AT510951B1 - PFAHL WITH AN ESSENTIALLY CYLINDRICAL SHANK - Google Patents

Abstract

Stake (1) with a substantially cylindrical shank (2), whose shank outer diameter (DSa) tapers conically in the region of a first pile end (1a), wherein the shank (2) in the region of a second pile end (1b) in an internally cone-shaped sleeve (3), wherein in the sleeve (3) a further pile (1) with its cone-shaped first pile end (1a) can be inserted up to a maximum insertion depth (T) defined by a stop, whereby from the beginning (4a) of the transition (4a) 4) from shank (2) to sleeve (3) to the second pile end (1b) the pile outer diameter (DPa) starting from the shank outer diameter (DSa) is getting larger, the beginning (4a) of the transition (4) of shank (2) to sleeve (3) starting from the second pile end (1b) at least 1.4 times the maximum insertion depth (T), preferably in the range between 1.4 times the maximum insertion depth (T) and 2.5 times the maximum insertion depth (T), more preferably at twice the maximum setting ecktiefe (T), lies.

Description

Austrian Patent Office AT 510 951 B1 2012-08-15

Description: The invention relates to a pile having a substantially cylindrical shank, the shank outer diameter of which tapers conically in the region of a first pile end, wherein the shank merges into an internally conical sleeve in the region of a second pile end, wherein a further pile into the socket its cone-shaped first Pfählende can be inserted up to a maximum insertion depth defined by a stop, from the beginning of the transition from stem to sleeve to the second Pfählende the pile outer diameter, starting from the shank outer diameter is always larger.

Such piles are usually made of ductile cast iron and are used in the construction industry as Rammpfähle. In making pile foundations, the individual piles, which are mostly predetermined lengths of e.g. five meters, are plugged through the design with a conically tapering first Pfählende and a socket formation in the region of the second Pfählendes each other. As a result, pile by pile can be driven into the ground, which makes it possible to quickly and inexpensively pile foundations of any length. Rammpfähle this type are usually produced in a centrifugal casting process with a shaping, rotating mold. This results in substantially tubular piles, which are hollow inside. Depending on the type of use, these hollow piles can be filled with concrete or encased in concrete to form a stable foundation after being driven into the ground.

By forming a sleeve at the second Pfählende to plug together a pile with another pile, results in a larger pile outside diameter in the region of the sleeve of the pile. Since the remainder of the pile has a substantially cylindrical shank, there is thus an increase in the diameter of the pile in the region of the sleeve, as a result of which there is an overall increased resistance to the pile driving into the ground.

The object of the invention is therefore to provide a comparison with the prior art improved pile. In particular, the stake should be designed so that it is easier to drive into the ground.

This object is achieved in that the beginning of the transition from shank to sleeve starting from the second Pfählende at least 1.4 times the maximum insertion depth, preferably in the range between 1.4 times the maximum insertion depth and the 2, 5 times the maximum insertion depth, particularly preferably at twice the maximum insertion depth.

As a result, the increase in the pile outer diameter in the region of the sleeve of the pile over a longer pole distance than in conventional driven piles. In particular, there is no step-like enlargement of the pile outer diameter. The enlargement of the pile outer diameter thus begins along the driving direction of the pile from its first to its second Pfählende already much earlier than known piles. This also results in a much flatter expansion of Pfahlaußendurchmessers, thereby setting a reduced resistance of the pile during ramming. The piles can also be processed faster, so that pile foundations can be erected overall faster.

Preferably, it may be provided that that angle, which includes a longitudinal axis of the pole intersecting tangent to an outer contour of the post with the longitudinal axis, less than or equal to 17 °, preferably less than or equal to 10 °, more preferably less than or equal to 8 ° ,

According to a preferred embodiment it can be provided that the taper of the shaft outer diameter in the region of the first Pfählendes and / or the taper of a sleeve inner diameter in a range of 1: 8 to 1: 20, wherein tapered the ratio of change in diameter to assigned Length is understood. It has proven to be particularly advantageous if the conicity of the outer shaft diameter in the region of the first piling end and / or the conicity of the inner sleeve diameter of from 1:15 to 1: 18, preferably 1:16 or 1:17. A change in diameter of the shaft outer diameter in the region of the first piling end and / or of the inner sleeve diameter by one unit of measurement is thus carried out particularly preferably over a pile length of 16 or 17 units of measurement. The proposed conicity makes it possible, in particular, to achieve a uniform voltage profile of the stresses occurring in the sleeve during a latching process. This leads to an improved distribution of forces in the material and a reduced risk of fractures during pile driving.

