Device and Method for Improved Pile Casting

Abstract

This invention deals with a device and a method for an improved concrete pile casting in swelling soils by substantially lowering or eliminating heave forces created in active soils from affecting said piles by surrounding selectable parts of the pile by an easily deformable material for lowering the horizontal and the vertical soil movement effect, and by providing a low friction surface for further lowering vertical forces effect. This inventive device and method further facilitates subsequent operations by permitting an easy and seamless casting of columns and by ensuring a clean and smooth pile surface for a better adhesion of new concrete to an old one, as well as preventing cement dough seepage to surrounding soil and concrete segregation.

1 . A device for in-situ casting of at least partly underground concrete pile within a borehole having a mouth, said borehole having a reinforcing cage at least partially disposed therein, said device comprising:
 A cylindrical inner sleeve mountable within said borehole for casting said pile, said inner sleeve having a length, an upper extremity and a lower extremity, and dimensioned to at least partially surround said reinforcement cage;   A filling sleeve having an upper extremity and a lower extremity and having substantially the same length as the length of said inner sleeve, said filling sleeve dimensioned to circumferentially encompass said inner sleeve, said filling sleeve being substantially deformable and made of material having a low elastic modulus;   An outer sleeve having an upper extremity and a lower extremity and having substantially the same length as said inner and filling sleeves, said outer sleeve dimensioned to circumferentially encompass said filling sleeve, said outer sleeve and said filling sleeve having a low coefficient of friction therebetween,   Wherein said lower extremities of said inner, filling, and outer sleeves are substantially coplanar when deployed within said borehole for affecting said casting.   
   
   
       2 . A device according to  claim 1  further comprising a sealing ring, said sealing ring dimensioned to be coupled at least to an extremity of said filling sleeve and to a matching extremity of said outer sleeve. 
   
   
       3 . A device according to  claim 1  further comprising a spacer for spacing apart said inner sleeve and said cage. 
   
   
       4 . A device according to  claim 1  wherein said outer sleeve comprises at least two essentially congruent layers. 
   
   
       5 . A device according to  claim 1  wherein any of said sleeves comprises a bent sheet. 
   
   
       6 . A device according to  claim 1  wherein at least one of said inner sleeve and filling sleeve is expandable for securing said outer sleeve to said borehole wall. 
   
   
       7 . A device according to  claim 1  wherein any of said sleeves comprises a tube. 
   
   
       8 . A device according to  claim 1  wherein any of said sleeves comprises of polymeric material. 
   
   
       9 . A device according to  claim 1  wherein said inner sleeve comprises of cardboard. 
   
   
       10 . A device according to  claim 1  wherein said inner sleeve comprises of metal. 
   
   
       11 . A method for in situ casting of at least partly underground concrete pile within a borehole, said borehole having a reinforcing cage therein and having a mouth, said method comprising any sequence of the steps of:
 inserting a cylindrical inner sleeve mountable within said borehole for casting said pile, said sleeve having a length, said sleeve surrounding at least a part of said cage;   inserting a filling sleeve having substantially the same said length, said filling sleeve made of substantially low elastic modulus and substantially deformable material   inserting an outer sleeve having substantially the same said length,   
     wherein each sleeve having a top extremity and a bottom extremity, and wherein said top extremities are coplanar and said bottom extremities are coplanar, wherein said outer sleeve encompasses said filling sleeve, said filling sleeve encompasses said inner sleeve, and only said bottom extremities are below said mouth, said outer sleeve having a low friction coefficient at the interface between itself and its encompassed sleeve. 
   
   
       12 . A method according to  claim 11  further comprising the step of attaching a sealing ring extending between an extremity of said filling sleeve and said outer sleeve. 
   
   
       13 . A method according to  claim 11  further comprising the step of inserting a spacer, said spacer being inserted between said inner sleeve and said cage for spacing apart said inner sleeve from said cage. 
   
   
       14 . A method according to  claim 11  wherein said outer sleeve comprises at least two substantially congruent layers. 
   
   
       15 . A method according to  claim 11  wherein any of said sleeves is formed of a bent sheet. 
   
   
       16 . A method according to  claim 11  further comprising the step of elastically bending at least one of said inner sleeve and said filling sleeve to expand and secure said outer sleeve to said borehole wall. 
   
   
       17 . A method according to  claim 11  wherein any of said sleeves is formed of a tube. 
   
   
       18 . A method according to  claim 11  wherein any of said sleeves comprises polymeric material. 
   
   
       19 . A method according to  claim 11  wherein said inner sleeve is formed of cardboard. 
   
   
       20 . A method according to  claim 11  wherein said inner sleeve is formed of metal.