75460 - STRUCTURAL DIAGNOSTICS AND SEISMIC ASSESSMENT M

Conoscenze e abilità da conseguire

At the end of the class, student has knowledge of the advanced concepts and tools for structural diagnosis, experimental testing and seismic assessment, with special attention for non-destructive techniques and in-situ structural assessment. In particular, at the end of the course he/she is able to assess historic structures, identify typical damage and conduct visual inspections, in situ investigation, non-destructive and slightly destructive techniques. In addition, he/she is able to carry out a seismic assessment, identify response spectrum analysis and damage and collapsing mechanisms in existing (particularly historical) structures.

Contenuti

The course comprises three modules:

• modulus 1 and 2 concern the seismic assessment of masonry structures (6 CFU in total), they will be referred to as Seismic Assessment in the following.
• modulus 3 concerns structural diagnostics techniques for masonry structures (3 CFU).

REQUIREMENTS

Fluent spoken and written English is a necessary prerequisite: all the lectures, tutorials, reference documents ad presentations will be in English.

A prior knowledge and understanding of structural mechanics and of the mechanics of masonry structures is required to attend this course. These topics are covered during the following courses:

• Advanced Structural Mechanics M
• Historic Masonry and Wood Structures M.

CONTENTS OF THE MODULI ON SEISMIC ASSESSMENT (6 CFU)

1. ENGINEERING SEISMOLOGY

a. Tectonics, faults, faulting mechanisms, earthquake recurrence, elastic rebound theory, magnitude measures, earthquake energy.

b. Accelerograms: recording, properties, basic intensity measures. Soil and topographic effects.

2. STRUCTURAL DYNAMICS OF SDOF SYSTEMS

a. Un-damped free vibrations;

b. Damped free vibrations;

c. Forced vibrations;

d. Response to a base acceleration: Duhamel integral and time-stepping procedures (Newmark method etc.).

3. RESPONSE SPECTRA

a. Acceleration, displacement, velocity, pseudo-acceleration and pseudo-velocity response spectra;

b. Ductility and constant ductility spectra .

4. SEISMIC HAZARD

a. Uniform hazard spectra.

b. Seismic Risk

5. STRUCTURAL DYNAMICS OF MDOF STRUCTURES

a. Mass, stiffness and damping matrixes;

b. Modal analysis of 2D structures;

c. Free vibration;

d. Response to ground acceleration;

e. Maximum response analysis (response spectrum analysis).

f. Damping models;

g. Modal combination rules: SRSS, CQC;

h. Analysis of 3D structures. Effects of regularity.

6. SEISMIC DESIGN FUNDAMENTALS

a. Performance based design: Definition of limit states and performance levels.

b. Design response spectra: behaviour factor;

c. Linear analysis methods;

d. Definition of masses and combination of seismic effects with the effects of other loads;

e. Capacity design fundamentals.

7. DESIGN OF MASONRY STRUCTURES

a. Design criteria for unreinforced masonry structures

8. SEISMIC VULNERABILITY OF EXISTING STRUCTURES

a. Behaviour of masonry elements under lateral loads

b. Analysis methods

c. Local failure modes.

d. Seismic vulnerability analysis of masonry structures

CONTENTS OF MODULUS ON STRUCTURAL DIAGNOSTICS (3 CFU)

1. INTRODUCTION TO THE KNOWLEDGE PATH FOR DIAGNOSE OF HISTORIC MASONRY CONSTRUCTION, VISUAL INSPECTION, SURVEY OF DAMAGE AND CRACK PATTERN MONITORING, EXPERIMENTAL TECHNIQUES FOR MASONRY STATE EVALUATIONS AND DETERMINATION OF MECHANICAL PROPERTIES:

a. in situ destructive, non-destructive, semi-destructive testing with preference to image diagnostic techniques;

b. laboratory testing from site sampling.

2. IN-SITU EXPERIMENTAL TECHNIQUES:

a. coring and sampling;

b. shear strength measurement using hydraulic jack or/and flat-jacks;

c. mortar compressive measurement strength using penetrometers;

d. in situ strength measurement by pull-out tests;

e. modulus of eleasticity measurement by using sonic tests;

f. masonry local compressive stress measurement using single flat-jack;

g. masonry deformability, compressive strength and elasticity modulus by double flat-jacks;

h. diagonal compression in panels

i. IR thermography

l. GPR radar.

3. LABORATORY TESTS

a. compressive strength and modulus of elasticity;

b. splitting tensile stregth using site cores;

c. mortar compressive strength by double punch;

d. splitting tensile test on cores with mortar joint.

Testi/Bibliografia

• SEISMIC ASSESSMENT

  • Steven L. Kramer, Geotechnical Earthquake Engineering
  • C.A. Chopra, Dynamics of Structures: Theory and Applications to Earthquake Engineering, 1999
  • Tomazevic, Earthquake-Resistant Design of Masonry Buildings, ICP
  • Thomas Paulay and M. J. N. Priestley, Seismic Design of Reinforced Concrete and Masonry Buildings
    

  DIAGNOSTICS

  • V.M. Malhotra, N.J. Carino: “Handbook on Nondestructive Testing of Concrete”, CRC Press, USA, 2004.
  • M.J. Sansalone, W.B. Street: “Impact-echo”, Bullbrier Press, Ithaca, N.Y., 1997.
  • Other references will be pointed out to during the course.

Metodi didattici

Cognitive and experiential learning. Theory lectures supported by powerpoint presentations and use of blackboard will be alternated with experiential lectures where learning methods include practical exercises and hands-on use of non-destructive equipment, lab demonstrations, site visits. Homework.

Modalità di verifica e valutazione dell'apprendimento

The final examination for the moduli on Seismic Assessment and for the modulus on Structural Diagnostics are independent. Students are allowed to take them in different sessions.

In each part, 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. The final grade will be computed as the weighted average of the grades obtained in each part. To obtain a final passing grade passing grades must be obtained in each of the two parts.

Structural Diagnostics and Seismic Assessment M is part of the integrated course "LABORATORY OF STRUCTURAL DIAGNOSTICS AND REHABILITATION M C.I." (15 CFU). The final grad for the integrated course will be computed as the weighted average of the grades of Seismic Assessment (6 CFU), of Structural Diagnostics (3 CFU) and of Structural Strengthening and rehabilitation M (6 CFU). Structural Strengthening and rehabilitation M is given during the second semester.

Seismic Assessment grade and exam

The final grade for Seismic Assessment is defined as follows:

25% Homework + 75% Final exam

Homework

During the course one homework assignment will be given to students, it aims at assessing the following skills:

• definition of elastic and design response spectra based on Eurocode 8 and Italian code Rules
• application of standard seismic analysis methods on simple masonry structures
• seismic verification of existing masonry structures.

The homework assignment must be completed and submitted in order to sit for the final examination. Deadlines are set for each final exam date and reported on Almaesami.

Final Exam

The final exam for "Seismic Assessment" is a closed-book written examination. This exam is based on either two or three open questions, aimed at evaluating the knowledge of the key concepts discussed during the course as well as their critical understanding. The duration of the final exam is between 1 hour and 1.5 hours.

Structural Diagnostics

Achievements will be assessed by means of one homework assignment and a final exam. The final exam for the modulus "Structural Diagnostics" will be oral. Both the homework assignment and the final exam are based on an analytical assessment of the "expected learning outcomes" described above.

 

Strumenti a supporto della didattica

Oral lectures with powerpont presentations. Blackboard. Computer lab. Demonstrations. Lab visit. Site visits. Application examples.

Orario di ricevimento

Consulta il sito web di Nicola Buratti

Consulta il sito web di Camilla Colla