Check punching shear for flat slabs and pad foundations to EN 1992-1-1 §6.4. Computes control perimeters u0/u1, eccentricity factor β, design stress vEd, concrete resistance vRd,c (§6.4.4), maximum stress vRd,max (§6.4.5), and required shear reinforcement Asw per ring.
What control perimeter u_1 does EN 1992-1-1 use for punching shear?
The basic control perimeter u_1 is located at a distance 2d from the column face (§6.4.2), where d is the effective depth of the slab. For a 300×300mm internal column on a 250mm slab with d=210mm: u_1 = 2(300+300) + 4π×210 ≈ 3837mm. A second perimeter u_0 at the column face is used to check v_Rd,max (crushing limit §6.4.5).
What is the eccentricity factor β?
β accounts for moment transfer at the column-slab joint. For simplified design (§6.4.3(6)): β=1.15 for internal columns, β=1.4 for edge, β=1.5 for corner. When moments M_Ed are provided, the detailed method (eq.6.39 with k from Table 6.1) gives a more accurate β. This tool calculates both; if no moment is supplied the simplified value is used.
When is shear reinforcement (punching studs) required?
Shear reinforcement is required when v_Ed > v_Rd,c at the u_1 perimeter. The required area per ring is A_sw = (v_Ed − 0.75·v_Rd,c)·u_1·d / (f_ywd,ef·sin α) per §6.4.5 eq.6.52. Reinforcement must extend to the outer perimeter u_out where shear stress drops below v_Rd,c.
How does the foundation enhanced resistance work?
For pad foundations (§6.4.4(2)), v_Rd,c is enhanced by the factor 2d/a ≥ 1, where a is the distance from the column face to the resultant of the applied soil pressure. This accounts for the direct strut mechanism. Select "Pad foundation" and enter a (mm) to apply this enhancement.