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002045

Dipl.-Ing. (FH) Richard Haase

2026-04-30

Punching Shear Design Using Double-Headed Anchors According to EOTA TR 060 for EC 2

This article focuses on double-headed anchor punching reinforcement according to the European technical guideline EOTA TR 060, which can be used in design based on EC2. The following sections describe its applicability, the consideration of manufacturer-specific parameters, and a breakdown of the required design check formats.

1 – Considering Manufacturer-Specific Parameters

In RFEM 6, the EOTA TR 060 technical guideline [1] is implemented in such a way that the product-specific parameters can be individually adjusted. The various properties from the manufacturers’ approvals (ETA) can be found in the ultimate configurations under the standard parameters.

The following parameters may vary:

γ_s – partial safety factor for double-headed anchors
k_pu,sl – factor for calculation of V_Rd,max for slabs
η (k₁,k₂) – considering the effective depth for slabs
k_pu,fo – factor for the calculation of V_Rd,max for foundations

Standard Parameters for Punching Reinforcement According to EOTA TR 060

Info

The plan is to also allow for the inclusion of compressive normal stresses in the calculation of the v_Rd,max value for slabs. It is necessary to explicitly mention this beneficial effect in the corresponding ETA approvals or by the manufacturer. If this requirement is met, an option can be activated in the ultimate configurations.

2 – Concrete Resistance Values

Slabs

The v_Rd,c calculation for slabs without punching reinforcement is similar to the calculation in EC 2 according to Equation 6.47. In [1], this equation is referred to as Equation 2.10.

v_{Rd,c} = C_{Rd,c} \cdot k \cdot \sqrt[3]{100 \cdot ρ_{l} \cdot f_{ck}} + k_{1} \cdot σ_{cp} \geq (v_{\min} + k_{1} \cdot σ_{cp})

Punching Shear Resistance for Slabs Without Punching Shear Reinforcement According to Eq. 2.10

To calculate the maximum resistance value v_Rd,max, the normal compressive stresses are neglected by default (as recommended in [1]). However, as also mentioned in Chapter 1, they can be taken into account by enabling this option in the ultimate configuration.

The resistance value for the maximum allowable punching load is calculated according to Equation 2.17.

v_{Rd,max} = k_{pu,sl} \cdot v_{Rd,c}

Maximum Punching Shear Resistance for Slabs According to Eq. 2.17

Foundations

To calculate the resistance value for the foundation design, the initial value C_Rd,c is assumed to be 0.18/γc (for foundation slabs and slender foundations). The spacing a is determined iteratively and results in the governing design ratio of v_Ed,red/v_Rd,c. However, the upper limit here is 2d. A detailed explanation can be found in the following technical article:

https://www.dlubal.com/en/support-and-learning/support/knowledge-base/001409

v_{Rd,c} = C_{Rd,c} \cdot k \cdot \sqrt[3]{100 \cdot ρ l \cdot f_{ck}} \cdot \frac{2 \cdot d}{a} \geq \frac{v_{\min} \cdot 2 \cdot d}{a}

Punching Shear Resistance for Foundations Without Punching Reinforcement According to Eq. 2.16

The resistance value v_Rd,max is calculated using Equation 2.19.

v_{Rd,max} = k_{pu, f o} \cdot v_{Rd,c}

Maximum Punching Shear Resistance for Foundations According to Eq. 2.19

3 – Applicability Limits of Punching Reinforcement

In principle, punching failure cannot be prevented simply by using arbitrarily high levels of punching reinforcement. As a prerequisite, it is necessary to fulfill the design requirement for maximum resistance v_Ed ≤ v_Rd,max. Only then can the punching shear design be fulfilled by selecting the appropriate punching reinforcement.

Therefore, the factors k_pu,sl and k_pu,fo mentioned in Chapter 1 have a significant influence. The concrete’s resistance value v_Rd,c is multiplied by the corresponding factor depending on the member type. Higher factors thus allow for a greater allowable punching load.

Tip

If the “UL0401” design is not fulfilled, it is possible to increase the surface reinforcement: The average flexural reinforcement ratio ρ_l influences the calculation of the resistance value v_Rd,c. However, the reinforcement ratio is limited to an application limit of min (2% ; 0.5 * f_cd / f_yd). If this is also insufficient, the only remaining options are to increase the concrete compressive strength or to use a greater effective depth d.

4 - Resistance Values for Double-Headed Anchors

Unlike in the Eurocode, the reinforcement value for double-headed anchors is not calculated per perimeter section. The guideline [1] distinguishes between two zones (see images for distance regulations).

