Tuesday, June 3, 2008
Wednesday, May 28, 2008
Structural info-
ProjectName Grosvenor Place Project Team - Architect Harry Seidler & AssociatesDavis Heather & Dysart - Structural engineer Ove Arup & Partners - Service engineers D.S. Thomas, Weatherall & Associates - Builder Concrete Construction Function Commercial office building Year 1988 Location Sydney, NSW Cost $350m Building Type office building with parking Form - Plan shape two crescents with elliptical central core - Number of stories 44 levels above ground (including a 3 storey lobby), 4 levels of basement - Typical floor area 3 000 sq m - Net rentable floor area 2 000 sq m - Number of zones 4 - offices, plant equipment, lobby and car parks Relationship to ground ground level pedestrian entrance with underground parking Primary Structure floor system -material composite structural steel/concrete - type beams, composite metal deck/concrete floor - pattern radial beams, edge beams and one-way floor slab - beam clear span 14 m - floor slab span 2.2 - 3.25m core - material reinforced concrete - type shear walls - shape elliptical - position in plan central support structures - material composite structural steel/concrete - types external columns, triangulated piloti and core walls - external column spacing 6.5 m - external column height 3.5m footings - material reinforced concrete - types raft slab for core and pads for columns
Design requirements
Grosvenor Place occupies one of the finest locations in Sydney, forming a transition between the CBD and The Rocks area, and has a site area of 7,192 square metres. The Sydney Cove Redevelopment Authority exercises development control over this area and required the site to become the gateway to The Rocks area by allowing diagonal pedestrian through traffic from George Street to Harrington Street. In addition, a height restriction of 176m above sea level was placed by requiring the office tower structure to form part of a stepping envelope between Qantas and the Regent Hotel. The brief called for a large energy efficient office building, with total rental office space of 90,000 square metres and each floor containing up to 2000 square metres of flexible floor space, and designed to meet the needs of a rapidly evolving office technology and changing user requirements. Provisions for parking 600 cars, truck docks and engineering services, in addition to food services for the anticipated 7000 occupants, were also required. The building designed to meet the above requirements had a diagonal siting of the tower with a low site coverage of 30% and consisted of 43 levels of offices, a three storey ground floor lobby and four levels of basements. The tower floor plan consists of two quadrants, offset but with a common axis on each side of a sharp ended elliptical service core, with each quadrant having a clear width of 14m. The plant and equipment floors are at levels 10/11 and 33/34 respectively. The ground floor lobby/reception area is to be more open than the office levels. The structural requirements arising from the above decisions are a span of 14m for the office floor system, a floor to floor height of 3.5m and supports at ground level around 19.5m spacing. Smaller functional modules, with dimensions varying from 8 to 8.5m are, however, permitted at the car park levels. In addition, office floor slabs are required to carry an applied load of 4.5 kPa (3 kPa for general, 1kPa for partitions, and 0.5 kPa for services and ceiling) for general areas and 10 kPa for areas - a zone approximately 4.8m around the core - where compactus type loading occur. Plant room slabs and the roof are required to carry a general loading of 5 kPa or specific plant loads where known. For car park slabs and loading dock areas the design live load is 5 kPa. The general design wind load, based on a 50 year return period, was considered to be 1.5 - 1.8 kPa for overall stability of building and 2.5 kPa for facade design. The site is underlain by Hawkesbury sandstone of Triassic age, which is generally of medium to high strength apart from a few near horizontal clay seams. The bearing pressure on the foundation should thus be limited to 3 MPa. The basement level is approximately 3.5m below mean sea level, and maximum water level of 2m above sea level is considered for the design of structural elements at basement level. Fire resistant level for structural adequacy is to be 120 min for all elements. Speed of construction was an important requirement due to high interest rates and holding charges. Vibration control requirements for different parts of the structure to keep vibration effects - particularly those arising from sway movements of the building and vibration of long span floors during normal use - below the level of human perception. Structural Solutions The key requirements that influenced the selection of structural solutions were (a) an efficient floor system to span 14m, (b) floor system that minimizes the floor to floor height and allows integration of structure and services, (c) speed of construction to enable early tenant occupancy and (d) cost. Structural Alternatives and System Selection The following structural alternatives were considered for the floor system based on the above key requirements. composite steel/concrete banded pre-stressed concrete beams reinforced concrete slab and beams pre-cast flooring systems between beams Each of the above systems was fully designed for a typical bay and comparisons were made between systems based on the above key requirements. Even though the initial material and fabrication cost is higher, the composite steel and concrete floor system was selected as overall economies can be achieved, including early return on investment. Steel has a high strength to weight ratio and is thus a more efficient material for spanning 14m and for minimizing the structural depth required for the floor system. The composite steel option allowed the building to have 2 more floors than the reinforced concrete option. With the height restriction on the