FR2535759A1 - METHOD FOR FORMING CONCRETE PILES AND NEW PREPARATORY PIEU FOR THIS PROCESS - Google Patents

Abstract

THE INVENTION RELATES TO A PROCESS FOR FORMING CONCRETE PILES AND A NEW PILE PREPARATORY FOR THIS PROCESS. THE PREPARATORY PIE 20 INCLUDES A SHAFT 21 AND A BASE 22 REMOVABLE ATTACHED TO THE LOWER PART OF THE SHAFT 21, WHILE IT ALSO CONTAINS, AT A HEIGHT REPRESENTING ABOUT FOUR TIMES THE DIAMETER OF THE SHAFT 21 ABOVE THE BASE 22 OF THE PREPARATORY PILE, A TUBING 24 OF A DIAMETER EQUAL TO THAT OF THE SHAFT OF THE PERMANENT PILE, THIS TUBING BEING ASSOCIATED IN ITS MOVEMENT WITH THE SHAFT 21 DURING THE SINKING OF THE PREPARATORY PILE 20. THE INVENTION IS USED FOR PREVENT SHEARING AND DISPLACEMENT OF SOIL DURING PREPARATORY PIE DRIVING.

Description

Method of forming concrete piles and new

  preparatory pile for this process.

  The present invention relates essentially to

  a process for forming concrete piles, as well as a new preparatory pile for this process. It is well known (particularly according to U.S. Patent No. 779,881) to form concrete piles by driving> into the ground a preparatory pile comprising a shaft, as well as a base or

  a pad removably attached to the lower portion

  of the pile, thus forming an opening which, at least around the pile pile, is filled by

  concrete whose permanent pile must be made ,.

  the base is then detached from the drum before removing

  the latter of the aforementioned opening.

  Several improvements have been made

  to the process described in the United States patent of

  No. 779 881, these improvements being the best

  illustrated by way of example in the United States patent.

  United States No. 3,851,485 to STEDING These improvements relate primarily to improved embodiments of the hopper

  to load the concrete into the opening, as well as to diversify

  its configurations of the preparatory piles.

  These methods and apparatus known for forming concrete piles have a disadvantage

  which consists in the fact that during

  deny the preparatory stake> there is a movement

  ground giving rise to a "choke" or a

  diameter of the barrel according to geo-

  well-known techniques with regard to shears

and the displacement of the soil.

  The object of the present invention is to

  for the first time, a solution preventing the restriction or reduction of the diameter of the ft occurring during the driving of the preparatory pile, thus avoiding the inconvenience of

  known solutions for driving.

  According to the present invention, this solution

  The method is carried out by a method of forming concrete piles, which method comprises driving into the ground a preparatory pile having an eye and a base or shoe removably attached to the lower portion of the pile shaft. thus forming an opening; fill the opening, at least around the shaft of the pile,

  with concrete whose permanent pile must be con-

  staggered and then detach the base of the pile before removing the barrel through the opening, characterized in that it also consists in equipping the barrel of the preparatory pile,

  at a height of about four times the diameter

  meter of the shaft of the permanent pile above the base of the preparatory shaft, a casing of a diameter equal to that of the permanent shaft, this casing being associated in

  its displacement with the pile of the pile during the

  of the preparatory pile, thus preventing the

  shearing and moving the soil.

  According to a particular embodiment

  Alternatively, this casing may consist of a circular membrane fixed to the pile at discrete points around the pile in order to drive the concrete downwards during the driving of the preparatory pile, this membrane being then removed by the 'opening

together with the pile shaft.

  According to another embodiment, the casing may have a length equal to four times the diameter of the shaft of the permanent pile and, consequently,

  it extends downwards from this height of

  four times the diameter of the shaft of the permanent pile to make contact with the base of the pile, this casing

  being attached to the pile shaft to be removed together

3.

  with the latter by the aforementioned opening.

