JP2714632B2 - Diagonal permanent ground anchor, its construction method and construction stand - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for preventing a building A built on a slope as shown in FIG. 18 from overturning, or a method for preventing a retaining wall B from overturning as shown in FIG. The present invention relates to a diagonal permanent ground anchor which is used semi-permanently as such, a construction method thereof, and a construction stand.

2. Description of the Related Art Conventionally, permanent ground anchors for permanent construction which have been developed for semi-permanent use and methods of construction thereof are well known (see, for example, JP-A-62-228521 and JP-A-62-228522).
As shown in FIG. 20, a supporting plate b is attached to the tip of a tensile steel material a, and the attachment is protected by a tip cap containing rust-preventive oil c. A tubular load-bearing body e is abutted on the drawing side of the support plate b so as to surround the outer periphery of the tensile steel material a, and further arranged on the drawing-out side of the load-bearing body e to surround the outer periphery of the tensile steel material a. , A tubular free-length portion sheath f is in contact. The outer periphery of the load-bearing body e and the free-length portion sheath f is filled with an injection material g, a prestress of a predetermined size is introduced into the tensile steel material a, and the upper end of the tensile steel material a is fixed on the frame h. ing. The upper end portion of the tensile steel material a is also protected by a head cap j filled with grease i for rust prevention, and thus has a configuration in which a useful life of about 100 years is exhibited.

Problems to be Solved by the Present Invention Conventional permanent ground anchors are installed vertically downward in the ground as shown in FIG. However, the use and function of the permanent ground anchor are not limited to the vertically downward use mode.
Rather than to prevent the falling of the building A built on the sloping ground as shown in FIG. 18 or the falling of the retaining wall B for retaining the earth as shown in FIG. bad. The diagonal permanent ground anchor must be installed obliquely downward at an appropriate angle to the direction of the resultant force of the earth pressure. Rather, the anchor has many such uses and uses.

However, in the configuration of the conventionally known vertical permanent ground anchor, it cannot be implemented as a diagonal anchor as it is. The reason for this is that, in terms of the structure of the permanent ground anchor, particularly, the thickness of the injected material g on the outer periphery of the load bearing body e is the most important condition in the mechanism (proof strength) for transmitting the anchor load to the ground. However, in the construction of the diagonal anchor, the content of the anchor sinks due to the gravitational action and comes into contact with the lower bottom surface of the diagonal hole. Therefore, in this contact portion, it is impossible to secure the covering thickness of the injected material on the outer periphery of the load-bearing body e, and therefore, it is impossible to secure the predetermined quality, function, and strength as the permanent ground anchor.

Accordingly, an object of the present invention is to provide a diagonal permanent ground anchor constructed by reliably lifting the anchor contents from the lower bottom surface of the diagonal drilling by an interval equivalent to the thickness of the injected material even under the action of gravity, and a method of constructing the same. And a mounting stand.

Means for Solving the Problems (First Invention) As means for solving the above-mentioned problems of the prior art, a diagonal permanent ground anchor according to the first invention is described in the first aspect of the drawings.
As shown in FIG. 11, FIG. 11, FIG. 16 and FIG. 17, an end support is installed at the front end of the load-bearing body 1 (the end of the tip cap 2), and at the rear end of the load-bearing body 1. An upper end spacer is provided, and the load-bearing body 1 is supported by being raised by a height corresponding to the covering thickness of the injection material 4 in the oblique hole 3 by means of the front end support and the upper end spacer.

Since the load-bearing body 1 is supported at both ends by a predetermined height above the lower bottom surface of the oblique drilled hole 3 by the tip support and the upper end spacer, the height is equal to the load-bearing body. 1
And the lower thickness of the injection material 4 between the oblique hole 3 and the lower bottom surface.

