Pad footing capacity
Bearing, punching, one-way shear and flexure of a concrete pad footing to CSA A23.3. Check a reinforced concrete pad footing under a column carrying axial load and moments about both axes. Soil bearing is gross, with the footing's own weight and the soil over it, linear at service and on Meyerhof's effective area at the factored level, and the resultant must stay inside the kern. The column bears on the footing concrete and on its own. Punching includes the unbalanced moment transfer, and one-way shear and flexure integrate the linear pressure in both directions. Minimum steel, neutral axis depth, bar spacing and development length of the bottom bars are checked, and the band steel of a rectangular footing and the minimum dowel area are reported.
Given
Type or drag any dotted value, everything below recomputes. Hover a symbol to trace it.
Resume your last case ()? Load it
This printed copy omits the derivation. The full report, with every step, is the PDF at https://calc.struct.work/calc/pad-footing-capacity.pdf.
Checks
| Check | D/C | Utilisation | Result |
|---|---|---|---|
| Column fits x\(\htmlClass{sym-b_c}{b_{c}} < \htmlClass{sym-B_f}{B_{f}} \quad \Rightarrow \quad \htmlClass{sym-b_c}{450\ \mathrm{mm}} < \htmlClass{sym-B_f}{3000\ \mathrm{mm}}\) | 0.15 | PASS | |
| Column fits y\(\htmlClass{sym-h_c}{h_{c}} < \htmlClass{sym-L_f}{L_{f}} \quad \Rightarrow \quad \htmlClass{sym-h_c}{900\ \mathrm{mm}} < \htmlClass{sym-L_f}{3600\ \mathrm{mm}}\) | 0.25 | PASS | |
| Bearing service\(\htmlClass{sym-q_s}{q_{s}} \leq \htmlClass{sym-q_a}{q_{a}} \quad \Rightarrow \quad \htmlClass{sym-q_s}{698.7\ \mathrm{kPa}} \leq \htmlClass{sym-q_a}{950\ \mathrm{kPa}}\) | 0.74 | PASS | |
| Contact service\(\htmlClass{sym-q_s_min}{q_{s,\mathrm{min}}} \geq 0\ \mathrm{Pa} \quad \Rightarrow \quad \htmlClass{sym-q_s_min}{464.2\ \mathrm{kPa}} \geq 0\ \mathrm{Pa}\) | 0.00 | PASS | |
| Bearing factored\(\htmlClass{sym-q_ue}{q_{\mathrm{ue}}} \leq \htmlClass{sym-q_ult}{q_{\mathrm{ult}}} \quad \Rightarrow \quad \htmlClass{sym-q_ue}{811.1\ \mathrm{kPa}} \leq \htmlClass{sym-q_ult}{1400\ \mathrm{kPa}}\) | 0.58 | PASS | |
| Contact factored\(\htmlClass{sym-q_u_min}{q_{u,\mathrm{min}}} \geq 0\ \mathrm{Pa} \quad \Rightarrow \quad \htmlClass{sym-q_u_min}{547.1\ \mathrm{kPa}} \geq 0\ \mathrm{Pa}\) | 0.00 | PASS | |
| Concrete bearing\(\htmlClass{sym-P_u}{P_{u}} \leq \htmlClass{sym-B_r}{B_{r}} \quad \Rightarrow \quad \htmlClass{sym-P_u}{7.575\ \mathrm{MN}} \leq \htmlClass{sym-B_r}{15.66\ \mathrm{MN}}\) | 0.48 | PASS | |
| Bearing column\(\htmlClass{sym-P_u}{P_{u}} \leq \htmlClass{sym-B_rc}{B_{\mathrm{rc}}} \quad \Rightarrow \quad \htmlClass{sym-P_u}{7.575\ \mathrm{MN}} \leq \htmlClass{sym-B_rc}{7.832\ \mathrm{MN}}\) | 0.97 | PASS | |
