JP3000345B2 - Ground anchor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground anchor used for stabilizing slopes, preventing landslides, stabilizing retaining walls and other structures.

[0002]

2. Description of the Related Art Conventionally, as this type of ground anchor, as shown in FIG. 6, there is a type in which a plurality of opening and closing blades are attached below a hollow pipe.
There was what was disclosed as an issue. In the figure, reference numeral 3 denotes a first pipe, which has a flange 1 near its upper end and a male screw 4 above it, and a jet port 4 near its lower end. The female screw 12 at the lower end of the second pipe 5 was detachably screwed to the male screw 4 of the first pipe 3. Reference numeral 7 denotes three blades, and the base ends of the blades 7, 7, 7 are respectively pivotally connected to bearing pieces 14, 14, 14 welded to a lower portion of the first pipe so as to be openable and closable.

Reference numeral 6 denotes a sliding piece, which is extrapolated above the first pipe 3, and the blade 7 is opened and closed as shown by a solid line and a two-dot chain line through a connecting rod 7a when the sliding piece 6 is moved up and down. Was supposed to. Then, a steel rod 8 is disposed through the first pipe 3 and the second pipe 5, and the lower end thereof penetrates the cap 15 and is fastened with nuts 16, 16. Was screwed to the lower end of the pipe 3. Reference numeral 9 denotes a pressing tube made of plastic, which is externally inserted into the second pipe 5 and whose lower end is in contact with the upper surface of the sliding piece 6.

Reference numeral 18 denotes a saw-toothed cylinder, which is formed by welding and hanging three angles 17, 17, 17 to a cap 15 and fixed to the same so that an anchor can be easily inserted into a pre-drilled hole. It is attached. The pressing tube 9 has a flange 9a integrally formed at the upper end thereof, a coil spring 10 wound around the second pipe 5, and a second
A cap 20 having a hole 19 is detachably screwed to the male screw 13 at the upper end of the pipe 5 and the coil spring 10
The upper end of the coil spring 10 is inserted into a ring 21 formed integrally with the cap 20, and the lower end of the coil spring 10 is connected to a flange 9a.
Was inserted into the ring 22 integrally formed.

[0005] In the figure, reference numeral 23 denotes a string, and hooks 24 are connected to upper and lower ends thereof. The coil spring 10 is contracted elsewhere before the coil spring 10 is externally inserted into the second pipe 5, and the hook is contracted. The coil springs 10 are locked above and below the coil spring 10, and then the coil spring 10 is inserted into the second pipe 5 and the cap 20 is screwed to the second pipe 5. Although not shown, the length of the rod 8 is limited as a product length and for convenience in transportation, so that the rod 8 is connected with a joint coupler in the middle.

[0006]

However, in the conventional ground anchor (underground anchor), since the expansion (opening) of the blade 7 in the ground is based on the elastic force of the coil spring 10, it is not uniform. The blade 7 did not open with the resilience of the coil spring 10 when there were no stratum and obstacles in the ground. The coil spring 10
There was a design limitation for the same excavation diameter, even when trying to increase the resilience of the drill.

In the drawing, a cord 23 and hooks 24, 24 are used to keep the coil spring 10 in a contracted state. However, this is inconvenient, so that a split spring having hooks at both ends is used at an actual use site. Although a case is used, in any case, it is necessary to perform attachment / detachment every time, and the safety at the time of detachment is lacking.

Although the rod 8 is connected by a joint coupler, an anchor with the blade 7 closed is inserted into the drilled hole, and the bottom of the hole is enlarged by the blade 7 after the blade 7 is opened. When the second pipe 5 is rotated by the drilling machine at the time of drilling and injection of the solidifying agent liquid, the screw of the coupler rubs against the inside of the second pipe 5 and the screw of the coupler is loosened and the rod 8 is moved It may remain in the pores.

Although the second pipe 5 is finally recovered, the connection of the second pipe 5 is usually screwed and provided with a stopper to prevent loosening, but is connected by welding on site. Unless the second pipe 5 is reversed and the second pipe 5 is removed from the external thread 4 above the flange 1 at the upper end of the first pipe 3, the connection point in the middle of the second pipe 5 becomes loose. In some cases, the entire length could not be recovered.