(Second Invention) As a means for solving the above-mentioned problem, a method for constructing an oblique permanent ground anchor according to a second invention is described in the second method in the drawing.
As shown in the embodiment in FIG. 3, FIG. 3 or FIG. 6, 7, or FIG. 12, 13, a) Diagonal drilling 3 is excavated in the ground 5 and the drilling water is replaced with the injection material 4. B) installing a tip support at the front end of the load-bearing body 1 on the ground in advance and installing an upper end spacer at the rear end of the load-bearing body 1 to diagonally cut the assembled anchor contents 9; Inserting into the hole 3 and operating the tip support and the upper end spacer to lift and support the load-bearing body 1 on the lower bottom surface of the oblique drilling hole 3 by a height corresponding to the covering thickness of the injection material 4; (C) a step of press-fitting and filling the injection material 4 into the outer peripheral portion of the load bearing body 1 over at least the range of the length of the load bearing body 1 in the oblique drilling 3.

In addition, in the construction method of the diagonal permanent ground anchor,
In the step of inserting the anchor contents 9 into the oblique drilling holes 3, the anchor contents 9 are suspended on the mounting base 6 installed outside the drilling holes 3, and the anchor contents 9 are substantially concentric with the oblique drilling holes 3. It is also characterized in that it is carried out while being supported substantially parallel.

When inserting the anchor contents 9 into the oblique drilling hole 3, the tip support and the upper end spacer are sufficiently reduced (reduced in diameter) to a diameter smaller than the hole diameter of the drilling hole 3 so as not to hinder the insertion operation. Is done.

At the stage when the anchor contents 9 are completely inserted into the oblique hole 3, the tip support and the upper end spacer are operated (expanded in diameter).
The load-bearing body 1 is lifted and supported at a certain height above the lower bottom surface of the oblique drilling 3.

Therefore, the injection material 4 press-fitted into the oblique drilling hole 3 thereafter sufficiently spills between the load-bearing body 1 and the lower bottom surface of the oblique drilling hole 3, and the covering thickness corresponding to the height is provided. Is achieved.

(Third invention) As a means for solving the above-mentioned problem, a mounting base for a diagonal permanent ground anchor according to a third invention has an embodiment shown in Figs. 3 to 6 and Fig. 13 of the drawings. As shown, a pair of columns 62, 62 are vertically and parallelly opposed to each other on a base frame 61, and a roller conveyor 63 is disposed between the pair of columns 62, 62. It is characterized in that the front and rear portions of the frame 64 of the conveyor 63 are supported with respect to the columns 62, 62 so that the inclination angle can be adjusted.

Function The angle of the roller conveyor 63 is adjusted to be concentric with and parallel to the oblique hole 3, and is supported by the columns 62,62. Therefore, the content of the heavy anchor suspended by a crane or the like 9
Is placed on the roller conveyor 63, and can be easily sent into the oblique drilling hole 3 without any difficulty, and an easy insertion operation can be performed.

Embodiment Next, the illustrated embodiment of the present invention will be described.

First, FIG. 1 shows a state in which a pilot cap 7 as a tip support is installed at the front end of the load-bearing body 1 and an upper end spacer 8 capable of expanding and reducing the diameter is provided at the rear end of the load-bearing body 1. The diagonal permanent ground anchor is shown in which the injecting material 4 is formed with a certain thickness or more over the entire circumference of the load-bearing body 1 which is installed and lifted above the lower bottom surface of the diagonal drilling 3 by these.

FIG. 2 shows a state in which a diagonal hole 3 has been drilled in the ground 5 as a first stage of construction of the diagonal permanent ground anchor.

FIG. 3 shows that the anchor contents 9 composed of anchor elements (see FIG. 20) such as a load-bearing body, a free-length sheath, and a tensile steel material which have been pre-assembled on the ground are obliquely drilled by using a construction stand 6. 3 shows a work procedure to be inserted into the apparatus 3.

