Posts For Road Safety Barrier

Abstract

A road safety barrier having a plurality of ropes supported by posts rigidly mounted on or in the ground is described. Each rope is held in tension against the posts and supported in a notch or groove in a side of the posts. The ropes are released from a post and the post is not pulled from the ground when a vertical force is exerted on the rope. The ropes when weaved are tensioned against the posts and this gives rise to a combined frictional resistance to displacement of the ropes relative to each post along the length of the safety barrier. The structure of at least some of the posts and/or their mounting with respect to the ground defines a minimum bending yield strength in a direction along the length of the barrier. This minimum bending yield strength is greater than the bending moment resulting from the combined frictional resistance forces acting on the post.

1 . A post for use with a road safety barrier having a plurality of wire ropes each rope supported by a plurality of posts, the post comprising:
 a post member adapted to be secured on or in the ground, the post member having a first side and a second side;   wherein the first side defines a first groove adapted to receive and support a first wire rope; and   such that the first wire rope is released from the groove when a vertical force is exerted on the first wire rope.   
   
   
       2 . The post of  claim 1  wherein the groove is a longitudinally oriented. 
   
   
       3 . The post of  claim 1  wherein the second side defines at least one longitudinally oriented groove adapted to receive and support a second wire rope;
 such that the second wire rope is released from the groove when a vertical force is exerted on the second wire rope.   
   
   
       4 . The post of  claim 3  wherein the groove on the first side is at substantially the same height as the groove on the second side. 
   
   
       5 . The post of  claim 1  wherein the first side defines a second longitudinally oriented groove adapted to receive and support a second wire rope, the second groove vertically displaced from the first groove;
 such that the second wire rope is released from the second groove when a vertical force is exerted on the first wire rope.   
   
   
       6 . The post of  claim 1  wherein the groove comprises a notch. 
   
   
       7 . The post of  claim 1  wherein the groove comprises a smooth support for the wire rope. 
   
   
       8 . The post of  claim 1  wherein the post comprises a flange and the groove is in the flange. 
   
   
       9 . A post for use with a road safety barrier having a plurality of wire ropes each rope supported by a plurality of posts, the post comprising:
 an elongate member having a first side and a second side, and a first end adapted to be secured on or in the ground;   wherein the first side defines at least one notch adapted to receive and support a first wire rope; and   such that the elongate member is not pulled from the ground when a vertical force is exerted on the first wire rope.   
   
   
       10 . The post of  claim 9  wherein the second side defines at least one notch adapted to receive and support a second wire rope;
 such that the elongate member is not pulled from the ground when a vertical force is exerted on the second wire rope.   
   
   
       11 . The post of  claim 9  wherein the first side defines a second notch adapted to receive and support a second wire rope;
 such that the elongate member is not pulled from the ground when a vertical force is exerted on the second wire rope.   
   
   
       12 . A road safety barrier comprising:
 a plurality of posts rigidly mounted on or in the ground; and   a plurality of wire ropes supported by the posts, the ropes held in tension along a length of the barrier;   wherein at least one of the posts comprises a first longitudinally oriented groove adapted to receive and support one of the plurality of wire ropes; and   such that the one wire rope is released from the groove when a vertical force is exerted on the wire rope.   
   
   
       13 . The road safety barrier of  claim 12  wherein the groove is arranged such that the post is not pulled from the ground when a vertical force is exerted on the first wire rope. 
   
   
       14 . The road safety barrier of  claim 12  wherein the post further comprises a second longitudinally oriented groove adapted to receive and support a second one of the plurality of wire ropes;
 such that the second wire rope is released from the groove when a vertical force is exerted on the second wire rope.   
   
   
       15 . The road safety barrier of  claim 14  wherein the first groove is disposed at a first height on the post and the second groove is disposed at a second height on the post. 
   
   
       16 . The road safety barrier of  claim 15  wherein the first groove and the second groove are on a first side of the post, such that the first height and the second height are vertically spaced apart. 
   
   
       17 . The road safety barrier of  claim 15  wherein the first groove and the second groove are on opposite sides of the post. 
   
   
       18 . The road safety barrier of  claim 17  wherein the first height and the second height are substantially the same. 
   
   
       19 . The road safety barrier of  claim 17  wherein the first height and the second height are vertically spaced apart. 
   
   
       20 . The road safety barrier of  claim 12  wherein the groove comprises a smooth support for the wire rope.