Post-earthquake Recovery Research Articles

Seismic performance of precast segmental bridge columns repaired with CFRP wraps

Precast segmental bridge columns (PSBCs) have many advantages compared with monolithic bridge columns. However, PSBCs could be severely damaged during an earthquake due to their limited seismic capacity. Rapid repair of the PSBCs and the seismic behavior of the repaired PSBCs are critical to the post-earthquake recovery of bridges with such columns. In this study, an original PSBC specimen is designed, constructed, and tested under cyclic loading. After the cyclic test on the original specimen is carried out, carbon fiber reinforced polymer (CFRP) sheets and sticky steel glue are used to repair the damaged specimen. The repaired PSBC specimen is then tested under the same loading protocol as the original specimen to compare their cyclic performance. Test results show that the concrete damage of the repaired specimen is reduced compared to the original specimen, and the repaired column has a relatively larger energy dissipation and residual displacement than those of the original column. To leverage the test results, detailed three-dimensional finite element models are developed and calibrated with the results from the experiments. Closely replicating the test results, the validated finite element models are used to replace the lab experiments for the parametric modeling of the seismic performance of bridges with PSBCs while capturing effects of CFRP. Specifically, the influence of CFRP design variables, including the CFRP cross-sectional area ratio and the CFRP height ratio, on the seismic performance of the repaired PSBCs is evaluated by using the validated finite element model. It is found that the CFRP cross-sectional area ratio has little effect on the seismic capacity of the repaired PSBCs, and the repaired PSBC with a CFRP height ratio of 2.0 is the most suitable for the repaired PSBCs investigated in this study.

The disaster relief and social work after the Wenchuan earthquake in Mainland China

ABSTRACT This paper mainly focuses on the development of disaster social work in Mainland China and the intervention of social work in disaster relief. Before the Wenchuan earthquake and in the initial stage of post-earthquake, disaster social work was mainly based on individual psychotherapy; from the earthquake to the year of 2012 in which post-earthquake recovery and reconstruction was completed, the disaster relief began to emphasise community building and integration, while the basic framework for disaster social work was also established. Social workers begin to explore the new mode of developmental and localised disaster social work. By combining with the practical experiences from disaster social work, this paper tries to highlight the dilemmas confronting disaster relief in Mainland China and put forward some corresponding countermeasures and suggestions, which could improve the future disaster relief system in Mainland China.

Compact Scheduling for Task Graph Oriented Mobile Crowdsourcing

With the proliferation of increasingly powerful mobile devices and wireless networks, mobile crowdsourcing has emerged as a novel service paradigm. It enables crowd workers to take over outsourced location-dependent tasks, and has attracted much attention from both research communities and industries. In this paper, we consider a mobile crowdsourcing scenario, where a mobile crowdsourcing task is too complex (e.g., post-earthquake recovery, citywide package delivery) but can be divided into a number of easier subtasks, which have interdependency between them. Under this scenario, we investigate an important problem, namely task graph scheduling in mobile crowdsourcing (TGS-MC), which seeks to optimize a compact scheduling, such that the task completion time (i.e., makespan) and overall idle time are simultaneously minimized with the consideration of worker reliability. We analyze the complexity and NP-complete of the TGS-MC problem, and propose two heuristic approaches, including BFS-based dynamic priority scheduling BFSPriD algorithm, and an evolutionary multitasking-based EMTTSch algorithm, to solve our problem from local and global optimization perspective, respectively. We conduct extensive evaluation using two real-world data sets, and demonstrate superiority of our proposed approaches.

Assessment of the impact of the 2010 Haiti earthquake on human activity based on DMSP/OLS time series nighttime light data

Earthquake disasters and postdisaster reconstruction have profound impacts on human society. We use time series nighttime light images collected by the defense meteorological satellite program-operational linescan system sensors as a proxy data source for human activities (HAs). After calibration, a time series analysis method is used to study the distribution and intensity of the changes in HAs after an earthquake. We consider the Haiti earthquake an example to analyze the HA sequence patterns and the aggregation patterns of the HA centers. The results show the following: (1) postearthquake recovery and reconstruction efforts led to increases in the long-term HAs, but the level of increased HA was usually low. (2) The level of postearthquake HAs in the most affected areas (seismic intensity zone VIII+) increased, whereas the postearthquake HAs in severely affected areas (seismic intensity zones VI and VII) were more fragmented. (3) The recovery of HAs in seismic intensity zone VIII+ (mainly Port-au-Prince) required 2 years, but the actual time may be far longer.

