Road safety barrier

Abstract

A road safety barrier ( 1 ) comprises a series of beam sections ( 2 a to 2 d ) together forming a length of barrier and supported above the ground by way of posts ( 3 a to 3 g ). The positions of successive posts along at least part of the length of the barrier shift relative to the centres of the beam sections (C). The shift may be progressive but uniform along a section thereof so that the flexibility of the barrier is substantially constant. Shifting the locations of the posts along the length of the barrier by an increasing or decreasing amount has the effect of increasing or decreasing the strength of the barrier so that different road conditions can be accommodated even though beam sections of constant length are used to construct the barrier.

1 . A road safety barrier comprising a series of beam sections together forming a length of barrier and supported above the ground by way of posts, wherein the positions of successive posts along at least part of the length of the barrier shift relative to the centres of the beam sections.  
   
   
       2 . A road safety barrier according to  claim 1 , wherein the shift in respect of the posts along part of the length of the barrier is progressive but uniform.  
   
   
       3 . A road safety barrier according to  claim 2 , wherein the uniform shift is such as to provide a substantially constant flexibility along that length of the barrier.  
   
   
       4 . A road safety barrier according to  claim 1 , wherein the shift in respect of the posts along part of the length of the barrier varies.  
   
   
       5 . A road safety barrier according to  claim 4 , wherein the flexibility of the barrier varies in accordance with the varying shift along that length of the barrier.  
   
   
       6 . A road safety barrier according to  claim 1 , wherein the spacing between adjacent posts along a first section of the barrier differs from that of a second section, such that the first section has a different flexibility characteristic from the second section, and that the lengths of the beam sections forming said first and second sections are substantially equal to one another.  
   
   
       7 . A road safety barrier according to  claim 1 , wherein the post spacing is substantially equal along said at least part of the length of the barrier.  
   
   
       8 . A road safety barrier according to  claim 1 , wherein over a given length of the barrier, the ratio of the post spacing to the beam section length or distance between adjacent centres lies within the range 0.5 to 1.25.  
   
   
       9 . A road safety barrier according to  claim 1 , wherein the beam sections along said at least part of the length of the barrier are each provided with fixing means positioned at more than five locations along their length, the fixing means providing for location and fixing of the posts to the beam section.  
   
   
       10 . A road safety barrier according to  claim 9 , wherein said fixing means of at least some of said beam sections are substantially equally spaced apart with respect to one another.  
   
   
       11 . A road safety barrier according to  claim 1 , wherein the beam sections are corrugated.  
   
   
       12 . A road safety barrier according to  claim 11 , wherein the corrugated beam sections have a ‘W’ profile.  
   
   
       13 . A road safety barrier according to  claim 1 , wherein at least some of the posts are ‘Z’-shaped in cross-section.  
   
   
       14 . A method of constructing a road safety barrier which at least in part comprises a series of beam sections of substantially equal length supported above the ground by posts, the method comprising shifting the locations of the posts relative to the centres of the beam sections from one beam section to the next.  
   
   
       15 . A method according to  claim 14 , wherein the spacing between the posts is substantially equal such that said part has a substantially uniform flexibility characteristic.  
   
   
       16 . A method according to  claim 14 , wherein the spacing between the posts progressively varies from one beam section to the next such that the flexibility of the part of the barrier varies along its length.  
   
   
       17 . A method of testing a crash barrier system, the system comprising a series of beam sections together forming a length of barrier and supported above the ground by way of posts, wherein the positions of successive posts along at least part of the length of the barrier shift relative to the centres of the beam sections such that the stiffness of the barrier varies along the length, the method comprising conducting road crash tests at differing points along the length and determining whether the results of said crash tests satisfy predetermined criteria.