Pumped vertical drain

Abstract

A vertical drain for consolidating soil, the drain comprising an elongate surrounding filter jacket having a proximal end and a distal end; and a suction tube having at least one suction aperture located within the jacket, wherein, in use, a suction pump connected to the suction tube is operable to pump flowable material through the suction tube.

1 . A vertical drain for consolidating soil, the drain comprising:
 an elongate surrounding filter jacket having a proximal end and a distal end; and   a suction tube having at least one suction aperture located within the jacket, wherein, in use, a suction pump connected to the suction tube is operable to pump flowable material through the suction tube.   
     
     
         2 . The vertical drain of  claim 1 , wherein the at least one suction aperture is located substantially at the distal end of the jacket. 
     
     
         3 . The vertical drain of  claim 1 , wherein the at least one suction aperture comprises at least one of:
 an open end of the suction tube; and   a perforated portion of the suction tube.   
     
     
         4 . The vertical drain of  claim 1 , wherein the at least one suction aperture comprises a perforated portion of the suction tube and wherein the suction tube is perforated at substantially 100 mm intervals along at least a part of the length of the tube. 
     
     
         5 . The vertical drain of  claim 1 , wherein the at least one suction aperture comprises a perforated portion of the suction tube and wherein the suction tube is perforated not more than 1 m from the distal end of the filter jacket. 
     
     
         6 . The vertical drain of  claim 1 , further comprising a drain core within the filter jacket to provide a support structure. 
     
     
         7 . The vertical drain of  claim 1 , wherein there is an opening in the filter jacket to receive a length of the suction tube. 
     
     
         8 . The vertical drain of  claim 1 , wherein there is an opening in the filter jacket to receive a length of the suction tube and wherein a length of the suction tube is perforated to provide the at least one suction aperture and is located inside the filter jacket, and a length of the suction tube without a suction aperture passes through the opening in the filter jacket and is located outside the filter jacket. 
     
     
         9 . The vertical drain of  claim 1 , wherein the vertical drains are in an array. 
     
     
         10 . The vertical drain of  claim 1 , further comprising an anchor plate. 
     
     
         11 . A method of consolidating soil, the method comprising:
 installing a vertical drain into the soil to be consolidated, the vertical drain comprising an elongate surrounding filter jacket having a proximal end and a distal end and a suction tube having at least one suction aperture located within the jacket; and   operating a suction pump connected to the suction tube to pump fluid and/or flowable material that permeates through the filter jacket from the surrounding soil through the suction tube.   
     
     
         12 . The method of  claim 11 , wherein at least one suction aperture is located substantially at the distal end of the filter jacket and at least 0.25 m from the proximal end of the jacket. 
     
     
         13 . The method of  claim 11 , further comprising securing at least a portion of the suction tube such that at least one suction aperture is located substantially at the distal end of the filter jacket. 
     
     
         14 . The method of  claim 11 , further comprising at least one of:
 adding an overburden layer to the soil;   using electro-osmosis; and   using vacuum consolidation to increase the rate of water released from the soil.   
     
     
         15 . A method of installing a perforated suction tube into a vertical drain, the vertical drain comprising an elongate surrounding filter jacket having a proximal end and a distal end, and the method comprising:
 forming an opening in the filter jacket;   inserting at least a portion of the suction tube through the opening;   subsequent to inserting at least a portion of the suction tube, sealing the opening in the filter jacket; and   subsequent to inserting and securing the suction tube, installing the vertical drain into an area of soil to be consolidated.   
     
     
         16 . The method of  claim 15 , further comprising:
 perforating a tube to form the perforated suction tube, the tube having two ends; and   sealing one end of the suction tube.   
     
     
         17 . The method of  claim 15 , wherein installing the perforated suction tube further comprises securing at least a portion of the suction tube inside the jacket such that at least one suction aperture is located substantially at the distal end of the filter jacket. 
     
     
         18 . The method of  claim 15 , further comprising perforating a tube to form the perforated suction tube, wherein the tube is perforated at substantially 100 mm intervals along at least a part of the length of the tube and wherein the suction tube is perforated not more than 1 m from the distal end of the filter jacket. 
     
     
         19 . The method of  claim 15 , wherein the opening in the filter jacket is formed substantially 1.5 m from the distal end of the filter jacket. 
     
     
         20 . The method of  claim 15 , wherein the vertical drain further comprises a drain core and the method further comprises securing the tube to the drain core.