Week 3 Anita Nicholls 698556
Structural Elements The design of structural elements must take into considera8on loads, material, form and shape. Elements include: Struts, 8es, beams, slabs/plates and panels. Struts a slender element design to carry load parallel to its long axis. The load produces compression Ties: A slender element designed to carry load parallel to its long axis. The load produces tension Beams (Part in tension, part in compression(top) ) Slabs/Plates a wide horizontal element designed to carry ver8cal load in bending usually supported by beams Panels: A deep ver8cal element designed to carry ver8cal or horizontal load
Foo#ngs and Founda#ons: Founda8ons are found at the bo<om of buildings where the building meets the ground. Foo8ngs are like the roots to a building and are designed by structural engineers Shallow Foo#ngs are used where soil condi8ons are stable and where the required soil bearing capacity is close to the ground surface. Examples of these include pad foo8ngs, strip foo8ngs and RaH founda8ons. Deep Founda#ons are used where soil condi8ons are unstable or where the soil bearing capacity is inadequate, they allow weight to be distributed through the structure right down to the bedrock and can generally be divided into two types: 1.End bearing piles: extend the founda8ons down to rock or soil that will provide support for the building loads 2.Fric8on piles rely on the resistance of the surrounding earth to support the structure These piles can be constructed by driving long 8mber, steel or concrete members into the ground or by drilling into the ground and then filling the hole with steel reinforcing then concrete. Retaining and founda#on walls: Are used when sites are excavated to create basements or where changes in site levels need to be stabilized. The pressure load of the earth behind the wall needs to be considered to prevent the wall from falling
BRICKS A brick is a standard size masonry unit made out of Standard size:: 230mm long, 76mm high, 110mm in depth, standard mortar is 10mm. Clay bricks are manufactured from clay or shale which is shaped and then hardened by a firing process (in a kiln) Bricks can be extruded and wire-‐cut, Machine moulded (pressed) and handmade (convict-‐made). Clay is a natural material so there is a wide varia8on in the colour of bricks.
MASS Main proper8es of mass construc8on: strong in compression but weak in tension, good thermal mass and insula8ng ability, extremely durable. Mass materials include stone, earth, clay and concrete. Mass construc8on is typically found in modular or non-‐modular forms. Modular: Clay brick, mud brick (adobe), concrete block, ashlar stone Non-‐modular: Concrete, Rammed earth, monolithic stone (columns and beams) MASONRY -‐Masonry refers to building with units of various natural or manufactured products… usually with the use of mortar as a bonding agent (Ching 12.06) -‐Masonry is a subset of mass construc8on made from smaller units of bricks, stone, earth, clay or concrete. And its proper8es are that the units together act as a monolithic whole. Bond: the pa<ern or arrangement of the units Course: a horizontal row of masonry units Joint: the way units are connected to each other Mortar: mixture of cement or lime, sand and water used as a bonding agent
BLOCKS The most common Australian concrete block is around 390 long, 90 wide and 190 high. Clay blocks typically have holes in them and weigh about 11 kg. (Whereas bricks weigh 3-‐4kg) The hollowness reduces the weight of the block, increases the insula8on ability of the block and also allows reinforcement to be placed in the holes if needed to increase the strength. Blocks are manufactured from cement, sand, gravel and water via a process involving mixing, moulding and curing. They can be classified as load-‐bearing or non-‐load bearing blocks. “Face shell” refers to the outside face of the block “web” refers to the interior por8ons between the hollow cells Proper8es common to both concrete blocks and clay bricks include hardness, fragility, duc8lity and flexibility. Key differences are found it their manufacturing and change over 8me. Concrete shrinks over 8me while clay bricks tend to expand. This is important to consider as movement joints are required for each material.
STONE Stone can be categorized into three different types: Igneous (e.g. granite, basalt, bluestone) :formed when molten lava cools and is typically very dense, very hard and dark in colour. There stones are used in the foo8ngs of a building where compressive strength is required and they are quite impervious to water. Sedimentary (e.g. limestone, sandstone): soH, less dense, can be carved and shaped easily, lighter in colour compared to igneous stones and Metamorphic (e.g. marble and slate): formed when the structure of igneous or sedimentary stone changes when subjected to pressure, high temperatures or chemical processes.
Lot 6 Café The structure is based on a Column System incorpora8ng the structural elements of column and post. Concrete (a non modular form of mass construc8on), steel and glass are the prominent materials found. The glass that can be seen in the front of the building does not carry load and is likely used for aesthe8c purposes. I would argue this building to be both concealed and expressed as some elements remain hidden whilst the essence of column and beam has been depicted at the front. Members are joined together by pin joints and the building also features control joints which account for the expansion and contrac8on of the concrete over 8me
Arts West Student Centre The Arts West Student Centre has been built using a truss system composed of hollow steel members allowing for strength and a reduc8on in weight. Truss systems are based upon the rigidity of the triangle and composed of linear members that are subject to either tension or compression (Ching, 2014) The main structural elements elements were columns and beams, such as the long 8mber beams that were used mainly for aesthe8c reasons but also to house parts of the ligh8ng system. These 8mber beams were bolted to the lower end of the truss.
