JP5028323B2 - Ground anchor method - Google Patents

Description

  The present invention relates to a ground anchor method for construction on a slope for stabilizing the slope.

The ground anchor method is generally performed as follows.
After drilling the anchor hole on the slope of the natural ground, insert a tensile material such as PC steel wire into the anchor hole, and then inject a grout material such as mortar into the anchor hole to place the tip of the tensile material underground To settle. After fixing, the pressure receiving plate is inserted into the tensile material protruding from the anchor hole, and tightened with a fastener to tension and fix the tensile material. This construction method supports the reaction force of the tensile force of the tensile material with a pressure receiving plate, an example of which is disclosed in the following Patent Document 1, and as the pressure receiving plate, a precast concrete block, steel, aluminum, FRP, etc. The one made of reinforced concrete is also known.
Japanese Patent Publication No.5-85696

  The light pressure plate has a weak point in terms of yield strength to withstand the reaction force of the tensile force of the tensile material, while the precast concrete block and steel pressure plate have sufficient tensile force of the tensile material. Although it can withstand the reaction force, it is heavy and it is not easy to carry materials to the construction site in addition to installing a crane or the like when constructing on a slope. If the slope is uneven, unevenness occurs between the slope and the pressure plate. In contrast, a reinforced concrete pressure plate for placing concrete on-site is easy to carry individual materials, can be installed without a crane, is cheaper, and has a slightly uneven slope. Even if it is, it will not become uneven with the slope, but at the time of construction, it is necessary to assemble the formwork or support work to prevent the assembled formwork from collapsing, and the method with a steep slope On the surface, it is not easy to perform such work.

  An object of the present invention is to provide a ground anchor method that can provide the above-described advantages of a pressure-receiving plate made of reinforced concrete in which concrete is placed on site, and can be provided more inexpensively without requiring a support work.

  The invention according to claim 1 is the step of cutting the anchor hole on the slope of the natural ground, and then inserting and fixing the tensile material in the anchor hole, or combining the vertical beam and the horizontal beam in a grid pattern, Alternatively, a fixing body having a structure made of grating and a pressure bearing plate connected to the structure through a connecting material is used, and the fixing body is inserted into a tensile material protruding from an anchor hole so that the structure becomes a slope. A step of fixing a tension member protruding from the fixing body with a fastening tool after installation, a step of installing a mold around the fixing body, and connecting the fixing body and the mold with a connector; It is characterized by comprising a step of placing a reinforcing bar inside and placing concrete so that at least the surface of the bearing plate of the fixing body is exposed.

  The invention according to claim 2 is the invention according to claim 1, wherein at least a part of the main members of the vertical beam and the horizontal beam or the grating constituting the structure has a tapered cross section and is easy to be sloped. It is characterized by being able to bite into.

  The invention according to claim 3 is characterized in that, in the invention according to claim 1 or 2, the structure is provided with a stopper that protrudes laterally and restricts the amount of biting into the slope.

  The invention according to claim 4 is the invention according to claims 1 to 3, characterized in that the fixing member is provided with a pipe through which a tensile material is passed, and the concrete is placed in a mold outside the pipe.

  According to the first aspect of the present invention, the pressure receiving plate made of reinforced concrete is formed by placing concrete in the mold, but the mold to be assembled at the time of placing the concrete is supported by being connected to the fixing body by the connector. No support work is required. In addition, each material such as a fixing body, fixing tool, formwork, and reinforcing bar for forming the pressure receiving plate is lighter and less bulky than the constructed pressure receiving plate made of reinforced concrete, so it can be easily brought into the field. It can be constructed without a crane and is inexpensive. Furthermore, even if the slope is somewhat uneven, it does not become uneven.

  According to the second aspect of the present invention, when the fixing body is attached to the slope, it is easy to bite into the slope, and it is possible to prevent the fixing body from temporarily slipping and falling off the slope.

