07-Str-A2, December 2018: worked solutions

Paper format. National Examinations, December 2018 — 07-Str-A2 Elementary Structural Design. Three hours, CLOSED BOOK (handbooks and textbooks permitted). Seven questions in three parts: Part A (A1–A3, steel to CSA S16), Part B (B1–B3, reinforced concrete to CSA A23.3), Part C (C1, timber to CSA O86). A candidate submits five solutions — two from Part A, two from Part B and the one question in Part C — all of equal value. All seven questions are solved below, because this set is a study resource rather than an exam script. Page 1 states that all loads shown are unfactored, so every load case is factored here (1.5 on the specified live/imposed loads, 1.25 on self weight) before any resistance is compared against it.

Reference texts.

CSA S16:19, Design of Steel Structures — and CISC, Handbook of Steel Construction, 11th ed. (section tables, Table 2 class limits, Clause 13.8 interaction, Clause 13.5 effective widths).
CSA A23.3:19, Design of Concrete Structures — and Cement Association of Canada, Concrete Design Handbook, 4th ed.
CSA O86:19, Engineering Design in Wood — and Canadian Wood Council, Wood Design Manual (glulam selection tables).
Kulak & Grondin, Limit States Design in Structural Steel, 11th ed., Chs. 4, 5, 8, 9.
MacGregor & Bartlett, Reinforced Concrete: Mechanics and Design (Canadian edition), Chs. 4, 6, 11.
National Building Code of Canada, Table 4.1.3.2 (load combinations).

Check — assumptions declared under Note 1 of the paper. (i) In A2 the single dimension h is the wall thickness of the whole fabricated panel (top plate and both stems), which is how the figure dimensions it. (ii) In A3 the bolted joint at the column is a simple (shear-only) connection and the steel tie is a two-force member, which is what makes the stub beam determinate. (iii) In B1/B3 the left column A–B is taken as 6 m high, level with the roller at D, as Figure B1 draws it; the beam self weight is included, the column self weight is not (it does not change any design action at C). (iv) In B2 and C1 the beam is drawn with a tapered soffit, but part (a) asks for a uniform cross-section, so a prismatic member is designed.

07-Str-A2: December 2018