| Punching adequate\(\htmlClass{sym-v_u}{v_{u}} \leq \htmlClass{sym-v_c}{v_{c}} \quad \Rightarrow \quad \htmlClass{sym-v_u}{522.8\ \mathrm{kPa}} \leq \htmlClass{sym-v_c}{826\ \mathrm{kPa}}\) | 0.63 | PASS | |
| Shear x adequate\(\htmlClass{sym-V_ux}{V_{\mathrm{ux}}} \leq \htmlClass{sym-V_cx}{V_{\mathrm{cx}}} \quad \Rightarrow \quad \htmlClass{sym-V_ux}{301.1\ \mathrm{kN}} \leq \htmlClass{sym-V_cx}{3.401\ \mathrm{MN}}\) | 0.09 | PASS | |
| Shear y adequate\(\htmlClass{sym-V_uy}{V_{\mathrm{uy}}} \leq \htmlClass{sym-V_cy}{V_{\mathrm{cy}}} \quad \Rightarrow \quad \htmlClass{sym-V_uy}{408.4\ \mathrm{kN}} \leq \htmlClass{sym-V_cy}{2.834\ \mathrm{MN}}\) | 0.14 | PASS | |
| Flexure x adequate\(\htmlClass{sym-M_fx}{M_{\mathrm{fx}}} \leq \htmlClass{sym-M_rx}{M_{\mathrm{rx}}} \quad \Rightarrow \quad \htmlClass{sym-M_fx}{2.256\ \mathrm{MN} \cdot \mathrm{m}} \leq \htmlClass{sym-M_rx}{4.588\ \mathrm{MN} \cdot \mathrm{m}}\) | 0.49 | PASS | |
| Flexure y adequate\(\htmlClass{sym-M_fy}{M_{\mathrm{fy}}} \leq \htmlClass{sym-M_ry}{M_{\mathrm{ry}}} \quad \Rightarrow \quad \htmlClass{sym-M_fy}{2.034\ \mathrm{MN} \cdot \mathrm{m}} \leq \htmlClass{sym-M_ry}{3.853\ \mathrm{MN} \cdot \mathrm{m}}\) | 0.53 | PASS | |
| Minimum steel x\(\htmlClass{sym-A_sx}{A_{\mathrm{sx}}} \geq \htmlClass{sym-A_sx_min}{A_{\mathrm{sx},\mathrm{min}}} \quad \Rightarrow \quad \htmlClass{sym-A_sx}{10500\ \mathrm{mm}^{2}} \geq \htmlClass{sym-A_sx_min}{10080\ \mathrm{mm}^{2}}\) | 0.96 | PASS | |
| Minimum steel y\(\htmlClass{sym-A_sy}{A_{\mathrm{sy}}} \geq \htmlClass{sym-A_sy_min}{A_{\mathrm{sy},\mathrm{min}}} \quad \Rightarrow \quad \htmlClass{sym-A_sy}{9000\ \mathrm{mm}^{2}} \geq \htmlClass{sym-A_sy_min}{8400\ \mathrm{mm}^{2}}\) | 0.93 | PASS | |
| Steel yields x\(\frac{\htmlClass{sym-c_x}{c_{x}}}{\htmlClass{sym-d_x}{d_{x}}} \leq \frac{700\ \mathrm{MPa}}{700\ \mathrm{MPa} + \htmlClass{sym-f_y}{f_{y}}} \quad \Rightarrow \quad \frac{\htmlClass{sym-c_x}{61.94\ \mathrm{mm}}}{\htmlClass{sym-d_x}{1.312\ \mathrm{m}}} \leq \frac{700\ \mathrm{MPa}}{700\ \mathrm{MPa} + \htmlClass{sym-f_y}{400\ \mathrm{MPa}}}\) | 0.07 | PASS | |
| Steel yields y\(\frac{\htmlClass{sym-c_y}{c_{y}}}{\htmlClass{sym-d_y}{d_{y}}} \leq \frac{700\ \mathrm{MPa}}{700\ \mathrm{MPa} + \htmlClass{sym-f_y}{f_{y}}} \quad \Rightarrow \quad \frac{\htmlClass{sym-c_y}{63.7\ \mathrm{mm}}}{\htmlClass{sym-d_y}{1.287\ \mathrm{m}}} \leq \frac{700\ \mathrm{MPa}}{700\ \mathrm{MPa} + \htmlClass{sym-f_y}{400\ \mathrm{MPa}}}\) | 0.08 | PASS | |
| Spacing x\(\htmlClass{sym-s_x}{s_{x}} \leq \htmlClass{sym-s_max}{s_{\mathrm{max}}} \quad \Rightarrow \quad \htmlClass{sym-s_x}{172.5\ \mathrm{mm}} \leq \htmlClass{sym-s_max}{500\ \mathrm{mm}}\) | 0.34 | PASS | |
