Periodic Reporting for period 1 - KaIROS (Keeping and Increasing Resilience Opportunities and Sustainability of communities against earthquakes)
Periodo di rendicontazione: 2018-09-01 al 2020-08-31
Earthquake related catastrophes are still a heavy toll that society is paying with certain frequency. This risk mainly comes from the damage to civil structures. Its extreme consequence for mankind is the collapse of structures since this leads to the loss of human lives. Not to mention that economical losses can reach the point of affecting the sustainable development of entire countries. Such socio-economical setbacks trigger poverty, inequality, casualties amongst many other negative consequences. In this respect, due to the world population growth, which exhibit higher rates in low-income regions, in a short time, there will hardly be a place where a moderate- to high-magnitude earthquake can occur without affecting society. For all these reasons, the effect of the ground motions on the performance of civil structures has been an important subject for researchers worldwide. KaIROS project focuses on enhancing current methodologies to mitigating the effects produced earthquake disasters. The main purpose is to provide beyond-state-of-the-art approaches to reduce seismic risk worldwide. The key to reducing seismic risk is decreasing the vulnerability of existing structures and providing new insights to improve the design of new ones. This can be achieved by proposing new strategies to augment the predictability of risk assessment methodologies.
The first research activity was intended to contribute in the characterization of an enhanced Building Typology Matrix (BTM). Thus, according to one of the main research programs of the GEM foundation, they have identified more than 500 structural types across the planet. After reviewing this comprehensive BTM, it was observed that most of the building types composing urban environments are reinforced concrete frame, reinforced concrete with waffle slabs, unconfined and confined masonry, reinforced concrete masonry and steel frame structures. From the identified set of structural typologies, the ER started to develop the methodological aspects of the research. Initially, for the sake of the project, the methodological implementations were developed by studying reinforced concrete buildings. Once this typology was fully studied, new structural types from the identified list would be investigated. Then a software identification was carried to perform structural analysis. This was a key aspect of the project since enhancing the model’s resolution along with an increase in the number of random variables is computationally expensive. The next step was oriented to the seismic hazard characterization. Several databases to consider the variability associated with seismic actions was studied and processed. A large database has been created so that several seismogenic zones can be properly represented. Once seismic hazard was characterized, the next action was to identify response parameters related to the structural damage. Thus, it was defined a set of response variables related to the overall structural damage, global instability, local damage, local instability, storey collapse, and damage level in non-structural components. Using this information, several methodologies to derive fragility functions were implemented. Geometrical variability, mechanical properties of the materials, gravity loads and soft-story were considered as random variables in the simulations.
In order to test the computational tools developed in the project, The ER along with other researchers of the host institution performed a risk assessment of the reinforced concrete buildings with waffle slabs of the Eixample, which is a well-known and emblematic neighbourhood in Barcelona. Building models were generated by considering information provided by researchers of the host institution. The results showed that these buildings are highly vulnerable, as expected.
Other subjects related to increasing sustainability and resilience by reducing vulnerability was also investigated. In line with this, the most relevant seismic codes worldwide were reviewed to analyse which parts of them could benefit from the results of the project. After this review, the ER realized that the best contribution to guidelines should be oriented to enhance the predictability of EDPs highly used in the design of structures. In addition, the study of the near-fault effect of ground motion records in design was also a subject that could be benefit from this enhancing in efficiency. Therefore, an investigation was developed focused on identifying these EDPs for both near- and far- fault records.
Social issues were also of importance during the project. Research on the exposure of women to several types of hazards has shown that gender inequality influences their risk to natural disasters. For instance, discrimination and injustice are greater in developing countries, in which people living below the poverty threshold face greater exposure to hazard. Seventy percent of the population in these countries are women. Moreover, several of them are housewives in charge of household chores and raising children. This makes the impact of disasters not gender neutral as their dwellings are highly vulnerable to several hazards, and women spend more time at home than men.
Weakening and directionality effects were also studied during the project. In order to analyse the weakening effect, the ER and researchers of the host institutions analysed signals coming from a measuring campaign of the dynamic properties of a building damaged by the Lorca earthquake. In order to include the directionality effect, the concept of consistent rotation was studied.
Finally, several computational tools that can be used to address several subjects of the Earthquake Engineering were developed. These computer programs allow to run probabilistic realizations of building models by considering as input random ground motion records selected from databases.
In order to test the computational tools developed in the project, The ER along with other researchers of the host institution performed a risk assessment of the reinforced concrete buildings with waffle slabs of the Eixample, which is a well-known and emblematic neighbourhood in Barcelona. Building models were generated by considering information provided by researchers of the host institution. The results showed that these buildings are highly vulnerable, as expected.
Other subjects related to increasing sustainability and resilience by reducing vulnerability was also investigated. In line with this, the most relevant seismic codes worldwide were reviewed to analyse which parts of them could benefit from the results of the project. After this review, the ER realized that the best contribution to guidelines should be oriented to enhance the predictability of EDPs highly used in the design of structures. In addition, the study of the near-fault effect of ground motion records in design was also a subject that could be benefit from this enhancing in efficiency. Therefore, an investigation was developed focused on identifying these EDPs for both near- and far- fault records.
Social issues were also of importance during the project. Research on the exposure of women to several types of hazards has shown that gender inequality influences their risk to natural disasters. For instance, discrimination and injustice are greater in developing countries, in which people living below the poverty threshold face greater exposure to hazard. Seventy percent of the population in these countries are women. Moreover, several of them are housewives in charge of household chores and raising children. This makes the impact of disasters not gender neutral as their dwellings are highly vulnerable to several hazards, and women spend more time at home than men.
Weakening and directionality effects were also studied during the project. In order to analyse the weakening effect, the ER and researchers of the host institutions analysed signals coming from a measuring campaign of the dynamic properties of a building damaged by the Lorca earthquake. In order to include the directionality effect, the concept of consistent rotation was studied.
Finally, several computational tools that can be used to address several subjects of the Earthquake Engineering were developed. These computer programs allow to run probabilistic realizations of building models by considering as input random ground motion records selected from databases.
Very likely, the activities leading to the most innovative outcomes have been the ones focused on establishing that new and updated intensity measures have to be used in seismic design and risk assessments, and in earthquake prevention and protection. It has been clearly shown that velocity and energy based intensity measures are more efficient and robust in predicting the expected performance of buildings and civil structures and infrastructures. The ER has also shown that seismic risk assessment methods may be enhanced in terms of efficiency if the location of the faults, the azimuthal position of structures together with the direction of their most flexible and stiffest axes are known and accounted for in an event-per-event, removing the pertinent uncertainties. This has been observed after deriving fragility functions for consistent rotations of a similar-horizontal-axes RC structure with respect to the source. Both findings will allow develop an enhanced probabilistic framework to design new and assess existing civil infrastructure. New data and software concerning to these methods and procedures have been developed and have been made accessible, in an open-acces basis, to the engineering and scientific-technical international community. Most of the outcomes and findings of the project have been disseminated in ad-hoc workshops and conferences and have been published in high impact open-access journals.