Architectural Design Lectures
Structures By: Dr. Yasser Mahgoub
Natural Structures
Natural Structures
Introduction
LOADS
LOADS
LOADS
LOADS
LOADS
LOADS
LOADS
Forces Acting in Structures • Forces induced by gravity – Dead Loads (permanent): self-weight of structure and attachments – Live Loads (transient): moving loads (e.g. occupants, vehicles)
• • • • •
Forces induced by wind Forces induced by earthquakes Forces induced by rain/snow Fluid pressures Others
Forces Acting in Structures
Vertical: Gravity
Lateral: Wind, Earthquake
Global Stability
Sliding
Overturning
Forces in Structural Elements 100 lb
100 lb
Tension
Compression
Forces in Structural Elements 100 lb
Bending
Torsion
Structural Systems
Arch
Structural Systems
Truss C
C
T
T Forces in Truss Members
C
Structural Systems
Frame
Structural Systems
Flat Plate
Structural Systems
Folded Plate
Structural Systems
Shells
Structural Systems
Shells
Basic Structural Elements Slabs
Basic Structural Elements Columns
Basic Structural Elements Columns
Basic Structural Elements Beams
Basic Structural Elements Beams
Basic Structural Elements Beams
Basic Structural Elements Beams
Basic Structural Elements Beams
Basic Structural Elements Beams
Basic Structural Elements Beam
Vierendeel Beams
Vierendeel Trusses
Structural Elements • The basic structural elements can be reduced to those which are: • Linear – Columns – Beams
Structural Elements • The basic structural elements can be reduced to those which are: • Surface – Walls – Slabs
Structural Elements • The basic structural elements can be reduced to those which are: • Spatial – Facade Envelope – Core – Building as System
Structural Expression
Structural Expression
Structural Expression
Structural Expression
Structural Expression
Structural Expression
Structural Expression
Structural Expression
Structural Expression
Structural Expression
Structural Expression
Structural Expression
Structural Expression
Structural Expression
General Structure and Lateral Forces Division
Revision
General Structure and Lateral Forces Division
Revision
General Structure and Lateral Forces Division
Revision
General Structure and Lateral Forces Division
Revision
STRUCTURAL REQUIREMENTS
• DURABILITY The durability of the structure depends entirely in the physical/chemical conditions of the structural material, and our willingness to continue using the building ( at the end of the lifecycle of a building, it may be demolished)
• STABILITY AND EQUILLIBRIUM When the structure is stable and in equilibrium it resists any load without suffering a major change of shape or collapsing.
• STRENGTH AND RIGIDITY Strength and rigidity are reached by the adequate specification of geometry, size, and the material of the structural elements. In example, for resisting the same structural load, a steel structural element needs a smaller cross section than a reinforced concrete element, and this is due to the difference between the strength of the kind of materials.
STRUCTURE TYPES ROOFS SUPPORTED WITH VERTICAL ELEMENTS SUBJECTS OF COMPRESSION:
ROOFS SUPPORTED WITH VERTICAL ELEMENTS SUBJECTS OF TENSION:
POST AND BEAM STRUCTURES: - LOAD BEARING WALLS - SKELETON FRAME
MASTED STRUCTURES
ROOF STRUCTURES
- ARCHES, VAULTED HALLS, AND DOMES - PORTAL FRAMES - TRUSSES - SPACE FRAMES - FOLDED ROOFS - SHELLS - MEMBRANES AND TENTS
Types of Structures
Types of Structures
Types of Structures
STRUCTURE TYPES: MATERIALIZATION OF A CUBE
POST AND BEAM STRUCTURES
Most architectural structures are of the post-and-beam type. Post and beam buildings carry the weight of their structural components (and the weight of objects and people in them) by bearing on one another. The weight of the roof and beams is carried by the posts down to the foundation and then into the ground. Horizontal beams are subject to bending loads, therefore the structural materials should be able of resisting both tension and compression. We can further subdivide the post and beam structures into:
POST AND BEAM STRUCTURES: LOAD BEARING WALLS
POST AND BEAM STRUCTURES: LOAD BEARING WALLS
POST AND BEAM STRUCTURES: LOAD BEARING WALLS
POST AND BEAM STRUCTURES: SKELETON FRAME
ARCHES, VAULTED HALLS, AND DOMES
ARCHES AND VAULTED ROOFS
DOMES
PORTAL FRAMES
PORTAL FRAMES
TRUSSES
TRUSSES
SPACE FRAMES
SPACE FRAMES
SPACE FRAMES
FOLDED ROOFS
FOLDED ROOFS
Examples of Structures
SHELLS
SHELLS
SHELLS
TENSILE STRUCTURES
TENSILE STRUCTURES
TENSILE STRUCTURES
TENSILE STRUCTURES
DETERMINATION OF THE STRUCTURAL FORM
DESIGN STRATEGIES
GENERIC TYPE OF STRUCTURE
STRUCTURAL MATERIAL
Materials • Stone and Masonry • Metals – Cast Iron – Steel – Aluminum
• Concrete • Wood • Fiber-Reinforced Plastics
Materials • Steel – Maximum stress: 40,000 – 120,000 lb/in2 – Maximum strain: 0.2 – 0.4 – Modulus of elasticity: 29,000,000 lb/in2
• Concrete – Maximum stress: 4,000 – 12,000 lb/in2 – Maximum strain: 0.004 – Modulus of elasticity: 3,600,000 – 6,200,000 lb/in2
• Wood Values depend on wood grade. Below are some samples – Tension stress: 1300 lb/in2 – Compression stress: 1500 lb/in2 – Modulus of elasticity: 1,600,000 lb/in2
Concrete Components • • • • •
Sand (Fine Aggregate) Gravel (Coarse Aggregate) Cement (Binder) Water Air
Examples of Typical Structures
Examples of Typical Structures
Thank you Dr. Yasser Mahgoub http://ymahgou.fortunecity.com/