Guardrail terminal
A guardrail terminal having a number of vertical supporting members fix into the ground one after the other along the edge of the road. The guardrail terminal, in certain embodiments, has a curved or straight first transverse horizontal retaining member fixed to the vertical supporting members at a given height off the ground, and curves in the horizontal plane so as to extend gradually away from the edge of the road. The guardrail terminal further may include a curled second transverse horizontal retaining member, which projects from the terminal end of the first transverse horizontal retaining member, curves back in the horizontal plane towards the first transverse horizontal retaining member, and is fixed by its own terminal end to the start end or to an intermediate portion of the first transverse horizontal retaining member, so as to form, together with the first transverse horizontal retaining member, a substantially tear-shaped collapsible annular member.
1. A guardrail terminal comprising:
a plurality of vertical supporting members fixed to the ground one after the other along the edge of a road;
a first transverse horizontal retaining member fixed to the vertical supporting members at a height off the ground, and positioned in a horizontal plane so as to extend gradually away from the edge of the road, with the first transverse horizontal retaining member having a first end closer to the edge of the road than a terminal second end; and
a second transverse horizontal retaining member which projects from the second end, curves back in the horizontal plane towards said first transverse horizontal retaining member, and is fixed by a terminal end to said first transverse horizontal retaining member, so as to define, together with the first transverse horizontal retaining member, a substantially tear-shaped collapsible annular member,
wherein the second transverse horizontal retaining member further comprise
an initial portion fixed to the terminal second end of said first transverse horizontal retaining member, and bent substantially into an L in the horizontal plane, so as to have, centrally, a given constant radius of curvature (r 2 );
an intermediate portion bent substantially into a V in the horizontal plane, so as to have, centrally, a given constant radius of curvature (r 3 ); and
an appropriately shaped end portion, the end of which is fixed directly to said first transverse horizontal retaining member.
2. A guardrail terminal as claimed in claim 1 , wherein said first transverse horizontal retaining member is curved.
3. A guardrail terminal as claimed in claim 2 , wherein said first transverse horizontal retaining member is curved in the horizontal plane with a constant radius of curvature (r 1 ).
4. A guardrail terminal as claimed in claim 1 , wherein said first transverse horizontal retaining member comprises at least one segment of corrugated sheet metal with a three-ridge or W-shaped cross section.
5. A guardrail terminal as claimed in claim 1 , wherein the end portion of said second transverse horizontal retaining member has a first portion and a second portion, and is bent substantially into an S in the horizontal plane, so that the first portion has a given first radius of curvature (r 4 ), and the second portion has a given second radius of curvature (r 5 ).
6. A guardrail terminal as claimed in claim 5 , wherein the second portion of the end portion of said second transverse horizontal retaining member has a radius of curvature (r 5 ) substantially equal to the radius of curvature (r 1 ) of said first transverse horizontal retaining member, so that a portion of the length of the second portion overlaps the first transverse horizontal retaining member.
7. A guardrail terminal as claimed in claim 1 , wherein said initial portion, said intermediate portion, and said end portion of said second transverse horizontal retaining member comprise at least one segment of corrugated sheet metal with a triple-ridge or W-shaped cross section.