Cable barrier guardrail system with steel yielding support posts

Abstract

In accordance with a particular embodiment of the present invention, a guardrail system includes at least one cable operable to contain and redirect an errant vehicle. The guardrail system also includes a plurality of guardrail support posts spaced apart in relation to one another. Each support post includes a lower portion, a mid portion, and an upper portion. The lower portion is for installing below grade adjacent the roadway. The mid portion lies substantially adjacent the grade and includes a weakened section operable to weaken the support post about a longitudinal axis. The upper portion is releasably coupled to the at least one cable such that the upper portion is uncoupled from the at least one cable when the support post is displaced.

1 . A guardrail system, comprising: 
 at least one cable operable to contain and redirect an errant vehicle; and    a plurality of guardrail support posts spaced apart in relation to one another, each support post comprising: 
 a lower portion for installing below grade adjacent the roadway;  
 a mid portion that lies substantially adjacent the grade, the mid portion including a weakened section operable to weaken the support post about a longitudinal axis; and  
 an upper portion releasably coupled to the at least one cable such that the upper portion is uncoupled from the at least one cable when the support post is displaced.  
   
   
   
       2 . The guardrail system of  claim 1 , wherein the at least one cable comprises a number of cables, the number of cables selected from the group consisting of two cables, three cables, four cables, and five cables.  
   
   
       3 . The guardrail system of  claim 1 , wherein the at least one cable comprises an upper cable, a middle cable, and a lower cable, the upper and middle cables separated by a first spacer, the middle and lower cables separated by a second spacer, the first spacer and the second spacer having substantially equal dimensions to uniformly separate the upper, middle, and lower cables.  
   
   
       4 . The guardrail system of  claim 1 , wherein the at least one cable comprises an upper cable a middle cable and a lower cable, the upper and middle cables separated by a first spacer, the middle and lower cables separated by a second spacer, the first and spacer and the second spacer having unequal dimensions.  
   
   
       5 . The guardrail system of  claim 1 , wherein the weakened section comprises one or more cutouts formed in the mid portion of the support post.  
   
   
       6 . The guardrail system of  claim 1 , wherein the weakened section comprises at least one notch formed in a surface of the support post.  
   
   
       7 . The guardrail system of  claim 1 , wherein the weakened section comprises at least one sawcut formed in a surface of the support post.  
   
   
       8 . The guardrail system of  claim 1 , wherein the weakened section comprises at least one aperture formed through the support post.  
   
   
       9 . The guardrail system of  claim 8 , wherein the at least one aperture is selected from the group consisting of a circular aperture, an oval aperture, a diamond aperture, a triangular aperture, a square aperture, and a rectangular aperture.  
   
   
       10 . The guardrail system of  claim 1 , wherein the support post is comprised of steel.  
   
   
       11 . The guardrail system of  claim 10 , wherein the support post is selected from the group consisting of an I-beam, an H-beam, a C-channel, a S-beam, a W-beam, and a M-beam.  
   
   
       12 . The guardrail system of  claim 10 , wherein the weakened section comprises a pair of cutouts formed in the mid portion of the support post.  
   
   
       13 . The guardrail system of  claim 1 , wherein the support post comprises a continuous structural member having a top edge, a bottom edge, and a generally uniform cross section from the top edge to the bottom edge, the structural member including first and second generally parallel flanges, and a web forming a coupling between, and extending generally perpendicular to the first and second flanges.  
   
   
       14 . The guardrail system of  claim 13 , wherein the weakened section of the mid portion comprises first and second cutouts formed in the first and second flanges, respectively.  
   
   
       15 . The guardrail system of  claim 13 , wherein the web of the support post includes a cable slot the cable slot comprising: 
 a first portion comprising a plurality of enlarged openings, each pair of adjacent enlarged openings separated by a restriction, each of the plurality of enlarged openings adapted to receive a cable; and    a second portion of a substantially U-shaped configuration, the second portion adapted to receive at least one cable    
   
   
       16 . The guardrail system of  claim 1 , wherein the support post is comprised of wood.  
   
   
       17 . The guardrail system of  claim 16 , wherein the weakened section comprises at least one notch formed in a surface of the support post.  
   
   
       18 . The guardrail system of  claim 16 , wherein the weakened section comprises at least one saw cut formed in a surface of the support post.  
   
   
       19 . The guardrail system of  claim 1 , wherein a connector releasably couples the upper portion of the support post to a selected one of the at least one cables.  
   
   
       20 . The guardrail system of  claim 19 , wherein the connector is selected from the group consisting of a J bolt, I bolt, U bolt, locking hook bolt, and bent piece of plate.  
   
   
       21 . The guardrail system of  claim 1 , further comprising at least one retaining band disposed around the support post.  
   
