[ \fracA_sws = \fracT_Ed2 A_k f_ywd \cot\theta = \frac45e62 \times 105,306 \times (500/1.15) \times 2.5 ] ( f_ywd = 435 \text MPa ) [ \fracA_sws = \frac45e62 \times 105,306 \times 435 \times 2.5 = \frac45e6228.9e6 \approx 0.197 \text mm^2/\textmm ] For 2 legs (torsion acts on all walls) → per leg: ( A_sw/s = 0.098 ) Use ( \varnothing 10 ) (78.5 mm²) → spacing ( s = 78.5 / 0.098 \approx 800 \text mm ) – too large; torsion rarely governs spacing; shear likely demands tighter.
), EN 1992-2 enforces a combined interaction limit for concrete struts: worked examples to eurocode 2 volume 2
heff=min[2.5(h−d),h−x3,h2]h sub e f f end-sub equals min of open bracket 2.5 open paren h minus d close paren comma the fraction with numerator h minus x and denominator 3 end-fraction comma h over 2 end-fraction close bracket Assuming neutral axis depth [ \fracA_sws = \fracT_Ed2 A_k f_ywd \cot\theta =