Soil retaining material for soil barrier devices

Abstract

To provide an earth retaining material for a soil cutoff device capable of effectively retaining soil even when a gable side wall surface of an excavation groove collapses.SOLUTION: The above-mentioned problem is solved by an earth retaining material used in a soil cutoff device in which a pair of square frames are rotatably connected in a substantially X-shape in front view and a pair of sheet members are stretched between an upper part of one square frame and a lower part of the other frame. Specifically, the earth retaining material for the soil cutoff device comprises: a plate material; an engaging member provided on a back surface of the plate material; and a flange provided on a lower part of a front surface of the plate material.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a device for preventing labor accidents in construction work such as water supply, sewerage, telecommunications facilities, gas supply facilities, etc. (hereinafter referred to as "water and sewerage work", etc.) involving small-scale trench excavation. More specifically, it relates to an earth stopping material for an earth blocking device capable of preventing casualties of workers caused by earth and sand collapse during trench excavation work and work in the trench.

Background Art

[0002] In water and sewerage work involving small-scale trench excavation work, in order to prevent labor accidents caused by earth and sand collapse during trench excavation work and work in the trench, earth stopping and shoring work may be installed prior to work in the trench. Specifically, it is excavated (raw excavation) by a drag shovel, and then lightweight steel sheet piles are built in so as to be attached to the excavation surface, and bracing and crossbeams are attached to assemble the earth stopping and shoring work.

[0003] Regarding such earth stopping and shoring work, in the guidelines determined by the Ministry of Health, Labour and Welfare, in the case of performing work of excavating a trench approximately vertically with a small-scale trench excavation work, specifically, a trench with an excavation depth generally of 1.5 meters or more and 4 meters or less and an excavation width generally of 3 meters or less, it is required to install appropriate earth stopping and shoring work, etc. by the earth stopping prior method.

[0004] Also, in the Labour Safety and Health Regulations, when there is a risk of harming workers due to collapse, etc., measures to prevent risks such as providing earth stopping and shoring work regardless of depth are obligatory.

[0005] However, it is not easy to objectively judge "when there is a risk of harming workers" in the above Labour Safety and Health Regulations. Also, since the target depth of the previous guidelines is 1.5 meters or more, in orders from public institutions, earth stopping costs are often not accumulated for excavations with a depth less than 1.5 meters.

[0006] Under these circumstances, numerous cases of worker injuries or fatalities due to soil collapse during trench excavation and trench work were reported, particularly in cases where the excavated trench was less than 1.5 meters deep.

[0007] To address this worrying situation, a sediment containment device that can be easily installed in small-scale excavated trenches has been proposed, as described in Patent Document 1. This sediment containment device consists of two rectangular frames connected in an X-shape so as to be rotatable, with a sheet that can block the collapsed sediment from the walls of the excavated trench stretched over these rectangular frames. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2019-218680 [Disclosure of the Invention] [Problems that the invention aims to solve]

[0009] The problems that this invention solves will be outlined below with reference to the drawings. In each figure, U represents the upward direction, D represents the downward direction, R represents the rightward direction, and L represents the leftward direction.

[0010] Figure 8 shows a sediment containment device 5 described in Patent Document 1. A rectangular frame 1 and a rectangular frame 2 are rotatably connected around an axis 4. A pair of sheets 3 are stretched across the upper end of rectangular frame 1 and the lower end of rectangular frame 2. Workers perform their tasks in the space between this pair of sheet members 3.

[0011] Figure 10 shows the implemented state of the sediment containment device 5, which is configured as described above. The collapsed sediment N presses against the sheet member 3 on the left side, creating tension. This tension causes the rectangular frame 1 to rotate counterclockwise (in the direction of arrow K1 in the figure) and the rectangular frame 2 to rotate clockwise (in the direction of arrow K2 in the figure). This force presses the upper and lower sides 1a and 1b of the rectangular frame 1 and the upper and lower sides 2a and 2b of the rectangular frame 2 against either the side wall M1 or the side wall M2 shown in Figure 11. Therefore, the earth pressure generated by the sediment N is transmitted to the upper and lower sides via the sheet tension and balanced with the earth pressure on the side wall.

[0012] In other words, the workspace enclosed by the pair of sheets 3 can be prevented from being buried by landslides as much as possible, thus reducing the risk of workers being caught in landslides.

[0013] Figure 11 shows the sediment containment device 5 installed in the excavation trench M. As described above, the conventional sediment containment device 5 is highly effective in preventing collapsed soil from the longitudinal side walls M1 and M2 of the excavation trench M that the sheet 3 faces. However, if the end wall surface M3 of the excavation trench M collapses, there is no sheet 3 on the side of the sediment containment device 5 facing wall surface M3, so the collapsed soil may not be contained and could enter the work space inside the sediment containment device 5.