Modeling post-earthquake business recovery time: An analytical framework

This study develops an analytical framework for modeling business recovery times after seismic events. These recovery times are important to understand, as business interruption (BI) is a significant factor in the survival of businesses and communities after disasters, and can cause a large proportion of the losses in such events. To date however, few post-earthquake recovery studies specifically account for business recovery time. The proposed framework considers multiple types of earthquake-induced downtime that may impact business recovery, such as building recovery and disruption to the wider community, as well as tactics employed by businesses to mitigate these times. The framework's potential to provide insight on business recovery is evaluated using observed recovery time data for 22 businesses affected by the 2011 Mw 6.1 Christchurch earthquake in New Zealand. It is found that recovery times calculated according to the framework align significantly better with observed business recovery times compared to calculated downtimes of businesses' pre-earthquake physical locations, which are often used as proxies for business recovery. These findings highlight the importance of accounting for multiple factors when modeling business recovery due to seismic events.

Operationalizing Sustainable Development Goals in Vulnerable Coastal Areas of Ecuador and Pakistan: Marginalizing Human Development?

Drawing on multi-sited ethnographic fieldwork in socially and ecologically vulnerable coastal areas of Ecuador and Pakistan, we focus on Chinese-funded investment projects to analyze how SDGs are susceptible to be instrumentalized in the context of exploitative economic dependencies, as well as national development agendas. In our case studies, forced displacement of vulnerable inhabitants during the post-earthquake recovery in coastal Ecuador and displacement of small-scale fishers in coastal Pakistan are justified by SDG implementation. We identify a techno-managerial approach to SDGs in order to discuss its effects in terms of endangering ecosystems and human freedoms, increased social vulnerability and dependence on wage labour. Despite contextual differences, both case studies reveal a similar pattern of intervention under the pretext of SDGs where human freedoms and capabilities are severely undermined by large-scale projects of territorial and social securitization.

Real-Time City-Scale Time-History Analysis and Its Application in Resilience-Oriented Earthquake Emergency Responses

The resilience of cities has received worldwide attention. An accurate and rapid assessment of seismic damage, economic loss, and post-event repair time can provide an important reference for emergency rescue and post-earthquake recovery. Based on city-scale nonlinear time-history analysis (THA) and regional seismic loss prediction, a real-time city-scale time-history analysis method is proposed in this work. In this method, the actual ground motion records obtained from seismic stations are input into the building models of the earthquake-stricken area, and the nonlinear time-history analysis of these models is subsequently performed using a high-performance computing platform. The seismic damage to the buildings in the target region subjected to this earthquake is evaluated according to the analysis results. The economic loss and repair time of the earthquake-stricken areas are calculated using the engineering demand parameters obtained from the time-history analysis. A program named, “Real-time Earthquake Damage Assessment using City-scale Time-history analysis” (“RED-ACT” for short) was developed to automatically implement the above workflow. The method proposed in this work has been applied in many earthquake events, and provides a useful reference for scientific decision making for earthquake disaster relief, which is of great significance to enhancing the resilience of earthquake-stricken areas.

