Checks the punching of a flat slab carried by the end of a wall or the corner of two walls, to SIA 262:2025: the control section, the slab rotation, the resistance without and with punching reinforcement, its detailing, and the integrity reinforcement against progressive collapse. Every step shows its formula and the clause it comes from.

What it checks

Control section at d_v/2 from the wall, d_v = (d_x + d_y)/2 (4.3.6.2.1). At a wall end it runs round the end face and 1.5 · d_v along both sides, u₀ = t + π · d_v/2 + 2 · 1.5 · d_v (Figure 23b). At a corner it runs round the outer corner and 1.5 · d_v along each wall (Figure 23c). Reductions of clause 4.3.6.2.3 for an opening (Figure 23d) and radial conduits (Figure 23e).
Design force: V_d = R_d − q_d · A, clause 4.3.6.2.6, and u = k_e · u_red, with k_e = 0.75 (4.3.6.2.5) or equation (57).
Slab rotation ψ, clause 4.3.6.4.1, equation (60), at level 1 or 3 (4.3.6.4.2), with r_s = 0.22 · l (4.3.6.4.4).
Resistance without punching reinforcement: V_Rd,c = k_r · τ_cd · d_v · u, clause 4.3.6.3.1, equation (58), with k_r by equation (59) and k_g by equation (37).
Top bars: spacing ≤ min(1.2 · h ; 300 mm), clause 5.5.3.1, and the anchorage length l_a, clause 5.5.3.7.
Detailing of the punching reinforcement: at least two rows and s₀ < s₁ (5.5.3.8); s₁ and Ø_sw against Table 21; the spacing along the second row below 1.5 · d_v (5.5.3.9); c_v ≤ d_v/6 (5.5.3.11).
Resistance of the punching reinforcement: V_Rd,s = ΣA_sw · k_e · σ_sd · sin β, clause 4.3.6.5.4, equation (68), with σ_sd by equation (69).
Deformation capacity, equation (67); first compression strut, V_Rd,max, clause 4.3.6.5.8, equation (70); outer control section with d_v,out = d_v − c_v, clause 4.3.6.5.10.
Integrity reinforcement: at least two bars each way (5.5.3.13), V_d,exc ≤ V_Rd,res, clause 4.3.6.7.2, equations (71) and (72), with k_β from Table 12; and at least one measure of clause 4.3.6.1.3.

What you enter and what you get

You choose a wall end or a wall corner and enter the wall thickness t, the slab thickness, the cover and the top bars both ways, any opening or conduits, the concrete with D_max, the steel, the resistance factors, R_d and q_d, the reduction k_e, the level for ψ and the spans. Then the punching reinforcement in rows and the integrity bars with V_d,exc.

You get every step from d_v to the residual resistance, each check with its utilisation and clause, and a drawing. With the Basic plan, it prints as an A4 calculation note.

Assumptions and limits

R_d is the part of the wall reaction that enters the counted zone, within 1.5 · d_v of the end or corner. Take it from your plate analysis.
k_e = 0.75 applies to regular flat slabs.
Level 2 is written for columns, equations (62) to (65), and is not offered. Level 3 uses your own uncracked plate analysis, with 1.2 in place of 1.5 in equation (60).
The rows lie on radial lines perpendicular to the wall faces.
Integrity bars along x leave through the end face; bars along y leave on both sides of the wall. Ductility class A gives no residual resistance.

Worked example

The end of a 250 mm wall under a 300 mm slab with Ø16 at 150 mm both ways at the top, f_ck = 30 N/mm², R_d = 280 kN, q_d = 14 kN/m², spans of 7 m at level 1, four rows of ten Ø12 links, and two Ø14 integrity bars along x and three along y with V_d,exc = 150 kN. These are the module's own results for its worked example, computed when this page was built.

