Constructing Environments ENVS10003 Semester 2 2014 A01-Logbook Week 5: Columns, Grids & Wall Systems Studio Report
The section of the Oval Pavilion that was designed to our group is to construct a 1:20 model of the East Portion of Canopy. Since the drawing scale is 1:100 and we have to multiply by 5. Each element before cutting needs to calculate into right scale to ensure the model in in a right proportion. We identified that the structure of this section is supported by a steel frame system with the canopy is held up by the spine truss system. Load paths for both top and bottom beams also considered before we started to build. Our Drawing detail are shown above.
The material we used to build this model is balsa which is hard wood. By considering the nature and characteristics of the steel beams, balsa is working more efficiently in tension and can carry the heavy loads. Also, it is better in resisting buckling than other materials. Both primary vertical and horizontal structures are used when considering the columns and walls. Firstly, we started cutting the balsa in order to create trusses and the central flat truss is the foundation of this model. We decided to attach the beams in parallel that is in rectangular and triangular shapes. Fixed joints are also used in constructing the beams so that it will be more stable and strong. Even though it is not fully completed but we did try to produce it in 3D form for a better representation of the canopy. For comparison, other groups are all really successful in 3D representation especially with the use of primary and secondary members. Also, right scales and proportions can also be seen.
As the photo shown above, the use of fixed joints is indicated by the sketch and photos. Â
Learning Loop Columns: There are two different types of columns, short and long columns. For short columns, they have shorter length and thicker cross sections. The ration should be less than 12:1 when considering the effective cross sectional area (dimensions). They also will be shorter when under compression and may fail by crushing. For long columns, the ratio of the effective cross sectional area (dimensions) is higher than 12:1. It is more unstable and will fail by buckling.
The buckling direction is determined by the cross section shape and the way it buckled is determined by the length and the fixed method of the columns.
Figure 1: long Columns Figure 2: Short Columns Concrete Frames: It is a grid of columns and concrete beams connecting columns and is commonly used in large scales such as the city high-rise buildings.
Figure 3: Concrete Frame Structure Steel Frames and Timber Frames: Steel frames are grids of steel columns connected to steel girders and beams. It is mainly used in industrial buildings.
Timber frames are grids of timber posts or poles connected to timber beams. Also, it is mainly used in sloping site. Load Bearing Walls: Many new buildings are constructed with precast concrete walls. They support for the roofs and floor slabs. For the reinforcement, they built from core filled hollow concrete block and the use of special concrete blocks with filled concrete can created bonded beams.
Figure 4: Load Bearing Walls
Glossary • LVL: Laminated Veneer Lumber • Glulam: Glue Laminated Timber • MDF: Medium Density Fibreboard • CLT: Cross Laminated Timber • Stud& Stud Walls: to prevent the long thin members from buckling. Stud is mainly 2”*4”. It may be the timber, steel or other composite materials.
• Lintel: It is a horizontal supporting member can be used in doors and windows. By installing it above an opening in order to carry the weight of the wall. • Buckling: it is the load when bending since the load is too much.
References: Ching, F. (2008). Building Construction Illustrated. NJ, Hoboken, John Wiley& Sons, Inc. Concrete Frame Structures, Understand Building Construction. (2014). Retrieved from http://www.understandconstruction.com/uploads/ 1/7/0/2/17029032/9886678_orig.jpg Intermediate Columns, Aussie Made CNC Beamline. (2014). Retrieved from http://www.efunda.com/formulae/solid_mechanics/columns/images/ CompressionMember_Intermediate.gif Renovation Advice From Professors, The Renovators of Canada. (2014). Retrieved from http://trocanada.com/wp-content/uploads/2014/07/ load_bearing_wall1332804855113.gif