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FIELD OF STUDY: STRUCTURAL ENGINEERING
FIELD OF STUDY:
STRUCTURAL ENGINEERING
Faculty Members
Asst. Prof. Dr. Mürüde Çelikağ
Asst. Prof. Dr. Giray Özay
Asst. Prof. Dr. Serhan Şensoy
Asst. Prof. Dr. Masoud Negin
Yarı – zamanlı
Prof. Dr. Ayşe Daloğlu
Prof. Dr. Semih Küçükarslan
Compulsory CoursesCIVL 211 StaticsCIVL 222 Strength of MaterialsCIVL 343 Intro. Structural MechanicsCIVL 344 Structural AnalysisCIVL 372 Fundamentals of Reinforced ConcreteCIVL 473 Steel StructuresCIVL 471 Design of Reinforced Conc. StructuresAlso AREA ELECTIVES
Structural engineering is the science and art of
Planning Designing Constructing
Structures that are
•Safe
•Serviceable
•Economical
Design Process
Design ProcessCIVL 372 Fundamentals of Reinforced Concrete
CIVL 471 Design of Reinforced Concrete Structures
Design ProcessCIVL 372 Fundamentals of Reinforced Concrete
CIVL 471 Design of Reinforced Concrete Structures
CIVL 211 Statics
CIVL 222 Strength of Materials
CIVL 343 Int. StructuralMechanics
CIVL 344 StructuralAnalysis
Design ProcessCIVL 372 Fundamentals of Reinforced Concrete
CIVL 471 Design of Reinforced Concrete Structures
CIVL 211 Statics
CIVL 222 Strength of Materials
CIVL 473 Steel Structures
CIVL 372 Fundamentals of Reinforced Concrete
CIVL 471 Design of Reinforced Concrete Structures
CIVL 343 Int. StructuralMechanics
CIVL 344 StructuralAnalysis
Design ProcessCIVL 372 Fundamentals of Reinforced Concrete
CIVL 471 Design of Reinforced Concrete Structures
CIVL 211 Statics
CIVL 222 Strength of Materials
CIVL 473Steel Structures
CIVL 372 Fundamentals of Reinforced Concrete
CIVL 471 Design of Reinforced Concrete Structures
CIVL 343 Int. StructuralMechanics
CIVL 344 StructuralAnalysis
What is Design?
suitable materials member sizes and shapes
The calculation of the expected loads on the members ofthe structure and then the selection of
to resist the forces, moments, stresses and deflectionscalculated during analysis.
Important:Design should comply with the relevant DESIGN CODES
What is Design?Good Structural Design is achieved through series of steps. Thesesteps are not all necessary for every design. Structural Design requiresexperience, logical thinking, good understanding of structuralbehaviour and knowledge in the following areas:
Materials Geotechnics (soil) Construction
Technology Health and Safety Eng. Economics Computer Usage Mathematics Probability & Statistics CE Drawing
Other Branches of CE
Static, Dynamic, Strength of Materials
Structural Analysis Structural Dynamics Design of Reinforced
Concrete Design of Steel Design of Masonry etc. Structural Systems Structural Stability
Structural Eng. Branch
How Do You Say That a Structure is Designed “Up To Standard”?
• Structural system and selected materials are suitable for the purposeof the building
• It is strong and stable enough to resist all the possible combinationof ultimate
- gravity dead and live loads- lateral wind loads- earthquake loads- accidental loads- blast loads
• It is stiff enough not to deform beyond the limiting design codevalues when subject to service loads.
• Safe for construction, daily use and maintenance• Economic and preferably recyclable at the end of its life span
What are the factors effecting Structural Safety?
Loading Material Strength Structural Behaviour
The Statistical Meaning of Safety
In real life it is not possible topredict the strength of anymaterial or structure withabsolute accuracy until it hasbeen tested to destruction.