building as one of the constraints, minimizing the floor to floor height maximizes the number of floors, and therefore the rentable floor area and hence the return on investment. There is also a reduction in the overall cost of the cladding relative to the usable space enclosed. Use of steel beams for the floor systems also permits the integration of structure and services, with the services zone being within the horizontal zone for the structure. There is thus no need to increase the floor to floor height to accommodate the service ducts. The air-handling ducts penetrate the webs of the beams at two locations, where the shear forces to be resisted by the web are not critical. The composite steel/concrete construction has a number of advantages which results in reduced construction time. The steel deck for the composite construction provides a working platform during construction, and eliminates the need to either prop or strip form work and the attendant delays resulting from these operations. By designing the steel columns to support the dead load of the floors, the upper frames can be assembled before concrete casing for the columns are in place, thus taking this operation off the critical path. With the traditional reinforced concrete systems, the construction time cycle per floor was 12 to 15 days (at the time of design), whereas the composite construction had a time cycle per floor of 4 to 6 days. It was estimated that the saving in construction time for the building, as a result of using composite construction, would be around 8 months, resulting in early return on investment, particularly at a time of high interest rates and holding charges. The exposed steel in the concrete construction, however, requires fire protection. In this project the cost of fire rating the structure was considered to be small in comparison to other costs, and did not influence the selection of this system. The penetration of steel beams by service ducts reduces the flexibility available for future changes, and may be considered as one of the disadvantages of the selected system. Final Structural Solution The floor system for the tower is of composite construction and consists of radially arranged universal steel beams - spaced a 2.2m at the core and at 3.25m (half column centres) at the perimeter - supporting concrete floor slabs cast on permanent steel form work. Composite steel beams span the 14m between the core and the outer columns. The steel beams placed between columns are supported at the perimeter by steel spandrel beams, that span between the columns. The central elliptical core is of reinforced concrete, with the two elliptical portions connected together by a number of concrete cross walls. The floor slab and the core are cast monolithically. The columns on the perimeter of the building are at 6.5m spacing and of composite construction, having high tensile steel fabricated steel sections encased in concrete, with strength varying with elevation. The column spacing at ground floor is increased by gathering sets of three columns via a triangulated piloti into single column supported on concrete caisson. Each piloti is fabricated from high tensile steel plate with post-tensioned plate girder tying the top of the piloti legs at the first floor level. The car park has in general a 8m column grid and flat slab floor system. The eight columns from the tower and the core are integrated with the column grid of the car park to provide vertical supports for the basement floor slabs. The footing for the core is a raft slab and for the columns are pads. The structural elements that contribute to the different functional systems are: Structural types: composite steel deck/ concrete floor , external columns and piloti , and core wallmaterial: composite steel/concrete Structural type: shear wallmaterial - reinforced concrete Structural types: - raft slab and pad footingsmaterials - reinforced concrete Design Decisions The decision to choose a plan configuration of a double curve and counter curve was to maximize the full sweep of the best views and open space outlook. The shape offers opportunities for long span, column free system of construction, where every structural span and beam are identical, and results in every column, its space, and the floor load it carries are the same, just as is every facade element. This decision also results in a core shape which is structurally more efficient for resisting lateral load and in reducing lateral load effects. The spacing of the column, of 6.5m, at the perimeter of the building was determined to keep the size of the column to within acceptable limits. The spacing of the radial beams was selected to (a) reduce the amount of concrete to be lifted, (b) eliminate propping of metal deck during construction and (c) keep to a minimum the floor to ceiling dimensions thus maximizing the number of floors possible within the building envelope. The car park grid of 8 - 8.5m was selected to accommodate three cars between the columns. Flat slab construction was selected as it is an efficient and cost effective system for this span and minimizes floor to floor heights, thus reducing the depth of excavation into the sandstone. References Grosvenor Place, Promotional brochure. Grosvenor Place, Consultants report. Interview with Bill Thomas, Ove Arup and Partners. Architecture in Steel, Alan Ogg Harry Seidler-Four Decades of Architecture by Kenneth Frampton, 1992 Thanks to http://www.arch.usyd.edu.au/kcdc/caut/html/GPT/front.htm
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I have retrieved this article from http://www.sydneyarchitecture.com/cbd/cbd4-041.htm. If you visit link this article also has pictures of the building discussed and also more information, however what i have copied and pasted is relevant to my project as it discusses steel UC into concrete slabs.
For the major project i will be visiting my uncle Michael Keeton who is an engineer, he will hopefully give us more detailed measurements for both the UC and the slab thickness.