  According to another embodiment, the casing may consist of a concrete or asbestos / cement envelope or it may consist of a plastic pipe or a metal sleeve of a length equal to about four the diameter of the pile of the permanent pile and extending downwards from this height located four times as long as the permanent pile above the base of the pile to make contact with this base. according to this embodiment, this envelope is located in a corresponding cavity of the barrel of the

  preparatory stake, the latter having, in trans-

  versale, a profiled length equal to the diameter of the

barrel of the permanent pile.

  Similarly, the present invention relates to a new preparatory pile comprising a drum and a base or a pad removably attached to the lower part of the pile shaft, this pile being characterized in that it further comprises at a height equal

  at about four times the diameter of the shaft of the pile

  manate above the base of the preparatory pile) a

  casing of a diameter equal to that of the pile of the pile

  are formed to form, this casing being arranged, relative to the pile of the pile, to be associated in its displacement

  with the latter during the insertion of the pre-existing pile

  paratoire. As a result, this casing can be realized

  in accordance with the actual embodiments

  which has been mentioned above.

  The present invention will be illustrated with reference to the accompanying drawings in which

2535? 59.

  Figure 1 is a schematic illustration of

  shear and soil displacement

  producing during the driving of the prepared pile

  in accordance with known methods of the prior art which are illustrated by way of example in US Pat. No. 779,881; Figure 2 is an elevational view of the method of the invention according to the first embodiment of the preparatory pile of the invention; Figure 2a is a sectional view taken along the line Ia-I Ia of Figure 2;

  FIG. 3 is also an elevational view of

  of the process of the invention according to a second

  embodiment of the preparatory pile of the invention

  tion; Figure 3a is a sectional view taken along the line IIa-II Ia of Figure 3; FIG. 4 is an elevational view of the method of the invention according to a third form of

  realization of the preparatory pile of the invention.

  Referring to Figure 1, the method.

  known is to sink, in the ground 1, a preparatory pile 2 comprising a shaft 3 and a base or a pad 4 removably attached to the lower part

  of the pile of the pile, thus defining an opening 5.

  This known method also consists in filling the opening

  5, at least around the pile 3 of the pile, with the concrete 6 whose permanent pile must be constituted by

  for example, using the concrete feed pipe 7.

  According to this known method, the level of concrete is now

  held constant in the hole formed by the pile

  to fill the opening 5 as it is formed When it is made of a tube

  hollow, barrel 3 of the preparatory bit

  3.5 digging holes 8 allowing concrete to

253,575

  move freely inside the pile of the pile The base is then detached before removing the drum 3

of the stake.

  According to this known method, during the

  of the preparatory pile 2, the base 4 or the plug of the preparatory pile 2 whose diameter D is

  necessarily equal to the diameter of the shaft of the pile

  manent, there is a movement of the soil following the

  arrows 10 shown in FIG.

  of the movement of the soil being indicated by the

outside line 12.

  From Figure 1 it can be seen that the lower limit of soil movement is

  approximately one depth equal to one

  of the base 4 of the pile, while this approximate limit of the movement of the ground ends at a height equal to four times the diameter of the base of the pile or the shaft of the permanent pile, since both the diameter of the base of the pile stake is that of the barrel

permanent pile to form.

  This movement of the soil gives rise to a "throttling" effect or a reduction in the diameter of the opening, ie a reduction in the diameter

of the permanent pile.

  This major disadvantage of the known process is avoided by the process of the present invention which will be

  described below with reference to three forms of

  really favorite which are illustrated

in Figures 2 to 4.

  With reference to FIG. 2, which represents the first embodiment of the preparatory pile of the invention, the preparatory pile 20 driven into the ground 1 of course also comprises a shank 21, as well as a base or a removable pad 22 constituting

  the tip of the permanent pile in a manner known prior-

2535? 59

  and illustrated as an example in Figure 1.

  In addition, according to the present invention, at a height approximately equal to four times the diameter of the barrel of the

  permanent pile above the base 22 of the prepa-

  the latter also comprises a casing 24 of a diameter equal to that of the shaft of the permanent pile, this casing being associated in its movement to the shaft 21 during the driving of the preparatory pile 20, thus preventing shearing and displacement of

ground.

