Void-maintaining geosynthetic laminates and drainage systems

Abstract

Void-maintaining geocomposite laminates, and drainage systems utilizing those laminates, are provided for location below a road surface or below a large structure such as a building, retaining wall or parking lot. The laminates include at least one fluid-transmissible layer adjacent an upper or lower surface of a polymer-based core. Optionally, another fluid-transmissible layer is provided adjacent a lower surface of the polymer-based core to form geocomposite laminates having high permittivity and high transmissivity. The one or more fluid-transmissible layers are preferably geotextiles. Characteristic of the core element is high transmissivity, that is, a high rate of horizontal flow of gases or liquids through the core. Characteristic of the at least one fluid-transmissible layer is high permittivity, that is, a high rate of vertical transmission of liquids and gases through the geotextile layer and into the core element. Also characteristic of fluid-transmissible layers of the invention is high exclusivity with respect to solid materials. Core elements and fluid-transmissible layers advantageously can be formed separately so that the components may be separately transported to a site and installed in sequence, or bonded to one another onsite by welding or adhesives. The systems include further drain means that communicate with the geocomposite structures of the system, such as perforated pipes and the like, which can connect further to culverts, ditches or waterways. The geocomposite structures and drain can form part of a greater subsurface geosynthetic system that provides reinforcement, separation, and drainage for the structure to thereby extend its useful life and decrease maintenance costs.

What is claimed is:  
     
         1 . A drainage system for draining fluids away from a roadway or other large structure, comprising: 
 A) a void-maintaining laminate comprising 
 i) a geocomposite core layer having a plurality of interconnected voids, said core layer having an upper surface and a lower surface, and  
 ii) at least one fluid-transmissible layer adjacent said upper surface, 
 wherein said layers are constructed and arranged so that said laminate maintains voids of sufficient dimension that said water from said roadway or other large structure can move freely through said laminate, and  
 wherein said laminate is sloped downwardly from said roadway or other large structure.  
 
   
     
     
         2 . The drainage system of  claim 1 , wherein said void-maintaining laminate further comprises 
 iii) at least one fluid-transmissible geotextile layer adjacent said lower surface of said laminate,    and wherein said at least one fluid-transmissible layer is a geotextile.    
     
     
         3 . The drainage system of  claim 1 , further comprising 
 B) drain means adjacent said laminate and communicating therewith such that said fluid can move from said laminate to said drain means, wherein said drain means is sloped downwardly from said laminate.    
     
     
         4 . The drainage system of  claim 1 , wherein said laminate is sloped downwardly away from a portion of said roadway or said large structure such that said fluid is directed away from said roadway or said large structure.  
     
     
         5 . The drainage system of  claim 3 , wherein said laminate communicates with said drain means at a margin of said roadway or said large structure.  
     
     
         6 . The drainage system of  claim 3 , wherein said drain means further comprises a ditch or culvert adjacent a margin of said roadway or said large structure.  
     
     
         7 . The drainage system of  claim 3 , wherein said drain means comprises perforated piping.  
     
     
         8 . The drainage system of  claim 7 , wherein said laminate wraps around the circumference of said perforated piping.  
     
     
         9 . The drainage system of  claim 7 , wherein said perforated piping is connected to further drains means and wherein said further drain means is one or more selected from the group consisting of non-perforated pipes, drainage ditches, sumps, canals, streams and rivers.  
     
     
         10 . The drainage system of  claim 2 , wherein one or both of said geotextile layers are attached to said geocomposite core layer.  
     
     
         11 . The drainage system of  claim 1 , wherein said geocomposite core layer comprises a geonet.  
     
     
         12 . The drainage system of  claim 1 , wherein said geocomposite core layer is tri-planar and comprises polyethlene.  
     
     
         13 . The drainage system of  claim 2 , wherein one or both said geotextile layers are nonwoven and needle punched.  
     
