(Solved): The architectural arrangement for a grandstand has necessitated the provision of a section of reinf ...

The architectural arrangement for a grandstand has necessitated the provision of a section of reinforced concrete floor that cantilevers 'a+e' meters ) past the centre of a supporting masonry wall, as depicted below. The support width is 200 mm . The parallel beams 450 mm -deep and

wide at

centres, cast integrally with a 120 mm -thick slab. One of these T-b near its outer end, a substantial load from a column that forms part of the support system for the grandstand. As shown on the diagram, this ultimate load (i.e. already factored up) is

. There will be no significant live loading on this section of the floor at the same time as this

design force is acting. Consider

and cover

. a) Allowing for the self-weight of the floor (assume

for concrete), determine the design ultimate bending moment in the beam supporting the

load (take this as occurring at the centre-line of the supporting wall) and go on to determine the number of N32 bars required to provide this flexural strength (yield strength

). The spacing achieved between the bars should be checked, but

need not be checked. It will be high, but sufficient compression bars will be provided to maintain adequate ductility. Assume the shear ligatures will comprise N10 bars. For the purpose of calculating d, take the slab rebars as N16. b) Assuming a constant shear ligature arrangement will be used over the entire length of the cantilever beam, determine a suitable spacing of N 10 (yield strength

MPa) shear stirrups for this beam. Explain at which point the maximum shear force is considered based on which clause of the standard. c) Assuming all of the tension bars selected in Part a) extend right through to the left-hand end of the beam, stopping at the required cover from the end, check whether the required development length is achieved for these bars at the critical section for B.M. (i.e. at the centre- line of the supporting wall). Regardless of what you find, if it was found that the development length was not provided by this arrangement, what would be an appropriate course of action to solve this problem?