A weakened guardrail mounting connection

Abstract

In accordance with a particular embodiment of the present invention, a guardrail safety system includes a guardrail beam and a plurality of support posts in spaced apart relation to one another. Each support post is configured to be releasably coupled to the guardrail beam. A plurality of connectors couple the plurality of support posts to the guardrail beam. Each connector includes a head portion that is configured to provide a sufficiently strong connection between the guardrail beam and the support post to support the guardrail beam and a sufficiently weak connection between the guardrail beam and the support post to enable the support post to detach from the guardrail beam when struck by the errant vehicle.

1 . A guardrail safety system, comprising: 
 a guardrail beam;    a plurality of support posts in spaced apart relation to one another, each support post configured to be releasably coupled to the guardrail beam; and    a plurality of connectors for coupling the plurality of support posts to the guardrail beam, each connector including a head portion that is configured to provide a sufficiently strong connection between the guardrail beam and the support post to support the guardrail beam and a sufficiently weak connection between the guardrail beam and the support post to enable the support post to detach from the guardrail beam when struck by the errant vehicle.    
   
   
       2 . The guardrail safety system of  claim 1 , wherein each of the plurality of connectors comprise a bolt having a countersunk head defined by a first surface and a second surface, the countersunk head having a tapered side between the first and second surfaces.  
   
   
       3 . The guardrail safety system of  claim 2 , the countersunk head includes a shoulder proximate a threaded shaft of the bolt.  
   
   
       4 . The guardrail safety system of  claim 2 , wherein each countersunk head of the bolt comprises: 
 a first surface having a substantially round configuration; and    a second surface proximate a threaded shaft of the bolt, the second surface having a substantially oval configuration to prevent the connector from rotating relative to the guardrail beam.    
   
   
       5 . The guardrail safety system of  claim 1 , wherein the guardrail beam comprises a plurality of mounting slots, the guardrail beam coupled to one or more support posts by at least one of the plurality of connectors passing through an associated slot of the guardrail beam.  
   
   
       6 . The guardrail safety system of  claim 1 , wherein each of the plurality of connectors comprise: 
 a threaded shaft;    a head portion coupled to the threaded shaft; and    a shoulder portion proximate the threaded shaft and configured to prevent the connector from rotating relative to the guardrail beam.    
   
   
       7 . The guardrail safety system of  claim 1 , wherein at least a portion of the plurality of support posts comprise: 
 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 first axis without substantially changing the behavior of the support post about a second axis that is generally perpendicular to the first axis; and    an upper portion releasably coupled to the LON portion of the guardrail beam.    
   
   
       8 . The guardrail safety system of  claim 7 , wherein the weakened section is selected from the group consisting of at least one cutout formed through the support post, at least one cutout formed in a surface of the support post, at least one notch formed in a surface of the support post, at least one diamond-shaped notch formed in a surface of the support post, at least one sawcut formed in a surface of the support post, at least one semi-circular opening formed in a surface of the support post, at least one semi-circular opening formed through the support post, and at least one aperture formed through the support post.  
   
   
       9 . The guardrail safety system of  claim 1 , wherein: 
 the support post is comprised of a material selected from the group consisting of steel, wood, plastic, and composites; and    the shape of the support post is selected from the group consisting of an I-beam, an H-beam, a C-channel, an S-beam, a W-beam, a M-beam, a rectangular member, a round member, a square member, and a tubular member.    
   
   
       10 . The guardrail safety system of  claim 1 , wherein: 
 the guardrail beam includes a plurality of apertures for receiving a respective one of the plurality of connectors;    each connector comprising a head portion of a size that is bigger than the aperture receiving the connector, the head portion overlapping an edge of the aperture by a distance that generates a desired pullout resistance, the size of the head portion selected as a function of a thickness of the guardrail beam.    
   
   
       11 . A guardrail safety system, comprising: 
 a guardrail beam;    a support post coupled to the guardrail beam, the 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 first axis without substantially changing the behavior of the support post about a second axis that is generally perpendicular to the first axis; and  
 an upper portion releasably coupled to the LON portion of the guardrail beam; and  
   a connector for coupling the support post to the guardrail beam, the connector including a head portion that is configured to provide a sufficiently strong connection between the guardrail beam and the support post to support the guardrail beam and a sufficiently weak connection between the guardrail beam and the support post to enable the support post to detach from the guardrail beam when struck by the errant vehicle.    
   
   
       12 . The guardrail safety system of  claim 11 , wherein the connector comprises a bolt having a countersunk head defined by a first surface and a second surface, the countersunk head having a tapered side between the first and second surfaces.  
   
   
       13 . The guardrail safety system of  claim 12 , the countersunk head includes a shoulder proximate a threaded shaft of the bolt.  
   
   
       14 . The guardrail safety system of  claim 12 , wherein each countersunk head of the bolt comprises: 
 a first surface having a substantially round configuration; and    a second surface proximate a threaded shaft of the bolt, the second surface having a substantially oval configuration to prevent the connector from rotating relative to the guardrail beam.    
   
   
       15 . The guardrail safety system of  claim 11 , wherein the guardrail beam includes a mounting slot, the guardrail beam coupled to one or more support posts by the connector passing through the mounting slot of the guardrail beam.  
   
   
       16 . The guardrail safety system of  claim 11 , wherein the connector comprises: 
 a threaded shaft;    a head portion coupled to the threaded shaft; and    a shoulder portion proximate the threaded shaft and configured to prevent the connector from rotating relative to the guardrail beam.    
   
   
       17 . The guardrail safety system of  claim 11 , wherein the weakened section is selected from the group consisting of at least one cutout formed through the support post, at least one cutout formed in a surface of the support post, at least one notch formed in a surface of the support post, at least one diamond-shaped notch formed in a surface of the support post, at least one sawcut formed in a surface of the support post, at least one semi-circular opening formed in a surface of the support post, at least one semi-circular opening formed through the support post, and at least one aperture formed through the support post.  
   
   
       18 . The guardrail safety system of  claim 11 , wherein: 
 the support post is comprised of a material selected from the group consisting of steel, wood, plastic, and composites; and    the shape of the support post is selected from the group consisting of an I-beam, an H-beam, a C-channel, an S-beam, a W-beam, a M-beam, a rectangular member, a round member, a square member, and a tubular member.    
   
   
       19 . The guardrail safety system of  claim 11 , wherein: 
 the guardrail beam includes an aperture for receiving the connector;    the connector comprising a head portion of a size that is bigger than the aperture receiving the connector, the head portion overlapping an edge of the aperture by a distance that generates a desired pullout resistance, the size of the head portion selected as a function of a thickness of the guardrail beam.    
   
   
       20 . A guardrail safety system, comprising: 
 a guardrail beam;    a plurality of support posts in spaced apart relation to one another, at least a portion of the support posts configured to be releasably coupled to the guardrail beam and 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 first axis without substantially changing the behavior of the support post about a second axis that is generally perpendicular to the first axis; and  
 an upper portion releasably coupled to the LON portion of the guardrail beam; and  
   a plurality of connectors for coupling at least a portion of the plurality of support posts to the guardrail beam, each connector comprising a countersunk bolt enabling the support post to detach from the guardrail beam when struck by the errant vehicle; and    wherein the guardrail beam is coupled to at least a portion of the plurality of support posts by at least one of the plurality of connectors passing through an associated slot of the guardrail beam.