   
       22 . The guardrail system of  claim 1 , wherein the weakened section of the mid portion is operable to weaken the support post about the longitudinal axis without changing the behavior of the support post in a lateral direction when loaded about the longitudinal axis.  
   
   
       23 . A guardrail support post, comprising: 
 a continuous structural member having first and second generally parallel flanges, and a web forming a coupling between, and extending generally perpendicular to the first and second flanges;    the structural member having a lower portion for installing below grade adjacent the roadway, an upper portion configured to couple with at least one cable, and a mid portion between the upper portion and the lower portion; and    wherein the upper portion includes a cable slot formed in the web of structural member, the cable slot comprising: 
 a first portion comprising a plurality of enlarged openings, each pair of adjacent enlarged openings separated by a restriction, each of the plurality of enlarged openings adapted to receive a cable; and  
 a second portion of a substantially U-shaped configuration, the second portion adapted to receive at least one cable.  
   
   
   
       24 . The guardrail support post of  claim 23 , wherein: 
 the plurality of enlarged openings comprise: 
 a first enlarged opening adapted to receive a first cable comprising an upper cable; and  
 a second enlarged opening adapted to receive a second cable comprising a middle cable; and  
   the second portion of the cable slot is adapted to receive a third cable comprising a lower cable.    
   
   
       25 . The guardrail support post of  claim 24 , further comprising: 
 a first spacer disposed between the upper and middle cables to separate the upper and middle cables by a first distance; and    a second spacer disposed between the middle and lower cables to separate the middle and lower cables by a second distance.    
   
   
       26 . The guardrail support post of  claim 25 , wherein the first distance and the second distance are substantially equal.  
   
   
       27 . The guardrail support post of  claim 25 , wherein the first distance and the second distance are unequal.  
   
   
       28 . The guardrail support post of  claim 23 , wherein: 
 the plurality of enlarged openings comprise: 
 a first enlarged opening adapted to receive a first cable comprising an upper cable;  
 a second enlarged opening adapted to receive a second cable;  
 a third enlarged opening adapted to receive a third cable; and  
 a fourth enlarged opening adapted to receive a fourth cable; and  
   the second portion is adapted to receive a fifth cable comprising a lower cable.    
   
   
       29 . The guardrail support post of  claim 23 , wherein the mid portion comprises a weakened section operable to weaken the support post about a first axis without substantially weakening the support member about a second axis that is generally perpendicular to the first axis.  
   
   
       30 . The guardrail support post of  claim 29 , wherein the weakened section comprises a pair of cutouts formed in each of the first and second flanges.  
   
   
       31 . The guardrail support post of  claim 29 , wherein the weakened section comprises one or more notches formed in each of the first and second flanges.  
   
   
       32 . The guardrail support post of  claim 29 , wherein the weakened section comprises one or more sawcuts formed in each of the first and second flanges.  
   
   
       33 . The guardrail support post of  claim 29 , wherein the weakened section comprises one or more apertures formed through each of the first and second flanges.  
   
   
       34 . The guardrail support post of  claim 33 , wherein the aperture is selected from the group consisting of a circular aperture, an oval aperture, a diamond aperture, a triangular aperture, a square aperture, and a rectangular aperture.  
   
   
       35 . The guardrail support post of  claim 23 , wherein the structural member is comprised of steel.  
   
   
       36 . The guardrail support post of  claim 35 , wherein the weakened section comprises a pair of cutouts formed in each of the first and second flanges.  
   
   
       37 . The guardrail support post of  claim 35 , wherein the weakened section comprises one or more notches formed in each of the first and second flanges.  
   
   
       38 . The guardrail support post of  claim 35 , wherein the weakened section comprises one or more sawcuts formed in each of the first and second flanges.  
   
   
       39 . The guardrail support post of  claim 23 , wherein the support post is comprised of wood.  
   
   
       40 . The guardrail support post of  claim 39 , wherein the weakened section comprises one or more notches formed in a surface of the support post.  
   
   
       41 . The guardrail support post of  claim 39 , wherein the weakened section comprises one or more saw cuts formed in a surface of the support post.  
   
   
       42 . A guardrail system, comprising: 
 a plurality of cables operable to contain and redirect an errant vehicle; and    a plurality of guardrail support posts spaced apart in relation to one another, each support post comprising: 
 a lower portion for installing below grade adjacent the roadway;  
 a mid portion that lies substantially adjacent the grade, the mid portion including a weakened section operable to weaken the support post about a longitudinal axis; and  
 an upper portion releasably coupled to the plurality of cables such that the upper portion is uncoupled from the plurality of cables when the support post is displaced, the upper portion including a cable slot formed in the web of structural member, the cable slot comprising: 
 a first portion comprising a plurality of enlarged openings, each pair of adjacent enlarged openings separated by a restriction, each of the plurality of enlarged openings adapted to receive a cable; and  
 a second portion of a substantially U-shaped configuration, the second portion adapted to receive at least one cable.