Punching Shear Calculator (Pu, M2, M3) - ACI 318

Punching Shear Design Check – Combined P_u, M_u2, M_u3

Developer: Engr. Mohammad Ismail Hossain, MIEB-42283, CEO at Ascending Consulting Engineers

Per ACI 318-19 Sec. 8.4 / 22.6 (two-way shear with unbalanced moment transfer), including slab-edge/overhang truncation of the critical section — algorithm consistent with CSI ETABS/SAFE RC Slab Design Manual

Developed by Engr. Mohammad Ismail Hossain, MIEB-42283 · CEO, Ascending Consulting Engineers · www.ace-bd.com

1. Input Data ● Live – updates automatically

Column Geometry (rectangular)

c1 – column width along 2-axis (mm)

c2 – column width along 3-axis (mm)

Column Location

Location Type

Slab & Reinforcement Cover

Slab thickness, h (mm)

Clear cover (mm)

Main bar dia, d_b (mm)

Effective depth used: d = h − cover − d_b (average, both directions)

Material Properties

f'c (MPa)

fyt – shear reinf. (MPa)

λ (lightweight factor)

φ for shear

Factored Design Forces at Column Centroid

P_u (kN)

M_u2 (kN·m)

M_u3 (kN·m)

Live Critical-Section Diagram

Column Active critical-section side Omitted side / slab free edge Overhang region 2-axis / 3-axis

2. Summary of Results

3. Full Calculation

4. Headed Shear Stud Assembly Sizing ACI 8.7.7.1.1

Minimum overall height (rail to head) of a manufactured shear-stud assembly, governed by slab thickness and the covers on both faces:

H_min = h − c_t − c_b − d_b/2ACI 8.7.7.1.1

Slab thickness, h (mm)

Top flexural cover, c_t (mm)

Tension bar dia, d_b (mm)

Base Rail Cover, c_b — per ACI 318 §20.5.1.3

Exposure category (auto-suggest c_b, mm)

Base rail cover used, c_b (mm) — editable

Base Rail Configuration

Base rail plate thickness — ASTM A1044/A1044M (manufacturer ICC-ES evaluation reports)

Stud shank diameter	Min. base rail plate thickness
3/8 in (9.5 mm)	3/16 in (4.8 mm)
1/2 in (12.7 mm)	1/4 in (6.4 mm)
5/8 in (15.9 mm)	5/16 in (7.9 mm)
3/4 in (19.1 mm)	3/8 in (9.5 mm)

c_b is not a special stud-specific value — it is simply the standard ACI 318 concrete cover (Table 20.5.1.3) applied to the bottom face of the slab, selected per exposure category. In the "upside-down" configuration, the bottom stud head (rather than a rail) defines this cover.