[0014] Therefore, the present invention aims to provide a soil retaining material for a soil barrier device that can effectively retain soil even when the end wall of an excavated trench collapses. [Means for solving the problem]

[0015] The configuration of the present invention that achieves the above objective is as follows.

[0016] (1) The earth-retaining material for the earth-blocking device described in claim 1 comprises a plate, a locking member provided on the back surface of the plate, and a flange provided on the lower surface of the plate.

[0017] (2) The earth-retaining material for the earth-blocking device described in claim 2 is constructed in which a slit is provided in the central part of the plate material in the vertical direction, as in the invention described in claim 1.

[0018] (3) The earth-retaining material for the earth-blocking device described in claim 3 is constructed using a sheet material instead of a plate material in the invention described in claim 1 or claim 2. [Effects of the Invention]

[0019] The present invention, configured as described above, will be outlined with reference to the drawings to explain how it works to solve the problem.

[0020] The earth-retaining material 10 for the earth-blocking device according to the present invention (hereinafter referred to as "earth-retaining material 10") is used by being locked to the earth-blocking device 5, as shown in Figures 1 and 6. Specifically, the earth-retaining material 10 is attached to the earth-blocking device 5 by locking the locking member 13 to the rectangular frame 1 and rectangular frame 2 at a position above the axis 4.

[0021] As described above, the soil retaining device 5 with the soil retaining material 10 attached is installed on the end wall surface M3 of the excavation trench M, with the soil retaining material 10 facing each other, as shown in Figure 5. The following details how the present invention, installed in this manner, acts to retain soil when the end wall surface M3 collapses.

[0022] As described above, the retaining wall material 10 is installed in a position facing the gable wall surface M3, thereby preventing collapsing soil and sand from entering the soil barrier device 5.

[0023] Furthermore, according to the present invention, the soil retaining material 10 receives the load of the collapsed soil, so that the soil barrier device 5 exerts an earth-retaining effect against the collapsed soil from the gable wall surface. This is outlined below.

[0024] In Fig. 6, the earth and sand that has collapsed in the direction indicated by arrow A is received by the flange 12, and a vertically downward load indicated by arrow B acts on the earth retaining material 10. This load resists the horizontal force indicated by arrow C generated by the load of the collapsed earth and sand. These two resistance mechanisms will be described. One is the resistance to the overturning moment. Considering the moment at the fulcrum O, the overturning moment due to the product of the horizontal load of arrow C and the height H of its action point is C×H. On the other hand, the stabilizing moment due to the product of the distance L between the square frame 1 and the square frame 2 and the vertical load of arrow B is expressed as B×L. Here, since the moment is clearly B×L > C×H, the earth and sand blocking device 5 does not overturn. That is, an action to hold back the collapsed earth and sand occurs in the earth and sand blocking device 5 and the earth retaining material 10.

[0025] In addition, the load applied to the flange 12 by the above-mentioned collapsed earth and sand has an effect of pushing down the square frame 1 and the square frame 2 that make up the earth and sand blocking device 5 through the locking member 13 of the earth retaining material 10. At the same time, since the locking member 13 is attached at a position above the shaft 4, the upper end sides 1a of the square frame and the upper end sides 2a of the square frame 2 are affected by the action of rotating in the counterclockwise direction and the clockwise direction respectively in Fig. 7, and each presses the side wall surface of the excavation groove M, and a friction D1 is generated between them and the side wall surface. Furthermore, a friction D2 due to the vertical load B is also generated on the lower end sides 1b and 2b. Due to both frictions D1 and D2, the earth and sand blocking device 5 to which the earth retaining material 10 is attached resists the horizontal pressing force C generated from the collapsed earth and sand, and sliding is suppressed. That is, regarding the horizontal resistance, which is another consideration, D1 + D2 > C, and the earth and sand blocking device 5 has an earth retaining effect on the collapsed earth on the side wall surface. The frictions D1, D2 and the vertical load B are as shown in Fig. 6.

[0026] In the invention according to claim 2, a slit 14 is provided in the vertical direction at the central part of the plate material 11 constituting the earth retaining material 10. This prevents the shaft 4 constituting the earth and sand blocking device 5 from interfering with the earth retaining material 10, and by engaging the slit 14 with the shaft 4, rotation and swaying of the plate material 11 are prevented.

Brief Description of the Drawings

[0027] [Figure 1] Explanatory drawing showing the implementation state of the present invention [Figure 2] Front view of the present invention [Figure 3] Same, left side view [Figure 4] Same, perspective view [Figure 5] Explanatory drawing showing the state where the present invention is installed in an excavation trench [Figure 6] Explanatory drawing showing the action due to the weight of the collapsed soil [Figure 7] Explanatory drawing showing the state where the present invention is installed in an excavation trench [Figure 8] Perspective view of the earth and sand blocking device [Figure 9] Explanatory perspective view showing the frame of the earth and sand blocking device [Figure 10] Explanatory drawing showing the implementation state of the earth and sand blocking device [Figure 11] Explanatory drawing showing the implementation state of the earth and sand blocking device

Modes for Carrying Out the Invention

[0028] Hereinafter, preferred embodiments of the invention will be outlined while referring to the drawings. Note that the embodiments of the components of the present invention are not limited to the following embodiments, and various forms can be adopted as long as they belong to the technical scope of the present invention.

