Anoushiravan Ghamsari, known as Anoush Ghamsari is a brilliant architect, the way he uses his creativity to create phenomenal concepts is beyond this world.
1. Structure of a Building
The primary function of a
building structure is to
support and transmit the
building loads and forces
to the ground.
Photos courtesy Tilt-up Concrete Association
3. Structural System
• Made up of many smaller structural subsystems that work together to provide a
strong, stable, and cost-effective structure.
• Examples of these smaller structural subsystems include:
Structural engineers design these structural systems.
4. Structural Sub-System
• Made up of many structural elements that
work together to provide a strong, stable,
and cost-effective system.
• Basic structural elements include:
Structural engineers design these structural systems.
5. Forces and Loads
• A force is any action that causes a change
in the shape or motion of an object.
• A load is a force that is supported by a
structural element.
• The terms force and load are often used
interchangeably.
WIND
SNOW
6. Structural Member Forces
Tension – A force that
stretches or pulls apart a
member, resulting in the
member elongating.
Compression – A force that
squeezes or presses a
member together, resulting
in the member shortening.
Shear – A force that acts
perpendicular to the axis of
the member, causing the
internal particles of the
member to slide against
each other.
7. Beam
• A structural element that carries a load that is
applied transverse (perpendicular) to its length.
• Usually a horizontal member that carries a
vertical applied load.
• The top fibers of a beam are in compression; the
bottom fibers are in tension.
8. Cantilever Beam
• A special type of beam that is supported
only at one end
• The top fibers of the cantilever are in
tension; the bottom fibers are in
compression
10. Truss
• A structural element that is composed of
smaller structural members typically
configured in triangular arrangements
• Some truss members carry a tension
force; others carry a compression force
11. Arch
• A curved structural
element that spans over
an open space
• In stone arches, the last
stone to be placed at the
top is called the keystone
KEYSTONE
13. Dome
A structural element that is made up of
arches that radiate around a center point
to create a half sphere
14. Hybrid Forms
• An infinite number of combinations of
these forms exist
15. Design Process
The same design
process used by
engineers and
designers in other
disciplines can be
used to design
structural systems.
16. Architectural Program
• Establishes overall concept and design
philosophy
• Includes
–
–
–
–
–
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Location of building on site
Architectural style
Interior space planning
Design elements
Construction materials
Building systems
• Encompasses the first four steps of the
design process
17. Structural Design Process
• An architectural program establishes
preliminary structural systems.
• The structural engineer must analyze
the structural systems and provide a
strong, stable, and cost-effective
design.
18. Structural Design Process
Identify Criteria and
Constraints
– Additional criteria needed:
• Types and magnitudes of
applied loads
• Load path that each load
will follow to the ground
19. Structural Design Process
Explore Possibilities
– Consider alternate
structural configurations,
materials, and spacing to
improve the design or
reduce costs
20. Structural Design Process
Select an Approach
– Based on structural
performance, compatibility
with the architectural
program, and cost
– Based on the possibilities
explored, select the
optimal design
21. Structural Design Process
Develop a Design
Proposal
– Create a preliminary
structural design
incorporating the
selections for all
structural elements
22. Structural Design Process
Model or Prototype
– Create a model to
represent your structural
design
• Sketches
• Structural analysis software
• 3D architectural software
23. Structural Design Process
Test and Evaluate
– Reanalyze structure based
on element selections
– Structural analysis
software
– 3D architectural software
24. Structural Design Process
Refine
– Revise the design as
necessary to correct
problems with strength,
stability, and compatibility
with other systems
25. Structural Design Process
Create or Make
– Based on the final design
after revisions
– Create working drawings
of the structural design
Strength is the capacity of a structure to carry the loads applied to it.
Stability means the structure can maintain its shape when loads or forces are applied. Loads and disturbances to the structure should not produce large movements or failure.
The economic value or cost effectiveness of the structural design depends on choices made regarding how the structure will carry loads, the structural systems used, and the materials chosen.
Each structural element is subjected to at least one type of load. Loads include people, furniture, equipment, wind, snow, earthquakes, floods, and soil pressure.
The loads applied impose member forces in the structural elements. Three types of force that we will analyze in structural elements are tension, compression, and shear.
Many structural members within a structure are technically beams but are called something else. For example, joists, girders, and elevated slabs act as beams.
An axial force is a force along the length of the member.
A space frame combines a 3D truss in the form of a dome.
[click] This structure combines curved beams with metal roofing to form a vault.
Each structural element – each beam, each column, each truss – must be individually designed to carry the applied loads.
Architects and engineers use an iterative design process to define, analyze, and solve the problem of creating a strong, stable, and cost-effective structure. The same process used by engineers in other disciplines can be applied to the design of structures.
Remember that a design process is never linear. If at any time you discover new information (or new constraints are placed on the design, or you come up with a better idea), you may need to return to an earlier step to incorporate the new information.
For most commercial projects, an architectural program is created by an architect or by a design team that may include many design professionals.
The architectural program is the foundation on which the design of the building is defined.
This program establishes the overall concept, philosophy, and design approach for the building.
The specific building design problem is established.
Ideas for the building are brainstormed.
Research is performed on existing building solutions and new technologies that can inform the decisions for this project.
The specific criteria and constraints for the building are defined.
The architectural program is in essence a design brief for the design of the project and typically includes preliminary drawings. This architectural program is shared with other professionals involved with the design, including the structural engineer, who will design the structural system to support the building design.
The architectural program typically identifies the general structural system(s) that will be used to support the building. For instance, the architectural program will establish the types of walls, floors, roof, and often the structural frame of the building.
The structural engineer has the responsibility of designing the specific elements of the system(s) to safely and effectively support the building and the loads that will be applied to the building.
Once the architectural program is established, a structural engineer must further define the loading criteria for the structure. The structural engineer must know exactly what types and magnitudes of loads to consider in the design of the structure and how each load will be carried and transferred through the structure to eventually be resisted by the ground.
Once the loading to each structural member has been established, options to resist the loads can be explored. For instance, you may want to explore the possibility of using both hollow core precast panels and composite concrete floors. If structural steel floor framing is to be used, you may want to consider both open web steel joists and structural steel I-beams. There is the opportunity to adjust spacing of structural members such as floor joists and columns if necessary to improve the design or reduce costs.
A design must be selected for every structural element in the structural system.
A design must be selected for every structural element in the structural system.
For structural designs, prototypes are not often practical. However, structures are very often modeled in structural analysis software and/or 3D architectural programs to check structural behavior and compatibility with other building systems.
Simply choosing a structural element slightly different from that originally assumed may change the loading conditions and affect the structural performance of an element. Therefore, you should always reanalyze each design to ensure its strength and stability if new conditions are present.
For example, assume that you choose joists that weigh 20 lb/ft of the member for the preliminary analysis of a floor system. However, that preliminary member did not provide adequate strength to carry the applied loads. You therefore revise your selection and choose a member that weighs 25 lb/ft. The increased weight will affect the design, and the member should be reanalyzed to make sure it can carry the additional weight.
Structural analysis software can check the strength and stability of a structural system, including all of the individually designed structural elements.
3D architectural models can include many building systems and equipment such as mechanical (HVAC), electrical, and plumbing systems. If all of the systems are included in one model, interferences can be identified and corrected before construction.