Ideally, in a pile foundation, the taper of the socket inside diameter of a pile corresponds to the taper of the socket outside diameter of the succeeding pile, which is inserted into the socket of the previous pile. This results in a substantially self-clamping and non-positive connection of the individual piles.

In order to limit the maximum insertion depth of a pile in the sleeve of a previous pile, the inner contour of the sleeve may have a stop. In this case, it can preferably be provided that the maximum insertion depth is limited by a circumferential shoulder formed radially on an inner wall of the sleeve in the direction of a longitudinal axis of the pile, wherein the peripheral shoulder has a circumferential contact surface. It is particularly advantageous if the circumferential contact surface is oriented substantially perpendicular to the longitudinal axis of the pile and the circumferential contact surface, starting from the inner wall of the sleeve radially in the direction of the longitudinal axis of the post has a width of 3 mm to 8 mm, preferably greater than or equal to 5 mm, having. As a result, a defined footprint is formed for the subsequent pile, which can abut against the circumferential bearing surface with the end face of its first Pfählendes. Overall, this makes it possible to achieve an optimum transfer of force of the ramming impacts during the ramming of a pile foundation.

Protection is also sought for a method for producing a proposed pile, wherein a liquid molten metal is introduced into a mold rotating about its central axis, wherein an inner contour of the mold defines an outer contour of the pile from a first Pfählende to a second Pfählende, wherein the mold has a substantially cylindrical shank portion corresponding to the shank of the pile, which merges in a transition section into a sleeve portion corresponding to the sleeve of the pile, wherein from the beginning of the transition from shank portion to sleeve portion to the second pile end a clear diameter of the inner contour becomes larger, wherein a mold is used, the beginning of the transition from shaft portion to sleeve portion starting from the second Pfählende at least 1.4 times the maximum insertion depth of the pile, preferably in the range between 1.4 times the maximum insertion depth of the pile and the 2.5 -fold maximum insertion depth of the pile, particularly preferably at twice the maximum insertion depth of the pile is.

Preferably, it can be provided that the angle, which includes a central axis of the mold intersecting tangent to the inner contour of the mold with the central axis, less than or equal to 17 °, preferably less than or equal to 10 °, more preferably less than or equal to 8 ° ,

In order to form a defined circumferential bearing surface in the form of a circumferential shoulder on an inner wall of the sleeve of a pile, may be provided in a preferred embodiment, that is used to form the sleeve of the pile, a substantially cylindrical sleeve core whose outer contour in Region of an end face of the sleeve core has a circumferential recess in the form of a shoulder. It is advantageous if the depth of the circumferential recess has a width of 3 mm to 8 mm, preferably greater than or equal to 5 mm, radially in the direction of a longitudinal axis of the sleeve core.

Moreover, protection for a sleeve core for use in a proposed process is also sought, wherein an outer contour of the sleeve core in the region of an end face of the sleeve core has a peripheral recess in the form of a shoulder. It is particularly advantageous if the depth of the circumferential recess radially in the direction of a longitudinal axis of the sleeve core has a width of 3 mm to 8 mm, preferably greater than or equal to 5 mm, and the circumferential recess forms a circumferential shoulder surface, wherein the circumferential shoulder surface substantially is aligned perpendicular to a longitudinal axis of the sleeve core.

A sleeve core may at least partially, preferably completely, consist of sand and may have a substantially frusto-conical lateral surface whose conicity in a range of 1: 8 to 1: 20, preferably from 1: 15 to 1: 18, particularly preferred 1:16 or 1:17. The conicity of the lateral surface of the sleeve core defines the conicity of the inner wall of a sleeve of a pile produced with the aid of the sleeve core.