Further, the clearance between the inner diameters of the second and first pipes 5 and 3 and the rod 8 (usually a PC steel rod is used) is small, and a drilling fluid such as bentonite or a solidifying agent such as cement milk is used. Because we cannot send enough liquid of liquid,
The slime could not be completely removed, and there were drawbacks such as the solidifying agent liquid being clogged on the way.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a ground anchor which is free from impairment of opening of a blade under any conditions in the soil, can be completely recovered, and has high tensile strength. Things.

[0012]

To achieve the above object, a ground anchor according to the present invention comprises an anchor and a blade opening device, wherein the anchor has a flange near an upper end and a male screw above the flange. A first pipe having a spout near the lower end, a second pipe in which a lower end female screw is screwed to the male thread of the first pipe, and a base end of the first pipe. Pivoted at the bottom of the pipe,
A plurality of blades which are opened and closed by elevating and lowering a sliding piece externally inserted above the first pipe, and which are inserted into the first and second pipes and whose lower end is fixed to the lower end of the first pipe; And a pressing tube which is inserted outside the second pipe and has a lower end in contact with the upper surface of the slide piece, wherein the blade opening device is capable of rotating a drill head of a drilling machine. An input shaft is gripped by the spindle, and an output shaft is connected to the second pipe.The swivel has an axis parallel to and equidistant from the axis of the spindle. And at least two hydraulic cylinders pivotally mounted at the other end to a presser tube presser, the presserer tube presser tube being connected to the output shaft of the swivel with the second pipe inserted through an axis. In addition, the end surface of the pressing tube is rotatably abutted. Therefore, since a plurality of blades are opened by at least two hydraulic cylinders, the opening force is strong. Also,
The blade opening device is mounted on the cylinder head of the drilling machine and moves together with the drilling machine.

According to a second aspect of the present invention, there is provided a ground anchor comprising an anchor and a blade opening device, wherein the anchor comprises a pipe having a jet port formed near a lower end thereof;
It is arranged along the outside of this pipe, the lower end is caulked by a crimping grip, and a plurality of PC steel strands covered with a cap and a predetermined length from the lower part of the PC steel strand are extrapolated and fixed. A sliding piece which is disposed near the upper part of the protection pipe and which moves up and down along the protection pipe and the pipe, and a base end is pivotally connected to a lower part of the pipe and is opened / closed by lifting and lowering the slide piece. A plurality of blades, and a pressure pipe which is extrapolated from the PC strand and has a lower end in contact with the upper surface of the sliding piece, wherein the blade opening device rotates a drill head of a drilling machine. The input shaft is gripped by the spindle, the output shaft is connected to the pipe, and the swivel is connected to the pipe. At least two hydraulic pressures whose ends are pivotally attached to the pressure tube retainer ; And a Linder, the pressing tube retainer, said pipe shaft center is connected to the output shaft of the insertion to the swivel, the end surface of the pressing tube is in contact with rotatably. Therefore, the force to open the blade is strong, and not only does the blade opening device move with the drilling machine, but also a plurality of PC steel strands, which are the to-be-pulled materials left with the blade in the hole, have a high tensile strength even with a small diameter. It is used with one long object each without connection. Further, since the entire cross-section of the pipe is a space, the flow of the liquid is good.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a partially broken side view of a first invention showing an embodiment of the present invention. FIG. 2 is a partially broken side view of the second invention showing the embodiment of the present invention. 3 is a cross-sectional view of FIG. 2, (a) is a line AA,
(B) shows a cross section taken along line BB. FIG. 4 is a side view showing a state in which the anchor of the second invention is tensioned and fixed. FIG. 5 is a view showing the tension and fixing parts shown in FIG. 4, wherein (a) is a longitudinal section of the wedge, (b) is a front view of the wedge, and (c) is a longitudinal section of an anchor head nut using the wedge. Are respectively shown.

In the first invention, the anchor C portion is the same as the conventional one, but the blade opening device D does not use a coil spring, and is configured to open the blade 7 with hydraulic cylinders 33,33. . Since the anchor C is the same as the conventional one, the description of the configuration is omitted.