ProjectName Grosvenor Place Project Team - Architect Harry Seidler & AssociatesDavis Heather & Dysart - Structural engineer Ove Arup & Partners - Service engineers D.S. Thomas, Weatherall & Associates - Builder Concrete Construction Function Commercial office building Year 1988 Location Sydney, NSW Cost $350m Building Type office building with parking Form - Plan shape two crescents with elliptical central core - Number of stories 44 levels above ground (including a 3 storey lobby), 4 levels of basement - Typical floor area 3 000 sq m - Net rentable floor area 2 000 sq m - Number of zones 4 - offices, plant equipment, lobby and car parks Relationship to ground ground level pedestrian entrance with underground parking Primary Structure floor system -material composite structural steel/concrete - type beams, composite metal deck/concrete floor - pattern radial beams, edge beams and one-way floor slab - beam clear span 14 m - floor slab span 2.2 - 3.25m core - material reinforced concrete - type shear walls - shape elliptical - position in plan central support structures - material composite structural steel/concrete - types external columns, triangulated piloti and core walls - external column spacing 6.5 m - external column height 3.5m footings - material reinforced concrete - types raft slab for core and pads for columns
Design requirements
Grosvenor Place occupies one of the finest locations in Sydney, forming a transition between the CBD and The Rocks area, and has a site area of 7,192 square metres. The Sydney Cove Redevelopment Authority exercises development control over this area and required the site to become the gateway to The Rocks area by allowing diagonal pedestrian through traffic from George Street to Harrington Street. In addition, a height restriction of 176m above sea level was placed by requiring the office tower structure to form part of a stepping envelope between Qantas and the Regent Hotel. The brief called for a large energy efficient office building, with total rental office space of 90,000 square metres and each floor containing up to 2000 square metres of flexible floor space, and designed to meet the needs of a rapidly evolving office technology and changing user requirements. Provisions for parking 600 cars, truck docks and engineering services, in addition to food services for the anticipated 7000 occupants, were also required. The building designed to meet the above requirements had a diagonal siting of the tower with a low site coverage of 30% and consisted of 43 levels of offices, a three storey ground floor lobby and four levels of basements. The tower floor plan consists of two quadrants, offset but with a common axis on each side of a sharp ended elliptical service core, with each quadrant having a clear width of 14m. The plant and equipment floors are at levels 10/11 and 33/34 respectively. The ground floor lobby/reception area is to be more open than the office levels. The structural requirements arising from the above decisions are a span of 14m for the office floor system, a floor to floor height of 3.5m and supports at ground level around 19.5m spacing. Smaller functional modules, with dimensions varying from 8 to 8.5m are, however, permitted at the car park levels. In addition, office floor slabs are required to carry an applied load of 4.5 kPa (3 kPa for general, 1kPa for partitions, and 0.5 kPa for services and ceiling) for general areas and 10 kPa for areas - a zone approximately 4.8m around the core - where compactus type loading occur. Plant room slabs and the roof are required to carry a general loading of 5 kPa or specific plant loads where known. For car park slabs and loading dock areas the design live load is 5 kPa. The general design wind load, based on a 50 year return period, was considered to be 1.5 - 1.8 kPa for overall stability of building and 2.5 kPa for facade design. The site is underlain by Hawkesbury sandstone of Triassic age, which is generally of medium to high strength apart from a few near horizontal clay seams. The bearing pressure on the foundation should thus be limited to 3 MPa. The basement level is approximately 3.5m below mean sea level, and maximum water level of 2m above sea level is considered for the design of structural elements at basement level. Fire resistant level for structural adequacy is to be 120 min for all elements. Speed of construction was an important requirement due to high interest rates and holding charges. Vibration control requirements for different parts of the structure to keep vibration effects - particularly those arising from sway movements of the building and vibration of long span floors during normal use - below the level of human perception. Structural Solutions The key requirements that influenced the selection of structural solutions were (a) an efficient floor system to span 14m, (b) floor system that minimizes the floor to floor height and allows integration of structure and services, (c) speed of construction to enable early tenant occupancy and (d) cost. Structural Alternatives and System Selection The following structural alternatives were considered for the floor system based on the above key requirements. composite steel/concrete banded pre-stressed concrete beams reinforced concrete slab and beams pre-cast flooring systems between beams Each of the above systems was fully designed for a typical bay and comparisons were made between systems based on the above key requirements. Even though the initial material and fabrication cost is higher, the composite steel and concrete floor system was selected as overall economies can be achieved, including early return on investment. Steel has a high strength to weight ratio and is thus a more efficient material for spanning 14m and for minimizing the structural depth required for the floor system. The composite steel option allowed the building to have 2 more floors than the reinforced concrete option. With the height restriction on the building as one of the constraints, minimizing the floor to floor height maximizes the number of floors, and therefore the rentable floor area and hence the return on investment. There is also a reduction in the overall cost of the cladding relative to the usable space enclosed. Use of steel beams for the floor systems also permits the integration of structure and services, with the services zone being within the horizontal zone for the structure. There is thus no need to increase the floor to floor height to accommodate the service ducts. The air-handling ducts penetrate the webs of the beams at two locations, where the shear forces to be resisted by the web are not critical. The composite steel/concrete construction has a number of advantages which results in reduced construction time. The steel deck for the composite construction provides a working platform during construction, and eliminates the need to either prop or strip form work and the attendant delays resulting from these operations. By designing the steel columns to support the dead load of the floors, the upper frames can be assembled before concrete casing for the columns are in place, thus taking this operation off the critical path. With the traditional reinforced concrete systems, the construction time cycle per floor was 12 to 15 days (at the time of design), whereas the composite construction had a time cycle per floor of 4 to 6 days. It was estimated that the saving in construction time for the building, as a