Further details and advantages of the present invention will be explained with reference to the following description of the figures. 1 shows a schematic longitudinal section through an exemplary embodiment of a proposed pile, FIG. 2 shows a schematic longitudinal section through a pile according to the prior art overlaid by an exemplary embodiment of a proposed pile and FIG. 3 shows a schematic longitudinal section through a proposed sleeve core.

Fig. 1 shows a schematic longitudinal section through a proposed pile 1. Such a pile 1 is usually used as a driven pile for pile foundations and consists at least partially, preferably completely, of ductile cast iron. Usually, the pile 1 is substantially tubular, with the shank 2 of the pile 1 having at least sections a substantially constant shank outer diameter DSa and / or a substantially constant shank inner diameter DSi. The piles 1 are usually prefabricated as precast elements and have defined lengths of, for example, five or six meters. To improve clarity, a portion of the shaft 2 was removed in this illustration (indicated by the dash-dotted lines of weakness).

In the region of the first Pfählendes 1 a, the shank 2 tapers conically up to the first end face 7 a of the pile 1. It is provided in this example that the shank 2 in the region of the conical taper of the shank outer diameter DSa in the region of the first Pfählendes 1 a having substantially constant shaft inner diameter DSi. This results in a total in the region of the conical taper of the first Pfählendes 1a decreasing in the direction of the first end face 7a wall thickness Ws of the shank 2. This decreasing wall thickness Ws leads to a reduced bending stiffness in this region of the pile 1, whereby the insertion or Ramming the pile 1 in the sleeve 3 of another pile 1 easier.

In the region of the second Pfählendes 1b of the shaft 2 of the pile 1 passes into a sleeve 3, which has an inner wall 6 with a sleeve inner diameter DMi, the conicity KM of the taper Ks of the shaft 2 in the region of the first Pfählendes 1 a corresponds. This results in each case for a substantially self-clamping, non-positive connection for nested piles 1.

The inner wall 6 of the sleeve 3, moreover, at a distance of the maximum insertion depth T, starting from the second end face 7b of the pile 1 a circumferential, substantially radially in the direction of a longitudinal axis L of the pile 1 formed shoulder 8. This circumferential shoulder 8 has a circumferential contact surface 8a, which is aligned substantially perpendicular to the longitudinal axis L of the pile 1. If another pile 1 is inserted or driven into the socket 3 of this pile 1 with its first pile end 1a, then this circumferential bearing surface 8a forms a defined contact surface for the driven pile 1, which can abut with its first end face 7a on the circumferential bearing surface 8a , This results in the one hand, a defined limited insertion depth T and on the other hand by the formation of the circumferential bearing surface 8a optimal power transmission of the pile joints in an existing pile 1 pile foundation. The circumferential contact surface 8a has, starting from the inner wall 6 of the sleeve 3 radially in the direction of the longitudinal axis L of the pile 1, a width of 3 mm to 8 mm, preferably greater than or equal to 5 mm , on.

In the region of the circumferential shoulder 8, a further wall reinforcement of the pile 1 is additionally provided, which is formed by the fact that the shank inner diameter Ds, slightly reduced in this area. This results exactly in the stress-critical area of the contact surface 8a, which absorbs Einrammstöße, an additional wall reinforcement, through which this voltage critical area is more stable overall and has a greater error tolerance with respect to, for example, obliquely set ram joints.

Since there is increased material stresses in the region of the sleeve 3 of a pile 1, it is preferably provided that the wall thickness WM of the sleeve 3 is greater than the wall thickness Ws of the shaft 2 of a pile 1. Preferably, it is provided that the sleeve 3, starting from the second Pfählende 1b to the maximum insertion depth T has a substantially constant wall thickness WM. This results in an increased flexural rigidity in the connection region of two piles 1, whereby the stability of a pile foundation consisting of piles 1 increases overall.