     
         14 . The drainage system of  claim 7 , wherein said void-maintaining laminate is constructed and arranged to form a wrapping adjacent to and around the circumference of said perforated piping such that a portion of one of said upper or lower fluid-transmissible geotextile layers is removed along the length of the wrapping so that said geocomposite core contacts said piping and said removed portion of said one of said upper or lower fluid-transmissible geotextile layers is overlapping and connected to the other surface fluid-transmissible geotextile layer.  
     
     
         15 . The drainage system of  claim 7 , wherein said overlapping portions of said fluid-transmissible geotextile layers are connected by welding.  
     
     
         16 . The drainage system of  claim 7 , wherein said overlapping portions of said fluid-transmissible geotextile layers are connected by sewing.  
     
     
         17 . The drainage system of  claim 7 , wherein said portions of said fluid-transmissible geotextile layers and said geocomposite core of said laminate are held adjacent to said piping by circumferencial ties around said laminate.  
     
     
         18 . The drainage system of  claim 1 , wherein said fluid comprises water.  
     
     
         19 . A drainage system disposed at a level below the top surface of a roadway for draining fluids such as water away from said roadway comprising: 
 A) a void-maintaining laminate comprising 
 i) a geocomposite core layer having a plurality of interconnected voids, said core layer having an upper surface and a lower surface, and  
 ii) at least one fluid-transmissible layer adjacent said upper surface, 
 wherein said layers are constructed and arranged so that said laminate maintains voids of sufficient dimension that said water from said roadway can move freely through said laminate, and  
 wherein said laminate is sloped downwardly from said top surface of said roadway.  
 
   
     
     
         20 . The drainage system of  claim 19 , wherein said void-maintaining laminate further comprises 
 iii) at least one fluid-transmissible layer adjacent said lower surface of said laminate    and wherein said fluid-transmissible layer is a geotextile.    
     
     
         21 . The drainage system of  claim 19 , further comprising 
 B) drain means adjacent said laminate and communicating therewith such that said fluid can move from said laminate to said drain means, wherein said drain means is sloped downwardly from said laminate such that said fluid is directed away from said roadway.    
     
     
         22 . The drainage system of  claim 19 , wherein said laminate is constructed and arranged to provide a capillary break between said roadway top surface and the earthen materials under said laminate.  
     
     
         23 . The drainage system of  claim 19 , wherein said laminate is positioned discontinuously below said top road surface.  
     
     
         24 . The drainage system of  claim 19 , wherein said laminate is positioned continuously below said top road surface.  
     
     
         25 . The drainage system of  claim 19 , wherein said laminate is positioned below said top road surface and above a subgrade.  
     
     
         26 . The drainage system of  claim 19 , wherein said laminate is positioned below said top road surface and above a subgrade.  
     
     
         27 . The drainage system of  claim 19 , wherein said laminate is positioned below said top road surface and below a subgrade.  
     
     
         28 . The drainage system of  claim 19 , wherein said laminate is positioned below said top road surface and below the ground water table.  
     
     
         29 . The drainage system of  claim 19 , wherein said laminate is positioned below said top road surface and above an aggregate structure.  
     
     
         30 . The drainage system of  claim 19 , wherein said laminate is positioned below said top road surface in portions which are interconnected such that said interconnecting voids are of sufficient dimension that said water from said roadway can move freely through said laminate.  
     
     
         31 . The drainage system of  claim 21 , wherein said drain means further comprises a ditch or culvert adjacent a margin of said roadway or said large structure.  
     
     
         32 . The drainage system of  claim 21 , wherein said drain means comprises perforated piping.  
     
     
         33 . The drainage system of  claim 32 , wherein said laminate wraps around the circumference of said perforated piping.  
     
     
         34 . The drainage system of claim 32 , wherein said perforated piping is connected to further drains means and wherein said further drain means is one or more selected from the group consisting of non-perforated pipes, drainage ditches, sumps, canals, streams and rivers.  
     
     
         35 . The drainage system of  claim 20 , wherein one or both of said geotextile layers are attached to said geocomposite core layer.  
     
     
         36 . The drainage system of  claim 19 , wherein said geocomposite core layer comprises a geonet.  
     
     
         37 . The drainage system of  claim 19 , wherein said geocomposite core layer is tri-planar and comprises polyethlene.  
     