  According to the third aspect of the present invention, the biting of the fixing body into the slope can be regulated to a certain level, and thereby the thickness (height from the slope) of the reinforced concrete pressure receiving plate can be kept constant.

  According to the fourth aspect of the present invention, the tensile material is passed through the pipe and surrounded by the pipe, so that the concrete is prevented from adhering to the tensile material at the time of placing the concrete, and the fixing by the fixing tool is not hindered.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view of a fixing body generally indicated by reference numeral 1, and FIG. 2 is a cross-sectional view of the fixing body 1 attached to a slope. The fixing body 1 includes a vertical beam 2a and a horizontal beam 2b except for the central portion. Combined in a lattice form, a steel structure 2 having a rectangular opening 3 in the center, or a grating (hereinafter simply referred to as a structure) provided with an opening 3 in the center, and from the four corners of the opening 3 Connected to the structure 2 through a connecting member 4 made of a standing steel pipe, a through hole 5 coaxial with the opening 3 is formed at the center, and a mounting portion 8 protruding laterally is attached to the periphery. The support plate 6 and the angle steel 7 fixed to the side surface of the structure 2 and projecting to the side from the intermediate portion of the structure 2 serve as a stopper.

  The vertical bars 2a and the horizontal bars 2b or the main members described above have an I-shaped cross section in the example shown in FIG. 2, but may be flat bars as shown in FIG. Preferably, the cross section as shown in FIG. 4 is formed in a tapered wedge shape.

  The bearing plate 6 is connected to the structure 2 via the connecting members 4 at the four corners of the opening, but may be connected by one connecting member made of steel pipe fixed to the periphery of the opening or the inside of the opening.

  Further, in the example shown in FIG. 1, the angle steel 7 is attached to the four side surfaces of the fixing body 1, but may be attached only to two opposite side surfaces as shown in FIG. 5.

Next, a ground anchor method using the fixing body 1 will be described.
First, as shown in FIG. 6, an anchor hole 9 is drilled on the slope and a grout material 11 such as mortar is poured into the bottom of the hole. Next, a tensile material 12 made of PC steel wire is inserted into the anchor hole 9, and the tip portion is pushed into the grout material and fixed.

  Next, the fixing member 2 is installed on the slope so that the opening 3 and the through hole 5 of the fixing member 2 shown in FIG. At the time of installation, the structure 2 is pushed in, and the front ends of the vertical beam 2a and the horizontal beam 2b (the main member that constitutes the grating when the structure is grating) are bitten into the slope. As a result, the fixing body 1 is temporarily fixed to the slope and does not slide down from the slope. In addition, if the vertical beam 2a and the horizontal beam 2b or the main member of the structure 2 are formed in a part, preferably all, in a tapered shape, the biting into the slope becomes easy. As for the bite into the slope of the structure 2, the part protruding to the side of the angle steel 7 functions as a stopper, the amount of bite into the slope is regulated by this part, and the part hits the slope It becomes possible to bite in. When the slope ground is soft, it is not necessary to taper the vertical beam 2a and the horizontal beam 2b or the main member. In this case, it is necessary to make the portion serving as the stopper of the angle iron wider so as to reliably perform the function as the stopper. After attaching the fixing body 1, a pipe 16 made of plastic, paper, metal, or the like is passed through the tension member 12 from above and inserted into the through hole 5 and the opening 3 of the structure 2.

  Thereafter, the mold 15 is assembled around the fixing body 1, and the fixing body 1 and the mold 15 are connected by a connecting tool 17 such as a reinforcing bar (FIG. 6). In order to attach the connector 17 to the fixing body 1, the connecting material 4, the pipe 16, the bearing plate 6, etc., for example, the mounting portion 8 (see FIG. 1) attached to the bearing plate 6 is used. Are attached to each mounting portion 8 by fastening means such as bolts and screws, or are attached by welding or the like, and are attached to the formwork 15 by welding or fixing bolts or screws as shown in FIG. Performed by the dressing 19.

