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Construction Technology 4 (Steel) 2012

Constructio n Technology 4 (Steel) This brief report has been prepared to identify a multi-storey building where there is major application of structural steelwork as well as steel framed systems within a mixed form of construction. Included in this report are some steel sections from the construction plans that specify the major steelwork of the structural system. Please see CD-ROM for fully detailed steel plans and photos of steel construction.

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Ralph Riz Ramadan A Jason Sak Lukas Leb GROUP 3Joseph Boust Andy Poli

Construction Technology 4 (Steel) 2012 Contents Project Background – Page 3 Plans & Drawings – Page 4 Footing Plans Pad Footing Schedule Table Level 3 Steel Plans Roof Framing Plan Bondek Details Building Loads – Page 8 Dead Loads Live Loads Wind Loads Earthquake Climate Information for Sutherland Wind Speed in Sutherland Air Pressure in Sutherland Air Temperature in Sutherland Connections for Steel Construction – Page 11 Bolted Connections Welded Connections Connection Details – Page 13 Load Calculations – Section 1 – Page 15 Loading Calculation on Rafter Load Calculations on Column Member Structural Analysis of Rafter Standard and Deflection Checking Load Calculations – Section 2 – Page 17 Loading Calculation on Rafter Load Calculations on Column Member Structural Analysis of Rafter Standard and Deflection Checking Fabrication of Steel Construction – Page 19 Photos – Page 20 Finished Product Reference – Page 22 2

Construction Technology 4 (Steel) 2012 Project Background The development project researched consists of four separate buildings, where two buildings are of five storeys and the other two are of four storeys on a 2000 metre squared block, at 8 Morley St Sutherland. This project holds 62 apartments, ranging from 1 to 4 bedrooms and a 3 level underground basement. This project has costed 15 million dollars to build and was finished 18 months after commencement. The structural steel alone costed 6 million dollars in material and labour. Hence, as structural steel construction was used in this project, the main structures of these 4 buildings only took 5 months to erect.

8 Morley St. Sutherland

In this report we are researching one of these dwellings which is the first building, towards the south east end. This project is a perfect example of structural steel construction. Each floor above ground level are constructed using pre-cast concrete slabs on permanent steel Bondek sheeting, supported by “I” steel beams. The building envelope consists of Hebel panels and the roofing of colour bond sheeting. Structural steel construction method for a high rise building is rarely used in Australia. This method can be very costly and can also impact with regulation of the BCA. However, Merhis Constructions, the building company who constructed this project also has a structural steel factory. This factory works under the name of Southern Cross Rigging and Constructions which can import and fabricate steel components, giving them an advantage of resources.

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Construction Technology 4 (Steel) 2012 Plans & Drawings Footing Plan This plan bellow is of the footing at Basement excavation level. Each “I” symbol represents a steel column encased in concrete. These columns are sitting on pad footings as shown in the diagram below. The depth of these pad footings are at 600 and 450 mm, both have a bearing capacity of 3500kpa. Note: This plan has been cut only to show directly underneath the building researched in this project.

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Construction Technology 4 (Steel) 2012

Pad Footing Schedule Table

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Construction Technology 4 (Steel) 2012 Level 3 Steel Plans This plan below is of the level 3 steel framing plan. Once again the “I” symbolises the steel columns, which are place between every second beam. The darker lines on the borders and around the lift shaft are the primary steel beams. Vertical beams between each column are 6m long and horizontal beams betweens each vertical beams are 8m long. Each rectangle section is 3 by 8m.

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Construction Technology 4 (Steel) 2012

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Construction Technology 4 (Steel) 2012 Roof Framing Plan The roof structure steel purlins. then fastened to screws.

is constructed using Colorbond roofing is the purlins using

Bondek Details Bondeck is laid on beams which permanent concrete slab. fast in construction the concrete slab Bondeck is beams using shear example below, 19mm.

top of the steel become a formwork for the Using this method is and can hold help hold greater loads. fastened onto the studs. Here is an shear studs are 95 by

Building

Loads

Dead Loads Dead load is the the weight of the members and non components that attached to the does not vary with position and a building may of the roof, purlins, slabs, beams, exterior walls and finishes and underceilings and their partitions, interior walls. In floors, such as ducts, water pipes, generally included allowance in the

vertical load due to various structural structural are permanently structure. Dead load time, with regards to weight. Dead load in consist of the weight floor decks, floor girders, columns, cladding, floor fill, suspended supports, permanent plumbing, and addition, services in weights for cables, and so on, are by an appropriate floor dead loads.