| Spacing y\(\htmlClass{sym-s_y}{s_{y}} \leq \htmlClass{sym-s_max}{s_{\mathrm{max}}} \quad \Rightarrow \quad \htmlClass{sym-s_y}{167.6\ \mathrm{mm}} \leq \htmlClass{sym-s_max}{500\ \mathrm{mm}}\) | 0.34 | PASS | |
| Development x\(\htmlClass{sym-l_dx}{l_{\mathrm{dx}}} \leq \htmlClass{sym-l_ax}{l_{\mathrm{ax}}} \quad \Rightarrow \quad \htmlClass{sym-l_dx}{766.7\ \mathrm{mm}} \leq \htmlClass{sym-l_ax}{1.2\ \mathrm{m}}\) | 0.64 | PASS | |
| Development y\(\htmlClass{sym-l_dy}{l_{\mathrm{dy}}} \leq \htmlClass{sym-l_ay}{l_{\mathrm{ay}}} \quad \Rightarrow \quad \htmlClass{sym-l_dy}{766.7\ \mathrm{mm}} \leq \htmlClass{sym-l_ay}{1.275\ \mathrm{m}}\) | 0.60 | PASS |
Results
| Quantity | Description | Value | Unit |
|---|---|---|---|
| \(\htmlClass{sym-q_s}{q_{s}}\) | Service bearing pressure, gross, worst corner | 698.7 | \(\mathrm{kPa}\) |
| \(\htmlClass{sym-q_ue}{q_{\mathrm{ue}}}\) | Factored bearing pressure, gross, on the effective area | 811.1 | \(\mathrm{kPa}\) |
| \(\htmlClass{sym-q_u}{q_{u}}\) | Factored net pressure, worst corner | 855.7 | \(\mathrm{kPa}\) |
| \(\htmlClass{sym-v_u}{v_{u}}\) | Factored punching shear stress | 522.8 | \(\mathrm{kPa}\) |
| \(\htmlClass{sym-v_c}{v_{c}}\) | Factored punching shear resistance | 826 | \(\mathrm{kPa}\) |
| \(\htmlClass{sym-V_cx}{V_{\mathrm{cx}}}\) | Factored one-way shear resistance, x | 3.401 | \(\mathrm{MN}\) |
| \(\htmlClass{sym-V_cy}{V_{\mathrm{cy}}}\) | Factored one-way shear resistance, y | 2.834 | \(\mathrm{MN}\) |
| \(\htmlClass{sym-M_rx}{M_{\mathrm{rx}}}\) | Factored flexural resistance, x | 4.588 | \(\mathrm{MN} \cdot \mathrm{m}\) |
| \(\htmlClass{sym-M_ry}{M_{\mathrm{ry}}}\) | Factored flexural resistance, y | 3.853 | \(\mathrm{MN} \cdot \mathrm{m}\) |
| \(\htmlClass{sym-B_r}{B_{r}}\) | Factored concrete bearing resistance, footing | 15.66 | \(\mathrm{MN}\) |
| \(\htmlClass{sym-B_rc}{B_{\mathrm{rc}}}\) | Factored concrete bearing resistance, column | 7.832governs | \(\mathrm{MN}\) |
| \(\htmlClass{sym-A_dowel}{A_{\mathrm{dowel}}}\) | Minimum dowel area across the interface | 2025 | \(\mathrm{mm}^{2}\) |
| \(\htmlClass{sym-l_dx}{l_{\mathrm{dx}}}\) | Development length, X bars | 766.7 | \(\mathrm{mm}\) |
| \(\htmlClass{sym-l_dy}{l_{\mathrm{dy}}}\) | Development length, Y bars | 766.7 | \(\mathrm{mm}\) |
| \(\htmlClass{sym-A_band}{A_{\mathrm{band}}}\) | Short-direction steel within the central band | 9545 | \(\mathrm{mm}^{2}\) |
| \(\htmlClass{sym-w_band}{w_{\mathrm{band}}}\) | Width of the central band | 3 | \(\mathrm{m}\) |
Derivation
NBCC Table 4.1.3.2.A