Drilling of the oblique drill hole 3 is performed by mounting a boring machine 11 on a root bottom surrounded by a retaining wall 10 and penetrating the retaining wall 10. For the drilling of the oblique drill hole 3, for example, a casing pipe (inner and outer double pipe) having a tip bit and having a diameter of about φ170 is used. The hole is drilled to a desired depth at a descent angle of about ゜. In addition, at the deepest part of the oblique drilling hole 3, a pre-drilling by an inner pipe is performed, and a pilot hole 13 having a diameter slightly larger than the maximum diameter of the pilot cap 7 is arranged concentrically with the oblique drilling hole 3 and the length of the pilot cap 7 It is excavated to a considerable depth. The drilling water in the oblique drilling 3 is replaced with cement milk 4 as an injecting material after the inner pipe is pulled out after drilling.

Thereafter, the anchor contents 9 pre-assembled on the ground are suspended on the construction stand 6 by a small crane or the like, and inserted into the oblique drilling holes 3 (FIG. 3).

As shown in FIGS. 4 and 5 in detail,
On a base frame 61 placed horizontally on the ground outside the diagonal hole 3, a pair of columns 62, 62 having a substantially mountain shape when viewed from the side (FIG. 4) is spaced apart by about 270 mm. Are erected so as to face each other in a parallel and symmetrical arrangement. A roller conveyor 63 having a length of about 3500 mm is provided between the pair of columns 62. Roller conveyor
The front portion of the side frame 64 on both sides of the column 63 is rotatably supported on the front frame 66 of the support column 62 by pins 65. The rear part of the same side frame 64,
Similarly, the support 62 is supported by passing an insertion pin 69 into one of a large number of pin holes 68 provided at a pitch of about 50 mm in a rear inclined frame 67 of the support 62. Roller conveyor 63 side frame
The slot 64 is provided with a slot 60 through which the insertion pin 69 passes. Therefore, the pin hole 68 of the post 62 through which the insertion pin 69 passes
By selecting the position of the roller conveyor 63, the inclination angle of the roller conveyor 63 can be freely set in a range from about 15 ° to about 50 ° with respect to the horizontal, so that the oblique drilling 3
Can be adjusted to be equal to the inclination angle of Therefore, when the anchor contents 9 are suspended by a crane or the like onto the roller conveyor 63 of the construction stand 6, the heavy and long anchor contents 9 are simply sent along the roller conveyor 63, and the slant holes 3 are formed. Can be inserted easily, smoothly and efficiently along the casing pipe.

The tapered cone-shaped pilot cap 7 installed at the tip of the tip cap 2 at the tip of the anchor content 9 is inserted into the pilot hole 13 at the deepest part of the oblique drilling hole 3 at the final stage of the insertion work (first). Figure). Accordingly, the load-carrying body 1 is supported by being lifted from the lower bottom surface of the oblique hole 3 by the difference in diameter between the oblique hole 3 and the pilot hole 13.

In addition, it is also possible to use the pilot cap 14 of the wedge pushing type (expanded diameter type) shown in FIGS. The pilot cap 14 has a cylindrical shape with a uniform diameter, and is divided into two along the diameter line as shown in FIG. This pilot cap 14,
It has a pressure contact surface 15 having the same inclination angle as the wedge portion 2a formed at the distal end of the distal end cap 2 constituting the anchor content. As shown in FIG. 6, the pilot cap 14 is used for inserting the anchor contents 9 mounted in a minimum diameter state in which the pressure contact surface 15 of the wedge portion 2a of the tip cap 2 is in close contact. Then, at the final stage of the insertion operation, the pilot cap 14 is inserted into the pilot hole 13, pressed against the inner end face of the pilot hole 13, and then the anchor contents 9 are further strongly pushed. The wedge portion 2a slides along the pressure contact surface 15, and the pilot cap 14 is expanded in diameter as shown in FIG.
The load-bearing body 1 is lifted up from the lower bottom surface of the oblique drilling hole 3 and supported.

