Splicing dowel for micropiles and micropiles including such dowels

Abstract

Splicing threaded dowel ( 1 ) for micropiles, characterized in that it includes several adjacent threads with a right or left helix, whose pitch is greater than or equal to 300. Unit shaped by such a dowel ( 1 ) and two micropile sections ( 3 ) with fins ( 7 ). Micropile with helical fins including such a unit. With tightening is obtained the alignment of the fins ( 7 ) of the adjacent sections.

1 . A threaded dowel for micropiles, comprising several adjacent threads with a right or left helix, the threads having a pitch which is greater than or equal to 300.  
   
   
       2 . Dowel according to  claim 1 , wherein the threads include three symmetrical buttress threads.  
   
   
       3 . Dowel according to  claim 2 , wherein the diameter of the dowel is less than 30 mm.  
   
   
       4 . Dowel according to  claim 1 , wherein the dowel is made out of stainless steel.  
   
   
       5 . Dowel according to  claim 4 , wherein the dowel is provided with an anti-corrosive coating.  
   
   
       6 . Dowel according to  claim 5 , wherein the dowel is provided furthermore with a coating facilitating sliding against the threads.  
   
   
       7 . A unit shaped and configured to threadingly receive the dowel according to  claim 1 , the unit comprising two micropile sections each including at least one fin, wherein the micropile sections each include one axial tapping emerging on the right of a crosswise bearing surface, the sum of the boring lengths of these tappings being greater than the length of the dowel.  
   
   
       8 . Unit according to  claim 7 , wherein the axial tappings of the two sections are identical.  
   
   
       9 . Unit according to  claim 7 , wherein the boring of tappings is 76.5 mm, the tappings extend over 64.5 mm, the overall length of the dowel is 144 mm, the length of the threading on the dowel is 120 mm, and the dowel protruding in relation to the crosswise bearing plane of one of the sections over a 55.5 mm length of threads when the dowel is screwed all the way into tapping of this section.  
   
   
       10 . A micropile including at least one unit according to  claim 7 , wherein sections of the micropile are made out of cast aluminum.  
   
   
       11 . Dowel according to  claim 4 , wherein the dowel is made of austenitic stainless steel 1.4404.  
   
   
       12 . Dowel according to claims  5 , wherein the anti-corrosive coating is a hot-applied epoxy paint.  
   
   
       13 . Dowel according to  claim 6 , wherein the coating facilitating sliding is a polytetrafluorethylene film.