\[\begin{aligned} \htmlClass{sym-P_u}{P_{u}} &= \max\left(1.4 \cdot \htmlClass{sym-D}{D}, 1.25 \cdot \htmlClass{sym-D}{D} + 1.5 \cdot \htmlClass{sym-L}{L}\right) \\ &= \max\left(1.4 \cdot \htmlClass{sym-D}{4500\ \mathrm{kN}}, 1.25 \cdot \htmlClass{sym-D}{4500\ \mathrm{kN}} + 1.5 \cdot \htmlClass{sym-L}{1300\ \mathrm{kN}}\right) \\ &= 7.575\ \mathrm{MN} \end{aligned}\]Assumed: each at its own worst combination
Assumed: dead and live moments act in the same sense
CSA A23.3 Cl. 3.2
\[\begin{aligned} \htmlClass{sym-d_v}{d_{v}} &= \max\left(0.9 \cdot \htmlClass{sym-d}{d}, 0.72 \cdot \htmlClass{sym-t_f}{t_{f}}\right) \\ &= \max\left(0.9 \cdot \htmlClass{sym-d}{1.3\ \mathrm{m}}, 0.72 \cdot \htmlClass{sym-t_f}{1400\ \mathrm{mm}}\right) \\ &= 1.17\ \mathrm{m} \end{aligned}\]CSA A23.3 Cl. 11.3.4
\[\begin{aligned} \htmlClass{sym-f_v}{f_{v}} &= \min\left(\sqrt{\htmlClass{sym-f_c}{f_{c}} \cdot 1\ \mathrm{MPa}}, 8\ \mathrm{MPa}\right) \\ &= \min\left(\sqrt{\htmlClass{sym-f_c}{35\ \mathrm{MPa}} \cdot 1\ \mathrm{MPa}}, 8\ \mathrm{MPa}\right) \\ &= 5.916\ \mathrm{MPa} \end{aligned}\]NBCC Table 4.1.3.2.A
\[\begin{aligned} \htmlClass{sym-P_ug}{P_{\mathrm{ug}}} &= \max\left(1.4 \cdot \left(\htmlClass{sym-D}{D} + \htmlClass{sym-W}{W}\right), 1.25 \cdot \left(\htmlClass{sym-D}{D} + \htmlClass{sym-W}{W}\right) + 1.5 \cdot \htmlClass{sym-L}{L}\right) \\ &= \max\left(1.4 \cdot \left(\htmlClass{sym-D}{4500\ \mathrm{kN}} + \htmlClass{sym-W}{479.5\ \mathrm{kN}}\right), 1.25 \cdot \left(\htmlClass{sym-D}{4500\ \mathrm{kN}} + \htmlClass{sym-W}{479.5\ \mathrm{kN}}\right) + 1.5 \cdot \htmlClass{sym-L}{1300\ \mathrm{kN}}\right) \\ &= 8.174\ \mathrm{MN} \end{aligned}\]CSA A23.3 Cl. 10.8.1
\[\begin{aligned} \htmlClass{sym-B_r}{B_{r}} &= 0.85 \cdot \htmlClass{sym-phi_c}{\phi_{c}} \cdot \htmlClass{sym-f_c}{f_{c}} \cdot \htmlClass{sym-A_c}{A_{c}} \cdot \min\left(\sqrt{\frac{\htmlClass{sym-A_2}{A_{2}}}{\htmlClass{sym-A_c}{A_{c}}}}, 2\right) \\ &= 0.85 \cdot \htmlClass{sym-phi_c}{0.65} \cdot \htmlClass{sym-f_c}{35\ \mathrm{MPa}} \cdot \htmlClass{sym-A_c}{405000\ \mathrm{mm}^{2}} \cdot \min\left(\sqrt{\frac{\htmlClass{sym-A_2}{10.8\ \mathrm{m}^{2}}}{\htmlClass{sym-A_c}{405000\ \mathrm{mm}^{2}}}}, 2\right) \\ &= 15.66\ \mathrm{MN} \end{aligned}\]CSA A23.3 Cl. 10.8.1
\[\begin{aligned} \htmlClass{sym-B_rc}{B_{\mathrm{rc}}} &= 0.85 \cdot \htmlClass{sym-phi_c}{\phi_{c}} \cdot \htmlClass{sym-f_cc}{f_{\mathrm{cc}}} \cdot \htmlClass{sym-A_c}{A_{c}} \\ &= 0.85 \cdot \htmlClass{sym-phi_c}{0.65} \cdot \htmlClass{sym-f_cc}{35\ \mathrm{MPa}} \cdot \htmlClass{sym-A_c}{405000\ \mathrm{mm}^{2}} \\ &= 7.832\ \mathrm{MN} \end{aligned}\]CSA A23.3 Cl. 15.9.2
\[\begin{aligned} \htmlClass{sym-A_dowel}{A_{\mathrm{dowel}}} &= \max\left(0.005 \cdot \htmlClass{sym-A_c}{A_{c}}, \frac{\htmlClass{sym-P_u}{P_{u}} - \htmlClass{sym-B_min}{B_{\mathrm{min}}}}{\htmlClass{sym-phi_s}{\phi_{s}} \cdot \htmlClass{sym-f_y}{f_{y}}}\right) \\ &= \max\left(0.005 \cdot \htmlClass{sym-A_c}{405000\ \mathrm{mm}^{2}}, \frac{\htmlClass{sym-P_u}{7.575\ \mathrm{MN}} - \htmlClass{sym-B_min}{7.832\ \mathrm{MN}}}{\htmlClass{sym-phi_s}{0.85} \cdot \htmlClass{sym-f_y}{400\ \mathrm{MPa}}}\right) \\ &= 2025\ \mathrm{mm}^{2} \end{aligned}\]CSA A23.3 Cl. 13.3.3
