Transcript Assumed knowledge - Deakin University

Erection of steel
portal frame for
warehouse
Construction
Presented to: Mr.Jeremy Ham
Done by: Oneil Baburam
ID: 400270468
Portal Frame
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Portal frame construction is a method of building and designing simple structures,
primarily using steel or steel-reinforced precast concrete.
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The connections between the columns and the rafters are designed to be moment
resistant, i.e. they can carry bending forces. This allows the frames to be stable
while only having simple foundations, only able to withstand compressive, tensile
and shear forces.
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Foundations capable of carrying moments can be deep and are generally very
expensive to build compared to connections. Portal frame construction is typically
seen in warehouses, barns and other places where large, open spaces are required at
low cost. Several companies manufacture software to assist in the efficient design
of portal frame structures.
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http://en.wikipedia.org/wiki/Portal_frame
Warehouse Visited
In order to accomplish the task of this assignment I visited current warehouses
Under construction and others which are complete.
The address for the warehouses are:
1).Hoppers crossing warehouse, Old Geelong road approximate 2mins from
Freeway.
2). Aldi Warehouse on Harricks Road, Keilor Park
Typical Warehouse Sketch
Plan
Portal frame construction is typically seen in warehouses, and other places
where large, open spaces are required at low cost.
Historically, most economical solution was a steel truss sitting on walls,
but now due to increased labour costs, rigid jointed portal frames are the
most economical
Erection of steel portal
frame warehouse
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Columns are part of a structure
whose purpose is to transmit
through compression the weight
of the structure. Other
compression members are often
termed columns because of the
similar stress conditions. Columns
can be either compounded of parts
or made as a single piece.
Columns are frequently used to
support beams or arches on which
the upper parts of walls or ceilings
rest.
In this warehouse The steel
columns are erected and bolted
down on the pad footing.
RE: Project 4: Case-study:
Portal Frame Construction
Steel Portal Frame
• Most warehouse and factory
buildings which are composed of
portal frames will have metal
cladding on the walls and roof.
• Cladding in this instance refers to
process of covering one metal
with another (usually achieved by
pressure rolling, extruding,
drawing, or swaging) until a bond
is achieved.
• The cladding is connected to the
roof using purlins.
RE: Project 4: Case-study:
Portal Frame Construction
Steel Portal Frame-cntd
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Purlins are typically C- or Zsections and are relatively thinwalled, cold-formed members.
The purlins run perpendicular to
the portal frames.
The cladding is attached to the
purlins using screws.
The purlins are attached to the
frames using cleats which are
welded to the roof beam.
Depths vary from 100 mm to 350
mm.
The cladding is connected to the
wall using girts.
Girts are the same as purlins
except they are on the wall.
• Splices are often used at the point of lowest bending moment for field erection
• The need for splicing is created due to required spans being larger than what
can easily be transported;
• Columns are generally bolted to beams using bolted moment end plate
connections which are considered to be rigid.
• Beams are generally bolted together at the ridge using bolted moment end
plate connections which are considered to be rigid
• Base plate connections are usually flexible (pinned).
• Below is a picture taken of a knee joint connection on the warehouse
HAUNCHES AND SPLICES
Ref: Centre for
Advanced
Structural
Engineering
BOLTED CONNECTION (Ridge & Eave)
Ref: Centre for
Advanced
Structural
Engineering
Steel Portal Frame buildings
• Buildings made from portal frames are usually one-way
rigid, one-way braced systems
• The portal frames span in one direction and are rigid
• Purlins and girts run perpendicular to the frames
• Bracing is used perpendicular to the frame as connections in
this direction are flexible so a bracing system is required to
take lateral loads
• Bracing is typically provided in the end bays;
• For longer buildings, bracing is generally provided about
every fourth bay
• Bracing is used in the roof and the walls to stabilise frames
and to resist load on the end of the building
Bracing Panels
Steel Portal Frame-cntd
• The warehouse consists of metal cladding on the walls and
roof;
• The cladding is connected to the roof using purlins;
• Purlins are typically C- or Z-sections and are relatively thinwalled, cold-formed members;
• The purlins run perpendicular to the portal frames
• The cladding is attached to the purlins using screws;
• The purlins are attached to the frames using cleats which are
welded to the roof beam;
• Depths vary from 100 mm to 350 mm;
• The cladding is connected to the wall using girts;
• Girts are the same as purlins except they are on the wall.
Purlin and Cleat
Warehouse Openings
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In the warehouse the Wall
openings should be big enough
for vehicles, heavy equipment,
and other large items to pass
through
The warehouse should have at
least two openings for in traffic
and out traffic, in general steel
portal frame buildings the Opening
is usually opened by a column and
lintel.
Acknowledgements
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Lots of Thanks to the SRT 251 Lecturer Mr.
Jeremy Ham for all the input that he gave to us
in the lectures which helped me in the
assignment.
Secondly, I would like to thank the tutorial Mr.
Rob for tirelessly helping me in some aspects
of the assignment.
References
Construction and Structures 2 reader
www.steel-sci.org
http://en.wikipedia.org/wiki/Portal_frame
Centre for AdvancedStructural Engineering
www.warehouse-building.com/standard-steel
portal