Transcript CONSTRUCTION AND STRUCTURES – II MAJOR ASSIGNMENT

CONSTRUCTION
AND STRUCTURES
– II
MAJOR PROJECT
PREPARED BY: Desai Prateek
500371764
PRESENTED TO: Mr. Jeremy Ham
PROJECT DETAILS
Selection of a construction process for the construction of
warehouse to undertake comprehensive research into for this
project.
The area of warehouse is minimum 1600 m2 of relatively
column free space for the storage and transportation of goods,
forklift, pallet systems, security, appropriate daylight.
For this project, I selecte a composite construction system
which is “ Tilt-up concrete panel with steel portal frame”.
PROJECT AIM
To obtain detailed understandings of commercial and industrial
construction technology and construction processes within a
Problem Based Learning environment.
To learn how construction technology is developed and
represented using models as the primary form of communication.
CONSTRUCTION SYSTEM
Tilt-Up Construction is a fast, economical and safe method of
construction and is now widely used in Australia - and not just for
industrial buildings; the variety of uses is almost endless.
As this is a wide span warehouse it is advisable to use steel
portal frame with tilt-up concrete panel.
The main purpose of the steel portal frames are to support the tiltup pannels, and to hold up and tie down the roof. Without the use
of portal frames, a clear span could not be achieved, and thus
lessen floor space for the warehouse.
CONSTRUCTION SYSTEM
Modern industrial buildings comprise a steel frame
supported on internal columns and tilt-up precast panels at the
perimeter of the building. The precast panels do not have columns
attached to them. The industrial buildings are built with long span
beams and high ceilings. The clear spans of the rafter range
between 15 to 30 meters and the rafters are spaced at 6 to 12 meter
centers.
(imagereference:www.civil.canterbury.ac)
CONSTRUCTION SYSTEM
Steel portal frames are commonly used for single-storey
construction, particularly for factory and warehouse buildings. These
frames provide support to a steel roof and a variety of forms of
external wall construction including: steel sheeting supported by girts,
masonry, dado walls, precast concrete panels and tilt-up concrete
panels.
The steel portal frame provides a one-way rigid/ one-way brace
system that holds the building together. If this system was not used,
the building would simply fall down and not function.
(image reference:www.onesteel.com)
CONSTRUCTION SYSTEM
Single storey industrial buildings and warehouse complexes
in Australia are used for manufacturing and storage purposes.
They are used to store materials with low fuel loads such as
vehicles to high fuel loads, such as petroleum products and wood
and paper products. Industrial buildings have large spans and
high ceilings to meet handling requirements for material
processing and storage purposes.
The above image shows the steel portal frame holding up the
panels and supporting the purlins and roof sheet.
DESIGN & construction
DETAILS
Connections are described as rigid or flexible; wall panels as
being short or tall; and supporting columns as weak or strong. A
wall panel is considered tall if its height is greater than 2.5 m. A
supporting column is considered strong if its ambient bending
capacity is greater than 50 kN-m.
(image reference:www.civil.canterbury.ac)
DESIGN & construction
DETAILS
Foundation Details
The cantilever wall panels are attached at the base to the
foundation beam and the floor slab by various types of
connections. The typical details used in practice are shown in
Figures on next slide.
These connections provide full fixity at the base so that the
walls resist overturning moments by cantilever action. The
connection methods at the base range from simple reinforcing steel
connections to proprietary connection methods, such as corrugated
ducts filled with non-shrinkage grout and starter bars screwed into
threaded inserts.
(image reference:www.civil.canterbury.ac)
DESIGN & construction
DETAILS
Rigid connection with short panels
When short external wall panels (height less than 2.5 m) are
used, each panel will be connected to the supporting members at
the four corners using rigid connections with details as shown
below. The details are suitable for column spacing up to 10 m, for
side or end wall situations.
(image refrence: www.onesteel.com.au)
DESIGN & construction
DETAILS
Tall panel supported by weak columns
This is also typical of an end wall situation where the panels are
supported by lightweight columns or mullions (having a bending
capacity of less than 50 kN-m). In this situation, the panels may be
rigidly connected to the columns or mullions which, in turn, are
supported by the roof members. Details of the connections are shown
below.
In this situation the designer must
also ensure that the atteched roof
members will enable the
connection to achieve their
capacity.
DESIGN & construction
DETAILS
Tall panels supported at top and bottom only
This is typical of an end wall situation where the panels are
supported at the top by the roof structure only. In this situation,
the panels may be rigidly connected to a raker member which, in
turn, is connected to the purlins. Details are shown below.
Each panel must have at least two connections to the raker
member unless the panels are designed to act as a single unit (eg.
interlocking panels).
(Figure is on next slide)
DESIGN & construction
DETAILS
The spacing of connections along the raker member should
not exceed 2m.
DESIGN & construction
DETAILS
• Flexible Connections
1) Tall panel supported by strong column
When an external wall consists of tall panels supported by
columns having a bending capacity of more than 50 kN-m, the
panels should be connected to the columns at the top by flexible
connections. It is anticipated that, during fire, all other
connections will fail and the panels will be supported by these
flexible connections only.
Two sets of details for the flexible connections are given on
next slide: one for larger columns and panels; and the other for
smaller columns and panels. These may be used for either side or
end wall situations. Each of these connections has been detailed to
allow substantial (as per BCA Specification C1.11) relative
movement between column and panel.
DESIGN & construction
DETAILS
DESIGN & construction
DETAILS
2) Tall panel supported by another tall panel
•
In situations where there is no column located at the corner of
the building to support the panels, the panels at that junction may
need to support each other. In these situations, adequate connection
between the panels can be achieved by a single flexible connection.
•
The details are similar to those where the panels are
supported by strong columns. The figure on next slide shows the
details which correspond to the larger connection. For smaller
panels, the smaller connection given in the previous section may be
used, provided the panels’ sizes are within the limits.
DESIGN & construction
DETAILS
The figure below shows the flexible connection between
two tall tilt-up panels
DESIGN & construction
DETAILS
Example of rigid connection
(figure source:www.oneteel.com.au)
DESIGN & construction
DETAILS
Example of flexible connection
(figure source:www.oneteel.com.au)
CONSTRUCTION EQUIPMENTS
This is an image of the tilt-up panels
being lifted into place by a crane. The
crane was positioned inside the complex
to allow easy access, as the loads that it
has to carry are quite heavy.
A scissor lift is used to take members up
and down for secure connection, the
crane is also used to help with larger
members.
CONSTRUCTION EQUIPMENTS
This slide shows the steel
portal frames being put into position
by a different crane. This crane had to
be positioned outside the building, as
the portal frames cover the rooftop,
and would trap the crane inside.
Different types of wrench is used to
tighten bolts to standard.
CONSTRUCTION PROCESS
The site was cleared and leveled so that the slab could be
properly poured.
The site was marked out and lined.
Holes where dug out for pad footings to be poured. Then
filled with concrete and connection rods placed evenly.
The concrete slab was then poured, with a week left for it to
curing.
The tilt up pannels were then poured, with a release agent
used to prevent bonding.
The tilt up pannels were then lifted into place via a crane,
then held in place with bracing.
Steel portal frames are then lifted into position by another
crane.
Diagional cross bracing and c-section purlins are then fixed
to the rafters.
-This is as far as construction went on the site-
REFERENCES
Economical structural steelwork, Forth edition, Australian
Institute of Steel Construction, 1997
McKAY. J.K, Building Construction Metric Volume 4, 1975,
Longman
www.onesteel.com.au
www.civil.canterbury.ac