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Lecture 1:Structural Dynamics Concepts, Design and Implementation 4 th year Final Project Structural Engineering Project Dr. Said El-kholy

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Page 1: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention

Lecture 1:Structural DynamicsConcepts, Design and Implementation

4th year Final ProjectStructural Engineering Project

Dr. Said El-kholy

Page 2: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention

Structural Dynamics• Introduction• What is Dynamic Loading?• Structural Dynamics• Concepts• Seismic Loadings• Method, Codes• Prevention• Advancements• Responsibilities as Engineer, Architect• Introduction to TMD

Page 3: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention

Inside Earth

Page 4: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention

Geographical Plates Location

Page 5: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention
Page 6: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention
Page 7: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention
Page 8: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention
Page 9: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention
Page 10: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention

Slips and Faults

Page 11: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention

Slips and Faults

Page 12: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention

Intensity Measuring Instruments

Page 13: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention

Tsunami Attack

Page 14: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention

Effect of Earth Quake

Page 15: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention

Resonance of Structure

Page 16: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention

Soft Story

•A common buildingdesign flaw is to make thefirst story much moreflexible than the upperstories. During anearthquake the upperfloors tend to move as aunit while the first floorflexes a great deal. Thiscan cause collapse of thefirst floor, as happenedduring to some apartmentbuildings during the 1994Northridge earthquake in

California

Page 17: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention

Earthquake Design Philosophy

•Under minor but frequent shaking, the main members of the building that carry vertical and horizontal forces

should not be damaged; however building parts that do not carry load may sustain repairable damage

•Under moderate but occasional shaking, the main members may sustain repairable damage, while the

other parts of the building may be damaged such that they may even have to be replaced after the earthquake

•Under strong but rare shaking, the main members may sustain severe (even) irreparable damage, but the

building should not collapse

Page 18: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention

Seismic basics

Page 19: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention

Intensity of Earth Quake

Page 20: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention
Page 21: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention
Page 22: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention
Page 23: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention
Page 24: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention
Page 25: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention
Page 26: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention
Page 27: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention
Page 28: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention
Page 29: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention
Page 30: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention
Page 31: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention
Page 32: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention

Many building collapses during earthquakes may beattributed to the fact that the bracing elements, e.g.walls, which are available in the upper floors, areomitted in the ground floor and substituted bycolumns. Thus a ground floor that is soft in thehorizontal direction is developed (soft storey). Oftenthe columns are damaged by the cyclic displacementsbetween the moving soil and the upper part of thebuilding. The plastic deformations (plastic hinges) atthe top and bottom end of the columns lead to adangerous sway mechanism (storey mechanism) with alarge concentration of the plastic deformations at thecolumn ends.

Page 33: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention
Page 34: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention
Page 35: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention
Page 36: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention

Asymmetric bracing is a frequent cause of buildingcollapses during earthquakes. In the two above sketchesonly the lateral bracing elements are represented(walls and trusses). The columns are not drawnbecause their frame action to resist horizontal forcesand displacements is small. The columns, which «only»have to carry the gravity loads, should however be ableto follow the horizontal displacements of the structurewithout loosing their load bearing capacity.

Page 37: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention
Page 38: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention
Page 39: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention
Page 40: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention
Page 41: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention
Page 42: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention
Page 43: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention
Page 44: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention
Page 45: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention

Large re-entrant corners creating a crucifix form would mean irregular configuration.

Page 46: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention

CENTRE OF MASS – CENTRE OF STIFFNESS

ECCENTRICITY

Page 47: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention

PLAN IRREGULARITIES

Page 48: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention

VERTICAL IRREGULARITIES -STIFFNESS

Page 49: Lecture 1:Structural Dynamics - · PDF fileStructural Dynamics •Introduction •What is Dynamic Loading? •Structural Dynamics •Concepts •Seismic Loadings •Method, Codes •Prevention

VERTICAL IRREGULARITIES - MASS