Another important property of steel structure that needed to pay attention on is its unit weight. Steel provides strength in both compressive and tensile members but

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Construction Technology 4 (Steel) 2012 its unit weight is relatively high compare to other structural materials. Consequently, structural steel buildings normally have higher dead load. In the building that has been selected for this project, it has been constructed mostly by steel frame (columns, beams and roof structure) and other materials combined. For instances, the cladding system of both concrete masonry and clay brick masonry are used for bearing and non bearing walls. Also, in some parts of roof structure, timber has been exploited. By using this type of construction, the dead load of whole structure to footing system has been significantly reduced but the strength to withstand the structure has still been maintained. Moreover, the buildings contains multi-stories, therefore, the total height of the buildings in this project is relatively high. It can be seen as a disadvantage in terms of load bearing capacity where trip footings have been used thoroughly. The overburden of structure or dead load is transferred from roof to beams, columns and footing system. This load is distributed effectively. Because the dead loads of structural members are accumulatively increased depends on building's height, as the result, lower buildings are more advance in dead load bearing capacity. Live Loads Live loads are those loads imposed on a structure by the use and occupancy of that structure and are the result of human actions. This sets them apart from natural forces, such as wind and snow loads, that may be assumed to conform to physical laws and to be predictable within specifiable limits on the basis of past experience. Human actions will never be predictable in the same way. Live loads vary with time in position and magnitude. They may be classified as movable loads or moving loads. 

Movable loads are the load that may be transported from one location to another on a structure without any dynamic effect, for example, human occupants, furniture, equipment, movable partitions and the likes.



Moving loads, on the other hand, are loads that move continuously over the structure, for example, cranes in a factory or trucks and trains on bridges.

Loads incidental to construction, maintenance, and repair should also be treated as live loads. In the selected buildings, the live loads are designed with different bearing capacity according to their using purposes. For example, the floor has been designed to sustain up to 3 kPa which satisfied the requirement of AS 1170.1 because the live loads (moving type) in floor areas might reach their peak at day and night time. Meanwhile, the living areas in this case, can maintain live loads as much as 5 kPa to 7.5 kPa because in those areas the more live loads (movable type) existing. In order to achieve more efficient buildings, it is necessary to design the live loads differently from one to another area as their using purposes are different. In term of roof live loads, live loads that apply to roof structure are including wind loads, vibration from noise and water from rains. The buildings in this project are designed with low pitch roofing system therefore the wind loads and water from rains do not affect much to the structure. Moreover, this educational facilities are surrounded thus the sound’s vibration from vehicles are not significant. For the reasons mentioned, the roof structure is designed to sustain it live loads of 0.25 kPa. Wind Loads Wind loads are important even for high buildings like the building in this project if they are not sheltered by surrounding buildings because the horizontal wind pressure can push the buildings over if they are not adequately braced.

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Construction Technology 4 (Steel) 2012 The building has been constructed with brick and concrete masonry cladding system which provided an effective bracing system for steel frame structure against wind loads. Wind produces both pressure and suction. It usually presses on one side of the building, as an effect, the suction occurs on the other walls and roof. The low pitch roof can reduce the force of this effect as the forces are re-directed. The wind speed of the site was measured to be 49.8 m/s which are relatively low. Moreover, the structure was also constructed using low pitch roofing system. As the result, the effect of wind loads to the structure has been minimised. In addition, the wind usually does not blow with a constant speed, high wind intensities may be of very short duration, from a few second to a fraction of a second. The probability of the wind speed exceed maximum estimated speed is 1/500. Under this condition the buildings may move backward and forward, and the dynamic effect of the wind must then be considered. Earthquake An earthquake is a sudden movement of the ground, which takes the foundation of the building with it but leaves the upper part of the building behind because of the high speed of the ground’s motion and the high inertia of the building. The effect is the same as if the building moved relative to the ground. The direction of the motion depends on the fault in the earth’s crust, but it can always be resolved into a horizontal and a vertical component. The vertical component of the earthquake’s motion is relatively harmless, because all buildings are designed to resist large vertical loads, but the horizontal component of the movement may produce serious cracking and even collapse of the building. The load-bearing walls of this project are built with brick and concrete masonry, thus, they might be considered as very low performance in earthquake even if they are well constructed. On the other hand, there are no severe earthquakes have been recorded in Australia therefore, can sustain against level 3 earthquake as designed should be adequate for this project’s buildings. Climate Information for Sutherland      

