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Sub-project 11: Disaster scenarios predictions and loss modelling for infrastructures The goal of this Sub-Project is to create a set of tools, based on state-of-the-art modelling software for earthquake loss scenarios, capable of: (a) Efficiently generating maps that quantify strong earthquake ground shaking at urban/regional scale, suitable for lifeline systems (not including road and transportation systems, covered in a different WP), as well as earthquake-induced permanent ground deformations (landsliding, liquefaction) (b) Constructing in a GIS environment earthquake-induced damage and loss scenarios for selected lifeline systems, providing a basis for estimating indirect costs and incorporating uncertainties involved in the analysis (c) Identifying and testing possible mitigation actions, to support decision-making by city and regional authorities for seismic risk mitigation actions (d) Performing GIS-based post-earthquake operational analysis, e. g. updating of ground shaking and expected damage maps as real time data flow in The previous tools are to be applied and tested in two/three case study areas in regions of moderate and high seismic risk. Examples of the questions to which answers are required to support such decision-making are: What are the benefits of restricting future urban development in particular zones of higher than average expected ground motion, or prone to significant, earthquake-induced permanent ground deformations?
The application of project results to reference cities in which significant experience and data have already been collected in previous projects is expected to calibrate the answers to the previous questions. The Sub-project is coordinated by SGI-MI, featuring also the participation of AUTH, INGV, KOERI and MUNICHRE. Disseminated material related to this Sub-Project can be found by clicking each of the links below: Deliverables
Presentations
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Meetings A summary of each of the tasks involved in this Sub-Project is provided below: Task 2.4b.1: Earthquake shaking scenarios
Unlike for above-ground structures, earthquake-generated inertia forces are not the main cause of damage to underground structures such as tunnels or pipelines. Rather, damage is closely related to ground motion. Therefore, loss modelling for underground infrastructures requires the use of predictive tools to map at urban/regional scale the most relevant ground motion parameters related to damage of lifelines. For this purpose, the seismic ground response can be roughly subdivided into two broad classes: a) so-called induced deformation effects, such as ground failure due to fault ruptures, slope instability, liquefaction; b) ground shaking, associated to dynamic longitudinal or shear strains in the structure. Given the spatial extension of the area covered by a lifeline network, the objective of this task is to calibrate simple methods for predicting the areal variation of both types of earthquake ground response, to be implemented in a GIS environment. Thus, the main steps of this task are outlined as follows: Ground failure
Ground shaking experimental and numerical analysis of effects of soil heterogeneity on the spatial variability of ground motion, with emphasis on parameters such as peak ground velocity and displacement, maximum axial and shear strains, duration, that closely control the seismic response of lifeline systems
development of empirical formulas, based on the previous results, relating peak ground strains to a few parameters representative of subsoil conditions (e.g. soil stiffness, local slope of the bedrock, depth of the bedrock, lateral impedance) and peak ground velocity or displacement; the subsoil configuration parameters may be estimated also by combining different geophysical methods such as refraction and gravimetric surveys
Task 2.4b.2: Improved vulnerability functions A comprehensive compilation will be undertaken on lifeline damage in past European earthquakes and on the derived vulnerability functions (if any) for estimating both the physical damage and the time required to restore damaged facilities. Such compilations should preferably go beyond correlations with intensities. This will require the consideration of available instrumental data and simulation of ground motion distributions in favourable circumstances. As an example, for power transmission and telecommunication systems, almost all the fragility curves are intensity based and empirical. A compilation of past earthquake damage data on these nodes needs also to be compared with worldwide data. Calibration of improved vulnerability functions for lifeline systems will be carried out for the previous two classes of ground motion, i.e. under permanent or transient ground deformations. As regards the case of permanent ground deformations, extensive use will be made of the results of the ongoing European project QUAKER (“Fault-Rupture and Strong Shaking Effects on the Safety of Composite Foundations and Pipeline Systems”), under the “Energy, Environmental and Sustainable Development” research programme, of which the co-ordinator of this Sub-Project is a partner. As for transient ground deformations, the following steps are envisaged: (i) because the identification of earthquake scenarios is more refined since the yielding of the pipeline lining or joint is evaluated taking additional account of the combined effects of (a) local soil conditions, (b) spatial variability/loss of coherence functions and (c) soil-structure interaction effects. (ii) the vulnerability functions are not expressed in terms of intensities but of specific ground motion. Task 2.4b.3: Calibration of loss models KOERILoss, a user-friendly software operating through Geo-cells systems, developed by the Earthquake Engineering Department of Bogazici University, Kandilli Observatory and Earthquake Research Institute for application to building populations, will be extended to lifeline systems. The software is capable of estimating losses either under probabilistic earthquake hazard or under a "scenario earthquake". The basic steps of the procedure are: 1) Select the region to be studied. 2) Create Probabilistic Earthquake Hazard or specify the scenario earthquake with potential fault breaks. 3) Collect/compile information for delineating local soil conditions. 4) Collect/compile information of inventory of lifelines. 5) Compute earthquake hazard information in the form of site-specific ground motion. 6) Using vulnerability data embedded in the software (or externally provided) assess damage to different classes of lifelines and nodes. KOERILoss will be integrated with the results of the previous tasks, specifically at steps (5) and (6).
Task 2.4b.4: Post earthquake operational analysis By combining the information contents of damage scenarios and the GIS capability, a powerful tool can be easily made available for supporting real time decisions in the post-event phase. Indeed, damage scenarios represent a virtual framework for identifying vulnerable portions of lifeline systems and potential damage areas, as well as for planning emergency response, and testing restoration strategies for system recovery. By exploiting the GIS ability to process real time information, the previous two goals of damage scenarios could be strengthened and fast comparisons, implementations and modifications of initially proposed scenarios could also be performed. The availability of the dense (100 free-field stations) urban array I-NET (Istanbul Earthquake Rapid Response and Early Warning System) in the Istanbul urban area suggests to study the feasibility of developing an early-warning system for the most risky lifeline networks, on the example of an already existing Japanese network for hazard monitoring and fast control on the gas distribution system. I-NET is capable of automatically generating ground motion and damage distribution maps to be communicated to end-users and SAR agencies. The Sub-Project 11 activity on this topic could benefit from integration and exchanges with the Joint Research Activity (JRA7) of the proposed NERIES network, because of the common participation of some partners (DPC and KOERI) and the common aims of the studies. A form of co-operation between the two research activities could be envisaged because, on one hand, both are supposed to collect data on the elements at risk, to organise the data through useful database architectures, and to provide methods that can be easily shared (within the EC community). On the other hand, since NERIES aims at producing a tool for quick assessment and common methods for loss estimation, it could benefit from the use of new methods and innovative techniques to be developed by the engineering research within the LESSLOSS IP, as a deepest level of investigation.
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