  After assembling the mold 15 around the fixing body 1, the reinforcing bars 18 are arranged in the mold 15. When the reinforcing bars 18 are arranged, the same applies to the connector 17, but the attachment portion 8 is attached to the fixing body 1, the connection member 4, the pipe 16, the bearing plate 6, and the like, and is attached to the attachment portion 8. Is desirable. Thereby, positioning and attachment at the time of reinforcing bar attachment become easy. After the bar arrangement, the mold 15 is covered and covered. The mold 15 is assembled so that the lower surface of the mold is flush with the lower surface of the support plate 6. Thereafter, concrete is placed in the mold through holes 20 formed in the mold 15 located on the upper side of the slope. Since the tension member 12 is passed through the pipe 16 at the time of placing the concrete, the concrete is prevented from adhering. After curing, each mold 15 is removed, and then a fastener 13 is attached to the tension member 12 protruding from the through hole 5 of the bearing plate 6 and the tension member 12 is tensioned and fixed on the bearing plate (FIG. 7). In this way, the pressure-receiving plate 21 made of reinforced concrete is constructed.

  According to this construction method, the formwork 15 is connected to the fixing body 1 by the connecting member 17, so that no support work is required, and the fixing body 1, the pipe 16, the formwork 15, the fastening tool 13, the reinforcing bar 18, and the connecting tool. The individual materials such as 17 are relatively light and not bulky, so that they can be easily carried into the site, can be assembled without installing a crane, and the fixing body 1 can be a beam 2a, 2b of the structure 2 or a main member. It is attached to the slope in a temporarily fixed state by pushing it into the slope, and it is prevented from slipping off the slope, and the part protruding to the side of the angle steel 7 is a stopper. The pressure receiving plate with a certain thickness or more can be manufactured, and the tension member 12 is passed through the pipe 16 to prevent the concrete from adhering to the concrete when it is placed. Z It is not, have an effect such as has never uneven surface of the pressure receiving plate and the slope is produced by the concrete be made somewhat uneven as slope is shown, it is filled.

The top view of a fixing body. Sectional drawing which attached the fixing body to the slope. Sectional drawing of the vertical beam or horizontal beam of a structure. Sectional drawing of another example of a vertical beam or a horizontal beam. The top view of another aspect of a fixing body. Sectional drawing which assembled | attached the formwork. Sectional drawing of the constructed pressure receiving plate.

Explanation of symbols

1 .. Fixing body 2.. Structure 2 a.. Vertical beam 2 b.. Horizontal beam 3. Opening 4. Connection portion 5. Through hole 6. Supporting plate 7. 9 .. Anchor hole 11. Grout material 12. Tensile material 13. Fastener 15. Form 16. Pipe 17. Connection 18. Reinforcing bar 19. Fastener 20. ..Pressure plate

Claims (4)

  After drilling an anchor hole on the slope of the natural ground, a step of inserting and fixing a tensile material into the anchor hole, combining a vertical beam and a horizontal beam in a lattice shape, or a structure made of grating and the structure Using a fixing body having a support plate connected to the structure via a connecting material, inserting the fixing body into a tensile material protruding from an anchor hole, and placing the structure on a slope, After fixing the protruding tension material with the fastening tool, installing the mold around the fixing body, connecting the fixing body and the mold with the connecting tool, and arranging the reinforcing bars in the mold A ground anchor method comprising: placing concrete so that at least the bearing plate of the fixing body is exposed.   The ground member according to claim 1, wherein at least a part of the main members of the vertical beam and the horizontal beam or the grating constituting the structure has a tapered cross section and can be easily bitten into a slope. Anchor construction method.   The ground anchor method according to claim 1 or 2, wherein the structure is provided with a stopper that protrudes laterally and regulates the amount of biting into the slope.   The ground anchor method according to any one of claims 1 to 3, wherein a pipe through which a tensile material is passed is attached to the fixing body, and concrete is placed in a formwork outside the pipe.

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