Lightweight support mat for equipment and vehicles

Abstract

A lightweight rig mat comprises a cellular soil stabilization material, with a plastic foam injected into the cells of the cellular material to provide required load-carrying capacity. The cellular material is preferably treated with a bonding agent to promote a structural bond between the plastic foam and the cellular material, thereby enhancing the overall shear strength, structural integrity, and flexural rigidity of the mat. The cell walls may also have textured surfaces to enhance the bond with the foam. The walls between the cells in the cellular material may have perforations to permit foam to flow between cells during the foam-injection process. The mat may be formed with connector pockets to facilitate interconnection of adjacent mats using suitable connection means, so as to prevent lateral separation between mats while allowing articulation between adjacent mats to accommodate irregular ground surfaces.

What is claimed is: 
     
         1 . A rig mat comprising a cellular material defining a plurality of cells enclosed by cell walls, with said cells being filled with a structural foam to form a foam-filled cellular panel of substantially uniform thickness and having an upper surface, a lower surface, and a perimeter. 
     
     
         2 . A rig mat as in  claim 1  wherein the at least some of the cell walls have perforations. 
     
     
         3 . A rig mat as in  claim 1 , further comprising an enclosure band around the perimeter of the foam-filled cellular panel. 
     
     
         4 . A rig mat as in  claim 1 , further comprising a top skin covering the upper surface of the foam-filled cellular panel and a bottom skin covering the lower surface of the foam-filled cellular panel. 
     
     
         5 . A rig mat as in  claim 3 , further comprising a top skin covering the upper surface of the foam-filled cellular panel and a bottom skin covering the lower surface of the foam-filled cellular panel. 
     
     
         6 . A rig mat as in  claim 1 , further comprising interconnection means, for interconnection with a laterally-adjacent rig mat. 
     
     
         7 . A rig mat as in  claim 6 , wherein the interconnection means comprises one or more connector pockets. 
     
     
         8 . A method for constructing a rig mat structure, said method comprising the steps of:
 (a) providing a plurality of rig mats in accordance with  claim 7 ;   (b) arranging the plurality of rig mats over a ground surface with each rig mat laterally adjacent to at least one other rig mat;   (c) providing a plurality of connection bars, each having two end legs and configured such that one of the end leg can be disposed within a selected connector pocket in a first rig mat and the other end leg can be disposed within a selected connector pocket in an adjacent second rig mat; and   (d) for each connection bar, disposing one of its end legs within a selected connector pocket in a first rig mat and disposing the other end leg within a selected connector pocket in an adjacent second rig mat.   
     
     
         9 . A method as in  claim 8 , further comprising the step of introducing a filler material into each connector pocket receiving an end leg of a connection bar. 
     
     
         10 . A method as in  claim 8  wherein at least one connection bar has a generally C-shaped configuration. 
     
     
         11 . A method as in  claim 8  wherein at least one connection bar has a generally S-shaped configuration.