Presentation on theme: "CONSTRUCTION AND STRUCTURES – II MAJOR PROJECT PREPARED BY: Desai Prateek 500371764 PRESENTED TO: Mr. Jeremy Ham."— Presentation transcript:
CONSTRUCTION AND STRUCTURES – II MAJOR PROJECT PREPARED BY: Desai Prateek 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 m 2 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 tilt- up 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.
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:
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