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Seminar
On
DIAGRIDS
Submitted To: Submitted By:
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CONTENTS
INTRODUCTION
THE TRIANGULAR DIAGRID MODULE
• INTRODUCTION
• MODULE GEOMETRY
STRUCTURAL ACTION OF A DIAGRID MODULE
§ EFFECT OF GRAVITY LOADING
§ EFFECT OF LATERAL LOADING
§ EFFECT OF SHEAR LOADING
§ EFFECT OF NON-APEX LOADING
§ EFFECT OF HORIZONTAL AND VERTICAL CURVATURE UNDER VERTICAL LOADING
§ EFFECT OF HORIZONTAL CURVATURE UNDER HORIZONTAL LOADING
DESIGN AND CONSTRUCTION OF DIAGRID NODES
§ MATERIALS USED FOR DIAGRIDDS
§ DIAGRID NODE DESIGN
§ NODE CONSTRUCTION FOR DIAGRID STRUCTURES
§ ERECTION OF DIAGRID NODES
MERITS AND DEMERITS OF DIAGRIDS
MERITS OF DIAGRIDS
DEMERITS OF DIAGRIDS
CONCLUSION
INTRODUCTION
The Diagrids are perimeter structural configurations
characterized by a narrow grid of diagonal members
which are involved both in gravity and in lateral load
resistance.
THE TRIANGULAR DIAGRID MODULE
Diagrid structure is modeled as a beam, and subdivided
longitudinally into modules according to this repetitive
diagonal pattern.
Each Diagrid module is defined by a single level of diagonals
that extend over ‘n’ stories.
MODULE DIMENSIONS
Height of the module: It depends on the number of stories
stacked per module.
Usually 2 – 6 stories are stacked per diagrid with average floor
height varying from 3.5 -4.15 m on an average.
Base of the module: It depends on the height and optimal
angle (apex angle) of the diagrid.
STRUCTURAL ACTION OF A DIAGRID MODULE
EFFECT OF GRAVITY LOADING
The diagrid module under gravity loads G is subjected to a
downward vertical force,NG,mod, causes the two diagonals
being both in compression and the horizontal chord in
tension.
EFFECT OF SHEAR LOADING
The global shear VW causes a horizontal force in the apex
joint of the diagrid modules, Vw,mod, which intensity
depends on the position of the module with respect to the
direction of wind load, i.e. the shear force VW is mainly
absorbed by the modules located on the web façades, i.e.
parallel to the load direction .
DESIGN AND CONSTRUCTION OF
DIAGRID NODES
a) Unit weight of the material.
b) Availability of the material.
c) Lead Time.
d) Erection Time.
e) Flexibility.
f) Durability.
g) Labor cost.
h) Fire resistance.
STEEL
Steel is by far the most popular material for Diagrid
constructions. The typical steel sections used are Wide
flanges, Rectangular HSS and Round HSS.
Advantages- The weight and Size of wide flanges are
optimized to resist the high bending loads many of the
members experience.
Disadvantages- Pre-fabrication of the Diagrid sections
takes a longer lead time.
CONCRETE:
Concrete is another widespread material for Diagrid
constructions.
It is used both in Precast and Cast-in-situ forms.
Advantages-The flexibility of precast sections allows them to
fit to the complex building geometries.
Concrete also offers extreme safety against structural fire
damage.
Disadvantages- The use of Concrete increases the dead load
on the foundations, deflections of long spans, etc
MERITS OF DIAGRIDS
1) The Diagrid structures have mostly column free exterior and
interior, hence free and clear, unique floor plans are Possible.
2) The Glass facades and dearth of interior columns allow
generous amounts of day lighting into the structure.
3) The use of Diagrids results in roughly 1/5th reduction in
steel as compared to Braced frame structures.
4) The construction techniques involved are simple, yet they
need to be perfect.
5) The Diagrids makes maximum exploitation of the structural
Material.
6) The diagrid Structures are aesthetically dominant and
expressive.
DEMERITS OF DIAGRIDS
1) As of yet, the Diagrid Construction techniques are not
thoroughly explored.
2) Lack of availability of skilled workers . Construction crews
have little or no experience creating a DiaGrid skyscraper.
3) The DiaGrid can dominate aesthetically, which can be an
issue depending upon design intent.
4) It is hard to design windows that create a regular language
from floor to floor.
5) The DiaGrid is heavy-handed if not executed properly.
CONCLUSION
We are at a time when the global population is inching the 7
billion mark.
Around the globe we witness frequent recurrence of natural
calamities, depletion and degradation of vital life supporting
systems, all presumed to be the impacts of Global warming,
making life miserable on earth.
It is high time for humanity to switch to sustainable and eco-
friendly lines of infrastructure development.
REFERENCES
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www.wikipedia.com
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