JPS6098013A - Permanent soil anchor and method for producing and attachingthe same - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to permanent fill anchors (Ver-pre
l3ankθr), having a tensile member that can be removed again over its entire length, the tensile member 4A being arranged in the outer tube in the fixed section, and a screw embedded in the fixed section of the outer tube. It relates to something that is screwed into the crest.

An example of conventional technology is the permanent force (hereinafter referred to simply as anchor and
"Tf-B" must be removed again after the construction procedure has been carried out, since the anchor is a foreign object in the ground and can be extremely disturbing to the construction carried out later.

When it is no longer necessary to remove the anchor, it is not possible to remove the part of the anchor that is firmly connected to the surrounding soil in the hole by means of the grouting material (VerpreBmasBe), i.e. in the area of the anchorage section. accompanied by difficulties. In order to remove this anchor section, a charge is attached together in the area of the fixing section and the hardened grouting material is detonated and destroyed before the anchor is removed while the anchor is being pulled, allowing the anchor to be pulled out over its entire length. It is known to do so (Federal Republic of Germany Patent Publication No. 2443282, document a).

Additionally, Federal Republic of Germany Patent Application No. 6.03908
Specification No. 0 discloses that the tensile beam is made from a number of separate wires spread out by spacers, at least in the area of the fixed section, in which case the spacers The grouting mortar is then withdrawn or broken, thereby breaking the bond between the individual wire or bar and the grouting mortar, so that the wire can be pulled out when a tensile force is applied to the wire during withdrawal.

The two known methods mentioned above have the disadvantage that the dissociation of the tensile fibers in a fixed area is difficult and is not always achieved in the desired manner. Prior to these methods, it was possible to arrange the tensile member in the outer tube also in the region of the fixing section, in order to relatively easily remove the anchor over its entire length. It has been proposed to provide a grouting mortar with a number of threaded rings arranged at intervals one behind the other, the internal threads of the threaded rings being external frl.
The tube VC is missing and a tensile member is screwed into the threaded ring. In this way, after use, the tensile member can be removed from the threaded ring while being rotated inwards and can be recovered over its entire length e.

However, this proposal requires that the force transmission from the tensile member to the threaded ring takes place in a relatively small number of threads;
In this case, the disadvantage is that the most forward threaded ring, ie the threaded ring closest to the open tension section, is loaded first and most strongly. This could lead to deformation of the threads in the area of this first threaded ring, making a subsequent extraction of the tensioning element impossible. Furthermore, the grouting mortar is loaded in tension first when tensioning the tensile member behind this first threaded ring, and later on behind another threaded ring. , cracks form in the grouting mortar which make the reliable fixation of the tensile member in the ground questionable. Furthermore, in this proposal the threaded ring must be left in the ground in any case, based on the fact that the threaded ring must be made of metal for the necessary strength.
This is undesirable.

OBJECTS OF THE INVENTION It is an object of the invention to improve a permanent fill anchor of the type mentioned at the outset in order to avoid the drawbacks of the various types mentioned above, so that it is possible to ensure that a large anchoring force is introduced into the ground from the anchor. The purpose is to make it possible to remove the VC7I and 11y reliably. Yet another object of the present invention is to provide a method for economically producing such permanent fill anchors for J4Y operation.

In order to achieve this objective of the IJJ development of the device, the invention provides a permanent fill anchor of the type mentioned at the outset, in which the tensile member is continuous in the area of the fixing section. Screw thread A1
and the outer cylindrical tube extends over at least a portion of its entire length,
The tensile member has an internal thread into which it is screwed.

In the configuration of the present invention, if there is flank play between the male thread of the tensile member and the female thread of the outer tube, screwing in and extraction of the tensile member is significantly simplified. In this case, it is advantageous if the space created by the flank play is filled with a plastic sliding material, such as grease or a plastic material.

