CIV4508 Structural Design II: Assignment 3-2017 1 School of Civil Engineering and Surveying University of Southern Queensland CIV4508 STRUCTURAL DESIGN II ASSIGNMENT 3 Weighting: 20% (200 marks out of 1000) Due date: 22 May 2017 STEEL BUILDING DESIGN PROJECT 1. PROJECT EXTENT AND ASSESSMENT Design the main structural elements as listed below for the new building constructed at Brisbane, Queensland, shown on the attached drawings. All elements to be designed are between Grids 1 to 9 and A to C inclusive, at the roof level (refer Figure 1) and columns to the second floor. The Plant Room will not be designed directly in this project. 2. BUILDING CONSTRUCTION 2.1 Walls: Exterior walls are lightweight framing with glazing or compressed sheet cladding in part, other parts are blockwork. Interior walls are lightweight (probably steel stud) framing. 2.2 Roof: Metal sheeting on steel purlins with suspended ceiling, insulation and airconditioning ducts. 2.3 Floors: Reinforced and prestressed concrete off-form floor slab. 3. CODES Loads AS/NZS 1170 Structural Design Actions Part 0: General Principles Part 1: Permanent, imposed and other actions Part 2: Wind actions Design AS 4100: Steel Structures 4. DESIGN METHOD Manual calculations will be used most in this project. Computer package Strand 7 can be used to determine the deflection, Shear Force and Bending Moment Diagram for roof beam RB6 only. Design Capacity Tables may be used as a check of your design but not for the original calculations. In practice, both design capacity tables and computer packages could be used for the final design, but until you have enough experience to understand the limitations of Design Capacity Tables and/or the results of the computer design and judge whether they are realistic, it is best to design manually and check with the other. 5. ADDITIONAL DESIGN INFORMATION 5.1 Wind Loads determination (60 marks)CIV4508 Structural Design II: Assignment 3-2017 2 The building (Figure 2) is located at 192 Bowhill Road, Willawong, Brisbane (please use google map as reference). Assume no shielding, Ms =1.0. Only consider the Westerly and Northerly wind directions. Determine the followings:  Design wind speed and pressure  Design pressures and Cfig for external surfaces: windward, leeward, sidewalls and roof, assuming Ka = 1,  = 5  Design pressures and Cfig for internal surfaces which may give the worst uplifted case for the roof  Determine the worst uplifted case for the roof 5.2 Purlin Design (20 marks) The roof sheeting will be fixed to steel purlins running along the length of the building (eastwest). Purlins will be attached to the top flange of the roof beams (RB1 and RB6 generally) and hence provide lateral restraint to the top flange of these beams.  Select purlin spacing to suit sheeting and geometry  Determine design loads and select purlin from tables 5.3 Roof Beams (70 Marks) Roof beams are usually Universal Beam sections. Roof Beam RB1 will be simply supported at columns on grids B and C (Figure 1). Roof Beam RB6 cantilevers over the top of columns on Grid A and is simply supported at columns on Grid B. RB6 supports the edge Fascia Truss FT1 (Figures 3 and 4). The fascia truss is simply supported at each end, being connected via a web cleat connection to RB6. Treat this fascia truss as a point load (material density = 4.6kg/m2). Ignore the effect of RB3, RB9 and RB14. 3a). Design Roof Beam RB1 on Grid 7 (Figure 1), consisting of (30 marks):  determine design loads for strength & serviceability load combinations  determine both positive and negative bending moment diagram for strength design  serviceability design (check deflection)  strength design:  section moment capacity strength design  member moment capacity (incl. effective lengths) for worst up and down load combinations, for positive and negative moments. 3b). Design Roof Beam RB6 design on Grid 7 (Figure 1), consisting of (40 marks):  determine design loads for strength & serviceability load combinations  determine both positive and negative bending moment diagram for strength design  serviceability design (check deflection)  strength design:  section moment capacity strength design  member moment capacity for worst up and down load combinations, for positive and negative moments.CIV4508 Structural Design II: Assignment 3-2017 3 5.4 Columns Design (50 marks) Columns on the intersections of Grids A and B with Grid 7 will be constructed from Universal beam sections. Columns between Grids 3 to 6 will support additional load from the Plant Room above but will not be designed in this project. The internal walls at Level 1 will be nonload bearing and will provide no buckling restraint under axial loads for any columns. When determine moment for this column, please consider the following points: You should use the code specified minimum eccentricities – see Clause 4.3.4 in steel code, second paragraph. The type of connection that will be used in this case (and in the vast majority of cases) is a web cleat connection. For this type of connection you need to assume that the reaction is transferred through the bolt holes and the code requires you to assume that this is located 100 mm past the face of the column (or at the point of bearing, namely the distance to the bolt holes, but for smallish beams like these this will be less than 100 mm so 100 will govern). So the total eccentricity you need to design for is 100 mm + half the depth of the column. Column design, 1C17 at grid reference B7, consisting of:  determine axial loads and bending moments for both positive and negative directions.  Strength design – tension (uplift)  strength design - compression  strength design – bending strength  design for combined actions 6. MARKING SCHEME Item Allocated mark Estimated Completion Date Wind load determination, consisting of:  Design wind speed and pressure (only consider the Westerly and Northerly wind directions)  Design pressures and Cfig for external surfaces, assuming Ka = 1,  = 5  Design pressures and Cfig for internal surfaces  Determine the worst uplifted case 60 15 20 5 20 5 May Purlin design  Select purlin spacing to suit sheeting and geometry  Determine design loads and select purlin from tables 20 10 10 9 May Roof Beam RB1 design on Grid 7, consisting of:  determine design loads & BM’s for strength & serviceability  serviceability design  strength design - section moment capacity  strength and stability design - member moment capacity (incl. effective lengths) for worst up and down load combinations, for positive and negative moments (assume fly bracing was used for purlin) 30 5 5 5 15 12 May Roof Beam RB6 design on Grid 7, consisting of:  determine design loads & BM’s for strength & serviceability  serviceability design 40 10 10 17 MayCIV4508 Structural Design II: Assignment 3-2017 4  strength design - section moment capacity  strength and stability design - member moment capacity for worst up and down load combinations, for positive and negative moments (assume fly bracing was used for purlin) 5 15 Column design, 1C17 at grid reference B7, consisting of:  determine axial loads and bending moments strength  design – tension (uplift)  strength and stability design - compression  strength and stability design – bending  strength and stability design - combined actions 50 15 5 5 10 15 21 May Total for final submission 200