The crucial need for simple and cost-effective strengthening or retrofitting solutions for existing buildings, designed according to older seismic code provisions, has been further emphasized in the last decade by the catastrophic effects of earthquake events.
Following decades on investigation on the hazard and the seismic risk (i.e. the problem), the urgency of a national implementation plan for the reduction of seismic risk (i.e. the solution) is thus no longer seen as 'just' an academic or scientific research statement, but is eventually being recognized as a critical socio-political priority at international level.
With no doubt, the assessment of the seismic vulnerability of existing buildings and the development of cost-effective, low-invasive, practical solutions possibly reversible as well as compatible and respectful of the architectural-historical heritage value of the building, hide a significant higher level of complexity when compared to the design of new structures.
And yet, as if the technical complexity was not enough, the inherent restraints of economical resources (budget and people) and the absence of a risk- and consequence-based prioritization plan, are often claimed as the primary obstacles to initiate a large scale, comprehensive and continuous implementation plan at national level.
This project intends to build on the most recent international developments (e.g. New Zealand, US, Japan) in the area of seismic risk assessment and retrofit, merging technical and non-technical (socio-economic) considerations, to develop a 'Risk-based and Performance-Based framework for the Reduction of Seismic Risk at National Level'- with focus on the Italian territory - to support the decision making via a multi-criteria cost-benefit approach.
The key innovative features of the research projects are:
1. Development of a practical analytical approach for seismic assessment of existing buildings.
In the past years, the trend has too often and unfortunately moved towards a black-box approach, with computer modelling becoming the ¿objective¿ of the design instead of, as they should better be, a support to the design itself. The recently developed (October 2016) New Zealand Society of Earthquake Engineering are reverting this dangerous trend, by revamping the key role and responsibility of the structural engineer as that of a ¿designer¿ and not a ¿calculator¿.
This project intends to help developing the SLaMA (Simplified Lateral Mechanism Analysis) for the Italian design environment and construction practice to re-establish the concept of diagnosis-prognosis and therapy and protocols in the seismic engineering environment. Ultimately this would allow technical players to improve the communication of risk with other non-technical stakeholders and end-users, thus increasing the likelihood to share a common mission to develop and support a long-term strategy for a national implementation plan for seismic risk reduction.
2. Integration of structure and non-structural components when considering the losses and the retrofit strategies for existing buildings
When dealing with existing building and retrofit/strengthening approach, the target has been too often limited at a Life Safety Objective. The recent Canterbury Earthquake Sequence, amongst others have confirmed the high costs (70% or more of the of the entire building) associated to the damage to the building ¿envelope/dress¿ or the so called non-structural components (partitions, facades, glazing, ceilings, services) and contents in a building during moderate-severe earthquake and associated aftershocks.
The project will look at the cost-benefit of considering the system as a whole, thus targeting the improvement of the seismic performance of the
The new Italian guidelines for the seismic risk classifications/rating of structures developed to support the new law on tax incentive law for seismic retrofitting (Sismo-Bonus) are confirming that, for a given level of Life Safety Risk, the EAL (expected annual loss) associated to the damage (and thus cost for the society) of damage to non-structural elements has a major contribution and needs to be reduced.
3. Development of a technically-sound and practical framework tool to support the high-level decision makers in complex socio-economic strategy
Too often we observe, in the Italian reality, a general lack of proper communication and synergy between academia/researchers, stakeholders/end-users and high-level decision makers. As a result, academic researchers tend to be ¿preaching to the converted¿, thus keeping the communication within the scientific community.
This project aims at bring to the attention of the non-technical but high-level decision makers, merge the pros (and minimize the cons) of two different socio-economic environment as Italy and New Zealand in terms of risk reduction policies and plans
It will be important to have a clear and simple output report that can be presented directly to the high level authorities (Parliament committees) to explain the tangible and significant benefit that a a long-term (20-30 years) risk reduction implementation plan and strategy can have in terms of economical benefit and loss reduction (victims, direct and indirect socio-economical costs).
Furthermore, such a national scale intervention plan would represent a fundamental economic boost in the construction sector, particularly in such a difficult recession (or just post-recession) times, with important positive effects on many other industry sectors. It is envisaged that a continuous investment of something in the low range of 0.2-0.3% of the GDP (Gross Domestic Product or PIL, Prodotto Interno Lordo) per year, corresponding to 3-5 billion Euros, might be sufficient to initiate such a positive virtuous circle.
Needless to say, targeting the rehabilitation (and value-adding) of our existing stock (assets) is already and is going to be the natural and mandatory approach for the next generation to come, considering the high density population of Italy and the need to limit the use of additional land. Already in the past few years focus has been given in the rehabilitation and refurbishment (structural energy efficiency, architectural) of existing buildings more than the construction of new ones.
Lastly, often the perception has been that the problem is in the existing historical buildings, while even post-War (1950-1970s) reinforced concrete buildings are at high risk, given their inherent vulnerabilities (obsolete code provisions or designed for gravity only considerations) and the higher than expected seismicity (regions later declared/discovered to be more seismically active).