A Bayesian approach for estimating the post-earthquake recovery trajectories of electric power systems in Japan

Post-disaster recovery modelling of engineering systems has become an important facet of catastrophe risk modelling and management for natural hazards. The post-disaster recovery trajectory of a civil infrastructure system can be quantified using (a) the initial post-disaster functionality level, Qo; (b) rapidity, h (i.e., the rate of functionality restoration); and (c) recovery time, Rt. This study uses a Bayesian estimation approach to derive a set of probabilistic models to estimate Qo, Rt, and h of electric power networks (EPNs) using post-earthquake recovery data from 16 large earthquakes in Japan between 2003 and 2022. The considered predictor (explanatory) variables include earthquake magnitude, year of occurrence, seismic intensity, and exposed population (PEX). Apart from being a simple and efficient stand-alone tool, the proposed data-driven models can be a useful benchmarking tool for simulation-based approaches for EPN recovery modelling

Influence of Earthquake-Tsunami Sequence Induced Corrosion on Residual Seismic Capacity of Concrete Structures

Field investigations have highlighted the high likelihood of chloride ingress in reinforced concrete (RC) buildings submerged by seawater and covered by mud during an earthquake-tsunami (EQ-TS) sequence. Chloride attack through EQ-induced cracks or spalling can cause a high corrosion rate in the reinforcement, thereby compromising the long-term durability of the structure and its performance in future events. Typically, this deterioration process is neglected when assessing the future performance of frame structures in tectonically-active coastal regions. This study demonstrates the influence of EQ-TS-induced corrosion on the residual seismic capacity of modern RC frame structures. The analyses show an undesirable component-level failure mode switch to a shear-dominated mechanism. The median collapse fragility of the frame is also seen to be significantly influenced by the reinforcement corrosion. The outcome of this study raises questions on the post-tsunami management of both modern and older-type RC frame structures

Hybrid EEFIT mission to february 2023 Kahramanmaraş earthquake sequence

The southwestern part of Türkiye was hit on 6 February 2023 by an Mw 7.8 (epicentre:Pazarcık) and then an Mw 7.5 earthquake (epicentre: Elbistan). The event was followed by tensof thousands of aftershocks including the Mw 6.3 event on 20 February (epicentre: Uzunbağ).This paper reports on the preliminary findings of the mission organised by the UK’s EarthquakeEngineering Field Investigation Team (EEFIT) to the Kahramanmaraş Earthquake sequence ofFebruary 2023. This mission followed a hybrid model, combining field and remote investigationtechniques, to investigate the characteristics of the earthquake sequence, its impact on buildingsand infrastructure, as well as the efficacy of relief, response and recovery operations. The keymessages include that the building stock is hard to categorise which brings along difficulties withdamage assessment, that the recovery and reconstruction require multi-sectoral engagement ofkey stakeholders, and that the auditing and quality control mechanisms within the constructionindustry need revisiting in the way forward for better disaster resilience in Türkiye