     
         38 . The drainage system of  claim 20 , wherein one or both said geotextile layers are nonwoven and needle punched.  
     
     
         39 . The drainage system of  claim 32 , wherein said void-maintaining laminate is constructed and arranged to form a wrapping adjacent to and around the circumference of said perforated piping such that a portion of one of said upper or lower fluid-transmissible layers is removed along the length of the wrapping so that said geocomposite core contacts said piping and said removed portion of said one of said upper or lower fluid-transmissible geotextile layers is overlapping and connected to the other surface fluid-transmissible geotextile layer.  
     
     
         40 . The drainage system of  claim 32 , wherein said overlapping portions of said fluid-transmissible geotextile layers are connected by welding.  
     
     
         41 . The drainage system of  claim 32 , wherein said overlapping portions of said fluid-transmissible geotextile layers are connected by sewing.  
     
     
         42 . The drainage system of  claim 32 , wherein said portions of said fluid-transmissible geotextile layers and said geocomposite core of said laminate are held adjacent to said piping by circumferencial ties around said laminate.  
     
     
         43 . The drainage system of  claim 1 , wherein said fluid comprises water.  
     
     
         44 . A method for constructing a drainage system for draining fluids away from a roadway or other large structure, comprising: 
 A) providing a void-maintaining laminate comprising 
 i) a geocomposite core layer having a plurality of interconnected voids, said core layer having an upper surface and a lower surface, and  
 ii) at least one fluid-transmissible layer adjacent said upper surface, 
 wherein said layers are constructed and arranged so that said laminate maintains voids of sufficient dimension that said water from said roadway or other large structure can move freely through said laminate, and  
 wherein said laminate is sloped downwardly from said roadway or other large structure.  
 
   
     
     
         45 . The method of  claim 44 , wherein said void-maintaining laminate further comprises 
 iii) at least one fluid-transmissible geotextile layer adjacent said lower surface of said laminate, and    wherein said fluid-transmissible layer is a geotextile.    
     
     
         46 . The method of  claim 44 , wherein said drainage system further comprises 
 B) drain means adjacent said laminate and communicating therewith such that said fluid can move from said laminate to said drain means, wherein said drain means is sloped downwardly from said laminate.    
     
     
         47 . The method of  claim 44 , wherein said laminate is sloped downwardly away from a portion of said roadway or said large structure such that said fluid is directed away from said roadway or said large structure.  
     
     
         48 . The method of  claim 44 , wherein said laminate communicates with said drain means at a margin of said roadway or said large structure.  
     
     
         49 . The method of  claim 44 , wherein said laminate is constructed and arranged to provide a capillary break between said roadway or said large structure and the earthen materials under said laminate.  
     
     
         50 . The method of  claim 44 , wherein said laminate is positioned intermittently below said roadway or said large structure.  
     
     
         51 . The method of  claim 44 , wherein said laminate is positioned continuously below said roadway or said large structure.  
     
     
         52 . The method of  claim 44 , wherein said laminate is positioned below said roadway or said large structure and above a subgrade.  
     
     
         53 . The method of  claim 44 , wherein said laminate is positioned below said roadway or said large structure and below a subgrade.  
     
     
         54 . The method of  claim 44 , wherein said laminate is positioned below said roadway or said large structure and at least two feet below a subgrade.  
     
     
         55 . The method of  claim 44 , wherein said laminate is positioned below said roadway or said large structure and above an aggregate structure.  
     
     
         56 . The method of  claim 44 , wherein said laminate is positioned below said roadway or said large structure in portions which are interconnected such that said interconnecting voids are of sufficient dimension that said water from said roadway can move freely through said laminate.  
     
     
         57 . The method of  claim 44 , wherein said drain means further comprises a ditch or culvert adjacent a margin of said roadway or said large structure.  
     
     
         58 . The method of  claim 44 , wherein the roadway base course comprises materials which have been excavated from said subgrade of said roadway.  
     
     
         59 . The method of  claim 44 , wherein the roadway base course comprises materials which have been excavated from said subgrade of said roadway mixed with imported materials.