75460 - Structural Diagnostics and Seismic Assessment M

Academic Year 2022/2023

  • Moduli: Nicola Buratti (Modulo 1) Nicola Buratti (Modulo 2) Camilla Colla (Modulo 3)
  • Teaching Mode: Traditional lectures (Modulo 1) Traditional lectures (Modulo 2) Traditional lectures (Modulo 3)
  • Campus: Ravenna
  • Corso: Second cycle degree programme (LM) in Engineering of Building Processes and Systems (cod. 8829)

Learning outcomes

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.

Course contents

The course comprises three modules:

· module 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.

· module 3 concerns structural diagnostic methods for historic structures (3 CFU).

REQUIREMENTS

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

Prior knowledge of historical construction materials and their forms of decay as well as technology of historical constructions is required. Prior knowledge and understanding of structural mechanics and mechanics of masonry structures is required, too to attend this course. All such topics are covered in previous year courses and in parallel 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 MODULE ON STRUCTURAL DIAGNOSTICS (3 CFU)

Not-attending students are required to contact teacher by email in advance to the semester’s or at course's beginning

1. INTRODUCTION TO THE KNOWLEDGE PATH FOR DIAGNOSE OF HISTORIC CONSTRUCTIONS

a. construction’s context and environment;

b. visual inspection methodology, identification of structural skeleton materials and construction details, vulnerabilities, damage;

c. crack pattern survey and monitoring aims, methodology and tools;

2. IN-SITU EXPERIMENTAL TECHNIQUES

Experimental techniques for masonry, mortar and timber state evaluations, determination of mechanical properties: in situ non-destructive, semi-destructive, destructive testing, image diagnostic NDTs. These include:

a. investigations by IR thermography;

b. investigations by GPR radar;

c. measurement of mortar compressive strength on site;

d. measurement of masonry modulus of elasticity by acoustical method and other testing aims;

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

f. masonry behaviour, compressive strength and elasticity modulus by double flat-jacks;

g. masonry shear strength via hydraulic jack or/and flat-jacks;

h. coring and sampling and their significance;

i. mentions to other in situ direct or indirect measurements;

l. timber moisture content and drilling penetration resistance determination.

3. LABORATORY TESTING ON SPECIMENS FROM SITE SAMPLING

a. optical monitoring for mechanical measurements;

b. tools and devices for mechanical properties measurement;

c. units’ and masonry’s compressive tests;

d. mortar layers compressive tests;

e. mentions to other lab tests.

Readings/Bibliography

    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

    STRUCTURAL DIAGNOSTICS

    • Student's personal notes of lectures' contents constitute study material.

    • In advance to the course starting lecture and during following lectures, some reference reading and viewing material will be pointed out to students attending the course.

    • Not-attending students are required to contact teacher by email in advance to the semester’s/course's beginning.

    • 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. Giovanni Pascale, Diagnostica a ultrasuoni per l'edilizia: costruzioni civili, beni culturali, Ed. Flaccovio, 2008

    • Statics and strength of structures / Mario Salvadori ; in collaboration with Jeremiah Eck and Giuseppe de Campoli, Englewood Cliffs : Prentice-Hall, 1971

    • Building : the fight against gravity / Mario Salvadori ; drawing by Saralinda Hooker and Christopher Ragus, New York : Atheneum, 1979

    • Structural design in architecture / Mario Salvadori, Matthys Levy, Englewood Cliffs [N. J.] : Prentice-Hall, c1967

Teaching methods

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 and site visits (when possible). Homework.

Assessment methods

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/ora 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. o obtain a final passing grade, passing grades must be obtained in each of the two course parts (modules 1+2 and module 3).

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 exam

Homework

During the course, homework may be assigned to students, who will be instructed if working on the assignment alone, in pairs or small groups. Homework could vary for different groups of students and it can vary in different academic years. The homework aims at gaining some practical experience of phenomena or some skills in inspection and survey or data analysis procedure. The homework assignment – which may involve presentation to class by students - must be completed and submitted during the semester, within the deadline(s) indicated by teacher.

Final Exam

Structural Diagnostics achievements are assessed via a final oral exam (including homework. Exam duration between half an hour and 1 hour approximately) aimed at evaluating the knowledge of the concepts and procedures discussed during the teaching module as well as their critical understanding.

 

Teaching tools

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

Office hours

See the website of Nicola Buratti

See the website of Camilla Colla

SDGs

Sustainable cities

This teaching activity contributes to the achievement of the Sustainable Development Goals of the UN 2030 Agenda.