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What is essential
Franco Bontempi
School of Civil and Industrial Engineering University of Rome La Sapienza
1
Declaratoria / Declaratory
• Il settore della Tecnica delle Costruzioni si interessa dell’attività scientifica e didattico-formativa inerente teorie e tecniche rivolte sia
alla concezione strutturale ed al progetto di nuove costruzioni, sia alla verifica ed alla riabilitazione strutturale di quelle esistenti.
• Tecnica delle Costruzioni is concerned with the scientific and didactic-learning activities inherent in theories and techniques directed at both the structural conception and the design of new constructions, as well as the structural verification and rehabilitation of existing ones.
9Bontempi – What is essential
• The scientific-disciplinary content concerns:
- building actions, including the effect of seismic action,
- the behavior of structures according to their typology and morphology, materials, techniques and technologies, soil interaction and l environment, ways and strategies of use and control;
- methods and tools for structural design, implementation and management of structures;
- vulnerability assessments, reliability, comfort, safety and durability; experimentation, testing and monitoring of buildings;
- historical surveys on construction, security checks and structural interventions applicable to historic buildings and monuments;
- structural architecture.
10Bontempi – What is essential
Bontempi – What is essential
1. Tecnica delle Costruzioni deals with structural design and design: it is a discipline of synthesis -in which ideas, theories, methods, tools, experimentation and empirical principles come together - leading to the choice of schemes, elements and components, structural materials, starting from a solid and broad cultural base.
2. The structural design involves a holistic view of the entire lifecycle of a construction and the environment in which it is immersed, necessarily envisaging a decision-making path characterized by assuming responsibility.
3. Structural analysis is the prerequisite for understanding and exploring qualitative and quantitatively structural behavior in terms of performance and safety: a proper understanding of the relationship between model and reality is essential for this purpose.
4. The study of real construction cases, particularly in cases of failures, is an essential source of increased knowledge of the discipline.
5. L’insegnamento della disciplina deve partire dai principi meccanici generali, favorire una valida comprensione dei comportamenti strutturali elementari e complessivi, predisporre a una fondata organizzazione della disposizione delle varie parti strutturali supportata da una coerente scelta dei materiali, aiutare ad individuare le possibili situazioni in cui una costruzione può trovarsi in termini di azioni e configurazioni.
11
Statements
Bontempi – What is essential
• La Tecnica delle Costruzioni si occupa della concezione e della progettazione strutturale: è una disciplina di sintesi - in cui confluiscono idee, teorie, metodi,
strumenti, sperimentazione e principi empirici – che porta alla scelta oculata di schemi portanti, elementi e componenti, materiali strutturali, partendo da
una solida e ampia base culturale.
• Tecnica delle Costruzioni deals with structural design and design: it is a discipline of synthesis - in which ideas, theories, methods, tools, experimentation and empirical principles come together - leading to the choice of schemes, elements and components, structural materials, starting from a solid and broad cultural base.
Statement #1
12Bontempi – What is essential
18Bontempi – What is essential
Constructive attitude
Knowledge of the design
method, how it is done or to
know things, is a liberating value:
it is a "do-it-yourself" yourself.
• L’ergonomia è la disciplina che si occupa dell’interazione tra un sistema e lo scopo per il quale è progettato, e si propone di
migliorarne la funzionalità rispetto al suo utente.
• Human factors and ergonomics (commonly referred to as HF&E), also known as comfort design, functional design, and systems, is the practice of designing products, systems, or processes to take proper account of the interaction between them and the people who use them.
27
Ergonomia
Ergonomics
Bontempi – What is essential
• "But a number of excessive rules involve various of the disadvantages mentioned above, and in particular:
- the impoverishment of autonomy and creativity, as the work of the designer is impatient with the norms;
- the difficulty of discerning what really matters;
- the feeling of having, under the shelter of the norms, much relieved responsibilities;
- the uncommon difficulty to realize the reasoning that justify certain rules, risking them to be regarded as algorithms, that is, operating patterns that, once learned, thought is no longer called to justify. "
32
- Proliferazione delle normative e tecnicismo. Ultima lezione ufficiale del corso di Tecnica delle costruzioni tenuta dal prof. Piero Pozzati nell'a.a. 1991-'92, presso la Facoltà di Ingegneria dell'Università di Bologna (3
giugno 1992).