Zone C is the area located 1.125d from the column edge, wall end, or wall corner for slabs, and 0.8d for foundations. All cross-sectional areas of the double-headed anchor shafts in Zone C are added together to yield the effective reinforcement value. In slab calculations, there is also an η-factor that accounts for the effective depth.

Zone D is located between the outer perimeter and Zone C.

V_{R d, s y} = n_{c} \cdot m_{c} \cdot \frac{{d^{2}}_{A} \cdot π \cdot f_{yk}}{4 \cdot γ_{s} \cdot η}

Double-Headed Anchor Resistance for Plates According to Eq. 2.18

V_{R d, s} = f_{ywd} \cdot A_{sw; 0.8d}

Double-Headed Anchor Resistance for Foundations and Slabs According to Eq. 2.20

5 – Outer Control Perimeter

The outer perimeter is located at a distance of 1.5d from the last perimeter section reinforced with double-headed anchors. The design requirement is fulfilled when the force acting on the outer perimeter no longer requires punching reinforcement—that is, when the concrete strength is sufficient. This design requirement is proven by comparing the required perimeter of the outer perimeter with its actual perimeter.

u_{out,erf} = \frac{β_{red} \cdot V_{E d}}{v_{R d, c} \cdot d}

Required Circumference of Outer Perimeter Section According to Eq. 2.21

6 – Detailing Rules

Slabs

The following applies to radial distances:

It is necessary to locate the first perimeter section between 0.35d and 0.5d (from the edge of the punching shear section).
The second perimeter section may be located at a maximum distance of 1.125d (from the edge of the punching shear section); this is the boundary line of Zone C.
Subsequent perimeter sections must not exceed a radial distance of 0.75d from the previous perimeter section.

The following applies to tangential distances:

Up to a radial distance of 1.0d (from the edge of the punching shear section), the tangential distance must be less than or equal to 1.7d.
At the boundary line of Zone C at 1.125d (from the edge of the punching shear section), the tangential distance must be less than or equal to 1.8d.
In Zone D, the tangential distance must be less than or equal to 3.5d.

Spacing Requirements for Double-Headed Anchors According to EOTA TR 060 for Plates

Single Foundations and Foundation Slabs

The following applies to radial distances:

The first perimeter section must be located at 0.3d (from the edge of the punching shear section).
The second perimeter section must not be located more than 0.8d (from the edge of the punching shear section); this is the boundary line of Zone C.
Subsequent perimeter sections must not exceed a radial distance of 0.5d to 0.75d (depending on the foundation type) from the previous perimeter section.

The following applies to tangential distances:

At the boundary line of Zone C at 0.8d (from the edge of the punching shear section), the tangential distance must be less than or equal to 1.5d.
In Zone D, the tangential distance must be less than or equal to 2.0d.

Spacing requirements for double-headed anchors according to EOTA TR 060 for Foundations

7 – Design Checks

To fulfill the punching shear design requirement, four conditions must be met.

As mentioned in Chapter 3, it is necessary to fulfill the V_Rd,max design in order to perform the punching shear design in general. k_ETA are the manufacturer-specific values in this context. They differ for slabs (k_pu,sl) and for foundations or foundation slabs (k_pu,fo).

V_Ed ≤ k_ETA ⋅ V_Rd,c

If the applied force V Ed ≤ V Rd,c (at the basic control perimeter), then no punching reinforcement is required and the design requirement is fulfilled. It is necessary to increase the punching reinforcement if V Ed ≥ V Rd,c , until the resistance value V Rd,s ≥ V Ed is reached.

V_Ed ≤ max (V_Rd,c ; V_Rd,s)

The outer perimeter is located at a distance of 1.5d times the distance from the last perimeter section installed with double-headed anchors. The existing perimeter of this outer perimeter must be greater than or equal to the required perimeter.

u_out,req ≤ u_out,prov

Furthermore, it is necessary to observe the construction rules, and the following conditions must be fulfilled:

At least two perimeter sections in Zone C
Radial distances between the perimeter sections
Tangential distances between the double-headed anchors on a perimeter section

Author

Richard works in Product Engineering, specializing in reinforced concrete, and also assists with Customer Support. He applies his expertise to develop practical solutions.

Links

Download Link for EOTA TR 060

References

https://www.eota.eu/sites/default/files/uploads/Technical%20reports/eota-tr-060.pdf

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