-tJ This is especially true if the female thread of the outer tube has a larger pitch than the male thread of the tensile member. With this configuration, when the tensile member screwed into the outer tube is tensioned, the flank of the first thread of the tensile member first comes into contact with the flank of the last thread of the outer tube, and the inside of the hole is In this case, the grouting material between the outer tube and the hole wall is brought under compressive stress from behind. If the tensile force is further increased, i"L, and the elongation of the tensile member in the fixation section increases accordingly, the thread from behind will be moved towards the other threads with its forwardly directed flanks, is in contact with the rearwardly facing flank of the thread, resulting in an increased tensile force on the grouting material over the entire thread face.It is important in this case that the force exerted by the anchor In the grouting material surrounding the outer mW, a compressive stress is created which is maximum at the rear end of the anchor and decreases towards the front end of the anchoring section.This prevents tensile cracks from forming in the grouting material. , the grouting material will be compressed in the axial direction.

This means that when prestressing is applied, the force is first introduced at the rear end of the fastening section, and only during the tensioning process the other threaded flanks of the tensile member are brought into contact with the threaded flanks of the sheath tube one after the other. It was only when I was pushed and the full tension was brought on as a result. All thread flanks of 'tB'M will contact the thread flanks of the sheath tube.

In a particularly advantageous embodiment of the invention, in the untensioned state of the tensile member, the forward facing flank of the first thread of the external thread of the tensile member is behind the last thread of the internal thread of the sheath tube. t) such that the rearwardly facing flank of the last thread of said external thread contacts the flank facing towards the end of the first thread of said internal thread; The two pitches of the female threads of the outer tube are set larger than the pitch of the male threads of the tensile member. In this way, the tensile member can be screwed into the end of the outer tube without any problems, and l'l: maximum possible elongation of the tension member;
It is thus possible to fully utilize the elongation corresponding to the maximum possible stress of the tensile member.

It is advantageous if the tensile element consists of a fastening part with an external thread and a tensioning part connected to the fastening part via a sleeve. This mating sleeve is preferably a threaded sleeve with a thread opposite to the external thread of the fastening part.

With this configuration, when the tensile member is pulled out while being rotated, it is avoided that the tension portion and the fixed portion are separated by M. Instead of such reverse threads, the ends of both tensile sections and/or the sleeve may be connected by a bayonet joint or the like and/or secured by a split bolt. It's okay.

The sleeve tube may be made of sheet metal, but it is advantageous if it consists of a thin-walled plastic tube with an integrally molded internal thread and is completely surrounded by cement mortar.

Such an outer tube with a small wall thickness can be used later in the row fr +
1+17. :hd Hit+1iap at (n If
f Fyk hL ・m Ministry' fy IjVsuUN?
Since it can be easily broken down and carried away together with the P III constant packing, it can be left in the ground. Another advantage is that during the use of the anchor, 'i+?
You can avoid the occurrence of corrosion and do it later.''
An example of this is that it is possible to eliminate the cause of the anchor sticking to the soil, which may make it difficult to extract the anchor.

The tension part of the anchor may be a single tension rod or a tension wire bundle consisting of a large number of stranded wires or bars;
However, the fixed part of the tensile member is advantageously a single threaded rod which is connected to the tensioning part by means of a sleeve. It is also advantageous if the tensile member and the outer tube have a trapezoidal thread, in particular a fine trapezoidal thread, so that even after a relatively long period of use the resistance to Easy screwing in and pulling out is possible.

The structure of the invention of the method also makes the permanent soil anchor according to the invention advantageous.
In the method of the present invention, the fixing portion of the tensile member is prefabricated in the factory by 1. screwed into the outer tube, optionally with the addition of a sliding substance, surrounding the outer tube with cement mortar (all these operations can be carried out under favorable conditions in the fabrication shop with the required degree of sheathing); The fixed filling body prefabricated in this way is fixed to the tensioned part of the tensile member and introduced into the hole for the permanent soil anchor and sealed against the hole wall at the front end of the solid foot section, after which ( 41 A grouting material is press-fitted into the intermediate chamber between the fixed filling body and the hole wall to bond the fixed filling body and the hole wall.

The grouting material used here is preferably cement mortar, which can also be modified with suitable plastics.

Example The invention will now be described in detail with reference to the drawings.

A hole, designated 10 in the drawing, extends into the ground 12 from the sheet pile wall 11 to be fixed. An anchor 13 is arranged in the hole 10.

The rear fixing part 14 of the anchor 13 is the fixing section 1 of the hole 10.
5, and the anterior tension section 16&J,
In front of the hole 10 it is released in the tension section 17, where it is only surrounded by the cladding tube 18 at a distance J6. J)'+ of the anchor 13: The extension 19 has a thread rJ on its free front end 19a, and the anchor 20 is screwed into this thread. This anchor 20 is supported on the sheet pile wall 11 to be fixed via an anchor plate 21, and is covered by a protective camp 22.