Effect of the Los Angeles Soft-Story Ordinance on the post-earthquake housing recovery of impacted residential communities

Post-earthquake recovery models can be used to quantify the resilience-related benefits of policies intended to mitigate building seismic risk. An assessment of the effect of the Los Angeles Soft-Story Ordinance on the post-earthquake housing recovery of residential communities is presented. An inventory of approximately 8000 buildings located in five Los Angeles neighborhoods is considered. The neighborhoods vary based on the percentage of soft-story buildings, population density and the fraction of renter- and owner-occupied residences. Archetype buildings that are representative of the target inventory are developed based on a building-by-building survey performed using Google Street View. Variations in the number of stories and presence and layout of the soft first story are considered in the development of the archetypes. Analytical building-level damage fragility curves are developed using the results from nonlinear analyses of structural models representing each archetype. A scenario-based damage assessment is performed using shaking intensities generated from the Southern California ShakeOut scenario, and a discrete-time state-based stochastic process model is used to represent post-earthquake recovery. The quantified effect of the Ordinance retrofit varied based on the considered recovery metric. For instance, the initial loss of occupancy for the entire inventory is reduced by 25%. However, if the time to restore 90% occupancy is used as the recovery performance metric, the Ordinance retrofit leads to a 64% reduction.

A Decision-Support Algorithm for Post-Earthquake Water Services Recovery and Its Application to the 22 February 2011 Mw6.2 Christchurch Earthquake

As the cost of lifeline disruption rises with the size and complexity of urban communities, increasing efforts are put into enhancing infrastructure resilience to natural disasters. Aiming to improve the understanding of water supply network seismic resilience, this paper examines in detail the initial performance and restoration of the water supply network following the 22 February 2011 Mw6.2 Christchurch, New Zealand earthquake. In addition, a method to optimize the recovery of such systems is developed in two phases: the prioritization of pipe inspection and prioritization of pipe repairs. The results inferred from the observed pipe repairs suggest that the recovery was carried out efficiently; however, applying the proposed methodology would have substantially improved the recovery of the system with a 30% reduction in the number of buildings deprived of water in the first two days. Assumptions and limitations of the modeling are also discussed and practical solutions given to apply this framework in real-time for post-earthquake restoration.

Learning from The Legacy of Post-Disaster Recovery in Indonesia for The Acceleration of Post-Disaster Recovery in Lombok

As a country known for its very disaster-prone areas, Indonesia has experienced frequent disasters, either large, medium and small-scale ones, which even in the last six months have had at least a fairly large-scale natural disaster, one of which is an earthquake occurred in Lombok in late July to mid-August 2018. Learning from the experiences of post-disasters management that have occurred before, especially after the earthquake and tsunami disaster in Aceh and Nias in 2004, the earthquake in Yogyakarta in 2006, the earthquake in West Sumatra in 2009, and eruption of Mount Merapi in 2010, the post-disaster recovery process needs to be carried out in an integrated and comprehensive manner, by involving participation of stakeholders at the national and regional levels, not only the central government, local governments and other government partners. In relation to the post-earthquake recovery efforts in Lombok in 2018 which affected seven districts/cities in NTB Province which resulted in recovery needs of more than Rp. 11 trillion, despite the issuance of the Presidential Instruction policy framework Number 5 of 2018 on the Acceleration of Post-Disaster Rehabilitation and Reconstruction in NTB Province, which assigns relevant ministries/agencies and Governor and Regents and Mayors whose areas are affected in NTB Province, to be able to accelerate the process of recovering local conditions and disaster-affected communities in the affected NTB region, which for implementation still requires operational policies and strategies in the field. For this reason, some best-practices in managing the recovery process from previous disasters can be used as input in establishing appropriate and applicable policies and strategies in order to accelerate the rehabilitation and reconstruction of post-disaster areas in Lombok further, to realize a recovery to rebuild a better one, safer and more sustainable.

A framework and case study for integrating household decision-making into post-earthquake recovery models

Prior empirical research has demonstrated that the decisions of affected populations can significantly influence housing recovery outcomes following a natural hazard event. The current study seeks to develop an integrated post-earthquake recovery model that explicitly accounts for household decision-making. An empirical probabilistic utility-based decision model is developed using data from a survey of Los Angeles households. The results from a multinomial logistic regression showed that the time in residence, neighborhood evacuation level, physical damage to residence, duration of utility disruption and loss of access to the building, household income and earthquake insurance coverage had a statistically significant association with homeowners’ decisions. For renter decision-making, only physical damage to the residence and duration of utility disruption are found to be statistically significant. In addition to household decision-making, the integrated model incorporates probabilistic building performance assessment and a discrete-state stochastic process representation of post-earthquake housing recovery. The results from a case study incorporating three Los Angeles neighborhoods (Koreatown, East Hollywood and Lomita) show that the influence of household decision-making on occupancy-based recovery trajectories is amplified as the scale of damage increases.

