Rapid Loss Estimation Research Articles

Empirical relationships between macroseimic intensity and instrumental ground motion parameters for the intermediate-depth earthquakes of Vrancea region, Romania

Empirical relationships between MSK macroseismic intensity and several engineering ground motion parameters are developed using the macroseismic and instrumental data available for five significant earthquakes (Mw magnitude 6 and above), which occurred during the past half-century in Vrancea region, Romania. The relations are suitable for the Carpathian bend zone and surroundings, and they are valid for intensity values between 5 and 8; in this range, the MSK intensity is basically defined by the level of structural damage. The capability of the selected ground motion parameters to predict the macroseismic intensity is evaluated by observing the standard deviations associated with the proposed regression models. Generally, the parameters which take into account the ground motion duration appear to be more stable predictors than the parameters based on the peak ground motion. The most reliable damage indicator appears to be the Arias intensity. The proposed regression relationships provide intensity predictions with uncertainty close to one-half unit; therefore, they are reliable tools for rapid loss estimation and emergency response coordination following a strong earthquake of Vrancea region. The derived equations represent also useful instruments for seismic risk assessment by methodologies based on macroseismic intensity, since in current practice the earthquake hazard and seismic impact are mainly given in terms of engineering ground motion parameters.

Power Loss Prediction for Distributed Energy Resources: Rapid Loss Estimation Equation

The rapid expansion of distributed energy resources has led to increasingly complex systems with numerous power converters. Accurate converter loss prediction in large grids and microgrids is essential for financial and reliability evaluation. Existing system-level analysis focuses on distribution losses and oversimplifies converter losses by assuming fixed efficiency. However, converter losses are highly variable under different operating conditions. Moreover, commercially-available multidomain simulation tools are too slow to be applied to system-level analysis. To provide computationally simple loss prediction under all operating conditions, the rapid loss estimation (RLE) equation is proposed. First, the real operating conditions of the converter are determined for the intended application. Then, accurate loss information is extracted from detailed converter behavior in multidomain simulations. Finally, the RLE equation is obtained: a parametric equation, which is fast enough for system-level simulation while capturing the converter's complexity at different operating conditions. A dc microgrid with three different converters, one each for solar generation, electric vehicle charging stations and battery storage, is considered to highlight the benefits of the proposed loss estimation tool.

Seismic Damage and Rapid Loss Estimation of Retaining Wall Based on the Data from 2008 Wenchuan Earthquake

about statistical probability method in his book.Retaining walls are important part of the highway system. After the Wenchuan earthquake, 375 damaged retaining walls in 3 provinces had been surveyed, the relationship between seismic damage extent with the intensity, the relative location with the fault line, the heights of retaining walls, construct methods, and foundation conditions were analyzed.

Estimating Economic Losses from Earthquakes Using an Empirical Approach

We extended the U.S. Geological Survey's Prompt Assessment of Global Earthquakes for Response (PAGER) empirical fatality estimation methodology proposed by Jaiswal et al. (2009) to rapidly estimate economic losses after significant earthquakes worldwide. The requisite model inputs are shaking intensity estimates made by the ShakeMap system, the spatial distribution of population available from the LandScan database, modern and historic country or sub-country population and Gross Domestic Product (GDP) data, and economic loss data from Munich Re's historical earthquakes catalog. We developed a strategy to approximately scale GDP-based economic exposure for historical and recent earthquakes in order to estimate economic losses. The process consists of using a country-specific multiplicative factor to accommodate the disparity between economic exposure and the annual per capita GDP, and it has proven successful in hindcast-ing past losses. Although loss, population, shaking estimates, and economic data used in the calibration process are uncertain, approximate ranges of losses can be estimated for the primary purpose of gauging the overall scope of the disaster and coordinating response. The proposed methodology is both indirect and approximate and is thus best suited as a rapid loss estimation model for applications like the PAGER system.