\[\begin{aligned} \htmlClass{sym-b_o}{b_{o}} &= 2 \cdot \left(\htmlClass{sym-b_1}{b_{1}} + \htmlClass{sym-b_2}{b_{2}}\right) \\ &= 2 \cdot \left(\htmlClass{sym-b_1}{1.75\ \mathrm{m}} + \htmlClass{sym-b_2}{2.2\ \mathrm{m}}\right) \\ &= 7.899\ \mathrm{m} \end{aligned}\]CSA A23.3 Cl. 13.3.5.3
\[\begin{aligned} \htmlClass{sym-gamma_vy}{\gamma_{\mathrm{vy}}} &= 1 - \frac{1}{1 + \frac{2}{3} \cdot \sqrt{\frac{\htmlClass{sym-b_1}{b_{1}}}{\htmlClass{sym-b_2}{b_{2}}}}} \\ &= 1 - \frac{1}{1 + \frac{2}{3} \cdot \sqrt{\frac{\htmlClass{sym-b_1}{1.75\ \mathrm{m}}}{\htmlClass{sym-b_2}{2.2\ \mathrm{m}}}}} \\ &= 0.3729 \end{aligned}\]CSA A23.3 Cl. 13.3.5.5
\[\begin{aligned} \htmlClass{sym-J_y}{J_{y}} &= \frac{\htmlClass{sym-b_1}{b_{1}} \cdot \htmlClass{sym-d}{d}^{3}}{6} + \frac{\htmlClass{sym-d}{d} \cdot \htmlClass{sym-b_1}{b_{1}}^{3}}{6} + \frac{\htmlClass{sym-b_2}{b_{2}} \cdot \htmlClass{sym-d}{d} \cdot \htmlClass{sym-b_1}{b_{1}}^{2}}{2} \\ &= \frac{\htmlClass{sym-b_1}{1.75\ \mathrm{m}} \cdot \left(\htmlClass{sym-d}{1.3\ \mathrm{m}}\right)^{3}}{6} + \frac{\htmlClass{sym-d}{1.3\ \mathrm{m}} \cdot \left(\htmlClass{sym-b_1}{1.75\ \mathrm{m}}\right)^{3}}{6} + \frac{\htmlClass{sym-b_2}{2.2\ \mathrm{m}} \cdot \htmlClass{sym-d}{1.3\ \mathrm{m}} \cdot \left(\htmlClass{sym-b_1}{1.75\ \mathrm{m}}\right)^{2}}{2} \\ &= 6.178\ \mathrm{m}^{4} \end{aligned}\]CSA A23.3 Cl. 13.3.5.3
\[\begin{aligned} \htmlClass{sym-gamma_vx}{\gamma_{\mathrm{vx}}} &= 1 - \frac{1}{1 + \frac{2}{3} \cdot \sqrt{\frac{\htmlClass{sym-b_2}{b_{2}}}{\htmlClass{sym-b_1}{b_{1}}}}} \\ &= 1 - \frac{1}{1 + \frac{2}{3} \cdot \sqrt{\frac{\htmlClass{sym-b_2}{2.2\ \mathrm{m}}}{\htmlClass{sym-b_1}{1.75\ \mathrm{m}}}}} \\ &= 0.4278 \end{aligned}\]CSA A23.3 Cl. 13.3.5.5
\[\begin{aligned} \htmlClass{sym-J_x}{J_{x}} &= \frac{\htmlClass{sym-b_2}{b_{2}} \cdot \htmlClass{sym-d}{d}^{3}}{6} + \frac{\htmlClass{sym-d}{d} \cdot \htmlClass{sym-b_2}{b_{2}}^{3}}{6} + \frac{\htmlClass{sym-b_1}{b_{1}} \cdot \htmlClass{sym-d}{d} \cdot \htmlClass{sym-b_2}{b_{2}}^{2}}{2} \\ &= \frac{\htmlClass{sym-b_2}{2.2\ \mathrm{m}} \cdot \left(\htmlClass{sym-d}{1.3\ \mathrm{m}}\right)^{3}}{6} + \frac{\htmlClass{sym-d}{1.3\ \mathrm{m}} \cdot \left(\htmlClass{sym-b_2}{2.2\ \mathrm{m}}\right)^{3}}{6} + \frac{\htmlClass{sym-b_1}{1.75\ \mathrm{m}} \cdot \htmlClass{sym-d}{1.3\ \mathrm{m}} \cdot \left(\htmlClass{sym-b_2}{2.2\ \mathrm{m}}\right)^{2}}{2} \\ &= 8.614\ \mathrm{m}^{4} \end{aligned}\]CSA A23.3 Cl. 13.3.4.3