Evaluating Seismic Effects on a Water Supply Network and Quantifying Post-Earthquake Recovery

This paper summarises the impact of major earthquakes, 2010–2011, on Christchurch’s water supply network and what recovery measures have been applied, what worked well, what did not and why. A number of issues related to the open nature of the Christchurch water supply network were identified during earthquakes. It was difficult to manage large water supply pressure zones during the post-earthquake emergency response due to multiple failures of assets. The performance of the post-earthquake, post-rebuild 2017 water supply network was compared with the pre-earthquake water supply network to investigate the success of the post-earthquake rebuild programme. A multi-million dollar repair and rebuild works helped to return the level of service of the network to the pre-earthquake level and the water leakage of the 2017 water supply network was found similar to the pre-earthquake level. Hydraulic model was used for immediate earthquake emergency response, what/if scenarios investigations and earthquake damage assessments. Hydraulic models were built for pre and post-earthquake water network of Christchurch. The performance of pre and post-earthquake hydraulic models were compared and the results are also reported in this paper. Hydraulic modelling was found to be a very powerful tool engineers can use to assess the impact of an earthquake on a water supply network and formulate alternative plans during emergency response.

Violence against women and girls with disabilities during and after the 2015 Nepal earthquake: thematic analysis of qualitative data

Abstract Background Disasters affect people with disabilities disproportionately. Violence against women and girls, including sexual and psychological violence, has been reported to increase during and after natural disasters. Despite worldwide attention on the devastation caused by the 2015 earthquake in Nepal, the risk of violence against women and girls with disabilities and their experiences during the crisis and recovery phases remain under-researched. In this study, we aim to explore the experiences of violence against disabled women and girls immediately after the earthquake and during the post-earthquake recovery period. Methods We undertook a thematic analysis of qualitative data collected through semi-structured interviews and focus group discussions with women and girls with disabilities from the districts worst affected by the 2015 Nepal earthquake: Kathmandu valley (n=16), Dhading (n=8), Sindhupalchok (n=8), and Gorkha (n=8). These qualitative data were a part of two larger studies; one that explored the experiences of people with disabilities during the 2015 Nepal earthquake and another that studied the effect of post-earthquake mental health and psychosocial support in women with disabilities. All participants for this part of the study were recruited through a snowball sampling technique. Findings We analysed data from interviews with 40 participants conducted between May, 2015, and February, 2018. Five focus group discussions each with eight participants lasted between 1 h and 1·5 h. Semi-structured interviews lasted between 30 mins and 45 mins. By comparison with their pre-earthquake experiences, women and girls with disabilities reported increased psychological, physical, and sexual violence immediately after the earthquake mostly in and around temporary shelters. Physical and psychological violence were reported to be committed by partners, family members, relatives, and sometimes by people who lived in the same community; sexual violence against girls with disabilities were reported to be committed by close relatives, family members, or an opportunist stranger. Interpretation Our findings highlight that being female with a disability, having limited rights and independence, and having limited access to financial resources lead to increased longer-term violence, even during the recovery and reconstruction phase of a natural disaster. We recommend that emergency responders undertake gender and disability sensitisation training to remove barriers and stigma against women and girls with disabilities. Government, national, and international humanitarian agencies should work together with local-level organisations to strengthen gender and disability-inclusive preventative, reporting, and justice mechanisms. Funding None.

Agent-Based Recovery Model for Seismic Resilience Evaluation of Electrified Communities.