Some of the reasons are:
• Variations in the weight and specification of materials• Uncertainty in materials, loading, strength etc. • External factors, such as weather conditions, how concrete was placed on site
Structural SystemsFramed Structures Load Bearing StructuresStructural Frame, slab,beams, columns carry theloads to foundations
Walls carry the loads to foundations
Structural Framing
MaterialsReinforced Concrete
Wood
Steel
Steel
Light Gauge Steel (EMU)Masonry
Structural Types
Residential Commercial
Industrial Leisure
Public
Bridges and Stadiums
Dynamics?
Dynamics is the science of the forces involved in movement! Particles or rigid bodies are not at rest. In other words, they are not static.Newton’s Second Law applies:
maF Suddenly applied forces or forces which arechanging with time cause structures to vibrate!
Why do we have to study dynamics?
Traffic loads on bridgesVibrating machines on structuresEffect of blasting due to terrorist attacks Effect of wind force on structuresEffect of Earthquakesetc.
What are the effects of wind force on structures ?Wind cause impact load on structuresVortex induced oscillations (suspension bridges) Tacoma Narrows bridge (after collapse) Tacoma Narrows bridge (today)
Failure of TacomaNarrows Bridge onNovember 7, 1940(picture from, Irvine1999).
Replacement of Tacoma Bridge (1950) (picture from Irvine, 1999).
How earthquakes effect structures ?An earthquake is a spasm of groundshaking caused by a sudden release ofenergy in the Earth’s lithosphere (i.e thecrust+part of the upper mantle).Earthquakes result from the dynamicrelease of elastic strain energy thatradiates seismic waves. Earthquakestypically result from the movement offaults, planar zones of deformation withinthe Earth's upper crust.
eg. Reverse Fault:In a reverse fault, the block above the fault moves up relative to the block below the fault. This fault motion is caused by compressional forces and results in shortening. A reverse fault is called a thrust fault if the dip of the fault plane is small. [Other names: thrust fault, reverse-slip fault or compressional fault]
Inertia Forces in Structures• Earthquake causes shaking of the ground. So a building resting on it
will experience motion at its base. From Newton’s First Law of Motion, eventhough the base of the building moves with the ground, the roof has atendency to stay in its original position. But since the walls and columns areconnected to it, they drag the roof along with them. This is much like thesituation that you are faced with when the bus you are standing in suddenlystarts; your feet move with the bus, but your upper body tends to stay backmaking you fall backwards!! This tendency to continue to remain in theprevious position is known as inertia. In the building, since the walls orcolumns are flexible, the motion of the roof is different from that of theground (Figure 1). (Ref. C.V.R.Murty Indian Institute of Technology Kanpur, Kanpur, India, May2002)
Figure 1: Effect of Inertia in a building when shaken at its base
Consider a building whose roofis supported on columns (Figure2). Coming back to the analogyof yourself on the bus: when thebus suddenly starts, you arethrown backwards as ifsomeone has applied a force onthe upper body. Similarly, whenthe ground moves, even thebuilding is thrown backwards,and the roof experiences aforce, called inertia force. If theroof has a mass M andexperiences an acceleration a,then from Newton’s Second Lawof Motion, the inertia force FI ismass M times acceleration a,and its direction is opposite tothat of the acceleration. Clearly,more mass means higher inertiaforce. Therefore, lighterbuildings sustain the earthquakeshaking better. (Ref. C.V.R.MurtyIndian Institute of Technology Kanpur,Kanpur, India, May 2002)
Figure 2: Inertia force and relative motion within a building
Inertia Forceu
Roof
Column
Foundation
Soil
Acceleration
u
The inertia force experienced by the roofis transferred to the ground via thecolumns, causing forces in columns.During earthquake shaking, the columnsundergo relative movement betweentheir ends. In Figure 2, this movement isshown as quantity u between the roofand the ground.
How do we analyze/design structures subject to earthquakes ?
Conventional methods: Equivalent static load applied at floor levels Linear dynamic analysis (Response
Spectrum Analysis)Recently developed methods:
Nonlinear static analysis (pushover analysis)
Nonlinear dynamic analysis
In which courses you will studydynamics and effects of dynamicforces on structures ?
Must courses: Dynamics Structural Design
Area Elective Courses: Structural Dynamics Earthquake Resistant Design of Structures Other relevant courses
