Portal Structure Material Course

1. Portal
Muhammad Kholif L. W., M.Sc.
Material & Construction Department of Architecture, Universitas Islam Indonesia

2. The Galarie des Machines
At the EXPOSITION UNIVERSELLE in Paris 1878, the engineer HENRI
DE DION progressed the science of vaulting with the first portal
frame of lattice girders where the forces were transmitted
directly to the foundations without tie bars. This Galarie des
Machines had a span of 35m and its pitched roof shape was a
forerunner of many sheds to follow.
History - Origin of Portal Structure

3. The Galarie des Machines
Section of the first portal frame in history
History - Origin of Portal Structure

4. Development Background
• Developed during second world war, but now the
most common form of enclosure for spans of 20 to
60 m.
• Driven by the need to achieve low-cost
building envelope.
• They are usually made from steel but can also be made
from concrete or timber.
History - Origin of Portal Structure

5. Typology
Portal Steel Frame Buildings is the most common structure system.
Portal Frames are generally used for single story construction
which require a large unobstructed floor space. It widely used in
light steel buildings such as factories, shopping centers,
warehouses, workshops, sheds, garages.
Features of Portal Structure

6. .
Advantages
• They are very efficient for enclosing large volumes,
therefore they are often used for industrial, storage,
retail and commercial applications as well as for
agricultural purposes.
• Compared with the reinforced concrete structure. The
portal steel frame has the advantages of a lightweight,
high rigidity, flexible design, reasonable force, and
convenient construction
Features of Portal Structure

7. .
Advantages
• Clear unobstructed floor area is available.
• With single story buildings natural lighting is gained by placing
clear sheets in roof layout. These sheets will run from eaves to
ridge at suitable intervals.
Features of Portal Structure

8. • Portal frames can be defined as two-dimensional rigid frames that have the basic characteristics of a rigid joint between
column and beam.
• The main objective of this form of design is to reduce bending moment in the beam, which allows the frame to act as one structuralunit

9. Pitched roof symmetric portal frame
Generally fabricated from UKB sections with a substantial
eaves' haunch section, which may be cut from a rolled section
or fabricated from plate. 25 to 35 m are the most efficient
spans.
Portal frame with internal mezzanine
Floor Office accommodation is often provided within a portal
frame structure using a partial width mezzanine floor.
Crane portal frame with column brackets
Where a travelling crane of relatively low capacity (up to say
20 tons) is required, brackets can be fixed to the columns to
support the crane rails.
Types of Portal Frame Structure

10. Types of Portal Frame Structure
Mansard portal frame
A mansard portal frame may be used where a large clear
height at mid-span is required but the eaves height of the
building has to be minimized.
Curved rafter portal frame
Portal frames may be constructed using curved rafters, mainly
for architectural reasons.
Cellular beam portal frame
Rafters may be fabricated from cellular beams for aesthetic
reasons or when providing long spans.

11. Lancashire Waste Development
Pitched Roof Symmetric Portal Frame
Types of Portal Frame Structure

12. Portal Frame With Internal
Mezzanine
Types of Portal Frame Structure

13. Crane Portal Frame with
Column Brackets
Types of Portal Frame Structure
Rebotting Plant, Hemswell

14. Cellular Beam Portal
Frame
Types of Portal Frame Structure
Hayes Garden World

15. Portal Frame Composition
• The portal structure is designed in such a way
that it has no intermediate columns.
• A portal frame building comprises a series
of transverse frames braced
longitudinally.
• The primary steelwork consists of columns and pitched rafters.
• The light gauge secondary steelwork consists of side rails for
walls and purlins for the roof.
• The roof and wall cladding separate the enclosed space
from the external environment as well as providing
thermal and acoustic insulation.

16. Portal Frame Composition

17. Komposisi Struktur Portal

18. Komposisi Struktur Portal

19. Komposisi Struktur Portal

20. Komposisi Struktur Portal

21. Sistem pada Struktur Portal
A. Transverse load-bearing structure
1. The composition of the transverse load-bearing structure includes steel roof beams, steel columns, and foundation);
2. Transverse load-bearing structure supports and transfers vertical and horizontal loads.

22. Sistem pada Struktur Portal
B. Longitudinal Frame Structure
1. Composition of longitudinal frame structure includes longitudinal columns, crane beams, wall bracing, rigid tie beam and foundation
2. Ensure the longitudinal rigidity and stability of the buildings;
3. Transmit and bear the longitudinal wind load, the longitudinal horizontal loading of the crane, the thermal stress, and the seismic acting
on the gable at the end of the building and roof.

