Structure of slope frame and construction method of slope frame

Abstract

To provide a structure of slope frames capable of forming an intersection point of a lattice using uniform concrete.SOLUTION: A structure of slope frames is a structure for stabilizing a slope face by being installed on the slope face, comprising: a frame body configured by arranging a pair of wire nets in a lattice pattern on the slope face; reinforcement bars arranged inside the frame body; concrete cast and cured inside the frame body; and a net cylinder placed at an intersection point of the lattice, the net cylinder forming an anchor hole into which an anchor for fixing the slope frames to the slope face is inserted.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to the structure of a slope protection frame and its construction method.

Background Art

[0002] In order to protect and stabilize a slope, the free frame method (registered trademark), which is a spraying formwork method for constructing a slope protection frame by spraying concrete, is widely used. In this method, steel bars are assembled in a formwork formed by arranging net bodies in parallel, and concrete is placed in the formwork by a spraying method to construct a lattice-shaped slope protection frame made of concrete. One of the characteristics of the free frame method is that by forming the formwork with a net body, rebound is eliminated (discharged) from the meshes during concrete spraying, and a high-strength slope protection frame can be constructed with uniform sprayed concrete. And in this method, when using anchors such as ground anchors or rock bolts to stably fix the slope protection frame to the slope, concrete is sprayed with a perforated pipe arranged at the center of the intersection of the lattice to form an anchor hole.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] The conventional spraying formwork method using a perforated pipe has the following problems. (1) Conventionally used core pipes are of two types: PVC pipes and void pipes. The surfaces of both these pipes are smooth curved surfaces, and when spraying concrete, they have no effect of eliminating rebound. In particular, at the center of the grid intersections, due to the main anchors, steel bars, additional steel bars, tie wires, etc. for fixing the core pipes, it is in a dense state, so it is difficult for the rebound to be discharged. For this reason, there is a risk that the rebound remains on the core pipe, resulting in non-uniform concrete or the formation of voids. (2) Since the concrete is sprayed from above, there is a risk of voids forming on the back of the core pipe where the sprayed concrete does not penetrate. (3) Despite the grid intersections being important locations where main anchors, steel bars, etc. are concentrated, there is a risk of strength instability due to non-uniform concrete or the formation of voids. (4) When voids form, there is a risk of water gushing or rainwater entering the voids, causing the steel bars to corrode. (5) When the core pipe is a PVC pipe, the core pipe remains in the formwork and the anchor work is carried out. In the anchor work, a filling material made of grout or stiff mortar is injected into the hole. However, since the PVC pipe remains, the formwork and the grout are in a separated state and do not become integrated. Also, due to the difference in the shrinkage and expansion rates of the PVC pipe and the concrete, there is a risk of cracks in the concrete around the PVC pipe. (6) When the core pipe is a void pipe, industrial waste is generated because it is removed and discarded before drilling the anchor hole or injecting grout into the anchor hole. Also, if the void pipe is removed before drilling the anchor hole, the slime during drilling may flow into the voids, resulting in non-uniform concrete. (7) Although the void pipe can be removed after drilling the anchor hole, even if the grout or filling material flows into the voids, the grout or filling material will not flow above the horizontal level, so the upper part will remain void.

[0005] The present invention has been made in view of the above points, and its object is to solve the above problems and provide a formwork structure capable of constructing the intersections of the lattice with uniform concrete and a construction method thereof.

Means for Solving the Problems

[0006] The present invention is a formwork structure installed on a slope to stabilize the slope, comprising a frame body formed by arranging a pair of wire meshes in a lattice pattern on the slope, reinforcing bars arranged inside the frame body, and concrete placed and hardened inside the frame body. It has a mesh cylinder that is arranged at the intersection of the lattice and forms an anchor hole through which an anchor for fixing the formwork to the slope is inserted. The mesh cylinder may be formed by bending a crimped wire mesh into a cylindrical shape, or may be formed by combining two U-shaped meshes obtained by bending a crimped wire mesh into a substantially U shape so as to exhibit a substantially hexagonal shape in plan view.