In this article, an agent-based framework to quantify the seismic resilience of an electric power supply system (EPSS) and the community it serves is presented. Within the framework, the loss and restoration of the EPSS power generation and delivery capacity and of the power demand from the served community are used to assess the electric power deficit during the damage absorption and recovery processes. Damage to the components of the EPSS and of the community-built environment is evaluated using the seismic fragility functions. The restoration of the community electric power demand is evaluated using the seismic recovery functions. However, the postearthquake EPSS recovery process is modeled using an agent-based model with two agents, the EPSS Operator and the Community Administrator. The resilience of the EPSS-community system is quantified using direct, EPSS-related, societal, and community-related indicators. Parametric studies are carried out to quantify the influence of different seismic hazard scenarios, agent characteristics, and power dispatch strategies on the EPSS-community seismic resilience. The use of the agent-based modeling framework enabled a rational formulation of the postearthquake recovery phase and highlighted the interaction between the EPSS and the community in the recovery process not quantified in resilience models developed to date. Furthermore, it shows that the resilience of different community sectors can be enhanced by different power dispatch strategies. The proposed agent-based EPSS-community system resilience quantification framework can be used to develop better community and infrastructure system risk governance policies.

Optimization for Postearthquake Resilient Power System Capacity Restoration Based on the Degree of Discreteness Method

The occurrence of a natural disaster such as a strong earthquake affects not only the capacity of a city’s power supply system but also the normal operation of other lifeline systems. An urban emergency power supply system is used to manage the power supply restoration with the consumers divided into three types based on their impact and importance during a power failure. In this study, a power supply system equipped to meet the requirements of different restoration level facilities and enable the restoration of power after the occurrence of an earthquake was developed. A three‐stage power restoration curve was formulated based on the postearthquake recovery process. The relative importance factors of consumers can be calculated with a normalization model based on membership degree. These relative importance factors were then combined with the postearthquake recovery capabilities of each consumer to calculate the overall recovery capability and equilibrium degree of the urban power system. Using the two foregoing indicators, the power supply recovery level of the power system after an earthquake was quantitatively analyzed, and the power supply scheme of the consumers with different power supply guarantee types was rationally optimized.

Mothers as active contributors to post-earthquake recovery in Christchurch

INTRODUCTION: An understanding of mothers as a subset of women who are active contributors to a recovery effort is crucial to building disaster resilience. This study explored the post-disaster experiences of mothers from the two Christchurch earthquakes in 2010 and 2011 to consider factors which both helped and hindered their recovery.METHOD: This research was a qualitative study involving semi-structured interviews with six married mothers who were present during the 2010 and 2011 Christchurch earthquakes. Interviews focused on understanding the personal, environmental and psychological impacts of the earthquakes. Data were analysed using thematic analysis.FINDINGS: Three key findings were established, highlighting: 1) Elements of resilience are essential for recovery; 2) mothers playing a constructive and proactive role in their community post-disaster; and 3) the importance of a sense of belonging to enhance post-disaster recovery.CONCLUSION: While participants were affected practically and psychologically by the earthquakes, core characteristics of resilience such as positivity, hope, flexibility and adaptability were portrayed in supporting their post-disaster recovery. These mothers played an active role in the recovery of their community and felt a clear sense of belonging which enhanced their recovery.

He kōrero takiwā, he takiwā korero/Stories within Spaces, Spaces Defined by Stories: A Footbridge Design Concept for New Zealand

This design concept was originated in response to a government-sponsored design contest for the North Frame Pedestrian Bridge (NFPB). The bridge, located on the Ōtākaro/Avon River in Christchurch, New Zealand, is one of a series of post-earthquake recovery projects aimed at attracting people to visit and live in the rebuilding city of Christchurch. The University of Canterbury entered this contest and established a design team of senior Engineering and Fine Arts students, supervised by three professors. The brief required the team to combine a strong design aesthetic with a tightly constrained and functional built object. This resulted in a unique design, fitting for inclusion in the public art collection. The structural system, based on a weathering steel tri-dimensional “Vierendeel” girder/truss, also responds to the art form of a traditional Māori fishing net. Both truss and trap are made of repeated rings, of variable size, connected by an organic net.

