Barrier for protection against falling stones or rocks - has long deformable net supported by inclined pivoted posts having net upper cable fixed to their tops and anchored in ground, posts having retaining cables at foot and shoring braces

The barrier has a long deformable net supported by inclined posts located downstream of the net. The posts can pivot in all directions relative to the ground. A net upper cable is fixed to the tops of the posts and anchored in the ground. Retaining cables are situated at the feet of the posts and post shoring braces. The upstream anchoring points (5) have return pulleys (25). Several lower cables (16-18) pass through several return pulleys and are fixed by their ends to downstream (7) or lateral (6) anchoring points. These cables have, in their downstream portions, friction systems (26) able to free lengths of supplementary cables. The upstream braces (35) have at their upper portions friction systems (40) able to free lengths of supplementary braces. The downstream braces do not have friction systems for freeing supplementary lengths. Selon l'invention, cette barrière comprend:- des points d'ancrage amont (5) munis d'organes (25) de renvoi vers l'aval, tels que des poulies;- plusieurs câbles de rive inférieure (16, 17, 18) successifs, qui traversent chacun plusieurs organes de renvoi (25) et sont fixés par leurs extrémités à des points d'ancrage aval (7) ou latéraux (6), ces câbles (16, 17, 18) comprenant, au niveau de leurs portions aval, des dispositifs (26) aptes à libérer avec friction des longueurs de câble (43) supplémentaires;- des haubans amont (35) d'étayage des poteaux (3), comprenant, au niveau de leurs portions supérieures, des dispositifs (40) aptes à libérer avec friction des longueurs (43) de hauban supplémentaires.