result of using composite construction, would be around 8 months, resulting in early return on investment, particularly at a time of high interest rates and holding charges. The exposed steel in the concrete construction, however, requires fire protection. In this project the cost of fire rating the structure was considered to be small in comparison to other costs, and did not influence the selection of this system. The penetration of steel beams by service ducts reduces the flexibility available for future changes, and may be considered as one of the disadvantages of the selected system. Final Structural Solution The floor system for the tower is of composite construction and consists of radially arranged universal steel beams - spaced a 2.2m at the core and at 3.25m (half column centres) at the perimeter - supporting concrete floor slabs cast on permanent steel form work. Composite steel beams span the 14m between the core and the outer columns. The steel beams placed between columns are supported at the perimeter by steel spandrel beams, that span between the columns. The central elliptical core is of reinforced concrete, with the two elliptical portions connected together by a number of concrete cross walls. The floor slab and the core are cast monolithically. The columns on the perimeter of the building are at 6.5m spacing and of composite construction, having high tensile steel fabricated steel sections encased in concrete, with strength varying with elevation. The column spacing at ground floor is increased by gathering sets of three columns via a triangulated piloti into single column supported on concrete caisson. Each piloti is fabricated from high tensile steel plate with post-tensioned plate girder tying the top of the piloti legs at the first floor level. The car park has in general a 8m column grid and flat slab floor system. The eight columns from the tower and the core are integrated with the column grid of the car park to provide vertical supports for the basement floor slabs. The footing for the core is a raft slab and for the columns are pads. The structural elements that contribute to the different functional systems are: Structural types: composite steel deck/ concrete floor , external columns and piloti , and core wallmaterial: composite steel/concrete Structural type: shear wallmaterial - reinforced concrete Structural types: - raft slab and pad footingsmaterials - reinforced concrete Design Decisions The decision to choose a plan configuration of a double curve and counter curve was to maximize the full sweep of the best views and open space outlook. The shape offers opportunities for long span, column free system of construction, where every structural span and beam are identical, and results in every column, its space, and the floor load it carries are the same, just as is every facade element. This decision also results in a core shape which is structurally more efficient for resisting lateral load and in reducing lateral load effects. The spacing of the column, of 6.5m, at the perimeter of the building was determined to keep the size of the column to within acceptable limits. The spacing of the radial beams was selected to (a) reduce the amount of concrete to be lifted, (b) eliminate propping of metal deck during construction and (c) keep to a minimum the floor to ceiling dimensions thus maximizing the number of floors possible within the building envelope. The car park grid of 8 - 8.5m was selected to accommodate three cars between the columns. Flat slab construction was selected as it is an efficient and cost effective system for this span and minimizes floor to floor heights, thus reducing the depth of excavation into the sandstone. References Grosvenor Place, Promotional brochure. Grosvenor Place, Consultants report. Interview with Bill Thomas, Ove Arup and Partners. Architecture in Steel, Alan Ogg Harry Seidler-Four Decades of Architecture by Kenneth Frampton, 1992 Thanks to http://www.arch.usyd.edu.au/kcdc/caut/html/GPT/front.htm
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I have retrieved this article from http://www.sydneyarchitecture.com/cbd/cbd4-041.htm. If you visit link this article also has pictures of the building discussed and also more information, however what i have copied and pasted is relevant to my project as it discusses steel UC into concrete slabs.
For the major project i will be visiting my uncle Michael Keeton who is an engineer, he will hopefully give us more detailed measurements for both the UC and the slab thickness.
Tuesday, May 20, 2008
Portal Framing
Almost every steel building has at least one, and most have several framed openings, usually outfitted with some type of overhead door. Many companies only offer "field located" framed openings, which the builder must measure and cut into the frame on the job site with no plans as a guide. Steelbuilding.com always pre-engineers "factory-located" framed openings. They are illustrated in the drawings, and all the parts are pre-cut and labeled. Perhaps more importantly, our online system automatically engineers each pre-engineered metal building system to withstand the stresses and loads created by the various framed openings specified in its design.
Connecting Clips for Steel Buildings
Connecting Clips for Steel Buildings
Steel plates called "clips" provide the connection points for framing components. Even a small building may use 100 or more clips. Many companies supply only loose clips that must be bolted onto the components before erection can begin. In the best of circumstances, this requires several hours' work. If clips are missing, your job can be held up for days. Steelbuilding.com engineers clip placement into each agricultural or industrial building and welds the clips onto the components in the right place with the correct bolt pattern during fabrication. With our buildings, you won't waste any time attaching clips, and you won't have to worry about missing clips. You can start erecting your frames immediately.
Standard Steel Building Bracing
Every building faces constant stress from forces like torsion, shear, compression, and lift. To counteract this pressure, steel buildings employ one or more forms of bracing. Flange bracing is standard on all steel buildings. It consists of structural angles connected between the rafters and purlins to prevent the rafters rolling from side to side under a load. Diaphragm bracing is created by the wall and roof paneling. When attached to the frame, the panels act like a membrane or "diaphragm" stretched over the building, pulling it together.
Additional Bracing
For most steel buildings under 65' wide engineered by our system, the diaphragm action provides all the bracing that is needed, but when high winds, heavy snow loads or even a large number of openings creates extra stress, an agricultural or industrial steel building may require one of the following types of additional reinforcement. X bracing employs steel rods or cables to connect various parts of the frame tightly. Weak axis bending increases the size of the main-frame base plates to prevent columns from twisting under heavy stress. A wind column is an additional vertical member, which reinforces a column. A portal frame or wind-bent column is a sub-frame consisting of two portal columns and a portal rafter placed between the two adjacent mainframe columns in a bay. Portal frames are fairly expensive and only necessary in extreme circumstances.