Next, the upper end spacer 8 installed at the rear end of the load-bearing body 1 in the anchor contents 9 is specifically shown in FIGS.
As shown in the figure, a movable plate 81 is provided on the outer periphery of a tube 80 joined between the free-length sheath and the load-bearing body so as to be movable in the tube axis direction. The movable plate 81 and the bracket 83 fixed to the left step in FIG. 9 are connected in series by two equal-length links 84, 84 each having a pair. The two links 84, 84 are configured such that the position of the central connecting pin 85 connecting them is in a normal state (reduced diameter r state) in the shape of a letter that protrudes slightly outward.
84, 84 can be bent freely at the position of the connecting pin 85. The long rope 86 guided from the outside of the oblique hole 3 is a bracket
A rotatable roller 88 supported by a connecting pin 87 on the side of 83
Is folded back, and the distal end is fixed to the movable plate 81.

Therefore, when the rope 86 is strongly pulled at the stage when the anchor contents 9 have been inserted into the oblique drill hole 3, the movable plate 81
It is drawn to the left of the figure, and accordingly two links
Numerals 84 and 84 perform a refracting movement outward, and are in a state of an enlarged diameter R. Since the link 84 in the expanded state protrudes from the lower bottom surface of the oblique drilling hole 3, the load bearing body 1 is supported by being lifted from the lower bottom surface of the oblique drilling hole 3.

Note that the movable plate 81 is used when inserting the contents 9 of the anchor.
A plurality of leaf springs 89 are pressed against the inner surface of the hollow portion of the donut-shaped movable plate 81 in the tube axis direction on the outer peripheral surface of the tube body 80 in order to prevent the problem of the wobble moving. Harmful shear movement of the movable plate 81 is prevented by the frictional force of the plate spring 89.

Second Embodiment Next, FIG. 11 shows that a tip spacer 15 capable of expanding the diameter is installed as a tip support at the tip of the load-bearing body 1, and the diameter-expanding operation is also performed at the rear end of the load-bearing body 1. -Capable tip spacer 8
Are shown, and the diagonal permanent ground anchor having a configuration in which the injection material 4 is supported so as to be formed with a covering thickness of a certain value or more over the entire circumference of the load-bearing body 1 in the diagonal hole 3 is shown.

FIG. 12 shows a state in which a diagonal hole 3 has been drilled in the ground 5 as a first stage of construction of the diagonal permanent ground anchor.

FIG. 13 shows that an anchor content 9 composed of an anchor element such as a load-bearing body, a free-length sheath, and a tensile steel material pre-assembled on the ground is inserted into the diagonal drilling hole 3 using a construction stand 6. The point is shown.

The procedure of the oblique drilling 3 and the operation of inserting the anchor contents 9 into the oblique drilling 3 using the construction stand 6 are the same as those in the first embodiment. However, since the pilot hole is not necessary, it is not drilled.

The configuration of the tip spacer 15 is specifically described in FIG. 14 and FIG.
As shown in the figure, a tube whose right end in FIG. 14 is joined to the tip of the cap 2 of the anchor contents 9 by welding or the like.
On the outer periphery of 150, fixed plate 153 and movable plate 151 are 110 mm in the tube axis direction.
It is installed at intervals of place. Fixing plate 153 is tube 150
The movable plate 151 is movable in the tube axis direction. And, between the fixed plate 153 and the movable plate 81,
They are connected in series by isometric links 154, 154, each pair being two. The two links 154, 154 are configured such that the central connecting pin 155 connecting the two links 154 is in a normal state (a state of a reduced diameter r) in which the position of the connecting pin 155 protrudes slightly outward. It can be refracted by. As shown in FIG. 15, the links 154 are provided radially in an arrangement in which the circumference of the tube 150 is equally divided into six. The long rope 156 guided from the outside of the oblique hole 3 is connected to the connecting pin 15 on the side of the fixing plate 153.
The rotatable roller 158 supported by 7 is folded back, and the tip is fixed to the movable plate 151.

