1329487208 Structural Aspects in Ports Engineering - Lesson 1

7/30/2019 1329487208 Structural Aspects in Ports Engineering - Lesson 1

1/42

University Roma Tre

Training Course of Ports Engineering for Iraqi experts - 2012

STRUCTURAL ASPECTS IN

P RT EN INEERINLESSON 1 INTRODUCTION TO STRUCTURAL ENGINEERING

Fabrizio Paolacci

University Roma Tre

Department of Structures


2/42

University Roma Tre


OUTLINE

Content of the course

Objective of structural engineering

Structural typologies

Old and new approaches in structural engineering:

Allowable stress and LRFD methods Limit states and method of partial factors

Introduction to structural safet

Ultimate (ULS) and Serviceability (SLS) limit

states of structures es gn va ues or ac ons

Examples ULS combinations of actions on

t ical structures

Structural aspects in Port Engineering Lesson 1


3/42

University Roma Tre


Content of the Course (1/6)

Limit states and method of partial factors

Introduction on structural safety concepts

Design values for actions and materials

Ultimate (ULS) and Serviceability (SLS)limit states of structures

o e an s an ar s or s ruc ura es gn

(European and American codes)

Example: identification ULS and SLS on a

frame structure



4/42

University Roma Tre



Actions and load combinations

Introduction

Verification of limit states

Combination of actions according toEuropean and American codes

Example: ULS and SLS load combinations



5/42

University Roma Tre


Content of the Course (3/6)a er a s proper es an ura y

Basic properties of steel

Qualification and acceptance criteria

Degradation and durability requirementsfor R.C and steel structures

or e eva ua on o ma er a

properties

Example: Evaluation of concrete strength

using PV test. In-field tests



6/42

University Roma Tre



Design and analysis of R.C. and pre-stressed R.C structures

Ultimate limit states for concrete

s ruc ures ax a exura ac ons,shear and torsion)

structure (cracking limitation and

deformability)

Example: ULS and SLS of a R.C. and a


s ruc ure


7/42

University Roma Tre



Basis of structural design

es gn an ana ys s o s ee an s ee -

concrete composite structures

concrete-steel composite beam andcolumns

Serviceability limit states of a steel

structure

Example: ULS and SLS of a frame

-



8/42

University Roma Tre



seismic-prone areas

Basis of seismic response of structure

Definition of seismic action and

per ormance

Analysis methods (linear and non-linear

Seismic damages suffered by ports and

harbors.Example: application of linear and non-

linear analysis to an industrial steel


ac y


9/42

University Roma Tre


REFERENCES

- uroco e : es gn o concre e s ruc ures

EN 1998 - Eurocode 8: Design of structures for earthquake

resistance

- ,

Concrete and Commentary ASCE 7-05 - Minimum Design Loads for buildings and

Robert Park, T. Paulay, Reinforced concrete structures,

John Wiley and Sons, 1975

Anil H. Cho ra D namic of Structures Prentice Hall 2007



10/42

University Roma Tre


Objectives of Structural Engineering

Structural engineering is the sciencean art o es gn ng an ma ng, w t

economy, buildings, bridges,

ramewor s, ports an ot er structuresso that they can safely resist the forces

o w c ey may e su ec e .



11/42

University Roma Tre


Structural Engineering process

Determine types magnitudes of loads

Determine structural context geometric and geological information

cost / schedule / height/ etc.

Limitations

Generate alternative structural systems

Analyze one or more alternatives

Select and perform detailed design mp ement usua y one y contractor



12/42

University Roma Tre


Structural typologies

Arch (masonry/concrete) anar russ stee concrete

Beam/Girder

Braced Frame (steel/concrete)

Ri id Frame (concrete)

Space Truss (steel)

Special Structures (Geotechnical)



13/42

University Roma Tre


Structural typologies (Arch)



14/42

University Roma Tre


Structural typologies (Planar Truss)



15/42

University Roma Tre


Structural typologies (Beam/girder)



16/42


17/42

University Roma Tre


Structural typologies (3D truss)



18/42

University Roma Tre


Structural typologies (3D truss)



19/42

University Roma Tre


Structural typologies (Cable suspended)



20/42

University Roma Tre


Structural typologies (Cable suspended)



21/42

University Roma Tre


Structural typologies (Special structures)

Breakwaters



22/42

University Roma Tre


Structural typologies (Special structures)

Gravity Retainingruc ure Walls

Berth Structures


eet p e wa pen p e uay


23/42

University Roma Tre


Load path

Load Path is the term used toescri e t e pat y w ic oa s are

transmitted to the foundations

Di erent structures ave i erentload paths

ome structures ave on y one pat

Some have several (redundancy good)



24/42

University Roma Tre


Load path

The structural scheme

determines the loadpath. The designer has

to select the most

appropr a e sc eme.