In the blade opening device D, hydraulic cylinders 33, 33 are arranged on both sides of a swivel 32 as shown in FIG.
The input shaft 32a of the swivel 32 is the drill head 3 of the drilling machine.
The output shaft 32b is held by the first spindle 31a
The pipe 5 is screwed. 32c is an inlet port for the drilling liquid or the solidifying liquid. Numerals 33, 33 denote hydraulic cylinders, the cylinder side of which is pivotally connected to the drill head 31, and the piston rod side of which is pivotally connected to both ends of the pressing tube presser 34, respectively, which are pushed and moved in the direction of arrow a.

Reference numerals 33a and 33b denote input / output ports for hydraulic pressure (in the present embodiment, hydraulic pressure) to the hydraulic cylinder 33, which are connected to spare operating valves of a drilling machine (not shown). Reference numeral 34 denotes a pressing tube retainer. The second pipe 5 is detachably screwed to the output shaft 32b of the swivel 32 through a through hole 34b of the shaft center.
4a is mounted, and the end face of the pressing tube 9 is rotatably abutted.

In order to perform construction using the ground anchor according to the first aspect of the present invention, the closed blades 7 are firstly drilled using a drilling machine.
Is drilled to the extent that the hole passes, and the anchor C is inserted into this hole to the bottom of the hole. In addition, the second pipe 5 and the rod 8 are formed to be added according to the depth of the hole. Subsequently, the base end of the second pipe 5 is screwed into the blade opening device D attached to the drill head 31 of the boring machine, and at the same time, the base end surface of the pressing pipe 9 is fixed to the thrust bearing 3 of the pressing pipe holder 34.
4c, the spindle 31 is rotated as shown by the arrow b while the hydraulic cylinders 33, 33 are extended, the second pipe 5 rotates, and the pressing pipe 9 descends while the sliding piece 6 Is pushed downward, so that the blades 7, 7, 7 start to spread as shown by a two-dot chain line while stirring the soil via the connecting rod 7a.

At this time, the excavation liquid such as bentonite liquid is discharged from the ground through the swivel 32 and discharged from the jet port 2 at the lower end of the first pipe. Whether or not the blades 7, 7, 7 are fully opened can be determined by the length of the piston rod of the hydraulic cylinder 33. Next, when the drill head 31 is moved up and down, cylindrical soil is excavated at an outer diameter where the blades 7 are substantially open. Therefore, the supply of the excavating liquid is stopped and the solidifying agent liquid such as cement milk, cement mortar or the like is removed. Upon injection, the latter is replaced by the former, since the specific gravity of the solidifying fluid is heavier than the specific gravity of the drilling fluid.
At this time, the rotation of the second pipe 5 and the vertical movement of the drill head 31 are continued.

When the injection of the solidifying agent liquid is completed, before the solidification, the screw engagement between the blade opening device D attached to the drill head 31 and the second pipe 5 is released, and the second pipe 5 is reversed, Unscrew the male screw 4 and the female screw 12 and
The pipe 5 is pulled up to the ground, and the pressing pipe 9 is also pulled up to the ground. The blade opening device D remains attached to the drill head 31. As a result, only the first pipe 3, the blades 7, 7, 7 and the rod 8 are buried in the ground. If it is necessary to insert the aggregate, then the aggregate may be inserted into the underground hole. As described above, the underground anchor is formed by the anchor C and the solidified soil by the solidification of the solidifying agent liquid, and the rod 8 protrudes a predetermined length to the ground. The length of the protruding portion will be described with reference to FIG. 4 in the second invention. However, an extra length for the pedestal and the jacking is required. After the jack is tensed, the jack is removed, and the end of the rod 8 is fixed with a nut.