23. Sistem pada Struktur Portal
C. Roof structure
1. Roof panel: It can bear the vertical load and horizontal wind load acting on the roof panel. Generally, it uses a single-color metal sheet
or sandwich panel.
2. Purlin: Support structure of roof panel, which can bear the vertical load and horizontal wind load transmitted from the roof panel.
3. Rigid frame beam: The primary load-bearing members mainly bear the self-weight of the roof structure and the live load transmitted
from the roof panel.

24. Sistem pada Struktur Portal
D. Wall structure
1. Exterior wall panels: vertical and gable wall. Mainly bear wind load. It uses a single-color metal sheet or sandwich panel.
2. Wall girt: bearing the vertical and horizontal wind load transmitted by the wall panel.

25. Sistem pada Struktur Portal
E. Bracing
Type: Roof horizontal bracing, wall bracing.
1. Roof horizontal bracing: enhance the overall
rigidity of the roof. It consists of a roof cross
bracing, tie beam, and fly bracing.
2. Wall bracing: It uses to improve the stability of
the wall frame structure
Use:
1. Enhancing the spatial rigidity of the building
structure
2. Guaranteed structural stability
3. Transmit wind load, crane brake load and
seismic load to the load-bearing members
Roof and
Wall Bracing

26. Sistem pada Struktur Portal
E. Bracing

27. Sistem pada Struktur Portal
External loads act directly on the envelope — vertical and lateral loads transmitted to the lateral portal frame of the primary structure
through the secondary structure. The portal frame relies on its stiffness to resist external effects. Longitudinal wind loads transferred to the
foundation through roof and wall bracing.
Transfer Path of
Horizontal Load

28. • The legs or stanchions of the portal frame need
connecting at the bottom to a foundation.
• Here we can see the base joint connection in
place.
Base Joint for Portal Frame

29. RI DG E JO INT FOR
PO RTAL FRAM E
Shown here is a ridge
joint or apex joint.
It is Important that this
joint is strong hence
the use of wedge
shaped pieces called
gusset pieces to
strengthen and
increase the bolt area.

30. KNEE JO INT FOR
PO RTAL FRAM E
Again the knee joint must be strong to support the
roof
loads and prevent bending.
Gusset pieces will be used to increase strength, give
greater bolt area and prevent deflection under load.

31. DIAGONAL
B R A C I N G F OR
PO R TA L F RAM E
With all types
of frameworks we
must think on
stability i.e.
movement. To help
strengthen the
framework and
prevent movement
diagonal bracing will
be used.

32. CLADDING RAILS
FOR PORTAL
FRAME
• This slide shows the
cladding rails for attaching
the external metal cladding
panels to.
• These rails can be fixed
horizontal or vertical
depending on the way the
cladding panels are fixed.

33. TIE CABLES FOR PORTAL FRAME
• These wire and tubular ties
are used to prevent
sagging of the cladding
rails which can add
considerable force unto the
joints of the external
cladding.

34. EXTERNAL WALL DETAIL
• Here we see the finish of
the external cladding
panels with the lower level
facing brickwork.
• The blockwork behind
creates a protective wall or
firewall.

35. ADVANTAGES
Speed and ease of erection
Building can be quickly closed in and made water tight.
Framework prefabricated in a workshop and not affected by
weather.
Site works such as drainage, roads etc can be carried out until
framework is ready for erection.
No weather hold up during erecting the framework.
Connected together in factories by welding and site connections
should be bolted.
• Cost effectiveness
• Sustainability
• Saves time
• Capable taking loads
immediately

36. DISADVANTAGES
Although steel is incombustible it has a poor
resistance to fire as it bends easily when hot.
Subject to corrosion

37. CONSTRUCTIO
N METHOD
Foundation –in situ
concrete, concrete
slab

38. COLUMN INSTALLATION
• Pinned
base.
• From left
to right.

39. RAFTER INSTALLATION
• Rigid
connection
• Haunches and
stiffener
installed

40. PURLIN ANDGIRT INSTALLATION

41. BRACING
INS TALLATION

42. SHEET INSTALLATION

43. FINAL DESIGN- CRANE INSTALLATION

44. MODERNART GLASS WAREHOUSE, THAMESMEAD.

45. NORMANFOSTER AND ANTONY
HUNT