Fall prevention member, and support assembly method

Abstract

To propose a fall prevention member capable of improving workability and safety during the construction of supports, and a support assembly method using the fall prevention member.SOLUTION: A support assembly method includes: a fall prevention member fixing step of fixing a fall prevention member 4 to a steel support 3; a construction step of installing the steel support 3 in an arch shape using heavy machinery; and a spraying step of spraying splay concrete 2 over the ground surface. The fall prevention member 4 includes: an insertion part 61 to be inserted into a sheath 5 formed in the steel support 3; an L-shaped anchor member 6 that has an embedded portion 62 extending from one end of the insertion part 61 in the tunnel axial direction and is embedded in the shotcrete 2; and fixing means 7 that is fixed to a corner between the insertion part 61 and an embedded part 62 to prevent the insertion part 61 from pulling out of a sheath 5 and suppressing the rotation of the anchor member 6 around the insertion part 61.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a fall prevention member for a steel support and a method for assembling a support using the fall prevention member.

Background Art

[0002] In tunnel construction by NATM, the ground surface exposed by tunnel excavation is quickly closed by a support. A tunnel support generally consists of shotcrete sprayed onto the ground surface, a steel support assembled along the ground surface, and rock bolts driven into the ground in the normal direction from the inside of the tunnel.

[0003] The steel supports are connected via a connecting member for fall prevention to existing steel supports (supports adjacent to the shaft side). Such connecting members generally employ a sleeve pipe method or a tie rod method. The sleeve pipe method connects the front and rear steel supports by inserting a hook formed at the tip of a connecting member made of a steel bar into a sleeve pipe fixed to the steel support (see, for example, Patent Document 1). Also, for a tie rod, nuts are tightened at the ends of the tie rods that penetrate the webs of the steel supports with a tie rod as a connecting member horizontally spanned between the steel supports.

[0004] Further, Patent Document 2 discloses that the integration of the front and rear supports is improved by embedding a pair of fixing members extending oppositely from the flanges of the front and rear steel supports formed of H-shaped steel with shotcrete. In the support of Patent Document 2, the integration of the steel support and the shotcrete is improved because the fixing members are embedded in the shotcrete. The fixing member of Patent Document 2 is composed of a rod-shaped rod portion with a base end welded to the flange and a fixing plate member with a plate surface fixed to the tip of the rod portion.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2021-67136 [Patent Document 2] Utility Model Registration Gazette No. 3241438 [Summary of the Invention] [Problems to be Solved by the Invention]

[0006] The installation work of the connecting member is generally carried out manually between a newly installed steel shoring and an existing steel shoring. Therefore, in the installation work of the connecting member, workers or the like need to enter the exposed ground before the shoring is completed or directly under the primary sprayed concrete to carry out the work. Furthermore, the installation work of the connecting member by manual work is time-consuming.

[0007] In the steel shoring of Patent Document 2, since the fixing members attached to the front and rear shorings are embedded in the sprayed concrete and the front and rear steel shorings are integrated, it is not necessary to enter the exposed ground before the shoring is completed or directly under the primary sprayed concrete to carry out the work manually. On the other hand, it takes time to fix the fixing member to the flange. In addition, since it is necessary to spray the sprayed concrete to a thickness required for embedding the front and rear fixing plates, the work is time-consuming and there is a risk of an increase in the amount of concrete.

[0008] An object of the present invention is to propose a fall prevention member that enables improvement of workability and safety during shoring construction, and to propose a shoring assembly method using this fall prevention member. [Means for Solving the Problems]

[0009] The fall prevention member of the present invention that solves such problems prevents the steel shoring from falling by fixing a single fall prevention member attached to the face side of the steel shoring to the ground with shotcrete, and includes an insertion part inserted into a sleeve pipe provided on the steel shoring, an anchor part extending in the tunnel axis direction from one end of the insertion part and embedded in the shotcrete, and a fixing part provided at a corner between the insertion part and the anchor part. The fixing part prevents the insertion part from coming out of the sleeve pipe and suppresses rotation about the axis of the insertion part.

[0010] The shoring assembly method using this fall prevention member includes a fall prevention member fixing step of fixing the fall prevention member, an erection step of erecting the steel shoring in an arch shape using a heavy machine, and a spraying step of spraying shotcrete onto the ground surface. In the spraying step, a preliminary spraying operation of spraying shotcrete so as to entangle the anchor part while holding the steel shoring by the heavy machine, and a main spraying operation of spraying shotcrete with the holding of the steel shoring by the heavy machine released after the preliminary spraying operation are performed.

[0011] According to such a fall prevention member, the anchor part is embedded in the shotcrete, functioning as an anchor and preventing the steel shoring from falling. Since the fall prevention member is installed in the steel shoring in advance, there is no need to enter the exposed ground before the shoring is completed or directly under the primary shotcrete for work.

[0012] If the fixing part includes a base part that abuts against a flange to which the sleeve pipe is fixed, a female screw part fixed to the base part, and a bolt that is screwed into the female screw part so that the tip can abut against the end face of the flange and can move forward and backward, the rotation of the fall prevention member can be suppressed by abutting against the steel shoring in two directions perpendicular to the plate surface and the end face of the flange. Also, the bolt's pressing force prevents the insertion part from coming out of the sleeve pipe.

