WP5 - Real time-dependent risk assessment
WP Leader: Kyriazis Pitilakis - AUTH

The objectives of this work package are two-fold:
- To develop time-dependent fragility functions for buildings, selected infrastructures, and utility systems.
- To develop real time loss estimation models over the lifetime of structures and systems of interest due to foreshocks, main shocks and their subsequent aftershock sequences.
Stationary hazard is the traditional way to evaluate risk, which in this case is also time-independent. As, however, hazard is time dependent, the risk is also time-dependent. Moreover, risk depends on the vulnerability of exposed structures, which changes with time. Degradation of material properties with time, anthropogenic actions, cumulative damage from past earthquakes and retrofitting measures may significantly affect the real vulnerability.
WP5 proposes to develop a coherent real time-dependent methodology to account for time-varying hazard developed in WPs 2, 3 and 4, and non-stationary vulnerability modeling to provide real time-dependent risk assessments.
In order to accomplish the goals defined in WP5, several research steps are required:
- Definition of the time periods necessary to distinguish different time-dependent structural risk. Three main periods will be defined: pre-seismic (or “normal”), co-seismic (or crisis) and post seismic. The post-seismic period may be further divided into “short”, “medium” and “long recovery” periods.
- Definition of the taxonomy and the associated inventory of the elements of interest (buildings, selected infrastructures and utilities).
- Definition of the mechanisms of damages and the performance/damages levels and states, which should be time-dependent, easily measurable and feasible to model.
- Definition of ground motion parameters considering site effects and accounting for uncertainties.
- Definitions of the different characteristics of a damaged building and how its actual state can be fast and easily assessed in different time periods (pre-event, co-event and post-event).
- Selection and validation of the most efficient techniques and methods to estimate the real-time earthquake physical losses to buildings, infrastructures and utility systems.
All these steps will be carefully treated in WP5 through 4 working tasks, having well-defined deliverables.

Structure of the WP
Task 5.1: Prerequisites for real time time-dependent vulnerability and risk assessment
Task 5.2: Time-dependent fragility functions
Task 5.3: Instrumentation needs and modalities for real-time risk assessment of critical urban structures, infrastructures and facilities
Task 5.4: Time-dependent loss estimation