Punching shear design

 

17.0

Punching shear is a type of failure of reinforced concrete slabs subjected to high localized forces. In flat slab structures, this occurs at column support points. The failure is due to shear. This type of failure is critical because no visible signs are shown prior to failure.

In this release, the designer can check if the required longitudinal slab or foundation reinforcement is adequate to resist the local shear force at the support. Moreover, the designer can proceed with the calculation and design the required shear reinforcement around the support, if necessary.

Highlights
Design and check punching shear reinforcement according to the safety concept of the Eurocode EN 1992-1-1
Calculation of punching shear for slabs and foundations
Automatically recognition of support shape and location
Different possibilities for the calculation of β factor
Two different types of reinforcement are supported for the checks of slab resistance

Punching shear design/ check (Steps of calculation)

  • New command 'Punching design' is introduced to enable the calculation and the design of punching reinforcement for select nodes using EN 1992-1-1:2004/A1:2014.

  • All necessary input data for calculation are automatically prepared from the model, followed by a procedure to construct basic critical control perimeter as a base to verify a concrete capacity of a member without punching reinforcement.
  • If the concrete capacity without shear reinforcement is not enough, a punching reinforcement is designed.
  • The whole calculation is reported in a brief output together with the presentation of results in a graphical window.
  • Internal, edge, and corner nodal or column support with rectangle or circle shape of the loaded area are supported.

User workflow and supported features

In this version of SCIA Engineer, both design and checks of punching reinforcement are supported. The workflow in this version is quite simple. The users models 2D members and under the concrete service he runs the punching shear design. There is no need to assign special data to the slab-column connection. All the concrete parameters are automatically taken from the concrete settings.

The following features are supported in term of punching shear checks and design.

1. Calculation of the flat slab or foundation resistance for shear according to Eurocode EN 1992-1-1 and NA.

2. Circular and rectangular columns are supported only. The users can also use the standard support to simulate the column support.

3. Calculation of the critical control parameters using a set of trails to find the more critical one.

4. Different possibilities for selection of nodes.

5. Both required and user provided reinforcement are supported for the calculation of slab / foundation resistance.

6. Different possibilities to calculate β-factor:

  • Approximate method according to EC2/ 6.3.4(6)
  • Taking into account the requirement of NA depending on support position
  • Formulas from EC2/ 6.4.3(3-5)

7. It is easy to understand whether the 2D members need punching shear reinforcement or not.