South Lawn underground car park The carpark’s vault system u8lises concrete in its monolithic mass construc8on. Steel rods can be found inside the columns ac8ng as reinforcement. The size and curbs of each concrete column suggests that they were built in-‐situ. Every column has its own foo8ng, which helps spread the weight force of the trees growing directly above. Tree roots are situated in a bowl above each column.
Stairs on West end of Union House The Stairs use a can8lever cable system. Galvanized steel plate steps and beams have been used appropriately as steel is a very strong and can deal with heavy loads. Galvanized steel also prevents the rus8ng of this exposed outdoor structure due to environmental factors such as rain. Members are joined together by welding and pin joints. These rigid joins prevent the wobbling of the stairs during use.
North Court Union House Membranes are tension structures that comprise of thin, flexible surfaces that can be supported by air pressure and suspended or stretched between posts (Ching, 2014). The Membrane shelter at North Court comprises of a sheet material and metals wires that are in tension. There is a hollow centre in the middle of the structure which allows water to fall or slide through with the help of gravity into a drain at ground level. This reduces the extra poten8al load of accumulated rain water on the roof of the structure.
Beaurepaire Centre Pool Steel framing has been used as a bracing system and brick on the eastern side of the building. As the windows act as en8re walls, the self-‐suppor8ng window frames provide the lateral bracing. Without sufficient bracing, the rectangular building would sway in the wind, and the glass would most likely collapse. Thus the rigidity of the structure is heavily reliant on the rigidity of the steel frames.
Oval Pavilion (North Side of Oval) The Oval pavilion is a recent addi8on to the University and it consists of a column and beam system. The main materials used for the structure and enclosing systems is 8mber, steel, concrete and bricks. Timber has been used for columns and for roof cladding . There are steel beams as well as a concrete floor. Of interest was the steel column and 8mber beam handrail construc8on found outside as this contrasted the arrangement of steel beam, 8mber column found for the majority of the buildings structure. Masonry was joined with mortar and there were observed sec8ons of the exterior walls with a silicone fixture.
New Melbourne School of Design under construc#on-‐ from various sides Can8lever and beam systems incorpora8ng the use of glass, steel columns, precast concrete and 8mber. Precast panels have been used for the façade system as well as sanded back pebbles for aesthe8c, steel frames have been used to support smaller windows whilst aluminium frames have been used for the main windows. Towards the North end of the building, can8levered steel is evident rather than concrete as it allows for a lighter system. Precast concrete has been used for both structural and non structural elements.
Old Geology South Lecture Theatre Entry Structure The entry structure incorporates the used of a can8lever system as a shelter/roof, whilst the entrance also comprises of post and beam elements. The main materials used include steel columns, a masonry wall (with a stretcher course bond pa<ern)l, steel and Concrete. Timber studs are used and load is transferred through mullions.
Frank Tate Pavilion (West of Sidney Myer Asia Centre)
Structural systems include a Framing System as well as a Post and Beam system with the elements of folding Planes, steel and 8mber beams as well as painted steel beams. The pavilion contains no concrete in it’s structure above the ground. Steel and 8mber beams, panted steel beams Pin joint connec8ons can be found under the structure.
GLOSSARY SeVlement: The compression of Earth by buildings over 8me that cause the buildings to sink. This sinking is called se<lement Note: Cracking in a building oHen occurs with DIFFERENTIAL SETTLEMENT (se<lement that is uneven) Point Foo#ngs: A pad foo8ng is a shallow foo8ng. It is also called an isolated foo8ng and is literally a pad under a stump. Pad foo8ngs help to spread a point load over a wider area of ground Strip foo#ngs are used when loads from a wall or columns (built on top of the strip) are spread in a linear ma<er Moment The force that influences the rota8on or turning of an object Retaining wall holds back earth, thus earth may be higher on one side than on the other side of the wall Slab on ground when a slab of concrete to serve as founda8on is placed directly or near ground level. Substructure The lowest division of a building
Addi8onal Terminology • • • •
Retaining walls are walls where earth may be higher on one side than on another side so they hold the earth back Monolithic stones are large individual stones forming columns and beams Ashlar is the term when stones are carved into smaller modular elements, they tend to be flat faced. Rubble stone is where stones are used as they are found, not smoothed off, require a li<le bit of skilled labour to sort and place the stone
Bibliography Ching, F. D. K. (2014). Building Construc/on Illustrated (5 ed.). New Jersey: John Wiley & Sons, Inc., Hoboken.