  Preferably, as shown in FIG. 2, the casing 24 has a length equal to approximately four

  the diameter of the pile of the permanent pile and, in

  sequence "from this height located at about four times the diameter above the base 22 of the pile, it extends downward to make contact with this base 22, as clearly shown in Figure 2 in the form of embodiment illustrated in Figure 2, the casing is fixed to the barrel 21 at discrete points around the latter with the aid of protrusions 26 which are directed towards the inside and which, in this case,

  This inclination may be effected

  killed by any known technique and these inner protuberances may be, for example,

welded on the barrel 21 of the pile.

  According to the embodiment illustrated in FIG. 2, it can therefore be observed that the

  tubing 24 prevents any "throttling" or any reduction

  the casing of the permanent pile, since this casing 24 extends over a length representing four times the diameter of the shaft of the permanent pile, thus preventing any movement of the soil during the entrenchement

of the preparatory stake 20.

  In the present embodiment, as in the other embodiment illustrated in FIG. 3, the barrel 21 of the pile consists of a tube comprising holes 28 enabling the concrete to be

  move freely inside this tube, then

  that both the concrete is loaded outside the preparatory pile 20, as indicated by the arrow C in Figure 2, the level-concrete being indicated by the letters C L inside the temporary casing 30

  which can be a hopper located in the opening

grounded 1.

  FIG. 2a shows that the barrel 21 of the pile comprises, in fact, a central tubular part 21a and radial extensions 21b which, in this case, are four in number, this number being obviously

be lower or higher.

  This casing 24 which is fixed to the barrel 21 of the preparatory pile, will be removed with this drum 21 when this

  -last will be removed from the opening at the end of the process-

  and after having detached, in a manner known per se,

  the base 22 of the pile constituting the tip of the pile

  These removable assemblies between the barrel and the base of the pile are well known in the art and can be used, for example, those of the US Pat.

  United States of America No. 779-881 or also

  described in the US patent

  No. 308510485 in the name of STEDING.

  Finally, it is also useful that the

  upper section 32 of the casing 24 which, in the case

  consists of a hollow tube of approximately circular cross section, inclined inwards, this inclined portion providing a free space 36 between the barrel 21 of the pile and the upper part of the

  casing 24, this free space representing, preferably

  approximately half the distance between the pile drum 21 and the inner wall of

the opening 34.

2535759-

  FIG. 3 represents another embodiment of the preparatory pile of the invention which,

  in this case, includes the same drum 21 as that illustrated

  However, in the present embodiment, the casing is constituted by a circular membrane 40 which, preferably, is fixed to the barrel 21 of the preparatory pile in the same manner as the casing. 24 of the embodiment of Figure 2, in particular using protuberances

  42 which are directed inwards and which are in-

  as shown in the drawing, Similarly, the upper portion 44 of the circular membrane 40 may

  advantageously be inclined inwards in

  swimming a free space 46 between the barrel 21 of the pile and

  the upper part 44 of the casing 40.

  As represented in FIG. 3, this circular membrane 40 constituting the casing is located at a height representing approximately four times the diameter D of the shaft of the permanent pile above the base 22 of the preparatory drum and, preferably, it ends exactly at this height and extends downward from this exact height to achieve the desired effect The minimum length to achieve this desired effect is about half the diameter of the shaft of the permanent pile, this minimum length including the In this embodiment, as in that of FIG. 2, thanks to the internal protuberances 42, the concrete is driven downwards during the depression.

of the preparatory stake.

  Figure 4 illustrates a third form

  embodiment of the preparatory pile of the invention.

  In this case, the preparatory pile 50 comprises a barrel

  51 which is shown in Figure 4a and which must

  a plate 51a on which two bars 51b, 51c

  have been fixed perpendicularly and in alignment.

  This fit 51 also includes holes 52 establishing a free communication between the compartments defined between the plate 51a and the bars 51b, 51c, as is clearly understood by examining Figure 4a.