Inputs
Input	Value	Ref.
Support	End of a wall	§ 4.3.6.2.3
Wall thickness t	250 mm
Slab thickness h	300 mm
Cover to the top bars c	30 mm
Outer top layer	Bars along x
Top bars along x, diameter Ø_x	16 mm
Top bars along x, spacing s_x	150 mm
Top bars along y, diameter Ø_y	16 mm
Top bars along y, spacing s_y	150 mm
Opening near the wall	None	§ 4.3.6.2.3
Embedded conduits near the wall	None	§ 4.3.6.2.3
Characteristic compressive strength f_ck	30 N/mm²	§ 3.1.2.2.2
Largest aggregate size D_max	32 mm	§ 4.3.3.2.1
Characteristic yield strength of the top bars f_yk	500 N/mm²
Modulus of elasticity E_s	205000 N/mm²
Resistance factor for concrete γ_c	1.5	§ 2.4.2.6
Resistance factor for steel γ_s	1.15	§ 2.4.2.6
Design support force at the wall end R_d	280 kN
Design load on the slab inside the control section q_d	14 kN/m²	§ 4.3.6.2.6
Reduction for the moment transfer k_e	By the type of support (4.3.6.2.5)	§ 4.3.6.2.4
Level of approximation	Level 1 — strip fully used	§ 4.3.6.4.2
Span in x l_x	7 m	§ 4.3.6.4.4
Span in y l_y	7 m	§ 4.3.6.4.4
Punching reinforcement	Vertical links or studs	§ 4.3.6.5
Diameter of the elements Ø_sw	12 mm	§ 5.5.3.12
Number of elements in each row n_sw	10
Number of rows n_r	4	§ 5.5.3.8
Distance from the wall face to the first row s₀	80 mm	§ 5.5.3.8
Radial spacing of the rows s₁	150 mm	§ 5.5.3.8
Distance from the bottom face to the lower anchorage c_v	30 mm	§ 5.5.3.11
Characteristic yield strength of the punching reinforcement f_yk,w	500 N/mm²	§ 4.3.6.5.4
Design of the punching reinforcement	With the concrete contribution (4.3.6.5.2)	§ 4.3.6.5.2
Mean tensile strength of the concrete f_ctm	2.9 N/mm²	§ 3.1.2.2.4
Integrity reinforcement	Straight bars at the bottom face	§ 4.3.6.7
Ductility class of the bars	B	Table 12
Bar diameter Ø_int	14 mm
Bars along x passing over the wall n_x	2	§ 5.5.3.13
Bars along y passing over the wall n_y	3	§ 5.5.3.13
Spacing of these bars s	100 mm
Cover to these bars at the bottom face c_int	30 mm
Design shear force, exceptional situation V_d,exc	150 kN	§ 4.3.6.7.4

Calculation: Effective depth
Step	Value	Ref.
Effective depth of the bars along xh − c − Ø_x/2	d_x = 262 mm
Effective depth of the bars along yh − c − Ø_x − Ø_y/2	d_y = 246 mm
Effective depth for punching(d_x + d_y)/2from the soffit, where the wall supports the slab, to the mean level of the two top layers (Figure 21b)	d_v = 254 mm	§ 4.3.6.2.1

Calculation: Control section at d_v/2 from the wall
Step	Value	Ref.
Length of the control sectiont + π·d_v/2 + 2·1.5·d_vFigure 23b: round the end, 1.5·d_v along both sides	u₀ = 1,411 mm	§ 4.3.6.2.3
Left out: straight parts beyond 1.5·d_v from a corner1.5·d_v = 381 mmFigure 23a, on the end face	Δu_23a = 0 mm	§ 4.3.6.2.3
Control section after the reductionsu₀ − the parts left out	u_red = 1,411 mm	§ 4.3.6.2.3
Area inside the control sectionthe counted part of the wall included	A = 0.249 m²	§ 4.3.6.2.6
Centroid of the control sectioncentroid of the line u_0, from the reference point	x_G ; y_G = -58 ; 0 mm	§ 4.3.6.2.4

Calculation: Design punching force
Step	Value	Ref.
Load inside the control section	q_d·A = 3.5 kN	§ 4.3.6.2.6
Design punching forceR_d − q_d·A	V_d = 276.5 kN	§ 4.3.6.2.6

Calculation: Reduction for the moment transfer
Step	Value	Ref.
Reduction factorend of a wallregular flat slabs	k_e = 0.75	§ 4.3.6.2.5
Effective control sectionk_e·u_red	u = 1,058 mm	§ 4.3.6.2.3

