(Solved): B3. In a construction project of a footbridge, a timber soffit form was desig ...

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B3. In a construction project of a footbridge, a timber soffit form was designed for casting a $$250\mathrm{mm}$$ thick concrete deck slab of $$4.8\mathrm{m}$$ by $$15.0\mathrm{m}$$ on plan. The plywood sheeting is supported by rows of secondary timber bearers $$(4.8\mathrm{m}$$ in length) spaced at $$500\mathrm{mm}$$ centre to centre (c/c), which rest on 4 rows of primary timber bearers ( $$15.0\mathrm{m}$$ in length) spaced at $$1600\mathrm{mm}\mathrm{c}/\mathrm{c}$$. The latter are in turn supported by vertical props spaced at $$3000\mathrm{mm}\mathrm{c}/\mathrm{c}$$. Assume the following design and formwork material information will be used. (a) Check the adequacy of the given spacing of all formwork components. (18 marks) (b) If the layout is not satisfactory, suggest alternative measure(s) to make good the deficiency. (4 marks) (c) Hence, find the new prop load based on layout in (b). (3 marks) Continuous Beam for more than 3 spans Max. Bending Moment $$=0.107?L^2$$ Max. Shear $$=0.607?L$$ Max. Deflection $$=\frac{0.00632?L^4}{EI}$$ 3-span Continuous Beam Max. Bending Moment $$=0.100?L^2$$ Max. Shear $$=0.600?L$$ Max. Deflection $$=\frac{0.00677?L^4}{EI}$$ Max. Support Reaction $$=1.1?L$$ Single-span Simply Supported Beam (Symmetrically loaded and for L close to $$\mathrm{X}$$ ) : Max. Bending Moment $$=\frac{1}{8}?L^2$$ Max. Shear $$=0.5?L$$ Max. Deflection $$??\frac{5?L^4}{384EI}$$ Where $$?=$$ Uniformly Distributed Load $$\mathrm{L}=$$ Span $$X=$$ Loaded Length $$EI=$$ Stiffness of Beam