Method of reinforcing a bridge

Abstract

A method of repairing, reinforcing or reinstating a bridge, comprising fixing a reinforcing plate in a spaced relationship with an existing plate or girder, especially on the underside of the bridge structure, to form a closed cavity, and injecting plastics or polymer material into said cavity in liquid form, whereby said plastics or polymer material sets or cures so as to bond to said reinforcing and existing plates with sufficient strength to transfer shear forces therebetween.

1 . A method of repairing, reinforcing or reinstating a bridge, comprising fixing a reinforcement plate in a spaced relationship with an existing plate or girder of the bridge structure to form a closed cavity, and injecting plastics or polymer material into said cavity in liquid form, whereby said plastics or polymer material sets or cures so as to bond to said reinforcing and existing plates with sufficient strength to transfer shear forces therebetween. 
   
   
       2 . A method according to  claim 1  wherein the existing plate or girder is on the underside of the bridge. 
   
   
       3 . A method according to  claim 2  wherein the bridge has a plurality of trough-shaped stiffeners, the reinforcing plate spans between the bottoms of the trough-shaped stiffeners and a lightweight form is provided in the space between the troughs prior to injection of the core material. 
   
   
       4 . A method according to  claim 3  wherein the lightweight form has a lower density than the core material. 
   
   
       5 . A method according to  claim 3  wherein the lightweight forms are hollow elongate bodies. 
   
   
       6 . A method according to  claim 5  wherein the lightweight forms are made of telescoping hollow prisms closed by end caps. 
   
   
       7 . A method according to  claim 6  wherein the prisms have trapezoidal cross-sections arranged to fit the space between the stiffening troughs. 
   
   
       8 . A method according to  claim 2  wherein the bridge has a plurality of plates spanning between girders and said step of fixing a reinforcing plate comprises fixing a first reinforcing plate to a first girder and a second reinforcing plate to a second girder adjacent the first girder, the first and second reinforcing plates cooperating to span the distance between said girders. 
   
   
       9 . A method according to  claim 8  wherein said first and second reinforcing plates overlap in a lap joint. 
   
   
       10 . A method according to  claim 8  wherein the first and second reinforcing plates are curved to match the curvature of the existing plates. 
   
   
       11 . A method according to  claim 1  wherein the existing plate is a web of a box or plate girder. 
   
   
       12 . A method according to  claim 1  wherein the reinforcing plate is metal, e.g. steel, stainless steel or aluminium. 
   
   
       13 . A method according to  claim 1  wherein the reinforcing plate has a thicknesses in the range of from 0.5 to 20 mm. 
   
   
       14 . A method according to  claim 1  wherein the plastics or polymer core is an elastomer such as polyurethane. 
   
   
       15 . A method according to  claim 14  wherein the elastomer is compact. 
   
   
       16 . A bridge comprising an existing structure adjacent which is provided a reinforcing plate, the reinforcing plate being bonded to the existing structure by an intermediate layer of plastics or polymer material that is bonded to the reinforcing plate and the existing structure with sufficient strength to transfer shear forces therebetween.