In EC5, a number of fasteners lying along a line running parallel to the grain direction, as shown in Figure 10.14, are referred to as a row of fasteners parallel to the grain.

Where there is only a single fastener in the row, the design strength of the row per shear plane will be the design lateral load carrying capacity of the fastener per shear plane and where there are r such rows, the design strength of the connection parallel to the grain per shear plane will be:

Design lateral capacity of connection per shear plane

= r x Design lateral capacity of the fastener per shear plane

Where there is more than one fastener per row parallel to the grain the strength of the row depends on the stiffness of the fastener and the strength of the bedding material and in general the stiffer the fastener the greater the design strength of the row. Several researchers have investigated this effect, and the effective characteristic load-carrying capacity of a row of fasteners parallel to the grain, Fv ef Rk, in EC5 is:

Fv,ef>Rk = nefFv Rk (EC5, equation (8.1)) (10.42)

where Fv ef jRk is the effective characteristic lateral load carrying capacity per shear plane of one row of fasteners parallel to the grain, nef is the effective number of fasteners per shear plane in the row parallel to the grain, and Fv Rk is the characteristic lateral load carrying capacity per shear plane of the fastener type being used.

10.4.1 The effective number of fasteners

The effective number of fasteners in a connection is dependent on the type of fastener and the direction of loading relative to the grain, and is covered in the following subsections.

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