Due to the nesting of piles 1 and the increase in the wall thickness WM of the sleeve 3 of a pile 1, however, increases in the region of a sleeve 3 of a pile 1, the entire pile outer diameter DPa. In order to make the increase of the pile outer diameter DPa in the pile-in direction of a pile 1 from its first pile end 1a to the second pile end 1b as slow as possible, the beginning 4a of the transition 4 from shank 2 to socket 3 of a pile 1 starts from the second pile end 1b at least 1.4 times the maximum insertion depth T, preferably in the range between 1.4 times the maximum insertion depth T and 2.5 times the maximum insertion depth T, particularly preferably at twice the maximum insertion depth T. This results in the transition region 4 from the shaft 2 to the sleeve 3 of a pile 1 a relative to the longitudinal axis L of the pile 1 relatively shallow rise of the pile outer diameter DPa. In particular, that angle a, which includes a tangent A intersecting the longitudinal axis L of the pile 1 to an outer contour of the pile 1 with the longitudinal axis L, is less than or equal to 17 °, preferably less than or equal to 10 °, particularly preferably less than or equal to 8 °.

This relatively shallow increase in the pile outer diameter DPa in conjunction with the wall reinforcement in the stress critical region of the circumferential shoulder 8 leads to a substantially more stable pile 1, which is also more fault tolerant to obliquely acting to the longitudinal axis L ramming. In particular, there is no constricting effect when ramming in a pile 1, since, starting from the peripheral shoulder 8, the wall thickness decreases as far as the wall thickness Ws of the shank 2 over a relatively long pile length.

In order to facilitate the insertion of a subsequent pile 1 in the sleeve 3 of a pile 1, in the example shown, a transition 5 of an inner wall 6 of the sleeve 3 in a second end face 7b of the pile 1 in the region of the second Pfählendes 1 b formed rounded , It is advantageous if the rounding of the transition 5 of the inner wall 6 of the sleeve 3 in the second end face 7b of the pile 1 in the region of the second Pfählendes 1b has a radius Rm of at least 5 mm, preferably from 6 mm to 10 mm, particularly preferably 8 mm , having.

Fig. 2 shows a schematic longitudinal section through a driven pile according to the prior art. The transition 4 from the shaft 2 to the sleeve 3 takes place along a relatively short pile length, resulting in a substantially S-shaped profile of the outer contour in this transition region. A tangent B intersecting the longitudinal axis L of this pile 1 through the inflection point of the S-shaped outer contour of the pile 1 encloses an angle β with the longitudinal axis L of the pile 1, which is approximately 20 ". This results in relation to the longitudinal axis L in the driving direction from the first Pfählende 1a to the second Pfählende 1b significantly steeper outer contour than in a proposed pile 1. This steeper outer contour sets the piling significantly increased resistance. 4.10

Claims (24)

