AIMS AND LEARNING OUTCOMES

The course will address the topic of seismic risk assessment, emergency management and mitigation of the built environment. After an introduction to natural disasters and risk elements (hazard, exposure and vulnerability), we will present the concept of resilience and its interdisciplinary applications. Then, starting from the basics of seismic hazard, seismic action and dynamic response of structural systems, we will discuss the effects on environment and structures, focusing on the concept of vulnerability of buildings (masonry and reinforced concrete ones). The next step will be an overview of different possible seismic risk reduction policies in the three phases of risk management (pre-event, emergency state and post-event). Finally, the course will focus on the damage survey activities run by the Civil Protection in the post-earthquake emergency phase to evaluate the structures’ usability. In particular, firstly we will describe the different forms currently available for damage, emergency provisions and practicability assessment of ordinary buildings and churches; secondly, we will see some practical examples of post-earthquake damage survey applied to some case-studies hit by the last Italian earthquakes in order to evaluate the damage and vulnerability indexes.

At the end of the course, students should be able to:

• know the concepts of seismic risk and risk elements (hazard, exposure and vulnerability) 
• define the resilience concept and its interdisciplinary applications
• know main steps, differences and analogies of seismic hazard analyses performed according to a deterministic vs a probabilistic approach
• know the principles of seismic response of masonry and reinforced concrete buildings
• discuss the main aspects of structural vulnerability and how they can affect the structural response
• understand and discuss the different possible seismic risk reduction policies in the three phases of risk management (pre-event, emergency state and post-event)
• know the different forms currently available for damage, emergency provisions and practicability assessment of ordinary buildings and churches
• manage large scale damage and vulnerability survey of existing buildings, cataloguing damage to evaluate the structures’ usability and identifying vulnerability elements and anti-seismic presidia to estimate a vulnerability index

TEACHING METHODS

Front lessons and practical applications:

• Practical exercise carried out through the IRMA (Italian Risk Maps) platform, developed by EUCENTRE for Civil Protection: the students will perform a seismic risk analysis on different territorial areas (municipalities, provinces, regions) in order to: implement the fragility curves of the different types of buildings; estimate the expected damage to buildings (number of collapses and unusable buildings).
• Practical application in field: the students will fill in the post-earthquake damage form available for Churches in order to compute the vulnerability index on a selected case-study (e.g. a church in Genoa).

SYLLABUS/CONTENT

1. Risk on the built environment

Introduction to natural disasters and risk elements (hazard, exposure and vulnerability); Resilience concept and its interdisciplinary applications

2. Seismic Hazard (recall to the basics concepts)

• Earthquakes origin, mechanics and effects (basics of seismology)
• Hazard as risk element: deterministic vs probabilistic hazard analysis

3. Exposure information

Introduction to the people, property, other assets or systems exposed to seismic hazards

4. Dynamic response of structural systems and seismic action (recall to the basics concepts)

Introduction to the basic concepts of structural dynamics by means of an elementary mathematical model: the SDOF system

5. Vulnerability to earthquakes, part I: seismic response of reinforced concrete (RC) structures

• Brief recall to the material behaviour 
• Introduction to the concepts of structural typologies, morphology and structural ductility
• Focus on structural deficiencies and collapse mechanisms exhibited by existing RC buildings after past earthquakes

6. Vulnerability to earthquakes, part I: seismic response of masonry structures

• Brief recall to the material behaviour 
• Vulnerability factors for masonry structures
• Seismic response of ordinary masonry buildings (1st mode and 2nd mode mechanisms)
• Seismic response of monumental structures (e.g. churches)

7. Vulnerability to earthquakes, part II: fragility curves

Analysis of the different approaches for the derivation of fragility curves: empirical, expert elicitation, numerical and hybrid methods; critical aspects in the derivation; treatment of uncertainties; practical example on the definition of numerical fragility curves

8. Seismic risk reduction policies in the three phases of risk management: pre-event, emergency state and post-event

Presentation of the three phases of risk management and overview on the different possible risk reduction policies: 1) pre-event (Mitigation efforts and Preparedness – education, emergency management planning); 2) response (Emergency state); 3) post-event (Recovery)

9. Post-earthquake damage survey

• Description of the survey forms at present used by the Civil Protection to evaluate post-earthquake damage and vulnerability at national level for residential and monumental buildings
• Practical examples: post-earthquake damage survey applied to some case-studies hit by the last Italian earthquakes in order to evaluate the damage and vulnerability indexes

RECOMMENDED READING/BIBLIOGRAPHY

• Course’s notes, available on AulaWeb
• References to journal papers provided by the teacher during the course