Rigid roof construction
Construction of a ridged roof
A simple ridged roof consists of inclined rafters that rest on horizontal wall-plates on top of each wall. The top ends of the rafters meet at the horizontal ridge plate or ridge beam. Horizontal purlins are fixed to the rafters to support the roof covering. Heavier under purlin are used to support longer rafter spans. Tie beams or ceiling joists, are connected between the lower ends of opposite rafters to prevent them from spreading and forcing the walls apart. Collar beams or collar ties may be fixed higher up between opposite rafters for extra strength.[1]
Roof under construction in high wind area.
The rafters, tie beams and joists serve to transmit the weight of the roof to the walls of the building. There are a number of structural systems employed to facilitate this, including the use of wall-plates set at the top of the wall, hammer-beams, which spread the weight down the wall and create an equilibrium between outward and upward thrust, king posts which transfer the weight of the roof ridge, and various types of trusses.
In cyclone and hurricane prone areas the main engineering consideration is to hold the roof down during severe storms. Every component of the roof (as of course the rest of the structure) has to withstand the uplift forces of high wind speeds. This is not normally a problem in areas not prone to high wind.
Modern roofing technologies, apparent in the accompanying photo of a house under construction in a cyclone-prone region of Northern Australia, include the purpose-made steel hook bracket which is bolted to the truss with M16 bolt. The bracket is bolted to an M16 bolt cast in situ, embedded 300 mm into the reinforced concrete block wall. This system is typically in place every 900 mm around perimeter.
A simple ridged roof consists of inclined rafters that rest on horizontal wall-plates on top of each wall. The top ends of the rafters meet at the horizontal ridge plate or ridge beam. Horizontal purlins are fixed to the rafters to support the roof covering. Heavier under purlin are used to support longer rafter spans. Tie beams or ceiling joists, are connected between the lower ends of opposite rafters to prevent them from spreading and forcing the walls apart. Collar beams or collar ties may be fixed higher up between opposite rafters for extra strength.[1]
Roof under construction in high wind area.
The rafters, tie beams and joists serve to transmit the weight of the roof to the walls of the building. There are a number of structural systems employed to facilitate this, including the use of wall-plates set at the top of the wall, hammer-beams, which spread the weight down the wall and create an equilibrium between outward and upward thrust, king posts which transfer the weight of the roof ridge, and various types of trusses.
In cyclone and hurricane prone areas the main engineering consideration is to hold the roof down during severe storms. Every component of the roof (as of course the rest of the structure) has to withstand the uplift forces of high wind speeds. This is not normally a problem in areas not prone to high wind.
Modern roofing technologies, apparent in the accompanying photo of a house under construction in a cyclone-prone region of Northern Australia, include the purpose-made steel hook bracket which is bolted to the truss with M16 bolt. The bracket is bolted to an M16 bolt cast in situ, embedded 300 mm into the reinforced concrete block wall. This system is typically in place every 900 mm around perimeter.
Thursday, May 15, 2008
Timber construction (Site visit)
Timber framing is the method of creating framed structures of heavy timber jointed together with pegged mortise and tenon joints (lengthening scarf joints and lap joints are also used). Diagonal bracing is used to prevent racking of the structure.
To deal with the variable sizes and shapes of hewn and sawn timbers the two main historical layout methods used were: scribe carpentry and square rule carpentry. Scribing was used throughout Europe, especially from the 12th century to the 19th century, and was brought to North America where it was common into the early 19th century. In a scribe frame every timber will only fit in one place so that every timber has to be numbered. Square rule carpentry developed in New England in the 18th century and features housed joints in main timbers to allow for interchangeable braces and girts. Today regularized timber can mean that timber framing is treated as joinery especially when cut by large CNC (computer numerical control) machines.
To finish the walls, the spaces between the timbers were often infilled with wattle-and-daub, brick or rubble, with plastered faces on the exterior and interior which were often “ceiled” with wainscoting for insulation and warmth. This method of infilling the spaces created the half-timbered style, with the timbers of the frame being visible both inside and outside the building.
Monday, May 12, 2008
http://www.youtube.com/watch?v=lhJZJbLij-c
this is the link to a video of the entrire construction process from excavation of the site to the the total project construction.
I found this video just as useful as actually going to the site visits as it gives a timeframe of how long various tasks take and a quick glance into the overall building process and the amount of planning which would be required by the construction manager in ordering and planning task management to all work efficently and as quickly as possible.
this is the link to a video of the entrire construction process from excavation of the site to the the total project construction.
I found this video just as useful as actually going to the site visits as it gives a timeframe of how long various tasks take and a quick glance into the overall building process and the amount of planning which would be required by the construction manager in ordering and planning task management to all work efficently and as quickly as possible.
Deakin Uni Site Visit
These images are take from the new building being constructed at Deakin university.
Each photo depicts a different type of joint used within the construction of the building.
The first picture basically shows an overall internal shot of the portal frame work used to construc the building, showing elements such as the distance between rafters, purlins etc...
The second photo basically shows the rigid connection of H frame to H frame using bolts.
Photo 3 illustrates how the water/sprinker pipes are connected to the roof, note the connection is seems fragile as thin light material is used, but is strong enough to support the weight of the pipes.
