72781 - EARTHQUAKE ENGINEERING

Conoscenze e abilità da conseguire

At the end of the course the student will know the main aspects of earthquake engineering, and in particular: seismology and hazard, behaviour of structures under earthquake action, with elastic and inelastic behaviour, definition of the seismic action, design methods according to the most important Codes and regulations, detailing. The methods will be described with reference to reinforced concrete, steel and masonry structures.

Contenuti

REQUIREMENTS

A prior knowledge and understanding of:

• structural mechanics;
• structural analysis;
• structural design of reinforced concrete structures;
• structural analysis of frame structures with FEM;

are required to attend this course. These topics are covered in the following courses: Advanced Design of Structures and Advanced Structural Mechanics. A background on the Finite Element method is also recommended. This latter is provided by the Numerical Methods course. Fluent spoken and written English is a necessary pre-requisite: all lectures, tutorials, and all reference documents will be in English.

CONTENTS

1. SEISMOLOGY FUNDAMENTALS

• Earth structure, tectonics, faults, faulting mechanisms, earthquake recurrence, elastic rebound theory, magnitude measures, earthquake energy.
• Accelerograms: recording, properties, basic intensity measures. Soil and topographic effects.

2. STRUCTURAL DYNAMICS OF SDOF SYSTEMS

• Un-damped free vibrations;
• Damped free vibrations;
• Forced vibrations;
• Response to a base acceleration. Time-stepping procedures (Newmark method etc.).
• Elastoplastic SDOF systems.

3. RESPONSE SPECTRA

• Acceleration, displacement, velocity, pseudo-acceleration and pseudo-velocity response spectra;
• Non-linear response spectra: constant strength-reduction-factor spectra, and constant ductility spectra.
• Ductility- and strength-based design.

4. SEISMIC HAZARD AND RISK

• Seismic hazard
• Site response
• Uniform hazard spectra
• Seismic Risk

5. STRUCTURAL DYNAMICS OF MDOF STRUCTURES

• Mass, stiffness and damping matrixes;
• Modal analysis of plane structures;
• Static condensation;
• Free vibration;
• Response to ground acceleration;
• Maximum response analysis (response spectra analysis).
• Damping models;
• Modal combination rules: SRSS, CQC;
• Analysis of 3D structures. Effects of regularity.

6. SEISMIC DESIGN FUNDAMENTALS

• Performance based design: Definition of limit states and performance levels.
• Design response spectra: behaviour factor;
• Linear analysis methods;
• Definition of masses and combination of seismic effects with the effects of other loads;
• Capacity design fundamentals.

7. SEISMIC DESIGN OF CONCRETE STRUCTURES

• Ductility classes;
• Capacity design of frame structures;
• Interaction between walls and frames;
• Design of ductile walls.

8. SEISMIC DESIGN OF STEEL STRUCTURES (Basics)

• Capacity design;
• Moment resisting frames;
• Concentrically Braced Frames;
• Eccentrically Braced Frames;
• Buckling Restrained Braced Frames;
• Other systems.

9. NONLINEAR ANALYSIS

• Nonlinear beam-column models;
• Nonlinear static analysis;
• Nonlinear dynamic analysis.

10. ADVANCED SEISMIC PROTECTION TECHNIQUES (Basics)

• Base isolation;
• Dampers.

Testi/Bibliografia

Refenrence books

1. Steven L. Kramer, Geotechnical Earthquake Engineering
2. C.A. Chopra, Dynamics of Structures: Theory and Applications to Earthquake Engineering
3. Penelis, G.G. and Kappos, A.J., Earthquake-resistant Concrete Structures
4. T. Paulay and M. J. N. Priestley, Seismic Design of Reinforced Concrete and Masonry Buildings
5. EN 1998-1 Eurocode 8: Design of structures for earthquake resistance - Part 1 : General rules, seismic actions and rules for buildings.  

All the presentations used during the lectures are available on IOL. Sample exam questions are available as well.

Metodi didattici

Lectures with the support blackboard and powerpoint presentations. Homework assignments.

Modalità di verifica e valutazione dell'apprendimento

Achievements will be assessed by means of two homework assignments and a final written examination. They are based on an analytical assessment of the learning outcomes described above, as described in the following.

Homework assignment #1 aims at evaluating the following skills:

• Defining mass, damping, and stiffness matrixes for 2D and 3D structures;
• Defining elastic and design spectra according to Eurocode 8 and to the Italian seismic design code;
• Using modal analysis to compute the response of 2D and 3D structures with base ground-motions.

Homework assignment #2 aims at evaluating the following skills:

• Designing reinforced concrete frame structures according to Eurocode 8.

Both the homework assignments are mandatory and must be submitted in order to take the final examination. Students can either work alone or in groups with no more than three members.

The written examination is closed-book ad aims at evaluating the knowledge and critical understanding of the key concepts of the course. It is based on either two or three open questions. The duration spans form 1 hour to 1.5 hours, depending on the questions.

The final grade will be computed as follows: 50% homework + 50% oral examination

In order to obtain a passing grade, students are required to demonstrate a knowledge of the key concepts of the subjects, some ability for critical application, and a comprehensible use of technical language. A failing grade will be awarded if students show knowledge gaps in key-concepts of the subject, inappropriate use of language, and/or logic failures in the analysis of the subject.

 

Strumenti a supporto della didattica

Blackboard and powerpoint presentations. For homework, educational versions of softwares for structural analysis. Instructional shaking table.

Orario di ricevimento

Consulta il sito web di Nicola Buratti