Average solar irradiation: 4.88 kWh/m²/day Average wind speed: 3.48 m/s Average air temperature: 15.44 °C Average earth temperature: 16.37 °C Average humidity: 65.93 Average air pressure: 94.92 kPa

Wind Speed in Sutherland 

Average wind speed: 3.48 m/s  Minimum (monthly avg) wind speed: 3.1 m/s  Maximum (monthly avg) wind speed: 3.9 m/s

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3.1

Wind Speed m/s

3.5

3.9

3.7

Construction Technology 4 (Steel) 2012 Air Pressure in Sutherland Average air pressure: 94.92 kPa Minimum (monthly avg) air pressure: 94.5 kPa Maximum (monthly avg) air pressure: 95.2 kPa

  

Air Pressure kPa

95.2 Jan Feb Mar Apr

May

95.2 Jun

94.8

95.2 Jul

Aug Sep

Oct

Nov Dec Air

Temperature in Sutherland   

Average air temperature: 15.44 °C Minimum (monthly avg) air temperature: 8 °C Maximum (monthly avg) air temperature: 21.8 °C

Conne framework. Any steel structure is an assemblage of different members such as beam, columns, and tension members, which are fastened or connected to one another, usually at the member ends. Members in steel structures are most often made of different components such as plates, angles, I-beams and channels. These different components have to be connected properly by means of fasteners, so that they will act together as a single composite unit. Connections between different members of a steel frame work to facilitate the flow of forces and moments from one member to another and transfer forces to the foundations. 11

Construction Technology 4 (Steel) 2012 Bolted Connections Bolted connections are connections where its components are fastened together primarily by bolts. Depending on the direction and line of action of the loads relative to the orientation and location of the bolts, the bolts may be loaded in tension, shear, or a combination of tension and shear. Bolted sections should be standardised as much as possible, with similar details and bolt sizes. The use of either bolting or welding has certain advantages and disadvantages. Bolting requires either the punching or drilling of the steel or materials that are to be joined. These holes may be a standard g on the type of connection. Bolts can be used ections. Bearing-type connections rely on the arts to transmit forces. Some slippage his type of connection. Slip-critical etween the connecting parts to transmit pected for this type of connection. Slip-critical ory or dynamic loads, such as bridges, smicity. Holes made in the connected parts for ong slotted. framework are detailed below.

Welded Connections Welded connections are connecti Welding is a process by which the d, with supplementary molten metal at th ome molten, and upon cooling, the structural steel and weld metal will act as one continuous part where they are joined. There are different types of welding processes that include:     12

Metal arc-welding (WMA or SMAW) with covered electrodes Metal active gas welding (MAG) Metal inert gas welding or flux cored arc welding (MIG) Submerged arc welding

Construction Technology 4 (Steel) 2012 Welds are typically classified to the type, position and joints of the welds as follows:   

The types of welds: fillet, butt, groove, plug and slot The positions of the welds: horizontal, vertical, overhead, and flat The types of joints: butt, unequal, tee, lap, open and closed