The forth photo, similarly to photo 3 demonstrates how the fan is connected and that the walls that will surround it (which can be visulized) will b non load bearing.
The final photo is simply the H beam footing connection to the ground.
Saturday, May 3, 2008
Rigid roof construction
Construction of a ridged roof
A simple ridged roof consists of inclined rafters that rest on horizontal wall-plates on top of each wall. The top ends of the rafters meet at the horizontal ridge plate or ridge beam. Horizontal purlins are fixed to the rafters to support the roof covering. Heavier under purlin are used to support longer rafter spans. Tie beams or ceiling joists, are connected between the lower ends of opposite rafters to prevent them from spreading and forcing the walls apart. Collar beams or collar ties may be fixed higher up between opposite rafters for extra strength.[1]
Roof under construction in high wind area.
The rafters, tie beams and joists serve to transmit the weight of the roof to the walls of the building. There are a number of structural systems employed to facilitate this, including the use of wall-plates set at the top of the wall, hammer-beams, which spread the weight down the wall and create an equilibrium between outward and upward thrust, king posts which transfer the weight of the roof ridge, and various types of trusses.
In cyclone and hurricane prone areas the main engineering consideration is to hold the roof down during severe storms. Every component of the roof (as of course the rest of the structure) has to withstand the uplift forces of high wind speeds. This is not normally a problem in areas not prone to high wind.
Modern roofing technologies, apparent in the accompanying photo of a house under construction in a cyclone-prone region of Northern Australia, include the purpose-made steel hook bracket which is bolted to the truss with M16 bolt. The bracket is bolted to an M16 bolt cast in situ, embedded 300 mm into the reinforced concrete block wall. This system is typically in place every 900 mm around perimeter.
A simple ridged roof consists of inclined rafters that rest on horizontal wall-plates on top of each wall. The top ends of the rafters meet at the horizontal ridge plate or ridge beam. Horizontal purlins are fixed to the rafters to support the roof covering. Heavier under purlin are used to support longer rafter spans. Tie beams or ceiling joists, are connected between the lower ends of opposite rafters to prevent them from spreading and forcing the walls apart. Collar beams or collar ties may be fixed higher up between opposite rafters for extra strength.[1]
Roof under construction in high wind area.
The rafters, tie beams and joists serve to transmit the weight of the roof to the walls of the building. There are a number of structural systems employed to facilitate this, including the use of wall-plates set at the top of the wall, hammer-beams, which spread the weight down the wall and create an equilibrium between outward and upward thrust, king posts which transfer the weight of the roof ridge, and various types of trusses.
In cyclone and hurricane prone areas the main engineering consideration is to hold the roof down during severe storms. Every component of the roof (as of course the rest of the structure) has to withstand the uplift forces of high wind speeds. This is not normally a problem in areas not prone to high wind.
Modern roofing technologies, apparent in the accompanying photo of a house under construction in a cyclone-prone region of Northern Australia, include the purpose-made steel hook bracket which is bolted to the truss with M16 bolt. The bracket is bolted to an M16 bolt cast in situ, embedded 300 mm into the reinforced concrete block wall. This system is typically in place every 900 mm around perimeter.
Friday, April 25, 2008
Site Visit (bunnings)
Looking at beams and columns
Internally, beams experience compressive, tensile and shear stresses as a result of the loads applied to them. Typically, under gravity loads, the original length of the beam is slightly reduced to enclose a smaller radius arc at the top of the beam, resulting in compression, while the same original beam length at the bottom of the beam is slightly stretched to enclose a larger radius arc, and so is under tension. The same original length of the middle of the beam, generally halfway between the top and bottom, is the same as the radial arc of bending, and so it is under neither compression nor tension, and defines the neutral axis (dotted line in the beam figure). Above the supports, the beam is exposed to shear stress. There are some reinforced concrete beams that are entirely in compression. These beams are known as prestressed concrete beams, and are fabricated to produce a compression more than the expected tension under loading conditions. High strength steel tendons are stretched while the beam is cast over them. Then, when the concrete has begun to cure, the tendons are released and the beam is immediately under eccentric axial loads. This eccentric loading creates an internal moment, and, in turn, increases the moment carrying capacity of the beam. They are commonly used on highway bridges.
The primary tool for structural analysis of beams is the Euler-Bernoulli beam equation. Other mathematical methods for determining the deflection of beams include "method of virtual work" and the "slope deflection method". Engineers are interested in determining deflections because the beam may be in direct contact with a brittle material such as glass. Beam deflections are also minimized for aesthetic reasons. A visibly sagging beam, though structurally safe, is unsightly and to be avoided. A stiffer beam (high modulus of elasticity and high second moment of area) produces less deflection. Mathematical methods for determining the beam forces (internal forces of the beam and the forces that are imposed on the beam support) include the "moment distribution method", the force or flexibility method and the matrix stiffness method.