Calculation: Slab rotation ψ — level 1
Step	Value	Ref.
Distance to zero moment, x0.22·l_x	r_sx = 1.54 m	§ 4.3.6.4.4
Distance to zero moment, y0.22·l_y	r_sy = 1.54 m	§ 4.3.6.4.4
Design yield strength of the top barsf_yk/γ_s	f_yd = 434.8 N/mm²	§ 2.4.2.5 (4)
Slab rotation, x1.5·(r_sx/d)·(f_yd/E_s)	ψ_x = 0.0193	§ 4.3.6.4.1 (60)
Slab rotation, y1.5·(r_sy/d)·(f_yd/E_s)	ψ_y = 0.0193	§ 4.3.6.4.1 (60)
Slab rotation, governingmax(ψ_x ; ψ_y)d = d_v = 254 mm	ψ = 0.0193	§ 4.3.6.4.1

Calculation: Check — punching resistance without punching reinforcement
Step	Value	Ref.
Design shear stress limit0.3·√f_ck/γ_c	τ_cd = 1.095 N/mm²	§ 2.4.2.4 (3)
Aggregate factor48/(16 + D_max·min(1 ; (60/f_ck)²)) ≥ 1.2	k_g = 1.200	§ 4.3.3.2.1 (37)
Factor for size, rotation and aggregate1/(0.45 + 0.18·ψ·d·k_g) ≤ 2, d in mm	k_r = 0.663	§ 4.3.6.3.2 (59)
Punching resistancek_r·τ_cd·d_v·u	V_Rd,c = 195.2 kN	§ 4.3.6.3.1 (58)
Utilisation without the punching reinforcementfor information	V_d/V_Rd,c = 1.42	§ 4.3.6.3.1 (58)

Calculation: Detailing of the top bars
Step	Value	Ref.
Spacing of the top bars along xs_x/s_max	η = 0.500 · Pass50 % of the capacity used	§ 5.5.3.1
Spacing of the top bars along ys_y/s_max	η = 0.500 · Pass50 % of the capacity used	§ 5.5.3.1
Full anchorage of the top bars, from the wall faced_v/2 + 2.5·d_v: 2.5·d_v beyond the control section, at most from the point of zero moment	l_a = 762 mm	§ 5.5.3.7

Calculation: Detailing of the punching reinforcement
Step	Value	Ref.
At least two rowsn_r	η = 0.500 · Pass50 % of the capacity used	§ 5.5.3.8
First row closer to the wall than the row spacings₀/s₁	η = 0.533 · Pass53 % of the capacity used	§ 5.5.3.8
Radial spacing of the rowss₁/s_1,max	η = 0.787 · Pass79 % of the capacity used	Table 21
Diameter of the elementsØ_sw/Ø_sw,max	η = 0.667 · Pass67 % of the capacity used	Table 21
Spacing of the elements along the second rows_t/(1.5·d_v)	η = 0.651 · Pass65 % of the capacity used	§ 5.5.3.9
Lower anchorage of the elementsc_v ≤ d_v/6 = 42 mmmet	c_v = 30 mm	§ 5.5.3.11

Calculation: Check — resistance of the punching reinforcement
Step	Value	Ref.
Rows between 0.35·d_v and d_v from the wall face89 mm to 254 mm	n_r,eff = 1	§ 4.3.6.5.4
Area of the counted elementsn_r,eff·n_sw·π·Ø_sw²/4	ΣA_sw = 1,131 mm²	§ 4.3.6.5.4
Design yield strength of the punching reinforcementf_yk,w/γ_s	f_yd,w = 434.8 N/mm²	§ 2.4.2.5 (4)
Stress in the punching reinforcement(E_s·ψ/6)·(1 + (f_ctm/f_yd,w)·(d/Ø_sw)) ≤ f_yd,w	σ_sd = 434.8 N/mm²	§ 4.3.6.5.4 (69)
Force for the punching reinforcementV_d − V_Rd,c	V_d,s = 81.3 kN	§ 4.3.6.5.2 (66)
Resistance of the punching reinforcementΣA_sw·k_e·σ_sd·sin β, β = 90°	V_Rd,s = 368.8 kN	§ 4.3.6.5.4 (68)
Resistance of the punching reinforcementV_d,s/V_Rd,s	η = 0.220 · Pass22 % of the capacity used	§ 4.3.6.5.4 (68)

