Joints Shear Forces (Eurocodes)

The diagonal compression induced in the joint by the diagonal strut mechanism shall not exceed the compressive strength of concrete in the presence of transverse tensile strains. EN 1998-1:2004 defines that this requirement is satisfied by means of the subsequent rules:

Interior beam-column joints
The following expression should be satisfied:

Where Vjhd is the horizontal shear acting on the core of a joint between primary seismic beam and column elements and is determined taking into account the most adverse conditions under seismic actions, i.e. capacity design conditions for the beams framing into the joint and the lowest compatible values of shear forces in the other framing elements. The value of Vjhd for the interior beam-column joints is calculated from the following expression:

The option to consider re-bar stresses from analyses rather than the yielding stresses for the calculation of joints horizontal shear force demand in nonlinear analysis is available in here. In this case, the value of Vjhd for the interior beam-column joints is calculated from the following expression:

Exterior beam-column joints
The following expression should be satisfied:

Where Vjhd for exterior beam-column joints is calculated from the following expression:

In the case where re-bar stresses are considered from analyses rather than the yielding stresses for the calculation of joints horizontal shear force demand in nonlinear analysis, the value of Vjhd for the interior beam-column joints is calculated from the following expression:

For information about the values in the equations above users may refer to sections 5.5.3.3(2) and 5.5.2.3(2) of EN 1998-1.