Grout free expandable standpipe

Abstract

A grout free expandable standpipe (10) and methods for its use for anchoring into ground formation (22) and injecting grout into the ground formation (22), without the need for first grouting the standpipe (10) into the ground formation (22). The expandable standpipe (10) has a swage seal (43) that can be expanded with a swage tool, such as, for example, a unitary construction inflatable swage packer (60), or similar, for anchoring and sealing the standpipe (10) into a pilot hole (16), without the need for grout. A grouting hole (96) can then be drilled through the bore of the expandable standpipe (10) and into the ground formation. Then grout can be injected into the ground formation (22) via the grout hole (96) without having to wait up to around 24 hours for grout to cure and harden to anchor and seal the expandable standpipe (10) into the pilot hole (16).

1 . A method of anchoring and sealing an expandable standpipe into a ground formation, including the steps of:
 forming a shallow pilot hole into the ground formation;   inserting the expandable standpipe most of the way into the pilot hole; and   expanding the standpipe radially outwardly to anchor and seal into the pilot hole;   whereby expanding the standpipe causes it to anchor and seal into the ground formation, without the need for grout.   
     
     
         2 . A method of grouting ground formation with an expandable standpipe, the method of grouting ground formation, including the steps of:
 forming a shallow pilot hole into the ground formation;   inserting the expandable standpipe most of the way into the pilot hole;   expanding the standpipe radially outwardly to anchor and seal into the pilot hole;   forming a grout hole through a bore of the expandable standpipe into the ground formation ahead of the pilot hole; and   injecting grout through the standpipe and through the grouting hole into the ground formation;   whereby expanding the standpipe causes it to anchor and seal into the ground formation without the need for grout.   
     
     
         3 . The method of  claim 2 , in which the expandable standpipe also comprises a swage seal and wherein the step of inserting the expandable standpipe into the pilot hole, also includes a step of positioning the swage seal proximate the blind end of the pilot hole. 
     
     
         4 . The method of  claim 3 , wherein the step of positioning of the expandable standpipe into the pilot hole leaves a space of between 150 mm to 500 mm, between an inserted end of the expandable standpipe and the blind end of the pilot hole. 
     
     
         5 . The method of  claim 3 , wherein the step of expanding the standpipe comprises a step of expanding the swage seal to anchor and seal the standpipe into the pilot hole. 
     
     
         6 . The method of  claim 2 , wherein the step of forming the pilot hole includes a step of making the pilot hole about the same length as the length of the expandable standpipe. 
     
     
         7 . The method of  claim 5 , wherein the step of expanding of the swage seal is performed with an inflatable packer. 
     
     
         8 . The method of  claim 5 , wherein the step of expanding the swage seal is performed with a high energy rate device (HERD) capable of rapidly expanding the swage seal into contact with the interior wall of the pilot hole. 
     
     
         9 . The method of  claim 8 , wherein high pressure liquid constitutes the HERD and is explosively injected into the swage seal to cause the swage seal to expand into contact with the pilot hole. 
     
     
         10 . The method of  claim 8 , wherein an explosive charge constitutes the HERD, and is located in the bore of the swage seal and detonated to cause the swage seal to expand into contact with the pilot hole. 
     
     
         11 . A grout free expandable standpipe for anchoring and sealing into a pilot hole in a ground formation without grout, the expandable standpipe being useful for pumping grout into a grout hole in the ground formation, the expandable standpipe comprising:
 an elongate tube comprising a delivery tube connected endwise to a swage tube, the elongate tube being dimensioned for insertion into the pilot hole, the elongate tube also comprising a bore which passes through the delivery tube and the swage tube, the bore being capable of receiving a setting tool for expanding the swage tube and for receiving a drill rod for drilling a grout hole, about half the diameter of the pilot hole, through a blind end of the pilot hole;
 the delivery tube being configured for inserting the elongate tube into the pilot hole, and the delivery tube being able to project, when in use, out of the pilot hole; and, 
 the swage tube being disposable in the pilot hole to a position proximate the blind end of the pilot hole, the swage tube being expandable radially outwardly with an inflatable packer element to contact the pilot hole; and 
   a swage seal located on the external curved surface of the end of the elongate tube proximate the blind end of the pilot hole, the swage seal being expandable radially outwardly to anchor and seal the standpipe into the pilot hole;   wherein anchoring and sealing of the expandable standpipe into the ground formation does not require grout; and   wherein grout can be pumped through the elongate tube and into the grout hole for stabilising the ground formation around the grout hole.   
     