  According to the present invention, this pile pre-

  paratory 50 also comprises a permanent casing made of concrete or another resistant material 54 having a length approximately equal to four times the diameter D of the shaft of the permanent pile, the lower portion 54a of this pile coming into contact with the base This permanent casing 54 is located inside a corresponding cavity 56 of the barrel 51 of the preparatory pile, the latter having in this embodiment and in

  outside the cavity 56, a length profiled in sec-

  cross section substantially equal to the diameter of the shaft of the permanent pile, as clearly

figure 4.

  As a result, the permanent casing is practically "locked" in the cavity 56 of the barrel 51

  With the help of the base 55 of the pile

  the base 55 is detached from the pile of the barrel 51 and when the latter is removed, the permanent casing 54 which in this case constitutes the casing of the invention, remains in the ground, thus preventing the movements of this casing. latest

  both during the pushing down of the stake and later

  is lying. Therefore, it is clear that one or the other of the three embodiments illustrated in FIGS. 2 to 4 is in accordance with the method of the invention

which has been described previously.

Claims (8)

  A method of forming concrete piles, which method comprises driving a preparatory pile into the ground with a barrel and a base or pad removably attached to the lower portion;   the barrel of the pile, thus forming an opening; replaced   crease the opening, at least around the pile of the pile, with the concrete whose permanent pile must be made, and then detach the base of the pile before removing   the barrel through the opening, characterized in that it   is also to equip the barrel of the preparatory stake,   at a height of about four times the diameter   meter of the shaft of the permanent pile above the base of the preparatory shaft, a casing of a diameter equal to that of the permanent shaft> this casing being associated in   its displacement with the pile of the pile during the   of the preparatory pile, thus preventing the   shearing and moving the soil.   2 Process according to claim 1, characterized in that the casing consists of a circular membrane fixed to the shaft of the pile at discrete points around the latter in order to drive the concrete   down during the depression of the prepared pile.   this membrane is then removed together with the pile of the pile.   Process according to Claim 1, characterized in that the casing has an equal length   at about four times the diameter of the shaft of the pile   and extends downward from this height about four times the diameter of the shaft of the permanent pile so as to come into contact with the base of the pile, this casing being fixed to the shaft of the pile to be   withdrawn together with the latter.   4 Process according to claim 1, characterized in that the casing consists of a casing of a resistant material of equal length   at about four times the diameter of the shaft of the pile   manent, while it extends downward from this height about four times the diameter of the shaft of the permanent pile above the base of the pile,   to get in touch with this base.   Method according to Claim 4, characterized in that the envelope is located in a corresponding cavity of the preparatory pile which,   in cross-section, has a profiled length   only equal to the diameter of the f t of the permanent pile, outside the cavity.   6 New preparatory pile having a drum and a base or a pad removably attached to the lower part of this drum, characterized in that it also comprises a casing (24; 40, 54) located   at a height of about four times the diameter   meter of the pile of the permanent pile above the base of the preparatory pile, this casing having an equal diameter   to that of the shaft of the permanent stake and being   associated in its displacement at the barrel of the stake during the sinking of the preparatory stake, thus preventing the shear and displacement of the solo   7 Preparatory pile according to the claim   6, characterized in that the casing (40) is constructed   a circular membrane fixed to the barrel (21) of the pile at discrete points around the latter so   to drive the concrete down during the   the preparatory pile, this membrane being   then removed together with the pile shaft (21).   8 Preparatory pile according to the claim   6, characterized in that the casing (24) has a length equal to about four times the diameter of the shaft of the permanent pile, while it extends downwardly from this height about four times the diameter of the shaft of the permanent pile to engage with the base (22) of the pile, this casing (24)   being fixed to the shaft (21) of the pile to be removed with the latter.   9 Preparatory pile according to the claim   6, characterized in that the casing (54) is constructed   provided with an envelope made of a resistant material of a length equal to approximately four times the diameter of the   bole of the permanent pile and extending downwards to   firing from this height approximately four times the diameter of the shaft of the permanent pile above the base (55) of the pile, to make contact with this base (55).   Preparatory pile according to the   cation 9, characterized in that the concrete envelope is located inside a corresponding cavity (56) of the barrel (52) preparatory pile, the latter having, in cross section, a profile length approximately equal to the diameter of the shaft of the permanent pile, in outside the cavity (56).