Therefore, when the rope 156 is strongly pulled at the stage when the anchor contents 9 have been inserted into the oblique hole 3, the movable plate 151
14 is pulled to the left in FIG. 14, and the two links 154, 154 are refracted outwardly, and are in a state of an enlarged diameter R. Therefore, the link 154 lifts and supports the load-bearing body 1 above the lower bottom surface of the oblique drilling 3.

In addition, when inserting the anchor contents 9, the movable plate 15
In order to prevent the trouble that the 1 moves wobble, several leaf springs 159 that are pressed from the inside to the inner surface of the hollow portion of the donut-shaped movable plate 151 are provided in the tube axis direction on the outer peripheral surface of the tube 150. . Harmful shear movement of the movable plate 81 is prevented by the frictional force of the plate spring 159.

Reference numeral 16 in FIG. 14 denotes an anti-friction hood attached to the distal end of the tube 150 in order to reduce the resistance due to the injection material 4 during the operation of inserting the anchor contents 9.

Other Embodiments (Part 1) FIG. 16 shows a diagonal permanent ground anchor using a tip spacer 17 which is an enlarged diameter type but has a different configuration. In the case of the tip spacer 17 also, the movable plate 171 is attached to the outer periphery of the front part of the tube 170 joined to the tip of the tip cap 2.
Is installed so as to be movable in the pipe axis direction. The movable plate 171
From the rear, a large-diameter plate 172 is attached so as to be rotatable in a radial direction by pins. Meanwhile, the tube
A tapered surface 173 at an angle at which the diameter of the large-diameter plate 172 is to be increased is formed in a step portion behind the 170. A rope 174 guided from outside the oblique hole 3 is fixed to the movable plate 171.

In the case of this tip spacer 17, the expanded plate 172 is connected to the tube 170
The anchor content 9 is inserted into the oblique drilling hole 3 while being laid down (diameter reduced state) along the
Pull 174 strongly. Then, the movable plate 171 is attracted, and accordingly, the large-diameter plate 172 is rotated to rise radially outward along the tapered surface 173 to be in the large-diameter state. It is supported in a form lifted from the lower bottom.

(Part 2) FIG. 17 shows an oblique permanent ground anchor having a configuration using packers 18 and 19 which can expand and contract as a tip support and an upper end spacer. Packer 18 and
Numeral 19 is made of rubber or the like, and each is connected to injection hoses 20, 21 for injecting air, liquid, or the like.

The anchor contents 9 are inserted into the oblique hole 3 in a reduced diameter state in which the two packers 18 and 19 are contracted. When the insertion is completed, the injection material such as compressed air or water or cement milk is injected under pressure through the injection hoses 20 and 21 so that the two packers 18 and 19 are in a fully expanded and expanded state. 1 is supported by being lifted from the lower bottom surface of the oblique hole 3.

Advantageous effects of the present invention As described in detail in conjunction with the embodiment above, according to the oblique permanent ground anchor according to the present invention, it can be implemented at the most effective angle according to the structure to be anchored, the anchor function Can be maximized. In addition, the thickness of the filling material 4 on the outer periphery of the load-bearing body 1 is sufficiently ensured, and the proof strength is sufficiently large.

Further, according to the method for constructing an oblique permanent ground anchor according to the present invention, an oblique anchor excellent in quality and function can be reliably implemented with high reliability.