     
         12 . The grout free expandable standpipe of  claim 11 , wherein the swage seal has an elastomer layer on its outer curved surface for conforming to the inside of the pilot hole. 
     
     
         13 . The grout free expandable standpipe of  claim 12 , wherein the elastomer layer has a longitudinal cross-section that is castellated, to better conform to the shape of the inside of the pilot hole. 
     
     
         14 . The grout free expandable standpipe of  claim 11 , also comprising an expansion tool for expanding the swage seal. 
     
     
         15 . The grout free expandable standpipe of  claim 14 , wherein the expansion tool includes an inflatable packer. 
     
     
         16 . The grout free expandable standpipe of  claim 15 , wherein the inflatable packer is of a unitary construction and is capable of multiple inflations and deflations for insertion into and retrieval from the swage seal. 
     
     
         17 . The grout free expandable standpipe of  claim 15 , wherein the inflatable packer is expandable to at least 130% of original diameter and wherein the inflatable packer can contract from its expanded diameter to approximately 100% of its original diameter. 
     
     
         18 . The grout free expandable standpipe of  claim 14 , wherein the expansion tool is a high energy rate device (HERD) capable of rapidly expanding the swage seal into contact with the interior wall of the pilot hole. 
     
     
         19 . The grout free expandable standpipe of  claim 18 , wherein the HERD is high pressure liquid, explosively injected into the swage seal. 
     
     
         20 . The grout free expandable standpipe of  claim 18 , wherein the HERD is an explosive charge located in the bore of the swage seal and detonated to cause the swage seal to expand into contact with the pilot hole. 
     
     
         21 . A grout free expandable standpipe system for pumping grout into a grout hole in formed in a ground formation, the expandable standpipe system comprising:
 an elongate tube comprising a delivery tube connected endwise to a swage tube, the elongate tube being dimensioned for insertion into the pilot hole, the elongate tube also comprising a bore which passes through the delivery tube and the swage tube, the bore being capable of receiving a setting tool for expanding the swage tube and for receiving a drill rod for drilling a grout hole, about half the diameter of the pilot hole, through a blind end of the pilot hole;
 the delivery tube being configured for inserting the elongate tube into the pilot hole, and the delivery tube being able to project, when in use, out of the pilot hole; and, 
 the swage tube being disposable in the pilot hole to a position proximate the blind end of the pilot hole, the swage tube being expandable radially with an inflatable packer element to contact the pilot hole; and 
   a swage seal located on the external curved surface of the end of the elongate tube proximate the blind end of the pilot hole, the swage seal being expandable radially outwardly to anchor and seal the standpipe into the pilot hole;   a setting tool comprising an inflatable packer element locatable within the standpipe for expanding the swage seal into contact with the pilot hole, the setting tool being removable from the standpipe once the swage seal is expanded; and   a high-pressure pump connected to the setting tool for inflating and deflating the inflatable packer;   wherein anchoring and sealing of the expandable standpipe into the ground formation does not require grout; and   wherein grout can be pumped through the expandable standpipe and into the grout hole for stabilising the ground formation around the grout hole.   
     
     
         22 . The method of  claim 1 , in which the expandable standpipe also comprises a swage seal and wherein the step of inserting the expandable standpipe into the pilot hole, also includes a step of positioning the swage seal proximate the blind end of the pilot hole. 
     
     
         23 . The method of  claim 22 , wherein the step of positioning of the expandable standpipe into the pilot hole leaves a space of between 150 mm to 500 mm, between an inserted end of the expandable standpipe and the blind end of the pilot hole. 
     
     
         24 . The method of  claim 23 , wherein the step of expanding the standpipe comprises a step of expanding the swage seal to anchor and seal the standpipe into the pilot hole. 
     
     
         25 . The method of  claim 1 , wherein the step of forming the pilot hole includes a step of making the pilot hole about the same length as the length of the expandable standpipe. 
     
     
         26 . The method of  claim 24 , wherein the step of expanding of the swage seal is performed with an inflatable packer. 
     
     
         27 . The method of  claim 24 , wherein the step of expanding the swage seal is performed with a high energy rate device (HERD) capable of rapidly expanding the swage seal into contact with the interior wall of the pilot hole. 
     
     
         28 . The method of  claim 27 , wherein high pressure liquid constitutes the HERD and is explosively injected into the swage seal to cause the swage seal to expand into contact with the pilot hole. 
     
     
         29 . The method of  claim 27 , wherein an explosive charge constitutes the HERD, and is located in the bore of the swage seal and detonated to cause the swage seal to expand into contact with the pilot hole.