Coursework guideline
Tips for the coursework (numbered according to the brief deliverables):
- (i) More than one load combination will be necessary, to derive maximum design moments at beam spans and supports. (ii) Do not forget to calculate beff of beams for the analysis. Assume that l0 is the whole length of each beam, effectively beff only for the span. (iii) Consider for simplicity, that each beam of your frame is loaded with half the load of each adjacent slab (no need to consider triangles or trapezia). (iv) Remove the cantilever slab of the walkway and apply equivalent vertical load and bending moment at the corresponding joint.
- (i) The column is to be designed in biaxial bending following the method presented during the lectures and the tutorial using biaxial bending diagrams; do not follow other methods (designing in uniaxial bending assuming an increased bending moment etc.). You will calculate the moment in one direction from your analysis; assume that the other one is 50% of the former (Mz = 0.5×My). (ii) Do not forget to check for 2nd-order effects (slenderness of the column). (iii) Do not forget to calculate anchorage lengths for your reinforcement and show them on your drawings.
- (i) No need to reiterate (i.e. repeat the analysis of the frame and design of the beam and column), if you have to change the prestressed beam section. It has no significant effect, anyway, as long as your calculations are correct. (ii) You have to provide an indicative sketch with the duct and the tendon (including the selected strands), after you design your beam.
(iii) If the actual losses are more than 15% higher than what has been assumed in 3.1, the stress verification and possibly the selection of tendon will have to be performed again, because there can be significant changes in the stresses (assumed losses are 10%, so you have to do it, if your actual ones are > 11.5%)