Calculation: Check — deformation capacity
Step	Value	Ref.
Deformation capacity of the punching reinforcement(V_d/2)/(ΣA_sw·k_e·f_yd,w)	η = 0.375 · Pass37 % of the capacity used	§ 4.3.6.5.3 (67)

Calculation: Check — crushing of the first compression strut
Step	Value	Ref.
Upper limit of the punching resistancemin(2·k_r ; 3.5)·τ_cd·d_v·u	V_Rd,max = 390.5 kN	§ 4.3.6.5.8 (70)
First compression strut next to the wallV_d/V_Rd,max	η = 0.708 · Pass71 % of the capacity used	§ 4.3.6.5.8 (70)

Calculation: Check — outside the zone with punching reinforcement
Step	Value	Ref.
Distance from the wall face to the last rows₀ + (n_r − 1)·s₁	r_out = 530 mm	§ 4.3.6.5.10
Effective depth outside the reinforced zoned_v − c_vFigure 26	d_v,out = 224 mm	§ 4.3.6.5.10
Length of the outer control sectionat r_out + d_v,out/2 from the wall face1.5·d_v,out along the wall	u_out,0 = 2,939 mm	§ 4.3.6.5.10
Largest gap between the outermost elementsalong the last row; each gap counts at most 3·d_v,out = 672 mmevery gap within 3·d_v,out (Figure 26)	s_t,out = 491 mm	§ 4.3.6.5.10
Outer control section after the reductionsu_out,0 − parts left out	u_out = 2,939 mm	§ 4.3.6.2.3
Design punching force at the outer sectionR_d − q_d·A_out, A_out = 1.322 m²	V_d,out = 261.5 kN	§ 4.3.6.2.6
Punching resistance outside the reinforced zonek_r·τ_cd·d_v,out·k_e·u_out	V_Rd,c,out = 358.6 kN	§ 4.3.6.5.10
Punching outside the reinforced zoneV_d,out/V_Rd,c,out	η = 0.729 · Pass73 % of the capacity used	§ 4.3.6.5.10

Calculation: Integrity reinforcement
Step	Value	Ref.
At least two bars in each directionn_min	η = 1.000 · Pass100 % of the capacity used	§ 5.5.3.13
Efficiency factorclass B, β = 0°	k_β = 0.37	Table 12
Distance between the top bars and the integrity barsd_v − c_int − Ø_int/2Figure 27a	d_int = 217 mm	§ 4.3.6.7.2
Groups of bars leaving the wall1 along x, 2 along ybars along x leave through the end face, bars along y on both sides of the wall	n_g = 3	§ 4.3.6.7.3
Area of the bars leaving the wallΣ over the groups of n·π·Ø_int²/4	ΣA_s = 1,232 mm²	§ 4.3.6.7.2
Control section after punchingΣ(s_int + π/2·d_int), s_int = (n − 1)·sFigure 27c	u_int = 1,523 mm	§ 4.3.6.7.2 (72)
Residual resistanceΣ(A_s·f_yd·k_β) = 198.1 kN ≤ 1.7·τ_cd·d_int·u_int = 615.3 kN	V_Rd,res = 198.1 kN	§ 4.3.6.7.2 (71)
Residual resistance after punchingV_d,exc/V_Rd,res	η = 0.757 · Pass76 % of the capacity used	§ 4.3.6.7.2 (71)

Calculation: Check — measure against progressive collapse
Step	Value	Ref.
At least one measure of 4.3.6.1.3η	η = 0.375 · Pass37 % of the capacity used	§ 4.3.6.1.3

How this module is verified

Verified clause by clause against SIA 262:2025 and against independent calculations used on real projects, before release.

Questions

Why is only part of the wall reaction entered?

The shear gathers at the end or the corner of the wall. Clause 4.3.6.2.3 counts the control section only up to 1.5 · d_v along the wall, so only the reaction in that zone is checked.

Why is the resistance without reinforcement shown?

For information. In the worked example V_d/V_Rd,c = 1.42, so the slab needs the links. With punching reinforcement, equations (68), (67), (70) and clause 4.3.6.5.10 replace equation (58).

Which plan includes this module?

The Basic plan, with its calculation note.

Norm: SIA 262:2025 · Page updated: 29 October 2026

Punching of a flat slab at a wall end or corner to SIA 262

Member

About this check