QA1. A trial cross–section of a ribbed slab floor is shown in Fig. QA1. The floor is constructed of
reinforced concrete, permanent 300 mm x 300 mm x 250 mm structural-type hollow clay
blocks, of wall thickness 20 mm, and a 12 mm-plaster ceiling. The floor is continuous over
several equal spans of 6.5 m, but may be treated as single span simply supported for analysis
and fire resistance purposes. Check the effectiveness of the trial section; design the floor for
flexure; check if deflection criteria are satisfied. Omit calculations for shear and anchorage.
Take the effective depth, d = 260 mm.
Characteristic loads: self weight
Grade 460 Type 2 deformed 20 mm diam. bars
(Attached: BS 8110/1 Cl 3.6; BS 8110/2 Cl 4.2)
QA2. The stiffened steel plate girder of Fig. QA2 is fully restrained throughout its length. Using
grade S275 steel and the requirements of BS 5950, check the moment capacity of the section
(ignore the web). Assuming the end panels are the most critical, check the shear capacity of
the girder. No checks are required on the end posts or stiffeners.
The design loading for the ultimate limit state is given in the Fig., with the point loads being
transferred via UBs.
QA3. Fig. QA3 gives details of the trial section for a fin wall of a warehouse building. The wall is
8 m high from d.p.c to the supported flat roof level, and the fins project on the external face.
Check the flexural adequacy of the trial section under a characteristic wind pressure of
The wall is constructed from 15 N, 215 mm x 102.5 mm x 65 mm clay bricks, having a water
absorption of 7 to 12%. The bricks are set in a grade (iii) mortar with special/normal control
I = 157 x 10-4 m4
(Attached information:- BS 5628:Part1, Fig. 10)
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