\[\begin{aligned} \htmlClass{sym-lambda_s}{\lambda_{s}} &= \min\left(1, \frac{1.3\ \mathrm{m}}{1\ \mathrm{m} + \htmlClass{sym-d}{d}}\right) \\ &= \min\left(1, \frac{1.3\ \mathrm{m}}{1\ \mathrm{m} + \htmlClass{sym-d}{1.3\ \mathrm{m}}}\right) \\ &= 0.5653 \end{aligned}\]CSA A23.3 Cl. 13.3.4.1
\[\begin{aligned} \htmlClass{sym-alpha}{\alpha} &= \min\left(0.19 \cdot \left(1 + \frac{2}{\htmlClass{sym-beta_c}{\beta_{c}}}\right), \frac{4 \cdot \htmlClass{sym-d}{d}}{\htmlClass{sym-b_o}{b_{o}}} + 0.19, 0.38\right) \\ &= \min\left(0.19 \cdot \left(1 + \frac{2}{\htmlClass{sym-beta_c}{2}}\right), \frac{4 \cdot \htmlClass{sym-d}{1.3\ \mathrm{m}}}{\htmlClass{sym-b_o}{7.899\ \mathrm{m}}} + 0.19, 0.38\right) \\ &= 0.38 \end{aligned}\]Branch: \(l_{x} \leq 2 \cdot d_{v}\) held
CSA A23.3 Cl. 11.3.4
\[\begin{aligned} \htmlClass{sym-V_cx}{V_{\mathrm{cx}}} &= \htmlClass{sym-phi_c}{\phi_{c}} \cdot \htmlClass{sym-beta_x}{\beta_{x}} \cdot \htmlClass{sym-f_v}{f_{v}} \cdot \htmlClass{sym-L_f}{L_{f}} \cdot \htmlClass{sym-d_v}{d_{v}} \\ &= \htmlClass{sym-phi_c}{0.65} \cdot \htmlClass{sym-beta_x}{0.21} \cdot \htmlClass{sym-f_v}{5.916\ \mathrm{MPa}} \cdot \htmlClass{sym-L_f}{3600\ \mathrm{mm}} \cdot \htmlClass{sym-d_v}{1.17\ \mathrm{m}} \\ &= 3.401\ \mathrm{MN} \end{aligned}\]Branch: \(l_{y} \leq 2 \cdot d_{v}\) held
CSA A23.3 Cl. 11.3.4
\[\begin{aligned} \htmlClass{sym-V_cy}{V_{\mathrm{cy}}} &= \htmlClass{sym-phi_c}{\phi_{c}} \cdot \htmlClass{sym-beta_y}{\beta_{y}} \cdot \htmlClass{sym-f_v}{f_{v}} \cdot \htmlClass{sym-B_f}{B_{f}} \cdot \htmlClass{sym-d_v}{d_{v}} \\ &= \htmlClass{sym-phi_c}{0.65} \cdot \htmlClass{sym-beta_y}{0.21} \cdot \htmlClass{sym-f_v}{5.916\ \mathrm{MPa}} \cdot \htmlClass{sym-B_f}{3000\ \mathrm{mm}} \cdot \htmlClass{sym-d_v}{1.17\ \mathrm{m}} \\ &= 2.834\ \mathrm{MN} \end{aligned}\]CSA A23.3 Cl. 10.1.7
\[\begin{aligned} \htmlClass{sym-alpha_1}{\alpha_{1}} &= \max\left(0.67, 0.85 - \frac{0.0015 \cdot \htmlClass{sym-f_c}{f_{c}}}{1\ \mathrm{MPa}}\right) \\ &= \max\left(0.67, 0.85 - \frac{0.0015 \cdot \htmlClass{sym-f_c}{35\ \mathrm{MPa}}}{1\ \mathrm{MPa}}\right) \\ &= 0.7975 \end{aligned}\]CSA A23.3 Cl. 10.1.7
\[\begin{aligned} \htmlClass{sym-beta_1}{\beta_{1}} &= \max\left(0.67, 0.97 - \frac{0.0025 \cdot \htmlClass{sym-f_c}{f_{c}}}{1\ \mathrm{MPa}}\right) \\ &= \max\left(0.67, 0.97 - \frac{0.0025 \cdot \htmlClass{sym-f_c}{35\ \mathrm{MPa}}}{1\ \mathrm{MPa}}\right) \\ &= 0.8825 \end{aligned}\]CSA A23.3 Cl. 10.1
\[\begin{aligned} \htmlClass{sym-M_rx}{M_{\mathrm{rx}}} &= \htmlClass{sym-phi_s}{\phi_{s}} \cdot \htmlClass{sym-A_sx}{A_{\mathrm{sx}}} \cdot \htmlClass{sym-f_y}{f_{y}} \cdot \left(\htmlClass{sym-d_x}{d_{x}} - \frac{\htmlClass{sym-a_x}{a_{x}}}{2}\right) \\ &= \htmlClass{sym-phi_s}{0.85} \cdot \htmlClass{sym-A_sx}{10500\ \mathrm{mm}^{2}} \cdot \htmlClass{sym-f_y}{400\ \mathrm{MPa}} \cdot \left(\htmlClass{sym-d_x}{1.312\ \mathrm{m}} - \frac{\htmlClass{sym-a_x}{54.66\ \mathrm{mm}}}{2}\right) \\ &= 4.588\ \mathrm{MN} \cdot \mathrm{m} \end{aligned}\]CSA A23.3 Cl. 10.1