Financial Imbalances in Regional Disaster Recovery Following Earthquakes—Case Study Concerning Housing-Cost Expenditures in Japan

In the aftermath of the 1995 Kobe Earthquake, a large-scale effort towards reconstruction of houses damaged by the quake was required. This led to increased mortgage, thereby financially plaguing a number of earthquake victims and inhibiting their long-term sustainability and self-supported recovery. The current framework of housing reconstruction assistance provided by the Japanese government does not account for regional disparities in cost and other socioeconomic factors. This study proposes a technique for estimating the cost of reconstructing household units damaged in an earthquake by considering the effects of construction methods influenced by regional climatic zones. The financial constraints on rebuilding resources have been estimated by considering the annual regional income and household savings, as determined by social factors and employment opportunities. The susceptibility of regions to the occurrence of earthquakes has also been factored in the calculation of recovery costs. Together, these factors are used to provide a more complete picture of economic costs associated with earthquake recovery in different regions of Japan, thereby revealing large disparities in the difficulty and financial burden involved in the reconstruction of household units. Results of this study could be used to develop a robust system for earthquake-recovery assistance that accounts for differences in recovery costs between different regions, thereby improving the speed and quality of post-earthquake recovery.

Replicating the Recovery following the 2014 South Napa Earthquake using Stochastic Process Models

Post-earthquake recovery models can be used as decision support tools for pre-event planning. However, due to a lack of available data, there have been very few opportunities to validate and/or calibrate these models. This paper describes the use of building damage, permitting, and repair data from the 2014 South Napa Earthquake to evaluate a stochastic process post-earthquake recovery model. Damage data were obtained for 1,470 buildings, and permitting and repair time data were obtained for a subset (456) of those buildings. A “blind” prediction is shown to adequately capture the shape of the recovery trajectory despite overpredicting the overall pace of the recovery. Using the mean time to permit and repair time from the acquired data set significantly improves the accuracy of the recovery prediction. A generalized model is formulated by establishing statistical relationships between key time parameters and endogenous and exogenous factors that have been shown to influence the pace of recovery.

Temporal Variability of Ground Shaking and Stress Drop in Central Italy: A Hint for Fault Healing?

Ground‐motion prediction equations (GMPEs) are calibrated to predict the intensity of ground shaking at any given location, based on earthquake magnitude, source‐to‐site distance, local soil amplifications, and other parameters. GMPEs are generally assumed to be independent of time; however, evidence is increasing that large earthquakes modify the shallow soil conditions and those of the fault zone for months or years. These changes may affect the intensity of shaking and result in time‐dependent effects that can potentially be resolved by analyzing between‐event residuals (residuals between observed and predicted ground motion for individual earthquakes averaged over all stations). Here, we analyze a data set of about 65,000 recordings for about 1400 earthquakes in the moment magnitude range 2.5–6.5 that occurred in central Italy from 2008 to 2017 to capture the temporal variability of the ground shaking at high frequency. We first compute between‐event residuals for each earthquake in the Fourier domain with respect to a GMPE developed ad hoc for the analyzed data set. The between‐events show large changes after the occurrence of mainshocks such as the 2009 Mw 6.3 L'Aquila, the 2016 Mw 6.2 Amatrice, and Mw 6.5 Norcia earthquakes. Within the time span of a few months after the mainshocks, the between‐event contribution to the ground shaking varies by a factor 7. In particular, we find a large drop in the between‐events in the aftermath of the L'Aquila earthquake, followed by a slow positive trend that leads to a recovery interrupted by a new drop at the beginning of 2014. We also quantify the frequency‐dependent correlation between the Brune stress drop Δσ and the between‐events. We find that the temporal changes of Δσ resemble those of the between‐event residuals; in particular, during the period when the between‐events show the positive trend, the average logarithm of Δσ increases with an annual rate of 0.19 (i.e., the amplification factor for Δσ is 1.56 per year). Breakpoint analysis located a change in the linear trend coefficients of Δσ versus time in February 2014, although no large earthquakes occurred at that time. Finally, the temporal variability of Δσ mirrors the relative seismic‐velocity variations observed in previous studies for the same area and period, suggesting that both crack healing along the main fault system and healing of microcracks distributed at shallow depths throughout the surrounding region might be necessary to explain the wider observations of postearthquake recovery.