what is essential

What is essential

Franco Bontempi

School of Civil and Industrial Engineering University of Rome La Sapienza

1

Bologna, 06/06/2017 2http://www.dcee2016.eu/

http://www.dcee2016.eu/

Bologna, 06/06/2017 3http://www.dcee2017.org/

http://www.dcee2017.org/

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.


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


• 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



Design method

Problem solving


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.


No archistar


Fundamentals

• 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


28

Aspetti cognitivi

Cognitive aspects


29

Aspetti cognitivi

Cognitive aspects


30

Esempio

Example


• "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).


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)

Failure Path (Reason)


• 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


RESILIENCE


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.


Disvalori

Anti-values

43

Esempio

Example


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


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!

47

Esempio

Example


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


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


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


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


57

Rappresentazione

grafica

Visual

Language



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 / [email protected]

• 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.

61

- IL CONVENZIONALISMO NEL CALCOLO STRUTTURALE SISMICO – P. Pozzati 5 marzo 2004


• 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


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.


Direct vs. Inverse Problems

Back-analysis

Forward-analysisDirect problem

Inverse problem


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


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

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

74

Mistificazione

Fallacy

• 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


Spazialita’

Spatiality

A

B

C

D E

F

G

H


B - and D - Regions

89

Bernoulli-Navier Beam Model


Drucker Beam Model



Ritter-Morsch Truss Model

92

Modelli di

Progetto

Design

Models


Stringer-Panel Model

94

Load Path: the flow of loads



Load Path: knowledge


Structural System

97

Sistema

Strutturale

Structural

System


9898Raccolta/Collection Trasmissione/Transfer Stabilizzazione/Bracing

• 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)


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)


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


Academics

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.


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.


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»


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.


Fenomeni di aderenza/scorrimento

116

125

https://www.youtube.com/channel/UCW3IyXTBJVIiS6OZeSdIN7g

https://www.youtube.com/channel/UCW3IyXTBJVIiS6OZeSdIN7g

126https://fr.linkedin.com/in/francobontempi

https://fr.linkedin.com/in/francobontempi