The primary tool for structural analysis of beams is the Euler-Bernoulli beam equation. Other mathematical methods for determining the deflection of beams include "method of virtual work" and the "slope deflection method". Engineers are interested in determining deflections because the beam may be in direct contact with a brittle material such as glass. Beam deflections are also minimized for aesthetic reasons. A visibly sagging beam, though structurally safe, is unsightly and to be avoided. A stiffer beam (high modulus of elasticity and high second moment of area) produces less deflection. Mathematical methods for determining the beam forces (internal forces of the beam and the forces that are imposed on the beam support) include the "moment distribution method", the force or flexibility method and the matrix stiffness method.
Tuesday, April 22, 2008
construcction in bejing article
Advertisement
Infrastructural construction in Beijing continues to increase( 2003-10-16 03:19) (China Daily)
A senior official with the Beijing Municipal Government on October 15 promised more opportunities for non-governmental capital in the city's stepped-up development of infrastructure facilities.
"We should use innovative ways to break industry barriers to attract more social funds through the market,'' Liu Yongfu, director of the Construction Commission of the Beijing Municipal Government, told the Standing Committee of the 12th Beijing Municipal People's Congress at its seventh session.
"By introducing a market competition mechanism, social funds should be allowed to be used in the construction of major municipal engineering projects through joint funding, joint operating, taking on shares, franchising, and project financing,'' Liu said.
Specifically, social funds will be welcomed in such areas as rail transport, public utilities and environmental projects.
The Beijing Municipal Government has been announcing major engineering projects each year, in order to give a substantial push to the city's infrastructure upgrades. Out of 60 such projects this year, 47 have been started construction, while the rest will be started before the end of this year, according to Liu.
As much as 32.81 billion yuan (US$3.97 billion) has been invested in these projects this year so far, roughly one third of the city's total investment on fixed assets for that period.
But were it not for financing difficulties, more projects would have been kicked off, said Liu. For example, construction of the Sixth Ring Road has been postponed to next year due to difficulties securing financing.
In particular, Liu said, the commission should pay more attention to the investment intentions of large international companies and attract more of them to get involved in the rapid economic development of Beijing through mergers, acquisitions and transfers of State-owned shares.
As far as Liu is concerned, the construction of these major engineering projects has produced obvious improvements in local investment and the city's natural environment.
One case in point, said Liu, is the completion of an afforestation project of 59,363 hectares aimed to reducing the city's sandstorms, which has helped the city enjoy 161 days of good air quality by September 15 this year, 62.6 per cent of the total number of days so far. Beijing's overall target for this year is 60 per cent.
Also at yesterday's session, the standing committee urged the municipal government to adopt effective measures to attract more investment from Taiwan as well.
Although the city has published various practical measures to ensure its appeal to Taiwan investors, Overseas Chinese Affairs Standing Committee Director Chen Xingbo said Beijing still needs better monitoring mechanisms to safeguard the legitimate rights of Taiwanese investors and their families.
By the end of July, Taiwanese investors had established 1,911 enterprises in the city, with a total contractual investment of US$1.41 billion.
from http://www.chinadaily.com.cn/en/doc/2003-10/16/content_272413.htm
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I found this arcticle very interesting in discussing how and why beijing is become such a growing country due to its extremely rapid growth in construction.
Infrastructural construction in Beijing continues to increase( 2003-10-16 03:19) (China Daily)
A senior official with the Beijing Municipal Government on October 15 promised more opportunities for non-governmental capital in the city's stepped-up development of infrastructure facilities.
"We should use innovative ways to break industry barriers to attract more social funds through the market,'' Liu Yongfu, director of the Construction Commission of the Beijing Municipal Government, told the Standing Committee of the 12th Beijing Municipal People's Congress at its seventh session.
"By introducing a market competition mechanism, social funds should be allowed to be used in the construction of major municipal engineering projects through joint funding, joint operating, taking on shares, franchising, and project financing,'' Liu said.
Specifically, social funds will be welcomed in such areas as rail transport, public utilities and environmental projects.
The Beijing Municipal Government has been announcing major engineering projects each year, in order to give a substantial push to the city's infrastructure upgrades. Out of 60 such projects this year, 47 have been started construction, while the rest will be started before the end of this year, according to Liu.
As much as 32.81 billion yuan (US$3.97 billion) has been invested in these projects this year so far, roughly one third of the city's total investment on fixed assets for that period.
But were it not for financing difficulties, more projects would have been kicked off, said Liu. For example, construction of the Sixth Ring Road has been postponed to next year due to difficulties securing financing.
In particular, Liu said, the commission should pay more attention to the investment intentions of large international companies and attract more of them to get involved in the rapid economic development of Beijing through mergers, acquisitions and transfers of State-owned shares.
As far as Liu is concerned, the construction of these major engineering projects has produced obvious improvements in local investment and the city's natural environment.
One case in point, said Liu, is the completion of an afforestation project of 59,363 hectares aimed to reducing the city's sandstorms, which has helped the city enjoy 161 days of good air quality by September 15 this year, 62.6 per cent of the total number of days so far. Beijing's overall target for this year is 60 per cent.
Also at yesterday's session, the standing committee urged the municipal government to adopt effective measures to attract more investment from Taiwan as well.
Although the city has published various practical measures to ensure its appeal to Taiwan investors, Overseas Chinese Affairs Standing Committee Director Chen Xingbo said Beijing still needs better monitoring mechanisms to safeguard the legitimate rights of Taiwanese investors and their families.