Austrian Patent Office AT 510 951 B1 2012-08-15 Dash-dotted the outer contour of the transition 4 of a proposed pile 1 is indicated. Here, clearly the flatter outer contour with a smaller angle α between a tangent A to the outer contour and the longitudinal axis L of a pile 1 can be seen. Fig. 3 shows a schematic longitudinal section through a proposed sleeve core 9. Such a sleeve core 9 can be used for the production of a proposed pile 1 in a forming mold. The conicity KK of the lateral surface 12 of the sleeve core 9 forms during the production of a pile 1, the taper KM of the inner wall 6 of the sleeve 3 of the pile 1. In the region of an end face 9a, the sleeve core 9 has a circumferential recess 10 in the form of a shoulder. The circumferential recess 10 has a circumferential shoulder surface 11, which is substantially perpendicular to a longitudinal axis LK of the sleeve core 9. The width BK of the circumferential shoulder surface 11 is preferably in a range of 3 mm to 8 mm, more preferably it is greater than or equal to 5 mm. The circumferential recess 10 with its peripheral shoulder surface 11 forms during the production of a pile 1 whose peripheral shoulder 8 or circumferential bearing surface 8a. When sleeve core 9 of this example, the lateral surface 12 merges into a substantially perpendicular to a longitudinal axis LK of the sleeve core 9 extending annular surface 13, wherein the transition 14 is formed from lateral surface 12 to annular surface 13 rounded. It is particularly advantageous if the rounding of the transition 14 of the lateral surface 12 in the annular surface 13 has a radius RK of at least 5 mm, preferably from 6 mm to 10 mm, particularly preferably 8 mm. This results in a finished pile 1 a correspondingly rounded transition 5 of the inner wall 6 of a sleeve 3 to the second end face 7b of a pile 1 (see Fig. 1). 1. Stake (1) with a substantially cylindrical shank (2) whose shank outer diameter (DSa) tapers conically in the region of a first pole end (1a) , wherein the shaft (2) in the region of a second Pfählendes (1b) merges into an internally conical sleeve (3), wherein in the sleeve (3) has a further pile (1) with its conical first Pfählende (1 a) to a through a stop defined maximum insertion depth (T) can be inserted, wherein from the beginning (4a) of the transition (4) from shank (2) to sleeve (3) to the second Pfählende (1b) of the pile outer diameter (DPa), starting from the shank outer diameter (DSa) is always larger, characterized in that the beginning (4a) of the transition (4) of shaft (2) to sleeve (3) starting from the second Pfählende (1b) at least 1.4 times the maximum insertion depth (T), preferably in the area between 1.4 times the maximum insertion depth (T) and 2.5 times the maximum insertion depth (T), particularly preferably at twice the maximum insertion depth (T). 2. Pile according to claim 1, characterized in that that angle (a), which encloses a longitudinal axis (L) of the pile (1) intersecting tangent (A) to an outer contour of the pile (1) with the longitudinal axis (L), less than or equal to 17 °, preferably less than or equal to 10 °, more preferably less than or equal to 8 °. 3. Pile according to claim 1 or 2, characterized in that the conicity (Ks) of the shank outer diameter (DSa) in the region of the first pile end (1a) and / or the taper (KM) of a socket inner diameter (DMi) in a range of 1: 8 to 1: 20, where conicity is understood to mean the ratio of diameter change to assigned length. 4. Pile according to claim 3, characterized in that the conicity (Ks) of the shaft outer diameter (DSa) in the region of the first Pfählendes (1 a) and / or the taper (KM) of the inner sleeve diameter (DMi) of 1:15 to 1:18 , preferably 1:16 or 1:17. 5/10 Austrian Patent Office AT 510 951 B1 2012-08-15 5. Pile according to one of claims 1 to 4, characterized in that the pile (1) is substantially tubular, wherein the shank (2) of the pile (1) at least partially a substantially constant Schaftaußendurchmesser (DSa) and / or has a substantially constant internal shaft diameter (DSi). 6. pile according to one of claims 1 to 5, characterized in that the shaft (2) in the region of the conical taper of the shaft outer diameter (DSa) in the region of the first Pfählendes (1 a) has a substantially constant internal shaft diameter (DSi). 7. Pile according to one of claims 1 to 6, characterized in that the sleeve (3), starting from the second Pfählende (1b) to the maximum insertion depth (T) has a substantially constant wall thickness (WM). 8. Pile according to one of claims 1 to 7, characterized in that a transition (5) of an inner wall (6) of the sleeve (3) in a second end face (7b) of the pile (1) in the region of the second Pfählendes (1b) rounded is formed. 