25/42

University Roma Tre


Outcomes of structural engineering

The structural Engineering :

identifies loads to be resisted

identifies alternatives for providing load

pa s arc , russ, rame, ...

designs structure to provide safe and

, ,

connections)

to be economical and safe, we must beable to predict what forces are in

structure.



26/42

University Roma Tre


Methods for the safety assessment: Load

Allowable Stress Design (ASD)

The evaluation of the structural safety is the first

Step of the design process, which has consequences on

the further choices. In articular the dimensionin of

the structure, the costs,etc..The levels of risk depends on the design method

. ,

design methods

Load and Resistance Factor Design



27/42

University Roma Tre


Load Resistance Factor Design (LRFD)

an owa e ress es gn

ASD

The general form for ASD is:Usually the effects of loads

are represented by the

resistance by the localstrength.

Rn= nominal resistance

represented by the unique

safety factor FS

= nom na ea oa e ect

Qt1, Qt2= nominal transient load effects

= load combination factor


= ac or o a e y


28/42

University Roma Tre



an owa e ress es gn

LRFD

The general form for LRFD is:

The uncertaint is

subdivided inuncertainty due to

n nom na res s ance

Qd= nominal dead load effect

Qt1, Qt2 = nominal transient

resistance. The

definition of resistance

1 = load factor associated with the

ithload effect

=

general



29/42

University Roma Tre



an owa e ress es gn

The main drawbacks of the allowable stress desi n are:

1. The analysis is purely deterministic

. ,

a physiologic effect in the designer of having highsafety margins.

.

a not convenient method to dimension a structure

4. It is not possible to verify quantities different from

e ens on e.g. corros on, re e c..

5. It is logic to discard a structure only on the basis of

the stress level.



30/42

University Roma Tre



an owa e ress es gn

On the contrar there are several advantan es

1. There is the possibility of using the superposition

behaviour .

. ,

for static actions

. oo e av our s own y a e s ruc ures

designed using the ASD method



31/42

University Roma Tre



an owa e ress es gn

The advanta es of the LRFD method are

1. Uncertainties of resistance and action are evaluated

2. For the estimation of the resistance it is possible to

-

and structures.

. evera m s a es can e cons ere , w c nvo ve

both ultimate and serviceability conditions



32/42

University Roma Tre


Limit states and partial factors

n ro uc on o s ruc ura sa e y

Resistance

WR Resistance

Load effects

Load



33/42

University Roma Tre




It is reco nized that Resistancesafety and integrity of

the structure can be WR

load effect W falls at apoint to the left of point

Load effects

the right on the curve R.

Failure, on the other

an , wou e expec e

if the point falls in the

shaded area



34/42

University Roma Tre




The definition of thesafety margin is done

using structural

.

In particular thereliability index is

WR = mean

22

WR +

Standard dev.



35/42

University Roma Tre






36/42

University Roma Tre


Limit states and partial factorsDefinition of limit states

Ultimate Limit States

To satisfy the ultimate limit state, the structure must not collapse whensu jecte to t e pea esign oa or w ic it was esigne . structure is

deemed to satisfy the ultimate limit state criteria if all factored bending,

shear and tensile or compressive stresses are below the factored resistance

ca cu a e or e sec on un er cons era on. ereas agn ca on ac or

is used for the loads, and Reduction Factor for the resistance of members.Serviciability limit states

,

functional for its intended use subject to routine (read: everyday) loading,

and as such the structure must not cause occupant discomfort under routine

.when the constituent elements do not deflect by more than certain limits laid

down in the building codes, the floors fall within predetermined vibration


,

applicable building code.


37/42

University Roma Tre




EQU (Equilibrium)

ruc ura

GEO (Geotechnical)

FAT (Fatigue)



38/42

University Roma Tre




EQU (Equilibrium)

ruc ura

GEO (Geotechnical)

FAT (Fatigue)

Mu > Md


U i i R T


39/42

University Roma Tre




EQU (Equilibrium)

ruc ura

GEO (Geotechnical)

FAT (Fatigue)


U i it R T


40/42

University Roma Tre



Serviciability Limit States

DEF (deformation)

ress eve

CR (craking level, for concrete)


U i it R T


41/42

University Roma Tre


Limit states and partial factorsULS Safety factors for actions and combinations

ULS

EC2 p. 2.3.3

n

Unfavorableeffects

Favorableeffects

++= =iikiikqkgd QQGF

1 g 1.4 1.0

q 1.5 0

Varia e actions orcivil structures

0.7

Office, schools 0.7

garages 0.7

Snow, wind 0.7


University Roma Tre


42/42

University Roma Tre


ULS Safety factors for actions and combinationsExample


Date post:	14-Apr-2018
Category:	Documents
Upload:	landon-mitchell
View:	226 times
Download:	0 times

1329487208 Structural Aspects in Ports Engineering - Lesson 1

Documents