As can be seen from FIG.
In the li example, it is connected to the fixed part by a sleeve 23, which is a threaded sleeve. This sleeve 23 is connected to the rear end 16b of the tensioning part 16 and the front end 14 of the fixed part 14.
a and is secured by a split pin 24. The tension section 16 of the tensile section 19 may be a tension section 16 formed from a large number of stranded wires, which is also used for prestressing the prestressed concrete or film component. In the illustrated embodiment, both the tensioning section 16 and the securing section 14 of the tensile member 19 are woven from a single piece of high strength steel rond.

The fixing part 14 of the tensile part 19 has on its rear part 14b a continuous 4L thread 25 in the form of a trapezoidal thread, which thread 25 is connected to the 11th part of the tensile part 4'A19. The outer cylindrical tube 27 that surrounds the constant part in (with some play)
It is threadedly engaged with the female thread 26 of. The outer tube 27 extends from the rear end of the fixed part 14 to the sleeve 23 and is made of plastic, for example polyethylene or PvC. The outer tube 27 has a trapezoidal thread like the fixed part 14 of the tensile member 19, and the pinch Ph of this trapezoidal thread is equal to the pitch Ph of the male thread 25 of the tensile member 19.
, and both screw threads 25 and 26 are screwed together at the same time.
There is considerable flank play B in I) 41 with. Furthermore, the pitch PI□ of the female thread 26 of the outer TII pipe 21 is greater than the pitch "kl" of the fiber thread 25 of the tensile member 19 by the following i1-, that is, the tension part 19 is not tensioned. In this state, the forward facing flank 28 of the first thread 29 of the external thread 25 is in contact with the rearward facing flank 30 of the last thread 31 of the internal thread 26 of the outer tube 27. , is set so large that the rearwardly facing flank 32 of the last thread 33 of the male thread 25 is in contact with the forwardly facing flank 34 of the first thread 37 of the tS thread 2G. (See Figure 2).

The outer cylindrical tube 27 surrounding the fixed part 14 of the 4X tension member 19 is surrounded over its entire length by a corrugated sheath tube 38 at intervals.

The intermediate chamber 39 between the outer cylindrical tube 21 and the cladding tube 38 is fixed to 4j1 by cement mortar, and by this cement mortar 40 the outer n"ih?'i27 is 16 in the range of its internal thread 2G ( In other words, in this case, the female thread 26 is integrally molded on the wall of the outer tube 27), and the male thread 26 corresponding to the female thread 26 is also formed on the outside of the outer wall. The bottom of this external thread is filled with cement mortar 40 in the intermediate chamber 39.

The fixing part 14 of the anchor 13 is preferably screwed into the sleeve tube 27 with an internal thread 26 in the manufacturing plant, with all hollow spaces between the sleeve tube 27 and the tensile member 19 being e.g. It is filled with a plastic sliding substance 41, such as viscous grease. Cement mortar 40 is then filled between the outer cylindrical tube 27 and the JHIt tube 38 surrounding the outer fh tube, and this cement mortar 40 is carefully sealed and then hardened. The fixed filling body thus prefabricated, designated as a whole by 42 in the drawing, is then connected by means of the sleeve 23 to the tensioned part 16 of the tensile member 19. In this case, the tension portion 16 is
The butt point between A %j 18 and the cladding tube 38 of the fixed part 14 is covered by a shrink hose collar 43.
-ru. The tensile member 19 is then introduced into the hole 10, and the fixing section 15 is then sealed by a suitable collar 44 in a manner known per se in a permanent Illusion force, and the cladding tube 18.38 and the hole wall 46 are sealed off in a manner known per se. Cement mortar is press-fitted into the intermediate chamber 45 between them.

After the grouting mortar has hardened, the free end '19a of the tensile member 19 is subjected to a tensile force in the direction of arrow 47 by a pre-stressing jack, not shown, so that the tensile member 19 is under stress. brought to you.

