Method for forming a pile wall in ground and a corresponding pile wall

Abstract

A method for forming a drilled pile wall in ground using a drilling device having a reamer and flushing with a medium to remove drilling waste during drilling, and non-rotating pipe piles equipped with interlocks. A vertical 1 hole is drilled while simultaneously placing a pipe pile in the drill hole. At least one subsequent vertical hole is drilled hole in the ground side by side with the drill hole while simultaneously placing a subsequent pipe pile in the subsequent drill hole while the interlocks of the subsequent pipe pile interlock with interlocks of the pipe pile to guide the subsequent pipe pile into the drill hole. Reinforcements are installed in the drill holes, concrete is cast into each pipe pile to form a concrete pile, and at least some of the pipe piles are lifted at least partly out of the drill hole after the concrete has been cast, but before the concrete has bonded rigid to form a unified watertight pile wall.

1 . A method for forming a unified watertight pile wall in ground using a drilling device with a reamer and flushing with a medium to remove drilling waste during drilling, and non-rotating pipe piles each equipped with interlocks and including a long interlocking member having a first length and a short interlocking member having a second length shorter than the first length, the method comprising steps of;
 drilling a first vertical drill hole in the ground using the drilling device in which the reamer has a diameter greater than an outer diameter of the pipe pile but limited such that the long interlocking member extends beyond the diameter of the reamer, and simultaneously using the drilling device to pull or push a first one of the non-rotating pipe piles into the first vertical drill hole;   drilling at least one subsequent vertical drill hole in the ground adjacent the first vertical drill hole using the drilling device while simultaneously using the drilling device to pull or push a subsequent one of the non-rotating pipe piles into the at least one subsequent vertical drill hole, wherein the long interlocking member of the subsequent pipe pile interlocks with the short interlocking member of the first pipe pile to guide the subsequent pipe pile into the at least one subsequent vertical drill hole;   installing reinforcements in each of the-vertical drill hole holes;   casting concrete into each of the pipe piles installed in a respective one of the vertical drill holes to form respective concrete piles; and   lifting the pipe piles at least partly out of some of the adjacent vertical drill holes after the concrete has been cast, but before a transition of the concrete from a fluid concrete paste to a rigid concrete to expand the concrete of each concrete pile laterally to adjacent vertical drill holes to form the unified watertight pile wall.   
     
     
         2 . The method according to  claim 1 , wherein the flushing includes flushing the pipe piles using water as a medium to lead drilling water out of the respective vertical drillhole on an outside of the pipe pile. 
     
     
         3 . The method according to  claim 1 , wherein the drilling includes drilling at least some of the vertical drill holes in non-cohesive soil, bedrock, or a stable layer of ground, to anchor the pile wall in place. 
     
     
         4 . The method according to  claim 1 , further including forming the pile wall with 2-100 pipe piles in a casting sequence, before the lifting of the pipe piles. 
     
     
         5 . The method according to  claim 1 , further including welding brackets to each pipe pile at an end travelling first into the vertical drill hole before placing the pipe pile into the ground, the welding including welding the brackets to the pipe pile on a side of the pipe pile facing an intersection with the adjacent vertical drill hole, so that each bracket welded on one side of the respective pipe pile aids to support and hold the pipe pile straight in the vertical drill hole during drilling. 
     
     
         6 . The method according to  claim 1 , wherein one of the long interlocking member and the short interlocking member of one of the pipe piles is a male interlocking member and an adjacent pipe pile to the one pipe pile has the other of the long interlocking member and the short interlocking member that has a female groove positioned and dimensioned to receive and be partly loose relative to the male interlocking member of the one pipe pile to leave an open space in the female groove of the adjacent pipe pile for injecting concrete into the vertical drill hole simultaneously as each pipe pile is lifted with vibration out of the vertical drill hole. 
     
     
         7 . The method according to  claim 1 , further including installing, after lifting of the pipe piles, a transverse support structure between the concrete piles to reinforce the pile wall. 
     
     
         8 . The method according to  claim 1 , wherein the using of reinforcements includes using vertical reinforcements and spring reinforcements to reinforce the pile wall, including arranging the spring reinforcements to be joined to the vertical reinforcements and compressed in a closed position inside the pipe pile, and to spread essentially in a transverse direction of the pipe piles in a longitudinal direction of the pile wall when the pipe piles are lifted out of the vertical drill holes. 
     
     
         9 . The method according to  claim 1 , further including welding at least one plough protrusion next to one of the interlocks at an end of the pipe pile travelling first into the vertical drill hole, before the pipe pile is drilled into the ground, wherein the at least one plough protrusion is on a continuous sector of the pipe pile and protrudes from the pipe pile by at most a same extent as the reamer for displacing ground when lifting the pipe pile, to assist in joining the concrete piles. 
     
     
         10 . The method according to  claim 1 , wherein the drilling includes drilling at least some of the vertical holes only down to a surface of a bedrock, the method further including placing in the reinforcements at least one hollow reinforcement inside of which is a reserve pipe, leaving the reserve pipe empty during concrete casting, after lifting of the pipe piles and hardening of the concrete pile, drilling a locking hole in the bedrock through the reserve pipe; and setting a rock bolt in the reserve pipe to lock the pile wall to the bedrock. 
     
     
         11 . The method according to  claim 1 , wherein the lifting includes lifting the pipe piles out of the drill holes by vibration while simultaneously compacting the concrete of the concrete piles. 
     
     
         12 . The method according to  claim 1 , further including forming a transverse support beam on the pile wall which is exposed on a construction side of the pile wall. 
     
     
         13 . The method according to  claim 1 , wherein the unified, watertight pile wall extends in contact with a body of water in a form of a harbour structure, and wherein lifting the pipe piles comprises raising at least a part of the pipe piles at least partially out of a respective one of the vertical drill holes by at least part of a length of the vertical drill hole in an area of the ground of a floor of the body of water after casting of the concrete but before the transition of the cast concrete from the fluid concrete paste to the rigid concrete, wherein the pipe piles remain as a part of the pile wall above the ground of the body of water. 
     
     
         14 . The method according to  claim 13 , and further including cutting off a part of each raised pipe pile that extends beyond the concrete pile. 
     
     
         15 . The method according to  claim 1 , further including installing the pipe pile in a sensitive area using compressed air inside the pipe pile for flushing up the drilled material mainly inside the pipe pile; and during drilling with compressed air, pumping water simultaneously to the drill hole in an area of a lower end of the pipe pile through a channel located outside the pipe pile to limit dropping of groundwater levels in the vertical drill hole. 
     
     
         16 . The method according to  claim 13 , wherein the lifting includes lifting the pipe piles by at least 1 m to allow the concrete to spread and at most by a length such that the pipe pile remains in the ground in the drill hole to protect the concrete pile from open water.