Next, the second invention will be described with reference to FIG. First, the anchor E will be described. A feature of the present invention is that a pipe 41 is provided at the center, and a plurality of PC steel strands 42 for supporting the tension of the anchor are provided outside the pipe 41. In the present embodiment, there are three PC strands. The pipe 41 has a spout 41a near the lower end. Then, along the outside of the pipe 41, as shown in FIGS.
2, 42 are provided, and the lower end thereof is caulked by a crimp grip 42a through a flange 41b. Then, a cap 41 is put on the flange 41b as shown by an arrow. However, as in the first invention, the cap 41 may be covered with the saw-toothed cylinder 18 instead of the cap 41. The protective tubes 42b, 42 of a predetermined length are connected to the PC steel stranded wire 42 from below.
b, 42b are extrapolated and then the pipe 41
And a band 43 for binding the PC steel stranded wire 42 are attached at predetermined intervals. A sliding piece 44 is provided near the upper portion of the protection tube 42b so as to be slidable along the protection tube 42b and the pipe 41 (see FIGS. 1 and 3A).

At the lower part of the pipe 41, bearing pieces 41d, 4
1d and 41d are welded (see FIG. 3 (b)), and three blades 45, 45, 45 are pivotally connected thereto, and both ends thereof are pivotally supported on the way and the sliding piece 44. The three blades 45, 45, and 45 are configured to open and close via the rod 46 as the sliding piece 44 moves up and down. However, a plurality of blades 45 may be used. In FIG. 1, reference numeral 47 denotes a pressing pipe of a thin steel pipe, which is connected on the ground by welding on the ground (plastic may be used as in the conventional embodiment, but strength is insufficient because it is pressed by a hydraulic cylinder described later). . The blade opening device D has the same structure as the blade opening device D shown in FIG. However, a pipe 41 is inserted through the axis of the pressing tube retainer 34 and is screwed to the output shaft 32 b of the swivel 32.
The only difference is that the ends of the three PC strands 42 are inserted.

The construction using the ground anchor of the second invention is the same as that of the first invention described above, except that the parts to be collected and left before the solidifying agent liquid is injected and solidified are completed. Different. That is, in the second invention, the screw engagement between the blade opening device D attached to the drill head 31 and the pipe 41 is released, and the blade opening device D is connected to the drill head 31.
When the pressing pipe 47 is pulled out of the soil, the pipe 41 to the ground and the blades 4 fixed to the
5, 45, 45, and three PC steel strands 42, 42, 4
2 are left in the soil.

The anchor is made of three PC steel strands 42, 4
An extra length of a predetermined length (no extra length is required because the pipe 41 is not tensioned) is provided for the jacks 2 and 42 to be tensioned and fixed, and the pedestal 51 is applied as shown in FIG. 5 (c), a hole 53a of the anchor head nut 53 on the plate 52 (this hole is provided in FIG. 5 (a),
(Wedge 53b shown in (b) is fitted))
The plate 5 passes through an axial hole (not shown) of the jack 55.
6 and a pooling head 57 (an anchor head nut 53 shown in FIG.
The terminal is set so that the terminal slightly protrudes through the PC steel strand 42 through which the wedge is inserted, and the terminal is fixed by driving the wedge. In the figure, reference numeral 54 denotes a jack chair which is provided between the jack 55 and the pedestal 51 and prevents the jack 55 from hitting the anchor head / nut 51.

Next, the jack 55 is extended. At this time, the "wedge" of the pooling head 57 has been tightened, but the "wedge" of the anchor head nut 53 has been loosened. Then, the anchor is tensioned through the feathers in the soil. After the tension is applied with a predetermined force, the wedge 53b of the anchor head nut 53 is driven in, the three PC strands 42 are tightened, and the nut 53c is further tightened. The jack 55, the plate 56, and the pooling head 57 are removed, and the three strands 42 of PC steel are cut at a position slightly out of the anchor head nut 53.

The operation in the case of the first invention is the same as described above.
The rod 8 is used instead of the three PC strands 42 and the nuts are used instead of the anchor head nut 53 and the pooling head 57.

[0027]

According to the present invention described in detail above, the following effects can be obtained.

(1) Since the blade opening device is not a coil spring but a hydraulic cylinder, the force is strong and there is no danger that the blade will not open (claims 1 and 2).

(2) The blade opening device is fixed to the drill head and can be moved together, so that there is no need for assembling as in the conventional case, and to compress and release the coil spring as in the conventional case. The safety is improved because of the fact that no action is taken (claims 1 and 2).

