EGB376-Steel Design
Assignment
Figure 1 shows the steel structural system for the top floor in a car park building in Brisbane. Currently there is a proposal to use the same steel structural system in another car park to be built later this year. M & M Structural Engineers responsible for this new project are considering using the same steel beam and column sections. Hence there is a need to verify the structural adequacy of this steel structural system for the new car park building. Attached project brief and figures provide the details of the steel structural system.
Figure 1: Steel Structural System
The main beam (1200WB342) shown in Figures 1 and 2 can be considered to have a span of 15 m with simply supported conditions at the two ends. The secondary beams (530UB82.0) that support the floor deck have a span of 10 m and are spaced at 5 m as shown in the figure. These secondary beams can be considered to be simply supported at the ends. The columns of 4.5 m height supporting the main beams are made of 400WC270. The main beams are bolted to the end cap plates that are welded to the columns at the top. The columns can be assumed to have pinned bases. Figure 2 provides a schematic diagram showing the details of the steel structural system. Secondary beam to main beam and main beam to column connection details are shown in Figure 3. For the new steel structural system, it is proposed that a smaller UB section is used for the secondary beams located near the columns.
Figure 2: Steel structural system (side view)
Figure 3: Connection detail
The design actions for the strength limit state of the car park building were calculated using the Australian action codes. They can be considered as follows.
1.The permanent action due to self-weight of floor deck is estimated as 2.5 kPa including the self-weight of the steel members.
2.The imposed action on the floor shown in Figure 1 can be taken as 4.5 kPa
3.The wind action can be taken as 4 kPa uplift on the deck.
4.The serviceability design wind action is 40% of that given for the strength limit state. However, assume that serviceability deflections can be considered to be within their limits.
Your group (four members) has been asked to investigate the structural adequacy of this steel structural system, and to recommend suitable structural improvements if found inadequate. If you find it to be over-designed, suggest improvements to the structural system.
Your tasks are as follows:
1) Investigate the steel structural system (beams, columns and connections) shown in Figure 1 based on the photographs supplied, develop a good understanding of the load path (wind and gravity loads), identify the main load carrying members including their connections and group them appropriately.
2) Undertake the load evaluation for the main load carrying steel members in the steel building (secondary and main beams and columns), conduct structural analysis, determine the design action effects, and undertake their designs including connections (only the connection between secondary and main beams assuming only shear action) using AS 4100. If they are found to be unsafe or over-designed, recommend suitable improvements based on revised section sizes.
3) Write a report that includes the details of the above including design calculations and design sketches
