Continued overleaf Page 1 of 4 University of Glasgow ADVANCED STEEL AND CONCRETE DESIGN 4 (ENG4124) Degrees of MEng, BEng, MSc and BSc in Engineering Monday 14th December 2020 Start time: 09:15 (GMT) for 4 hours This exam should take you: 2 hours to complete However, you have a 4-hour window to download/complete/upload your submission Attempt ANY FOUR questions. Total 100 marks The numbers in square brackets in the right-hand margin indicate the marks allotted to the part of the question against which the mark is shown. These marks are for guidance only. A calculator may be used. Show intermediate steps in calculations. Candidates must use their OWN copies of Eurocode Extracts & Data Sheets Continued overleaf Page 2 of 4 Q1 University of Glasgow is planning on building a new multi-storey building consisting of laterally-rigid steel frames of five 4 m storeys and three 6 m bays to accommodate new research facilities. The rigid frames will be pinned and braced together in the longitudinal direction. You are being asked to calculate the approximate distribution of forces in the frame by using a relevant simplified hand analysis model that will reveal the overall combined axial load and bending moment values. The results should also include the maximum design forces in the (i) beams, (ii) inner columns and (iii) outer columns. To perform this analysis, you can take the un-factored vertical frame loads as 20 kN/m for the DL and 28 kN/m for the LL; and 30 kN (at each floor) and 15 kN (at the roof) for the horizontal WL. The calculation should include an assumption of maximum loading simultaneously throughout the entire structure. You only need to consider the EC0 vertical and lateral load combination of 1.35DL + 1.05LL + 1.5 W during this analysis. [25] Q2 University of Glasgow has received funds to renovate the Rankine Building. As a part of this renovation, you are being asked to evaluate an existing straight-wire pre- tensioned concrete beam that has a width of 0.4 m and depth of 0.8 m. The beam, which spans 12 m is simply supported and is made of C50/60 concrete. On top of its own self-weight, the beam carries a SLS super-imposed dead load from slabs and finishes of 10 kN/m. The original design of the beam was for a pre-stress force of P = 1600 kN at an eccentricity e = +180 mm. The losses (k) were assumed to be 0.8. (a) Calculate the maximum imposed SLS live load that the beam could carry by using the pre-stressed concrete design equations. As a part of this approach, you are being asked to ensure that the in-service surface stresses do not exceed fs,c = 30 N/mm2 and fs,t = -2 N/mm 2. [20] (b) Calculate and comment on the in-service stresses at the end supports of the beam for this same live load condition. [5] Continued overleaf Page 3 of 4 Q3 A new commercial building is being planned as a part of the Glasgow’s City Development Plan. This building will incorporate a composite steel and concrete beam system which spans 13.8 m simply supported. The beams will be S275 610x178x82 at 4 m centre, whereas the slab will be made of C25/30 concrete with a thickness of 130 mm. (a) Calculate the ULS moment of resistance of this composite section. [15] (b) Determine the capacity of 22 mm diameter and 450 N/mm2 UTS shear studs at ULS. Also show your intended layout on a sketch. [5] (c) Comment on the expected adjustment in the number and spacing of studs if the stud diameter was changed from 22 mm to 16 mm. [5] Q4 You are hired as one of the structural engineers working on an extensive campus renovation project for Glasgow. As a part of this project, one of the buildings will involve the use of a long spanning composite steel and concrete beam, which will span 10 m simply supported. The beam will include S275 grade steel with 457x191x106 UBs at 4 m centres. The concrete slab is 120 mm thick and is made up of C25/30 concrete. (a) You are being asked to calculate the maximum in-service deflection of this composite section by considering the self-weight of the slab, as well as the characteristic superimposed dead loads of 2 kN/m2 and live loads of 4 kN/m2. As a part of this calculation, assume un-propped construction and consider all load as permanent long-term. [20] (b) Briefly discuss some of the advantages and disadvantages of propped construction in composite construction. Explain some of the key reasons some contractors may prefer to use un-propped construction. [5] End of question paper Page 4 of 4 Q5 Laterally-rigid steel frames that are pinned and braced together longitudinally are being used in the design of a new office building in Glasgow city centre. The roof and floor beams involve the use of 457x191x133 UB, whereas the inner and outer columns are made of 254x254x167 UC. The maximum factored design combination loads at the junction of the critical beam with the inner column are noted as: (i) 330 kN shear force, (ii) 350 kNm bending moment and (iii) 30 kN axial force. (a) Considering these given loads and section properties, you are asked to provide the preliminary design for the welds, bolts and plate of an extended end-plate connection. [20] (b) How is the prying action taken into account in the normal routine design of an extended end-plate according to BS 5950 [5]