Bontempi – What is essential
Excess of Standards
Vn = 100
Cu = 2
q0 = 4
NB:
Caratteristiche
Struttura
Vn = 100
Cu = 2
q0 = 2
Periodo
di ritorno
sisma
Vn = 50
Cu = 1
q0 = 2
Opere ordinarie, ponti, opere infrastrutturali
e dighe di dimensioni contenute o di importanza normale
Grandi opere, ponti, opere infrastrutturali
e dighe di grandi dimensioni o di importanza strategica33
Statistics
(apparently
scientifically
based)
Human
Decision
(arbitrary)
• Il progetto strutturale riguarda con una visione olistica tutto il ciclo di vita di una costruzione e l’ambiente in cui è immersa, prevedendo necessariamente
un percorso decisionale caratterizzato da assunzione di responsabilità.
• The structural design involves a holistic view of the entire lifecycle of a construction and the environment in which it is immersed, necessarily envisaging a decision-making path characterized by assuming responsibility.
Statement #2
35Bontempi – What is essential
42
Luxury is the manifestation of the
uncivilized wealth that wants to
impress who is poor.
It is the manifestation of the
importance that is given to the
exteriority and reveals the lack of
interest in the whole cultural
elevation.
It's the triumph of appearance on
the substance.
Bontempi – What is essential
Disvalori
Anti-values
45Bontempi – What is essential
Simplifying means trying to solve the
problem by eliminating everything that is
not needed to perform the functions
Simplifying is to reduce costs, reduce
machining, assembly, and finishing times.
One wants to solve two issues together in
one solution. Simplifying is a hard work and
requires a lot of creativity.
Complicating is much easier, just add
anything what comes to your mind without
worrying if costs go beyond sales limits,
you take more time to realize the object,
and so on.
Valori
Values
46Bontempi – What is essential
It is necessary, however, to say that the general public is more inclined to evaluate the manual "so much work" that it takes to do a complicated thing than to recognize the "so much work" mental that it wants to simplify, since then you can not see it. Indeed, people in the face of simple solutions, which may have required lengthy research and trials, say: but how, is everything here? but this I knew I did too!
49Bontempi – What is essential
It is important to consider things not only for what they are, but also for what they might be. Generally, the same thing can be looked at in many respects, and sometimes the less obvious points of view are most useful. It's always worth it, when something is happening for what it is, to go deep into the exam to see what else it might be.
Sostenibilità
Sustainability
• L’analisi strutturale è il presupposto per capire ed esplorare qualitativamente e quantitativamente il comportamento strutturale in termini di prestazioni e
sicurezza: la corretta comprensione della relazione fra modello e realtà è essenziale a tal fine.
• Structural analysis is the prerequisite for understanding and exploring qualitative and quantitatively structural behavior in terms of performance and safety: a proper understanding of the relationship between model and reality is essential for this purpose.
Statement #3
50Bontempi – What is essential
START
END
MODIFICA
K=K+1
K=0
DATI
K
CALCOLO
RISULTATI
K
TESTSI’ NO
AN
ALY
SIS
SY
NT
HE
SIS
53
Analysis vs Synthesis
Bontempi – What is essential
Synthesis is the combining of the constituent elements of separate material or abstract entities into a single or unified entity (opposed to analysis as the separating of any material or abstract entity into its constituent elements).
Usu
al
UL
S &
SL
S
Ve
rifi
ca
tio
nF
orm
at
Structural Robustness
Assessment
1st level:
Material
Point
2nd level:
Element
Section
3rd level:
Structural
Element
4th level:
Structural
System
55
Level of Structural Failures
Bontempi – What is essential
Bad vs Good CollapseSTRUCTURE
& LOADSCollapse
Mechanism
NO SWAY
“IMPLOSION”OF THE
STRUCTURE
“EXPLOSION”OF THE
STRUCTURE
is a process in which
objects are destroyed by
collapsing on themselves
is a process
NOT CONFINED
SWAY
56Bontempi – What is essential
58Bontempi – What is essential
STRUCTURAL
QUALITY
- design life
- railway
runability
- highway
runability
- free channel
- robustness
- durability
- management
GLOBAL
GEOMETRY
AND
TOPOLOGY
TOPOLOGY
- suspension system
- towers
- towers foundation
- anchor system
- main deck
- deck landing
- ...