[0007] Further, the present invention is a formwork construction method, comprising the steps of arranging a frame body composed of a pair of wire meshes in a lattice pattern on a slope, arranging reinforcing bars inside the frame body, arranging a mesh cylinder at the intersection of the lattice, placing concrete inside the frame body to construct a formwork, drilling an anchor hole in the slope through the mesh cylinder, fixing an anchor in the anchor hole, and fixing the formwork to the slope via the anchor. The mesh cylinder may be formed by bending a crimped wire mesh into a cylindrical shape, or may be formed by combining two U-shaped meshes obtained by bending a crimped wire mesh into a substantially U shape so as to exhibit a substantially hexagonal shape in plan view.

Effects of the Invention

[0008] The present invention has at least the following one effect. (1) Since the rebound is eliminated by the mesh of the mesh cylinder, the intersection part of the lattice of the formwork can be constructed with uniform concrete. (2) Since the rebound is eliminated by the mesh of the mesh cylinder, there is no possibility of forming a cavity in the concrete, and water gushing or rainwater cannot enter the cavity, and the reinforcing bars will not corrode. (3) Since the concrete and the wire cylinder are integrated, there is no risk of cracks in the concrete around the wire cylinder. (4) The concrete of the formwork protrudes from the meshes of the wire cylinder, and since there are no cavities on the back or around the wire cylinder, the formwork and the anchor are integrated by the injection material. (5) The wire cylinder is integrated with the formwork, and it is not necessary to extract it like a void tube, and no industrial waste is generated.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0010] Hereinafter, based on the drawings, the structure of the formwork of the present invention and its construction method will be described in detail.

[0011] [Example 1] <1> Overall Configuration of the Formwork The formwork 1 of the present invention is installed on the slope surface for stabilization, and includes a frame body 2 formed by arranging a pair of wire meshes 21, 21 facing each other in a lattice pattern on the slope surface, and reinforcing bars 3 arranged inside the frame body 2. Further, concrete 4 is placed and hardened inside the frame body 2. Also, a wire cylinder 5 is arranged at the intersection of the lattice of the formwork 1 inside the frame body 2 (FIG. 1). The reinforcing bars 3 are arranged, for example, by fixing them with steel wires or the like to a connecting member (not shown) arranged between the wire meshes 21 arranged opposite to each other. The concrete 4 is formed by spraying it into the formwork 2 with steel bars 3 arranged therein and curing it by the conventionally known spraying method. An anchor hole 6 is formed on the slope surface at the bottom of the wire cylinder 5, and a fixture 71 is provided on the head of the anchor 7 inserted and fixed in the anchor hole 6 to fix the formwork 1 to the slope surface (Fig. 2). In the anchor hole 6 or the wire cylinder 5, an injection material 8 such as a grout or a stiff mortar injected in the anchor work is cured.

[0012] <2>Wire cylinder The wire cylinder 5 is a columnar member having a mesh 51 on its circumferential surface (Fig. 3), and its height is made substantially the same as the height of the wire mesh 21 of the formwork 2. The wire cylinder 5 is formed, for example, by bending a crimped wire mesh into a cylindrical shape. Since the wire cylinder 5 has the mesh 51, the concrete 4 sprayed on the mesh 51 enters the inside of the wire cylinder 5 and becomes integral with the formwork 1.

[0013] <3>Construction method of the formwork The formwork 1 is arranged with a formwork 2 composed of a pair of wire meshes in a lattice pattern on the slope surface, steel bars are arranged in the formwork 2, and the wire cylinder 5 is arranged at the intersection of the lattices. The formwork 2 and the steel bars 3 are fixed via the connecting materials and the main anchors and sub-anchors (both not shown) placed on the slope surface described above.

[0014] <3.1>Spraying of concrete Then, the concrete 4 is sprayed into the formwork 2. Since the wire cylinder 5 is a cylindrical shape with a circular shape in plan view, it can resist the spraying pressure of the concrete 4. Since the wire cylinder 5 has the mesh 51 similar to the formwork 2, the sprayed concrete 4 protrudes inside the mesh 51, and the wire cylinder 5 and the concrete 4 are integrated. Thus, since the concrete 4 and the wire cylinder 5 are integrated, there is no possibility of cracks occurring in the concrete 4 around the wire cylinder 5. In addition, since the wire cylinder 5 has meshes 51, the rebound during the spraying of the concrete 4 is eliminated by the meshes 51, so that there are no voids, and the structure is such that the rebound accumulates inside the wire cylinder 5. The elimination of the voids prevents water gushing and rainwater from entering the voids and corroding the reinforcing bars 3. And since the rebound is eliminated, the intersection of the grids of the formwork 1 can be constructed with uniform concrete 4. In particular, the intersections of the grids are important locations where main anchors, reinforcing bars 3, etc. are concentrated, and the strength can be maintained by making the concrete 4 uniform. Regarding the lower part of the wire cylinder 5 as well, by spraying from above the wire cylinder 5, the concrete 4 passes through the meshes 51 and is sprayed onto the lower part, and there is no possibility of voids forming in the lower part of the wire cylinder 5. At this time, not only the above-mentioned rebound but also the concrete 4 is sprayed inside the wire cylinder 5, and even if these harden, they can be drilled and removed in the subsequent anchor work described later. Note that the upper part of the wire cylinder 5 may be cured and temporarily blocked when spraying the concrete 4. After that, the concrete 4 hardens and the formwork 1 is constructed.