By the end of July, Taiwanese investors had established 1,911 enterprises in the city, with a total contractual investment of US$1.41 billion.
from http://www.chinadaily.com.cn/en/doc/2003-10/16/content_272413.htm
----------------------------------------------------------------------------------------
I found this arcticle very interesting in discussing how and why beijing is become such a growing country due to its extremely rapid growth in construction.
Saturday, April 19, 2008
Steel construction
Steel construction and the industry
Because of the critical role played by steel in infrastructural and overall economic development, the steel industry is often considered to be an indicator of economic progress.
The economic boom in China and India has caused a massive increase in the demand for steel in recent years. Between 2000 and 2005, world steel demand increased by 6%. Since 2000, several Indian and Chinese steel firms have risen to prominence like Tata Steel (which bought Corus Group in 2007), Shanghai Baosteel Group Corporation and Shagang Group. ArcelorMittal is however the world's largest steel producer.
The British Geological Survey reports that in 2005, China was the top producer of steel with about one-third world share followed by Japan, Russia and the USA.
In 2008, steel will be traded as a commodity in the London Metal Exchange.
Uses of Steel
Iron and steel are used widely in the construction of roads, railways, infrastructure and buildings. Most large modern structures, such as stadiums and skyscrapers, bridges and airports, are supported by a steel skeleton. Even those with a concrete structure will employ steel for reinforcing. In addition to widespread use in major appliances and cars (despite growth in usage of aluminium, it is still the main material for car bodies), steel is used in a variety of other construction-related applications, such as bolts, nails, and screws.
Because of the critical role played by steel in infrastructural and overall economic development, the steel industry is often considered to be an indicator of economic progress.
The economic boom in China and India has caused a massive increase in the demand for steel in recent years. Between 2000 and 2005, world steel demand increased by 6%. Since 2000, several Indian and Chinese steel firms have risen to prominence like Tata Steel (which bought Corus Group in 2007), Shanghai Baosteel Group Corporation and Shagang Group. ArcelorMittal is however the world's largest steel producer.
The British Geological Survey reports that in 2005, China was the top producer of steel with about one-third world share followed by Japan, Russia and the USA.
In 2008, steel will be traded as a commodity in the London Metal Exchange.
Uses of Steel
Iron and steel are used widely in the construction of roads, railways, infrastructure and buildings. Most large modern structures, such as stadiums and skyscrapers, bridges and airports, are supported by a steel skeleton. Even those with a concrete structure will employ steel for reinforcing. In addition to widespread use in major appliances and cars (despite growth in usage of aluminium, it is still the main material for car bodies), steel is used in a variety of other construction-related applications, such as bolts, nails, and screws.
Tuesday, April 15, 2008
Week 5
This diagram shows a basic section of wall to concrete panel again labeled with the key componentsWednesday, April 9, 2008
Week 4
This week we looked at concrete construction in detail. In particularly learning about the two main categories; Pre-cast and tilt up.
Thursday, April 3, 2008
Second SIte visit
Reinforced concrete is concrete in which reinforcement bars ("rebars") or fibers have been incorporated to strengthen a material that would otherwise be brittle. In industrialised countries, nearly all concrete used in construction is reinforced concrete.
Concrete is reinforced to give it extra tensile strength; without reinforcement, many concrete buildings would not have been possible.Reinforced concrete can encompass many types of structures and components, including slabs, walls, beams, columns, foundations, frames and more.Reinforced concrete can be classified as precast concrete and cast in-situ concrete.Much of the focus on reinforcing concrete is placed on floor systems. Designing and implementing the most efficient floor system is key to creating optimal building structures. Small changes in the design of a floor system can have significant impact on material costs, construction schedule, ultimate strength, operating costs, occupancy levels and end use of a building.
Concrete is reinforced to give it extra tensile strength; without reinforcement, many concrete buildings would not have been possible.Reinforced concrete can encompass many types of structures and components, including slabs, walls, beams, columns, foundations, frames and more.Reinforced concrete can be classified as precast concrete and cast in-situ concrete.Much of the focus on reinforcing concrete is placed on floor systems. Designing and implementing the most efficient floor system is key to creating optimal building structures. Small changes in the design of a floor system can have significant impact on material costs, construction schedule, ultimate strength, operating costs, occupancy levels and end use of a building.
Wednesday, April 2, 2008
Week 3
This diagram shows a typical portal frame. The Lecturer heavily focused on the joining options for U breams, looking at booth rigid connections and flexible connections and the load and axial load properties of each.
Wednesday, March 19, 2008
Tuesday, March 11, 2008
Week 1
STEEL CONSTRUCTION -KD STUART CENTER (located on Deakin Waurn Ponds campus)
The photo above photo shows the bolts used to connect the steel beams. The bolts would be mech
anically tightened.
The photo above photo shows the bolts used to connect the steel beams. The bolts would be mech
The second photo shows the stadium is built with a K frame and is then attached to the wall.
The third photo on the right shows how the steel frame is connected to the roof and how it allows room for the ventillation.
Like most steel framed buildings these days this would have been prefabricated which is a more accurate and efficient manufacturing process. However larger steel buildings require professional construction workers to ensure proper assembly.
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