GLOBAL GEOMETRY
- main span
- sx span
- dx span
SECTIONAL GEOMETRY
- continuous girder sections
- transverse section
- main cables
- hangers
- towers
- secondary elements
MATERIALS
CHARACTERISTICS
- girders
- cables
SYNTHESIS OF
STRUCTURAL
SOLUTION
AND
DOCUMENTATION
BOUNDARY
CONDITIONS
CONSTRAINTS:
rigid and elastic
constraints,
imposed
displacements
NATURAL
ACTIONS
- temperature
- wind
- earthquake
ANTROPIC
ACTIONS
a) permanent
loading
system
b) variable
- railway
- highway
c) accidental
CO
NV
EN
TIO
NA
L M
OD
ELIN
G:
QU
AS
I ST
AT
IC R
EP
RE
SE
NT
AT
ION
BASIC STRUCTURAL
CONFIGURATION
PARAMETERS
- individuation
- definition
- uncertainty
- description
- bounding
GLOBAL
MODELING
- 2D
- 3D
MODELING WITH
DYNAMIC INTERACTION
ALTERNATIVE STRUCTURAL
CONFIGURATIONS
GLOBAL
OPTIMIZATION
- topology
- morphology
- parametric
LOCAL
OPTIMIZATION
- girders section
- transverse
section
- restraint zone
EXPERT AND
FIXED CHOICES
MEASURES
a) qualitative
b) materials volumes
c) serviceability
- modal characteristics
- deflections
- deformations
- reversibility
d) collapse scenarios
- collapse characteristics
- robustness
e) accidental scenarios
- configurations
- risks
DETAILED
MODELING
EXTENDED
MODELING
12 3
4
5
6
7
Numerical Modeling for the
Structural Analysis and Design of
MESSINA STRAIT BRIDGE:
subdivision and development of activities.
FB - june 6, 2005 / franco.bontempi@uniroma1.it
• But, in addition to these observations, it seems appropriate to conclude by observing in general that, with regard to the methods of calculation and the rules, it should be avoided to give them too much importance, in order not to shadow the actual design.
• Which has only one of its phases, even if it is fundamental, while in other matters it is equally qualified: above all I mean the general conception of structures; the harmonious distribution of masses; the constructive details; analysis of executive and cost problems; the critical examination of the general construction behavior including, and not only, the presence of non-structural elements and the part of the soil involved in the structure. These are those who have to get into the living of the design process, becoming a unique force each time.
• Facts that can not be comprehensively acquired by numerical elaborations and computers as they can, however, succeed in making the human mind with the irreplaceable auxiliaries, peculiar to it alone, intuition, inventiveness, imagination, and creativity.
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- IL CONVENZIONALISMO NEL CALCOLO STRUTTURALE SISMICO – P. Pozzati 5 marzo 2004
Bontempi – What is essential
• Lo studio di casi reali di costruzioni, in particolare nei casi di fallimento, è fonte essenziale di aumento di conoscenza della disciplina.
• The study of real construction cases, particularly in cases of failures, is an essential source of increased knowledge of the discipline.
Statement #4
62Bontempi – What is essential
69
The Almö Bridge (inaugurated in 1960), that connected the island of Tjörn (Sweden's 7th largest island) to the mainland. The bridge collapsed January 18th 1980, when the bulk carrier MS Star Clipper struck the bridge arch. Eight people died that night as they drove over the edge until the road on the Tjörn side was closed 40 minutes after the accident. A new cable-stayed bridge, Tjörn Bridge, was built and inaugurated in 1981.
Bontempi – What is essential
Direct vs. Inverse Problems
Back-analysis
Forward-analysisDirect problem
Inverse problem
70Bontempi – What is essential
COSE – STRUTTURE - SISTEMITHINGS – STRUCTURES - SYSTEMS
PERSONE – COMPORTAMENTIPEOPLE – HUMAN BEHAVIOR
COSAWHAT
CHIWHO
ROTTURA – COLLASSO - CRISIFAILURE – COLLPASE - CRISIS
PERCHE’WHY
SPIEGAZIONE – CAUSEREASON - DISCLOSURE
CO
NO
SCEN
ZAKO
NW
LED
GE
Aumento conoscenza – Knowledge gain
71Bontempi – What is essential
http://territorio.regione.emilia-romagna.it/codice-territorio/sismica/dossier-sentenze-della-causa-penale-conseguente-al-crollo-delledificio-scolastico-jovine-di-san-giuliano-di-
puglia 72
• L’insegnamento della disciplina deve partire dai principi meccanici generali, favorire una valida comprensione dei comportamenti strutturali elementari e
complessivi, predisporre a una fondata organizzazione della disposizione delle varie parti strutturali supportata da una coerente scelta dei materiali,
aiutare ad individuare le possibili situazioni in cui una costruzione può trovarsi in termini di azioni e configurazioni.