[0029] The earth stopping material 10 according to the present invention is used by being attached to a conventional earth and sand blocking device 5 as shown in FIG. 8. Therefore, an embodiment of the earth and sand blocking device 5 will be briefly outlined.

[0030] The earth and sand blocking device 5 has a pair of square frames 1 and square frame 2 rotatably connected in a form that presents a substantially X shape in a front view as shown in FIG. 8. The means for making it rotatable is to provide a shaft 4 for rotation at the intersection position of the square frame 1 and the square frame 2.

[0031] As shown in Figure 9, rectangular frame 1 and rectangular frame 2 are rectangular frame members each consisting of four sides. Then, as shown in Figure 8, sheet 3 is stretched between the top side 1a of rectangular frame 1 and the bottom side 2b of rectangular frame 2. Similarly, sheet 3 is stretched between the top side 2a of rectangular frame 2 and the bottom side 1b of rectangular frame 1.

[0032] Figures 2 to 4 show the earth-retaining material 10 described in claim 2. This earth-retaining material 10 is made by attaching a flange 12 to the lower part of a plate material 11 which is a rectangular metal plate.

[0033] The material of the plate 11 can be anything that can withstand the weight of the collapsed soil, but one example is that aluminum plates can be used.

[0034] Flange 12 uses an L-angle. The material of flange 12 is not restricted as long as it can withstand the weight of the collapsed soil, but aluminum plate is one example of a material that can be used. Flange 12 is also fixed to plate material 11 with bolts. Of course, this is just one example; welding is also acceptable as long as it can withstand the weight of the collapsed soil.

[0035] The plate material 11 is provided with a locking member 13 for attaching the soil retaining material 10 to the soil barrier device 5. The locking member 13 consists of a long bolt 13a and nut 13b, and a plurality of donut-shaped discs 13c fixed to the bolt 13a. The soil retaining material 10 is attached to the soil barrier device 5 by fitting the diagonal frame members of the rectangular frame 1 or rectangular frame 2 into the space between the opposing discs 13c.

[0036] Furthermore, the plate material 11 is provided with multiple holes 15 for passing through the bolts 13a of the locking member 13. This allows the mounting position of the locking member 13 to be variable.

[0037] A slit 14 is provided in the central part of the plate material 14 in the vertical direction. However, in the invention described in claim 1, this slit 14 is not provided.

[0038] In the invention described in claim 3, a sheet material is used instead of the plate material 10 in the invention described in claim 1 or claim 2. This sheet material is a polypropylene fiber sheet with fiber strength capable of withstanding the weight of the collapsed soil. Of course, other materials can be used as long as they can withstand the weight of the collapsed soil.

[0039] Furthermore, as a method for attaching the locking member 13 to the sheet material, for example, a long, narrow metal plate can be attached in the width direction of the sheet material, and the locking member 13 can be attached to the metal plate. Alternatively, a hook-shaped locking member can be directly attached to the sheet material. In this case, it is necessary to provide projections or holes in the rectangular frame constituting the soil barrier device for hooking the hook-shaped locking member.

[0040] Methods for attaching the flange 12 to the lower part of the sheet material include sandwiching the sheet material between the flange 12, which is made of an L-angle, and a long, narrow metal plate and fastening them with bolts, or attaching the flange 12 directly to the sheet material. [Explanation of Symbols]

[0041] 1. Rectangular frame 2. Square frame 3 seats 4-axis 5. Sediment barrier device 10. Soil retaining material for soil barrier devices 11...Plate material 12. Flange 13...Locking member 14 slits 15...hole

Claims

1. A soil retaining material used in a soil barrier device, wherein a pair of rectangular frames are rotatably connected in a manner that presents a substantially X shape when viewed from the front, and one sheet member of a pair of sheet members is stretched between the upper part of one rectangular frame and the lower part of the other rectangular frame, and the other sheet member of the pair is stretched between the lower part of one rectangular frame and the upper part of the other rectangular frame, A plate, a locking member provided on the back surface of the plate, and a flange provided on the lower surface of the plate. This is due to, The aforementioned plate material is configured to be positioned in the substantially X-shaped portion of the pair of rectangular frames by the locking member, and is a soil retaining material for a soil barrier device.

2. The earth retaining material for a soil barrier device according to Claim 1, wherein a slit is provided in the vertical direction in the central part of the plate material.

3. The earth retaining material for a soil barrier device according to Claim 1 or Claim 2, wherein a sheet material is used instead of the plate material. 。

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