\[\begin{aligned} \htmlClass{sym-M_ry}{M_{\mathrm{ry}}} &= \htmlClass{sym-phi_s}{\phi_{s}} \cdot \htmlClass{sym-A_sy}{A_{\mathrm{sy}}} \cdot \htmlClass{sym-f_y}{f_{y}} \cdot \left(\htmlClass{sym-d_y}{d_{y}} - \frac{\htmlClass{sym-a_y}{a_{y}}}{2}\right) \\ &= \htmlClass{sym-phi_s}{0.85} \cdot \htmlClass{sym-A_sy}{9000\ \mathrm{mm}^{2}} \cdot \htmlClass{sym-f_y}{400\ \mathrm{MPa}} \cdot \left(\htmlClass{sym-d_y}{1.287\ \mathrm{m}} - \frac{\htmlClass{sym-a_y}{56.22\ \mathrm{mm}}}{2}\right) \\ &= 3.853\ \mathrm{MN} \cdot \mathrm{m} \end{aligned}\]CSA A23.3 Cl. 7.8.1
\[\begin{aligned} \htmlClass{sym-A_sx_min}{A_{\mathrm{sx},\mathrm{min}}} &= 0.002 \cdot \htmlClass{sym-t_f}{t_{f}} \cdot \htmlClass{sym-L_f}{L_{f}} \\ &= 0.002 \cdot \htmlClass{sym-t_f}{1400\ \mathrm{mm}} \cdot \htmlClass{sym-L_f}{3600\ \mathrm{mm}} \\ &= 10080\ \mathrm{mm}^{2} \end{aligned}\]CSA A23.3 Cl. 7.8.1
\[\begin{aligned} \htmlClass{sym-A_sy_min}{A_{\mathrm{sy},\mathrm{min}}} &= 0.002 \cdot \htmlClass{sym-t_f}{t_{f}} \cdot \htmlClass{sym-B_f}{B_{f}} \\ &= 0.002 \cdot \htmlClass{sym-t_f}{1400\ \mathrm{mm}} \cdot \htmlClass{sym-B_f}{3000\ \mathrm{mm}} \\ &= 8400\ \mathrm{mm}^{2} \end{aligned}\]CSA A23.3 Cl. 13.10.4
\[\begin{aligned} \htmlClass{sym-s_max}{s_{\mathrm{max}}} &= \min\left(3 \cdot \htmlClass{sym-t_f}{t_{f}}, 500\ \mathrm{mm}\right) \\ &= \min\left(3 \cdot \htmlClass{sym-t_f}{1400\ \mathrm{mm}}, 500\ \mathrm{mm}\right) \\ &= 500\ \mathrm{mm} \end{aligned}\]Branch: \(c_{c} \geq d_{\mathrm{bx}}\ \text{and}\ s_{x} - d_{\mathrm{bx}} \geq 2 \cdot d_{\mathrm{bx}}\) held
CSA A23.3 Cl. 12.2.3
\[\begin{aligned} \htmlClass{sym-l_dx}{l_{\mathrm{dx}}} &= \max\left(\frac{\htmlClass{sym-k_x}{k_{x}} \cdot \htmlClass{sym-k_1}{k_{1}} \cdot \htmlClass{sym-k_2}{k_{2}} \cdot \htmlClass{sym-k_3}{k_{3}} \cdot \htmlClass{sym-k_4x}{k_{4x}} \cdot \htmlClass{sym-f_y}{f_{y}}}{\htmlClass{sym-f_v}{f_{v}}} \cdot \htmlClass{sym-d_bx}{d_{\mathrm{bx}}}, 300\ \mathrm{mm}\right) \\ &= \max\left(\frac{\htmlClass{sym-k_x}{0.45} \cdot \htmlClass{sym-k_1}{1} \cdot \htmlClass{sym-k_2}{1} \cdot \htmlClass{sym-k_3}{1} \cdot \htmlClass{sym-k_4x}{1} \cdot \htmlClass{sym-f_y}{400\ \mathrm{MPa}}}{\htmlClass{sym-f_v}{5.916\ \mathrm{MPa}}} \cdot \htmlClass{sym-d_bx}{25.2\ \mathrm{mm}}, 300\ \mathrm{mm}\right) \\ &= 766.7\ \mathrm{mm} \end{aligned}\]Branch: \(c_{c} \geq d_{\mathrm{by}}\ \text{and}\ s_{y} - d_{\mathrm{by}} \geq 2 \cdot d_{\mathrm{by}}\) held
CSA A23.3 Cl. 12.2.3