9. pile according to claim 8, characterized in that the rounding of the transition (5) of the inner wall (6) of the sleeve (3) in the second end face (7b) of the pile (1) in the region of the second Pfählendes (1b) has a radius (RM) of at least 5 mm, preferably from 6 mm to 10 mm, particularly preferably 8 mm. 10. Pile according to one of claims 1 to 9, characterized in that the pile (1) at least partially, preferably completely, consists of ductile cast iron. 11. Post according to one of claims 1 to 10, characterized in that the maximum insertion depth (T) by a on an inner wall (6) of the sleeve (3) radially in the direction of a longitudinal axis (L) of the post formed circumferential shoulder (8). is limited, wherein the circumferential shoulder (8) has a circumferential contact surface (8a). 12. pile according to claim 11, characterized in that the circumferential bearing surface (8 a) is aligned substantially perpendicular to the longitudinal axis (L) of the pile (1). 13. Pile according to claim 11 or 12, characterized in that the circumferential bearing surface (8 a) starting from the inner wall (6) of the sleeve (3) radially in the direction of the longitudinal axis (L) of the pile (1) has a width of 3 mm 8 mm, preferably greater than or equal to 5 mm. 14. A method for producing a pile (1) according to any one of claims 1 to 10, wherein a liquid molten metal is introduced into a mold rotating about its central axis, wherein an inner contour of the mold an outer contour of the pile (1) of a first Pfählende (1a ) to a second piling end (1b), the mold having a substantially cylindrical shank portion corresponding to the shank (2) of the pile (1) merging in a transition section into a sleeve portion corresponding to the sleeve (3) of the pile (1) , wherein from the beginning of the transition from shank portion to sleeve portion to the second Pfählende (1b) a clear diameter of the inner contour is always larger, characterized in that a mold is used, the beginning of the transition from shank portion to sleeve portion starting from the second Pfählende (1b) at least 1.4 times the maximum insertion depth (T) of the pile (1), preferably in the region between the 1.4 times the maximum insertion depth (T) of the pile (1) and 2.5 times the maximum insertion depth (T) of the pile (1), particularly preferably at twice the maximum insertion depth (T) of the pile (1) , 15. The method according to claim 14, characterized in that that angle (a), which includes a central axis of the mold intersecting tangent to the inner contour of the mold with the central axis, less than or equal to 17 °, preferably less than or equal to 10 °, particularly preferably less than or equal 8 °, is. 6/10 Austrian Patent Office AT 510 951 B1 2012-08-15 16. The method according to claim 14 or 15 for producing a pile (1) according to any one of claims 11 to 13, characterized in that for the formation of the sleeve (3) of the pile (1) a substantially cylindrical sleeve core (9) is used, whose outer contour in the region of an end face (9a) of the sleeve core (9) has a circumferential recess (10) in the form of a shoulder. 17. The method according to claim 16, characterized in that the depth (BK) of the recess (10) radially in the direction of a longitudinal axis (LK) of the sleeve core (9) has a width of 3 mm to 8 mm, preferably greater than or equal to 5 mm , 18. sleeve core (9) for use in a method according to one of claims 14 to 17, characterized in that an outer contour of the sleeve core (9) in the region of an end face (9a) of the sleeve core (9) has a circumferential recess (10) in Form of a shoulder. 19. sleeve core according to claim 18, characterized in that the depth (BK) of the circumferential recess (10) radially in the direction of a longitudinal axis (LK) of the sleeve core (9) has a width of 3 mm to 8 mm, preferably greater than or equal to 5 mm, having. 20. sleeve core according to claim 18 or 19, characterized in that the circumferential recess (10) forms a circumferential shoulder surface (11), wherein the circumferential shoulder surface (11) is aligned substantially perpendicular to a longitudinal axis (LK) of the sleeve core (9) , 21. sleeve core according to one of claims 18 to 20, characterized in that the sleeve core (9) has a substantially frusto-conical lateral surface (12) whose taper (KK) in a range of 1: 8 to 1: 20, preferably from 1 : 15 to 1:18, more preferably 1:16 or 1:17. 22. sleeve core according to claim 21, characterized in that the lateral surface (12) merges into a substantially perpendicular to a longitudinal axis (LK) of the sleeve core (9) extending annular surface (13), wherein the transition (14) from the lateral surface (12). is formed rounded to ring surface (13). 23. sleeve core according to claim 22, characterized in that the rounding of the transition (14) of the lateral surface (12) into the annular surface (13) has a radius (RK) of at least 5 mm, preferably from 6 mm to 10 mm, particularly preferably 8 mm, has. 24. sleeve core according to one of claims 18 to 23, characterized in that the sleeve core (9) at least partially, preferably completely, consists of sand. 3 sheets of drawings 7/10