[0015] <3.2> Anchor work After the construction of the formwork 1, anchor holes 6 are drilled into the slope surface through the wire cylinder 5. Although the concrete 4 and its rebound have hardened inside the wire cylinder 5, they can be removed during the drilling with a drilling machine. The wire cylinder 5 is integrated with the formwork 1 and does not need to be removed like a void tube, and no industrial waste is generated. Also, since there are no voids around, the slime during drilling does not enter either. Then, after drilling the anchor holes 6, the anchors 7 are inserted and fixed, and injection materials 8 such as grout and plugging materials are injected into the wire cylinder 5 and the anchor holes 6. The concrete 4 of the formwork 1 protrudes inside from the meshes 51 of the wire cylinder 5, and since there are no voids on the back or around the wire cylinder 5, the formwork 1 and the anchors 7 are integrated by the injection material 8. After the injection material 8 hardens, a fixture 71 is provided at the head of the anchor 7 to fix the formwork 1 to the slope surface.

[0016] [Example 2] <1>Configuration of the wire cylinder In the above-described Example 1, the wire cylinder 5 was formed in a cylindrical shape. However, two U-shaped wires 52 obtained by bending a crimped wire net into a substantially U shape may be combined (Fig. 5) so as to form a substantially hexagonal shape in plan view (Fig. 6(a)) (Fig. 6(b)). The assembly of the wire cylinder 5 (combination of the U-shaped wires 52) can be carried out on site. Since the U-shaped wire 52 is easy to manufacture and can be polymerized and carried into the site, the manufacturing and transportation costs can be reduced.

Explanation of reference numerals

[0017] 1 Formwork 2 Frame body, 21 Wire net 3 Reinforcing bar 4 Concrete 5 Wire cylinder, 51 Mesh, 52 U-shaped steel 6 Anchor hole 7 Anchor 8 Injectable material

Claims

1. A structure of a retaining wall installed on a slope surface to stabilize the slope surface, A frame body formed by arranging a pair of wire meshes in a lattice pattern on the slope surface, Reinforcing bars arranged inside the frame body, And concrete placed and hardened inside the frame body, characterized by Having a net cylinder arranged at the intersection of the grids and forming an anchor hole for inserting an anchor for fixing the retaining wall to the slope surface. Structure of the retaining wall.

2. The net cylinder is formed by bending a crimped wire mesh into a cylindrical shape, characterized by The structure of the retaining wall according to claim 1.

3. The net cylinder is formed by combining two U-shaped nets obtained by bending a crimped wire mesh into a substantially U shape so as to present a substantially hexagonal shape in plan view, characterized by The structure of the retaining wall according to claim 1.

4. A construction method of a retaining wall, comprising: A step of arranging a frame body composed of a pair of wire meshes in a lattice pattern on the slope surface; A step of arranging reinforcing bars inside the frame body; A step of arranging a net cylinder at the intersection of the grids; A step of placing concrete inside the frame body to construct the retaining wall; A step of drilling an anchor hole in the slope surface through the net cylinder; A step of fixing an anchor in the anchor hole and fixing the retaining wall to the slope surface through the anchor. Construction method of the retaining wall.

5. The net cylinder is formed by bending a crimped wire mesh into a cylindrical shape, characterized by The construction method of the retaining wall according to claim 4.

6. The net cylinder is formed by combining two U-shaped nets obtained by bending a crimped wire mesh into a substantially U shape so as to present a substantially hexagonal shape in plan view, characterized by The construction method of the legal framework according to claim 4.

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