Base mat assembly and method of constructing the same

Abstract

A precast reinforced concrete base mat element, a base mat assembly and method for constructing a base mat assembly from a plurality of the base mat elements are described. The base mat element comprises a concrete body having first and second conduits extending there through in first and second generally perpendicular directions and a liner plate anchored in the concrete body. Preferably the concrete bodies have interlocking surfaces formed there on. A plurality of the base mat elements may be juxtaposed together with the interlocking surfaces interlocking with one another and with the tensile members extending through the first and second tensile conduits and being post-tensioned and anchored about the base mat elements to clamp the base mat elements together. The liner plates may then be welded together to form a a generally planar membrane. In one embodiment, at least one of the first and second tensile conduits is located above and one below the horizontal center planes of the concrete bodies to limit the base mat elements from displacing vertically relative to one another.

1 . A method of constructing a base mat assembly for supporting a primary container storing liquefied natural gas tank, the method comprising:
 providing a plurality of precast base mat elements, at least some of the base mat elements having:
 a concrete body having first and second tensile conduits extending there through and a top membrane plate anchored in the concrete body; 
   juxtaposing a plurality of the base mat elements;   inserting tensile members through the tensile conduit members of the base mat elements and tensioning and anchoring the tensile members about the base mat elements to clamp the base mat elements together; and   welding the membrane plates of the base mats together to form a generally horizontally extending base mat assembly with a generally contiguous membrane.   
     
     
         2 . The method of  claim 1  wherein:
 the first and second tensile conduits in a concrete body extend in generally perpendicular first and second directions to one another; and   the tensile members clamp the base mat elements in generally perpendicular directions.   
     
     
         3 . The method of  claim 2  wherein:
 the first and second conduits include at least two conduits in each of the first and second directions, the at least two conduits being located above and below the horizontal center plane of the concrete body.   
     
     
         4 . The method of  claim 1  further comprising:
 interlocking the concrete bodies of the at least two base mat elements to one another prior base mat elements being clamped together by the tensile member and anchors, the concrete bodies having interlocking surfaces.   
     
     
         5 . The method of  claim 4  further comprising:
 interlocking the concrete bodies in a horizontal direction.   
     
     
         6 . The method of  claim 4  further comprising:
 interlocking the concrete bodies in the vertical direction.   
     
     
         7 . The method of  claim 4  further comprising:
 interlocking the concrete bodies in a horizontal direction and in the vertical direction.   
     
     
         8 . The method of  claim 1  further comprising:
 mounting the base mat elements upon piles to provide enhanced stiffness to the base mat assembly.   
     
     
         9 . A base mat assembly for supporting a primary container storing liquefied natural gas, the base mat assembly comprising:
 a plurality of precast reinforced concrete base mat elements, at least two of the base mat elements including a concrete body having first and second tensile conduits extending there through in first and second generally perpendicular directions and a liner plate anchored in the concrete body; and   a plurality of post-tensioned tensile members extending through the first and second conduits and a plurality of anchors which are anchored on the tensile members and clamp the base mat elements together in first and second generally perpendicular directions;   wherein the liner plates are welded together to form a generally horizontally extending base mat assembly with a generally contiguous membrane on top the concrete bodies.   
     
     
         10 . The base mat assembly of  claim 9  wherein:
 the concrete bodies of the base mat elements have interlocking surfaces; and   the concrete bodies are interlocked with one another utilizing the interlocking surfaces.   
     
     
         11 . The base mat assembly of  claim 9  wherein:
 the base mat elements interlock in first and second horizontal directions.   
     
     
         12 . The base mat assembly of  claim 11  wherein:
 the base mat elements interlock in a vertical direction.   
     
     
         13 . The base mat assembly of  claim 11  wherein:
 at least one of the first and second tensile conduits extends horizontally above and at least one extends horizontally below the horizontal center plane of the concrete bodies of the base mat elements.   
     
     
         14 . The base mat assembly of  13  further comprising:
 a plurality of piles driven into the earth which support the base mat elements and provide additional stiffness to the membrane formed by the liner plates.   
     
     
         15 . A base mat element for constructing a generally horizontally extending base mat assembly, the base mat element comprising:
 a concrete body having first and second conduits extending there through in first and second generally perpendicular directions and a generally planar and horizontally extending liner plate anchored in the concrete body;   wherein a plurality of the base mat elements may be juxtaposed one another with tensile members extending through the first and second tensile conduits with anchors anchoring about the tensile members to clamp the base mat elements together with a generally planar membrane surface being formed by the clamped together base mat elements.   
     
     
         16 . The base mat element of  claim 15  wherein:
 the concrete body has interlocking surfaces formed thereon such that the interlocking surfaces of a plurality of such base mat elements can interlock with one another when the base mat elements are juxtaposed one another.   
     
     
         17 . The base mat element of  claim 15  wherein:
 at least one of the first and second tensile conduits is located above and one below the center horizontal plane of the concrete body so that when tensile members are passed through and anchored about the base mat elements, the clamped base mat elements resist displacing vertically relative to one another.   
     
     
         18 . The base mat element of  claim 15  wherein:
 the base mat element has interlocking surfaces which allow a plurality of the base mat elements to be juxtaposed one another and interlocked.   
     
     
         19 . The base mat element of  claim 18  wherein:
 the interlocking surfaces allow a plurality of the base mat assemblies to be interlocked in first and second horizontal directions and in a vertical direction.