(3) The pc steel stranded wire, which is a tensile material, has a higher tensile strength than conventional steel rods, and the strength of the stranded wire can be adjusted by increasing or decreasing the number of wires even when the same diameter is used in soil. . In the conventional one, since the rod was inserted into the second pipe, there was a design limitation in increasing or decreasing the diameter. (Claim 2).

(4) The conventional rod is connected by a coupler because the length of one rod is limited due to manufacturing restrictions and transportation reasons, and therefore, the rod is rotated after inserting the anchor into the hole. However, in the present invention, there is no connection point, so there is no danger (claim 2).

(5) Unlike the prior art, since the rod is not inserted in the second and first pipes, there is no clogging of the drilling liquid or the solidifying agent liquid and a sufficient amount of liquid can be sent. 2).

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view of a first invention showing an embodiment of the present invention.

FIG. 2 is a partially broken side view of the second invention showing the embodiment of the present invention.

3 (a) is a cross-sectional view of FIG. 2, (a) is a line AA, (b) is a BB
2 shows a cross section of the line.

FIG. 4 is a side view showing a state where the anchor of the second invention is tensioned and fixed.

FIG. 5 is a drawing of the tensioning and fixing parts shown in FIG. 4, wherein (a) is a longitudinal section of the wedge, (b) is a front view of the wedge, and (c) is a longitudinal section of an anchor head nut using the wedge. FIG.

FIG. 6 is a partially broken side view of a conventional ground anchor.

[Explanation of symbols]

 C, E Anchor D Blade opening device 1 Flange 2, 41 (a) Spout 3 First pipe 4 Male screw 5 Second pipe 6, 44 Sliding piece 7, 45 Blade 8 Rod 9, 47 Pressing tube 31 Drill head 31a Spindle 32 Swivel 32a Input shaft 32b Output shaft 33 Hydraulic cylinder 34 Pressing tube retainer 41 Pipe 41c Cap 42 PC stranded wire 42a Crimping grip 42b Protective tube

──────────────────────────────────────────────────の Continuation of front page (56) References JP-A-57-155429 (JP, A) JP-A-2-279819 (JP, A) JP-B3-44603 (JP, B2) JP-B-53- 3168 (JP, B1) (58) Field surveyed (Int. Cl. ⁷ , DB name) E02D 5/80 102

Claims (2)

(57) [Claims] A first pipe having a flange near an upper end thereof, a male screw threaded above the flange, and a spout near the lower end; A second pipe in which a female screw at a lower end is screwed to the male thread of the first pipe; and a slide whose base end is pivotally attached to a lower part of the first pipe and which is externally inserted into an upper part of the first pipe. A plurality of blades that are opened and closed by raising and lowering a piece, a rod inserted into the first pipe and the second pipe, and a lower end fixed to the lower end of the first pipe; A pressure pipe having a lower end in contact with an upper surface of the sliding piece; the blade opening device includes an input shaft held by a rotatable spindle of a drill head of a drilling machine, and an output shaft connected to the second shaft. A swivel connected to the pipe, and an axis of the spindle At least two hydraulic cylinders having axes at parallel, equidistant positions, one end pivotally connected to the drill head, and the other end pivotally connected to the presser tube presser; A ground anchor, wherein the second pipe is inserted through an axis and connected to an output shaft of the swivel, and an end face of the pressing tube is rotatably abutted. 2. An anchor and a blade opening device, wherein the anchor is provided with a pipe having a spout near the lower end, and is disposed along the outside of the pipe, and the lower end is caulked by a crimping grip. A plurality of PC steel stranded wires covered with caps, and a predetermined length from the lower portion of the PC steel stranded wire is disposed near an upper portion of a protection tube which is extrapolated and fixed. A plurality of vanes whose base end is pivotally connected to the lower part of the pipe, and which is opened and closed by elevating the sliding piece; A swivel in which an input shaft is gripped by a rotating spindle of a drill head of a drilling machine, and an output shaft is connected to the pipe. And parallel to the axis of the spindle At least two hydraulic cylinders having an axis at equidistant positions, one end pivotally attached to the drill head, and the other end pivotally attached to the presser tube retainer, wherein the presser tube retainer comprises: A ground anchor, wherein the pipe is inserted through an axis and connected to an output shaft of the swivel, and an end surface of a pressing tube is rotatably abutted.