Fillet welds are generally weaker than butt welds however they are generally used more often because they allow for larger tolerances during erection. In addition they are less costly as they required less preparation, simple equipment, less skilled labour and time to be completed in application or practice. Even though butt welds are stronger than typical fillet welds they have their own disadvantages which include high costs in labour and quality. They require more time as they need to cover the cross section of the materials to be joined together requiring fuller and deeper penetration. This results in more preparation work, more weld material and highly skilled labour to complete. Quality control of such welds is difficult because inspection of the welds is rather difficult and can only be achieved through advanced quality inspection procedures such as ultrasonic and radiography testing. Welding eliminates the need for punching or drilling the steel or material that will make up the connection. However, the labour associated with welding requires a greater level of skill than the installation of bolts. Welding requires highly skilled tradesman who are trained and qualified to make the particular welds called for in a given connection configuration. They need to be trained to make the varying degrees of surface preparation required depending on the type of weld specified, the position that is needed to properly make the weld, the material thickness of the parts to be joined, the preheat temperature of the parts and many other variables. A fully welded structural framework is shown in the below cross section detail below.

ls The connection between t of beams is one of the most important connections in the job. ny different types of stress, including compressive stress, tensile such as wind load stresses, possibility of snow loads, temperature, high rain and even earth movements. In a Splice Joint the bolts are under both tensioning forces and shearing forces. The example below shows just how a bolt used in a Splice Joint is affected by shear stress.

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Construction Technology 4 (Steel) 2012

Bearing this in mind the area around the base of columns had to be designed so that it is not hazardous to any people coming or going. In our design the base plate and connection bolts have been protected by 20mm of grout. There are 3 main types of load transfer methods in bolt connection area;   

Shear force Tension force Combined action

In the Diagram below it shows where shear forces apply to a bolt.

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Construction Technology 4 (Steel) 2012 The above simple connection detail is of a square column connected by cord and also by the webbing. This is therefore a rigid connection as there is no movement throughout the web and the connection.

In this connection detail 2, 3, 4 chemical anchors are used to embed the plate into the concrete floor. The plate is not hard flush against the concrete floor and is separated by a small amount of grout. The column is welded to the base plate therefore making a rigid joint.

Here we have a typical roof bracing detail. In the detail we have shop weld 10mm cleat plate fixed with 3/M16 bolts both sides. This is to prevent lateral movement of the roof framing.

Load Calculations – Section 1 Loading Calculation on Rafter – Ralph Rizk Steel Rafter R1 24482mm span, 9723mm spacing (typical) Roof Sheeting DL – 40kg/m² , LL – 25kg/m² Dead Load: Self weight

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= 45kg/m² x 9.8 = 441N/m = 0.44kN/m

Construction Technology 4 (Steel) 2012 Weight of roof sheet = 0.4kN/m² Roof sheet on beam

= 0.4kN/m²x9.732 = 3.9kN/m

Dead Load

= 0.44+3.9 = 4.34kN/m

Live Load

= 0.25x9.732 = 2.43kN/m

Load Calculations on Column Member – Jason Sakr Steel Column C1 Steel Rafter DL – 4.73Kn/m LL – 2.63kN/m Roof Sheeting DL – 0.4kPa LL – 0.25kPa Dead Load: Self weight

= 67x9.8 = 656.6 N/m = 0.66 kN/m Weight of Roof sheet = 0.4kN/m²x9.732 = 3.89kN/m Dead Load

= 0.66+3.89 = 4.55 kN/m

Live Load

= 0.25x9.732 = 2.43kN/m

Structural Analysis of Rafter (to obtain bending moment and shear force) – Ralph Rizk Bending Moment = WL² / 8 MDL MLL M

= 4.73 x 15²/8 = 133kNm = 2.63 x 15²/8 = 74kNm = (1.25x1.33)+(1.5x74) = 277.25 kNm

Shear Force = WL/2 MDL

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= 4.73 x 15/2 = 35.47 kNm

Construction Technology 4 (Steel) 2012 MLL M

= 2.63 x 15/2 = 19.72kNm = (1.25x35.47)+(1.5x19.72) = 73.91 kNm

Compression: Sheeted roof = 9.732 x 0.0024 = 0.0252kN/m DL

= 0.54kN/m + 0.0252 kNm = 0.565kNm

Standard and Deflection Checking (by Australian Standards) – Ramadan Ali Deflection Limit: General Criteria Δ ≤ L/250 Supporting Precast Wall Δ ≤ L/500 No Articulated...