Further, according to the construction stand according to the present invention, the heavy anchor contents 9 can be easily and quickly inserted into the oblique drilling hole 3 without relying on humans, thereby reducing labor, releasing from heavy labor, and inserting. This contributes to improving work efficiency.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of an oblique permanent ground anchor according to the present invention, FIGS. 2 and 3 are construction procedures for installing the anchor, and FIGS. FIGS. 6 and 7 are construction sectional views showing the reduced and expanded diameters of the pilot cap, FIG. 8 is a left side view of the pilot cap, FIGS. 9 and 10 is a front view and a left side view of the upper end spacer, FIG. 11 is a cross-sectional view showing a second embodiment of the oblique permanent ground anchor, FIGS. 12 and 13 are construction procedures for installing the anchor, FIG. 14 and 15 are a front view and a left side view of the tip spacer, and FIGS. 16 and 17 are construction sectional views showing main parts of the diagonal permanent ground anchors of the third and fourth embodiments, and FIG. Fig. 19 and Fig. 19 are cross-sectional views showing examples of the use of diagonal permanent ground anchors, and Fig. 20 is a cross-sectional view of a conventional vertical permanent ground anchor. is there. 1 ... load-bearing body 7,14 ... pilot cap (tip support) 15 ... tip spacer (tip support) 8 ... top spacer, 3 ... oblique drilling 4 ... injection material, 9 ... anchor contents 6 ... Construction stand, 61 ... Base frame 62 ... Post, 63 ... Roller conveyor 64 ... Frame

 ──────────────────────────────────────────────────続 き Continuing on the front page (73) Patent holder 999999999 Suzuki Metal Industry Co., Ltd. 1-8-2, Marunouchi, Chiyoda-ku, Tokyo (73) Patent holder 999999999 Tokyo Seizo Co., Ltd. 2-chome, Nihonbashi Muromachi, Chuo-ku, Tokyo No. 3-14 (73) Patent holder 999999999 Nittoku Construction Co., Ltd. 8-14-14 Ginza, Chuo-ku, Tokyo (73) Patent holder 999999999 Light Industrial Co., Ltd. 4-35 Kudankita, Chiyoda-ku, Tokyo (72) Inventor Masao Maruoka 2-5-114 Minamisuna, Koto-ku, Tokyo Inside Takenaka Corporation Technical Research Institute (72) Inventor Yuyasu Ikuta 2-5-114 Minamisuna, Koto-ku, Tokyo Takenaka Corporation Inside the Technical Research Institute (72) Inventor Masaji Aoki 2-5-1-14 Minamisuna, Koto-ku, Tokyo Inside the Technical Research Center Takenaka Corporation (72) Inventor Osamu Ozaki No. 251-12, Bercy Kashiwa 103, Toyoshiki, Kashiwa City, Japan (72) Norio Watanabe, Inventor 1286-18-18 Miyanogicho, Chiba City, Chiba Prefecture 208 (72) Inventor Yasuo Kogei 2-16-1, Kyobashi, Chuo-ku, Tokyo Inside Shimizu Construction Co., Ltd. (72) Inventor Yutaka Katsura 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction Corporation (72) Inventor Hideyuki Mano 2-16-1 Kyobashi, Chuo-ku, Tokyo Shimizu Corporation

Claims (4)

(57) [Claims] 1. A tip support is provided at a tip of a load-bearing body,
An upper end spacer is installed at the rear end of the load-bearing body, and the load-bearing body is lifted and supported at a height equivalent to the covering thickness of the injection material in the oblique drilling by the front end support and the upper end spacer. Diagonal permanent ground anchor. (2) a) excavating diagonal holes in the ground and replacing the drilling water with the injection material; and (b) installing a tip support at the tip of the load-bearing body in advance on the ground. At the rear end of the load-bearing body, insert the anchor contents assembled by installing the upper end spacer into the oblique drilling,
(C) lifting and supporting the load-bearing body on the lower bottom surface of the oblique drilling by a height corresponding to the thickness of the injected material by using the tip support and the upper end spacer; Press-fitting and filling the outer periphery of the load-bearing material over the range of the length of the load-carrying body. 3. The step of inserting the contents of the anchor into the oblique drilling includes suspending the contents of the anchor on a construction stand installed outside the hole, and making the anchor substantially concentric with the oblique hole. 3. The method for constructing an oblique permanent ground anchor according to claim 2, wherein the method is performed after being supported substantially in parallel. 4. A pair of pillars are erected vertically and parallel on a base frame, and a roller conveyor is arranged between the pair of pillars. A mounting base for permanent ground anchors, characterized in that the rear portion is supported so that the inclination angle can be adjusted with respect to the column.