As a result, the tensile member 19 & 1 is stretched over its entire length, and the tensile force is transmitted to the external thread 26 of the outer tube 27 via the external thread 25 of τb 14. In this case, the resulting tensile force is initially J4j of the tensile member 19.
From the forward facing flank 28 of the first thread 29 of the thread 25 to the last thread 31 of the internal thread 26 of the sheath tube 27
is transmitted to the rearwardly facing flank 30 and thus to the fixed light body 42, thereby causing this fixed packing 4
2 is brought under compressive stress. When the tensile force transmitted to the tensile member 19 is increased and the tensile section 4/419 is correspondingly stretched more, the tensile section 19)
The forward facing flank of the next thread of the 41-mm thread 25 contacts the next rearward facing flank of the female thread 26 of the outer tube 21 and transmits a portion of the tensile force to this flank, As a result, compressive stress is similarly generated in the fixed packing body 42 surrounding the outer cylindrical tube 27 in the axial direction of the tensile portion 19.

In a similar manner, as the tensile force increases and the tensile member 19 stretches, the threads of the threads 25 of the tensile part 19 become the same as the corresponding flank IC of the female threads 2G of the outer tube 27. contact and eventually the forward facing flank 48 of the last thread 33 of the male thread 25 contacts the rearward facing flank 49 of the first thread 37 of the female thread 26 (see FIG. 61); The compressive stress distribution shown in FIG. 4 is obtained.

In other words, when the tensile member 19 is in tension, all the forward facing flanks of the external thread 25 of the tensile member 19 are connected to the outer tube 2.
7 in contact with the rearwardly facing flanks of the a threads 26, each thread transmitting a portion of the tensile force to the fixing section 15.
convey to the grouting mortar. However, in this case, in the fixed filling section 42, the compressive stress σ9 at the rear end of the fixed section 15 is maximum, and this compressive strength is j
#+ decreases toward the starting end of the thread 25 (see FIG. 6).

When the anchor 13 is no longer needed and it is desired to remove it, the anchor 13 is first untensioned, that is, the anchor nut 20 is first relaxed and then completely released. This causes the tension Fa 11 wing 19 to return to its elongation, and its fixing part 14 now occupies the starting position shown in FIGS. 1) Most of the flanks facing i['A fFi) are no longer td in contact with the flanks of the threads of the tube 27 and have considerable play with respect to them.Then the tensile member 19 tension part 16
The front end of - is grabbed and rotated,
4)'+: The tension member 19 is extracted from the outer cylindrical tube 27.

Due to the fact that the sleeve 23 is provided with an opposite thread, the tensile part 16 of the tensile member 19 is connected to the fixed part 14.
remains tightly connected.

As soon as the tensile part side 19 is extracted by rotation from the internal thread 26 of the outer cylinder 27, the tensile member 19 is pulled out axially through the bore 10 over its entire length and can be used at another location if necessary. Ru. Fixed filling body 4 underground
2 and the grouting 61 that surrounds this again remain, and these are removed from thin plastic! ] %l
'27 can be crushed and removed during subsequent excavation work.

The invention is not limited to the embodiments shown and described, but many different embodiments are possible within the framework of the invention. For example, the fixed part 14 on the tensile part side 19 and the outer tube 2
7 may be engaged with each other by triangular threads or square threads, and the attachment of the anchor 13 may also be in accordance with the law.
Outer cylinder with cement mortar 40 and covered 4N pipe 38! - 27 in advance, instead, the tensile member 19 and the outer cylindrical tube 27 screwed to the tensile member are directly introduced into the hole 111j, and cement mortar is press-fitted into the fixed section 15 of this hole 10. It is also possible to do so.

As can be seen from the effect of the invention of the device, the JL15 is constructed as in the present invention, and the tensile part side is brought to the outer cylindrical tube and eventually to the grouting mortar surrounding the outer tube. The tensile forces applied to the grouting mortar in the fixation section are distributed almost evenly over the entire fixation length, thus eliminating the possibility of a screw-out fluid type O(ζ) and, moreover, causing the grouting mortar in the fixation section to be susceptible to loosening of its tissue. This has the advantage that large cracks will not occur.Therefore, the tensile part of the anchor can be easily removed from the fixed section again after its tension has been relaxed.
jjl The anchor can be removed along its entire length by pulling it out. Moreover, since the wall support outer cylinder Tj itself usually has threads into which tensile members are screwed, what about the metal parts that are inconvenient underground? P Tsutaku will not be left behind.

