study show that the natural regeneration of the residential housing stock contributes to the reduction of the expected seismic economic losses in Portugal, at an average rate of 14 % per 10 years, and to the reduction of the expected annualized human losses to almost one half after 10 years. The results support the conclusion that the natural regeneration of the residential housing stock contributed to the mitigation of the seismic risk in mainland Portugal, in the 10 year period under analysis, even though there was an increase of the building exposure in the region.

Study on Fast Prediction Model of Seismic Economic Loss Based on GA-ANN Macroscopic Vulnerability Method

It is well-known that seismic disaster will cause serious damage, so the prediction and evaluation of seismic loss before earthquake event happened can provide foundation of disaster reduction program. And after seismic event happened, it is very important to fast evaluate the seismic disaster loss. Traditional seismic loss prediction method is vulnerability list method which need detailed information about all kinds of structures and facilities of the evaluated areas, and for most areas, it is very difficult to get such detailed information. This paper brings forward a new simple fast prediction method for seismic economic loss. Firstly, a macroscopic vulnerability model was discussed. secondly, a three-layer BP network model for seismic economic loss prediction is built up, BP network model is one of the most widely used artificial neural network (ANN) model, but due to its deficiencies such as easy to get into local extreme minimum value, genetic algorithm (GA) is introduced to overcome the deficiencies. In this model, seismic intensity, average GDP per capita and per area, population density are selected to be the input layer index, and GDP loss ratio as the output layer, 80 earthquake events which happened recent years are regarded as training and check up samples. Finally, the economic loss caused by Wenchuan earthquake is evaluated by the proposed model, and the feasibility and practicability are validated by the numerical example.

An Earthquake Loss Assessment Method to Buildings in Urban Zones and Its Application in Wenchuan Ms8.0 Great Earthquake

The national standard《Post-earthquake field works Part 4: Assessment of direct loss》 (GB 18208.4-2005) has been playing an important role in earthquake loss assessment, relief organization and homeland rehabilitation since it was issued in 2005 in China. The earthquake losses assessed are much less than other natural disasters (such as floods, drought) or foreign earthquake losses. How to assess seismic economic loss reasonably has been a key issue domestic seismic workers concern. In this paper, an earthquake-induced building decoration loss assessment method for urban zones is presented firstly. Then, based on statistical analysis of collected more than 600 pieces of cost data and 30 pieces of expert questionnaires, the distribution proportion of moderate–and–high–grade decoration building, the proportion of decoration cost and total structure cost, the loss ratio of decoration damage in small, Medium and big cities are given, respectively. The correction coefficients are also given depending on different economic development and use. Finally, its practical application in Sichuan Wenchuan Ms8.0 great earthquake loss assessment is introduced. Thus, some references and basis for further modifying and perfecting earthquake loss assessment standard in China are provided.

Research on performance-based seismic design criteria

The seismic design criterion adopted in the existing seismic design codes is reviewed. It is pointed out that the presently used seismic design criterion is not satisfied with the requirements of nowadays social and economic development. A new performance-based seismic design criterion that is composed of three components is presented in this paper. It can not only effectively control the economic losses and casualty, but also ensure the building’s function in proper operation during earthquakes. The three components are: classification of seismic design for buildings, determination of seismic design intensity and/or seismic design ground motion for controlling seismic economic losses and casualties, and determination of the importance factors in terms of service periods of buildings. For controlling the seismic human losses, the idea of socially acceptable casualty level is presented and the ‘Optimal Economic Decision Model’ and ‘Optimal Safe Decision Model’ are established. Finally, a new method is recommended for calculating the importance factors of structures by adjusting structures service period on the base of more important structure with longer service period than the conventional ones. Therefore, the more important structure with longer service periods will be designed for higher seismic loads, in case the exceedance probability of seismic hazard in different service period is same.