The inventive girder (10) for a support wall curtain comprises a core (12) and two parallel wings (14, 16) which are supported by said core and provided with connection means (20). Said wings (14, 16) are reinforced on the largest part of the width thereof on the side opposite to the core (12) by an excessive material thickness which starts only at a certain distance (d.sub.1) from the longitudinal edges of the wing, thereby leaving the thinner wing ends (21) carrying said connection means (20) free. The non-reinforced ends (21) of the wings make it possible to use a conventional connection systems (18) in order to integrate such a girder (10) provided with a high resistant module into the support wall curtains.