ELER software – a new tool for urban earthquake loss assessment

Abstract. Rapid loss estimation after potentially damaging earthquakes is critical for effective emergency response and public information. A methodology and software package, ELER-Earthquake Loss Estimation Routine, for rapid estimation of earthquake shaking and losses throughout the Euro-Mediterranean region was developed under the Joint Research Activity-3 (JRA3) of the EC FP6 Project entitled "Network of Research Infrastructures for European Seismology-NERIES". Recently, a new version (v2.0) of ELER software has been released. The multi-level methodology developed is capable of incorporating regional variability and uncertainty originating from ground motion predictions, fault finiteness, site modifications, inventory of physical and social elements subjected to earthquake hazard and the associated vulnerability relationships. Although primarily intended for quasi real-time estimation of earthquake shaking and losses, the routine is also equally capable of incorporating scenario-based earthquake loss assessments. This paper introduces the urban earthquake loss assessment module (Level 2) of the ELER software which makes use of the most detailed inventory databases of physical and social elements at risk in combination with the analytical vulnerability relationships and building damage-related casualty vulnerability models for the estimation of building damage and casualty distributions, respectively. Spectral capacity-based loss assessment methodology and its vital components are presented. The analysis methods of the Level 2 module, i.e. Capacity Spectrum Method (ATC-40, 1996), Modified Acceleration-Displacement Response Spectrum Method (FEMA 440, 2005), Reduction Factor Method (Fajfar, 2000) and Coefficient Method (ASCE 41-06, 2006), are applied to the selected building types for validation and verification purposes. The damage estimates are compared to the results obtained from the other studies available in the literature, i.e. SELENA v4.0 (Molina et al., 2008) and ATC-55 (Yang, 2005). An urban loss assessment exercise for a scenario earthquake for the city of Istanbul is conducted and physical and social losses are presented. Damage to the urban environment is compared to the results obtained from similar software, i.e. KOERILoss (KOERI, 2002) and DBELA (Crowley et al., 2004). The European rapid loss estimation tool is expected to help enable effective emergency response, on both local and global level, as well as public information.

Computational and rapid expected annual loss estimation methodologies for structures

AbstractExpected annual loss (EAL), which can be expressed in dollars, is an effective way of communicating the seismic vulnerability of constructed facilities to owners and insurers. A simplified method for estimating EAL without conducting time‐consuming non‐linear dynamic analyses is presented. Relationships between intensity measures and engineering demand parameters resulting from a pushover analysis and a modified capacity‐spectrum method are combined with epistemic and aleatory uncertainties to arrive at a probabilistic demand model. Damage measures are established to determine thresholds for damage states from which loss ratios can be defined. Financial implications due to damage can then be quantified in the form of EAL by integrating total losses for all likely earthquake scenarios. This rapid loss estimation method is verified through the computationally intensive incremental dynamic analysis, with the results processed using a distribution‐free methodology. To illustrate the application of the proposed method, the seismic vulnerability of two highway bridge piers is compared; one bridge is traditionally designed for ductility while the other is based on an emerging damage avoidance design (DAD) philosophy. The DAD pier is found to have a clear advantage over the conventional pier; the EAL of the DAD pier is less than 20% of its ductile counterpart. This is shown to be primarily due to its inherent damage‐free behaviour for small to medium earthquake intensities, whose contribution to EAL is significantly more than that of very rare events. Copyright © 2007 John Wiley & Sons, Ltd.

Northridge Welded Steel Moment-Frame Damage Data and Its Use for Rapid Loss Estimation

FEMA-351, Recommended Seismic Evaluation and Upgrade Criteria for Existing Welded Steel Moment-Frame Buildings, offers two methods for estimating seismic losses in pre-Northridge WSMFs: detailed and rapid. The rapid method uses empirical relationships between seismic demand parameters and either damage levels or repair costs. The relationships are based on actual damage data collected after the 1994 Northridge earthquake. This paper summarizes the Northridge data, explains the FEMA-351 rapid method loss functions, and comments on the nature of the damage data and its application to loss estimation. Use of the loss functions can be enhanced by understanding their inherent assumptions and uncertainties and by considering how the underlying data was collected and interpreted in the years following the 1994 earthquake.