Advantages of the Process The method of the invention allows the highly advantageous permanent soil anchors obtained according to the invention to be produced and removed economically in a highly advantageous manner.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the permanent soil anchor of the present invention in the installation state VC, taken along a plane passing through the hole axis; Fig. 21
Z1 is an enlarged view showing the first thread and the last thread of the tensile member and the outer pipe when the anchor is in the untensioned state, and FIG. 1
FIG. 41 shows the fastening part of the anchor according to the invention together with a diagram showing the compressive stress distribution in the grouting material.

Claims (1)

[Claims] 1. A permanent soil anchor having a tensile part side that can be removed again over its entire length, the tensile member being arranged in the sheath tube in the fixed section, and the sheath A tensile member (19
) is a continuous male thread (25) within the fixed section (15).
), characterized in that the outer cylindrical tube (27) has, over at least part of its entire length, a continuous internal thread (26) into which the tensile member (19) is screwed. . 2. The external thread (25) of the tensile member (19) and the outer tube (2)
The permanent soil according to claim 1, wherein there is a flank play (8) between the internal thread (26) of the permanent soil and the internal thread (26) of the permanent soil of claim 1, wherein the space created by the flank play is filled with a plastic sliding material (41). Anchor. 6. The female thread (26) of the outer tube (27) is on the tensile part side (1
9) The permanent soil anchor according to claim 1 or 2, having a larger pitch (Ph) than the male thread (25) of claim 9). 4. When the tensile part side (19) is in an untensioned state, the tensile part side (19)
) is the forward facing flank (28) of the first thread (29) of the Mb thread (25) the outer cylinder? J)i touch the rearwardly facing flank (30) of the last thread (31) of the female thread (26) of (27) and
) of the last thread (33) of the rearward facing flank (3
2) of the #Ij thread (26) of the external pipe (21) by such a value that it contacts the forward facing flank (34) of the first thread (37) of the female thread (26). Pitch (P
h) is the pitch (
Ph) The first claim set to be larger than Ph)
The permanent soil anchor according to any one of items 6 to 6. 5. The tensile member (19) consists of a fixing part (14) with an external thread (25) and a tensioning part (16) connected to the fixing part (14) via a sleeve (23). Permanent soil anchor according to any one of claims 1 to 4. 6. The sleeve (23) is threaded in the opposite direction to the external thread (25) of the fixed part (14). Permanent soil anchor according to claims 1 to 5, which is a threaded sleeve having threads.
Any one of the chairs according to claims 1 to 5, connected by said sleeve (23) or a bayonet joint or the like and/or fixed by a split pin (24). Permanent fill anchor as described in section. 8. The outer n'5 tube (27) consists of a thin-walled plastic tube with an integrally molded internal thread (26) and is completely surrounded by a measuring material such as cement mortar (4o). 'IIl'it'F The permanent soil anchor according to claim 1, wherein the anchorage according to claims 1 to 7 is a permanent soil anchor according to claim 1. Claims 1 to afA that are non-trivial
A permanent soil anchor according to any one of the preceding items. io, J>'+, can part I iJ' (19) fJ tube outside (
27) A permanent solenoid anchor according to any one of claims 1 to 9, wherein the bolt has a trapezoidal thread.11. the tensile member is disposed within the sheath tube in the fixing section and is screwed into a recessed threaded portion of the sheath tube in the area of the fixing section; Permanent soil anchors can be fabricated and ordered in which the outer cylinder has a continuous male thread over at least a portion of its entire length and a continuous female thread into which the tension section is screwed. In the method, the fixing part (14) of the tensile member (19) is prefabricated in a factory and screwed into the outer tube (27), and the outer tube is surrounded by cement mortar (40), and the prefabricated part (14) is screwed into the outer tube (27). The fixed filling body (42) is fixed to the tension part (16) of the Y tensile member (19) and is attached to the permanent soil anchor (1).
3) into the borehole (10) and sealed against the borehole wall (46) at the front end of the fastening section (15), and then between the fixed filling body (42) and the borehole wall (46). intermediate chamber (
The grouting material is press-fitted into the fixed filling body (45).
) and the hole wall (46).