• The teaching of the discipline must start from the general mechanical principles, promote a good understanding of the elementary and overall structural behaviors, prepare for a well-structured arrangement of the various structural parts supported by a coherent choice of materials, help to identify the possible situations where a construction can be in terms of actions and configurations.
Statement #5
77
• Micro-level: local size of the sections, i.e. thickness, area, inertia, …
(Detailed Geometry)
• Meso-level: form of the structural element or structural part (substructure), i.e. main longitudinal axis, curvature, profile, …
(Global Geometry)
• Macro-level: connections of the different structural parts
(Load Path)
99Bontempi – What is essential
Structure Essential
Micro-level:local size of the sections,
i.e. thickness, area, inertia, … (Detailed
Geometry)
Meso-level: form of the structural
element or structural part (substructure), i.e. main
longitudinal axis, curvature, profile, … (Global Geometry)
Macro-level: connections of the different structural parts (Load Path)
100Bontempi – What is essential
Optimization Levels
• Spazialità
• Comportamento trave (B-regions)
• Regioni diffusive (D-regions)
• Modelli discreti traliccio/graticcio
• Modelli di progetto (S&T – SPM)
• Percorso dei carichi
• Sistema strutturale
• Nonlinearità
• Imperfezioni e incertezze101
Concetti chiave – Key Concepts• Spatiality
• Basic beam behavior (B-regions)
• Diffusive regions (D-regions)
• Discrete models (truss/gridworks)
• Design models (S&T – SPM)
• Load path
• Structural system
• Nonlinearity
• Imperfections and uncertaintyBontempi – What is essential
Titolo 11- ASN
• Specifiche esperienze professionali caratterizzate da attività di ricerca attinenti al settore concorsuale per cui è presentata la domanda per l'abilitazione.
• Il titolo verrà riconosciuto nel caso di esperienze professionali caratterizzate da problematiche complesse, affrontate con approcci e metodi non standard.
103Bontempi – What is essential
107
It was the task of the Engineering Schools to teach about artificial things: to explain how artifacts have the properties they want and how they are designed. ... Given the fundamental role that designers undertake in professional activities, it is an irony that in this century the Natural Sciences have driven the Science of Artificial training from their courses. ... The tendency toward natural sciences and the removal from the Science of Artificial have occurred more and more quickly in Engineering, Economics ... than in other professional fields. ... there are few doctoral dissertations dealing with authentic planning problems considered something different from the problems of solid state physics or stochastic processes. ... This universal phenomenon must have a root cause. And, in fact, it has one completely obvious. As vocational schools, including polytechnics, are increasingly absorbed by general university culture, aspiring to academic respectability. And, according to today's dominant standards, academic respectability means subjects that are intellectually difficult, analytic, and can be formalized and taught.
Bontempi – What is essential
Bartolo Nigrisoli
108
«Il concetto morale del carattere e della dignità umana, che mi aveva aperta la strada alla cattedra fu lo stesso che mi fece destituire, essendo sotto il fascismo il bene morale diventato un male»
Bontempi – What is essential
110
On October 8, 1931, Mussolini imposed on university professors the oath of allegiance to fascism. About a thousand ordinary people only twelve refuse to bend to the duce, losing the chair, and undergoing a massive isolation in the massively subdued regime in Italy. Twelve men, different by origin, character, ways of thinking, social attitudes, in that autumn of 1931 impart the most masterful of the lessons teaching that saying no is a choice first of all to themselves. Ernesto Buonaiuti, Mario Carrara, Gaetano De Sanctis, Giorgio Errera, Giorgio Levi Della Vida, Fabio Luzzatto, Piero Martinetti, Bartolo Nigrisoli, Francesco and Edoardo Ruffini, Lionello Venturi, Vito Volterra - these names of those who make an essential gesture in the name of those "ideals of freedom, dignity and inner consistency" in which they grew up.
Bontempi – What is essential
125
https://www.youtube.com/channel/UCW3IyXTBJVIiS6OZeSdIN7g
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