\[\begin{aligned} \htmlClass{sym-l_dy}{l_{\mathrm{dy}}} &= \max\left(\frac{\htmlClass{sym-k_y}{k_{y}} \cdot \htmlClass{sym-k_1}{k_{1}} \cdot \htmlClass{sym-k_2}{k_{2}} \cdot \htmlClass{sym-k_3}{k_{3}} \cdot \htmlClass{sym-k_4y}{k_{4y}} \cdot \htmlClass{sym-f_y}{f_{y}}}{\htmlClass{sym-f_v}{f_{v}}} \cdot \htmlClass{sym-d_by}{d_{\mathrm{by}}}, 300\ \mathrm{mm}\right) \\ &= \max\left(\frac{\htmlClass{sym-k_y}{0.45} \cdot \htmlClass{sym-k_1}{1} \cdot \htmlClass{sym-k_2}{1} \cdot \htmlClass{sym-k_3}{1} \cdot \htmlClass{sym-k_4y}{1} \cdot \htmlClass{sym-f_y}{400\ \mathrm{MPa}}}{\htmlClass{sym-f_v}{5.916\ \mathrm{MPa}}} \cdot \htmlClass{sym-d_by}{25.2\ \mathrm{mm}}, 300\ \mathrm{mm}\right) \\ &= 766.7\ \mathrm{mm} \end{aligned}\]CSA A23.3 Cl. 15.4.4
\[\begin{aligned} \htmlClass{sym-r_band}{r_{\mathrm{band}}} &= \frac{2}{\htmlClass{sym-beta_f}{\beta_{f}} + 1} \\ &= \frac{2}{\htmlClass{sym-beta_f}{1.2} + 1} \\ &= 0.9091 \end{aligned}\]Branch: \(B_{f} > L_{f}\) did not hold
Branch: \(L_{f} > B_{f}\) held
Questions
Are q_a and q_ult gross or net, and is the footing's weight included?
Gross, at the underside of the footing. The concrete at 24 kN/m³ over t_f and the soil over it, gamma_s h_s, are added to the column load in the soil bearing checks; they are uniform, so they cause no shear or moment in the footing, and the structural checks use the net pressure from the column alone. If your geotechnical report gives net values, add gamma_s (h_s + t_f) to them.
Why does bearing_factored use B_e and L_e rather than the whole footing?
At the ultimate limit state the soil check uses Meyerhof's effective area: the footing is shrunk by twice the eccentricity each way, B_e = B_f - 2 e_x and L_e = L_f - 2 e_y, and the factored load is spread uniformly over what is left. The service check and the structural checks keep the linear pressure over the whole footing, which is only valid with the resultant inside the kern; contact_service and contact_factored check that, and partial contact is not analysed.
Where do the short-direction bars go under Cl. 15.4.4?
In a rectangular footing CSA A23.3 Cl. 15.4.4 puts the fraction 2 / (beta + 1) of the short-direction steel in a band as wide as the short side, centred on the column, and the rest outside it. The sheet reports that area and the band width. It takes the bars as evenly spaced, so place them to the band yourself.
What does a column bearing FAIL under Cl. 10.8.1 mean for the dowels?
That the column load is more than bearing alone can carry across the interface. CSA A23.3 Cl. 15.9 lets reinforcement carry the rest, and the minimum dowel area reported is then that excess over phi_s f_y, never less than 0.005 of the column area. Tension in the dowels from the column moment is not designed here.