[0013] Further, if the fixing portion includes a base portion that abuts against the web to which the sheath pipe is fixed, a female screw portion fixed to the base portion, and a bolt that is screwed into the female screw portion so as to be able to advance and retreat and whose tip can abut against the flange, by abutting against the web and the flange, rotation of the fall prevention member can be suppressed. Also, the pressing force of the bolt prevents the sheath pipe from coming off.

[0014] In addition, when the anchor portion further includes a net-like member fixed parallel to the ground, the shotcrete may be sprayed so as to entangle the net-like member in the prior spraying operation. By doing so, like in Patent Document 2 or a general fixing plate anchor or a hook anchor, not only at the fixing point but also on the entire surface of the net-like member, it is fixed to the shotcrete, so the fixing property is improved. Also, the shotcrete does not become thick like a fixing plate.

Advantages of the Invention

[0015] According to the fall prevention member of the present invention and the shoring work assembly method using the same, it is possible to improve the workability and safety during shoring work construction.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0017] <First Embodiment> Hereinafter, the case of performing tunnel construction by NATM will be described. As shown in FIGS. 1(a) and (b), the tunnel T is stabilized by closing the ground surface Gs exposed by excavating the ground G with a support 1 composed of shotcrete 2, steel supports 3, etc. Further, at the time of tunnel construction, auxiliary construction methods such as forepoling (short temporary support), mirror bolt work, and leg reinforcement work may be used in combination as necessary.

[0018] In tunnel construction, first, the ground G is excavated to form an excavation hole (tunnel T). The excavation method of the tunnel T is not limited. For example, it may be blasting excavation or mechanical excavation. The advance length of the tunnel T for each cycle is determined according to the ground conditions (ground grade, soil cover, etc.). In this embodiment, it is set to 1.0 to 1.2 m.

[0019] After the tunnel T is excavated to a predetermined extension (1.0 to 1.2 m in this embodiment), the support 1 is formed along the ground surface Gs exposed by excavating the ground G. The support 1 of this embodiment includes shotcrete 2 composed of primary shotcrete 21 and secondary shotcrete 22, steel supports 3 installed at predetermined intervals in the tunnel axis direction, and an anti-tip member 4 attached to the steel supports 3. The construction (support assembly method) of the support 1 of this embodiment includes a primary shotcreting process, an anti-tip member fixing process, an erection process, and a secondary shotcreting process (spraying process).

[0020] In the primary shotcreting process, the primary shotcrete 21 is sprayed onto the ground surface Gs exposed by excavating the ground G. The primary shotcrete 21 is also sprayed onto the wall surface (side surface) of the tunnel T and the face K. The spraying thickness of the primary shotcrete 21 may be determined as appropriate. For example, it is set to 5 cm.

[0021] In the anti - tipping member fixing process, the anti - tipping member 4 is fixed to the steel support 3 before erection (see Fig. 2). Note that the timing of performing the anti - tipping member fixing process is not limited as long as it is before the erection process. For example, it may be performed before the first spraying process or in parallel with the first spraying process.

[0022] The anti - tipping member 4 prevents the steel support 3 from tipping over. The steel support 3 is formed by processing a so - called H - shaped steel consisting of a pair of flanges 31, 31 and a web 32 horizontally mounted on the pair of flanges 31, 31, as shown in Fig. 2(b).

[0023] On the outer flange 31 (side of the ground G) of the steel support 3, as shown in Figs. 2(a) and (b), a sheath pipe 5 is fixed. The anti - tipping member 4 is attached to the steel support 3 using the sheath pipe 5 provided on the steel support 3. The anti - tipping member 4 of this embodiment has an anchor member 6 and a fixing means 7, as shown in Fig. 3.

[0024] The anchor member 6 is composed of a steel bar or a reinforcing bar bent in an L - shape having an insertion portion 61 inserted into the sheath pipe 5 (see Fig. 2) provided on the steel support 3 and an embedding portion 62 extending in the tunnel axis direction from one end of the insertion portion 61 and embedded in the sprayed concrete 2. The material constituting the anchor member 6 is not limited to a steel bar. For example, it may be a steel pipe or a steel plate subjected to bending processing. Also, the anchor member 6 may be formed by joining a member constituting the insertion portion 61 and a member constituting the embedding portion 62. Furthermore, the cross - sectional shape of the steel bar constituting the anchor member 6 is not limited. For example, it may be circular, rectangular, etc.

[0025] A net-like fixing member 63 is fixed to the embedding portion 62. The fixing member 63 is made of a rectangular wire mesh (for example, expanded metal or the like). Note that the material constituting the fixing member 63 is not limited, and for example, it may be formed by combining reinforcing bars, steel bars, etc. in a lattice shape. The method of fixing the fixing member 63 to the embedding portion 62 is not limited, and for example, it may be welded or fixed via a jig.

[0026] The fixing means 7 prevents the insertion portion 61 from coming out of the sheath pipe 5 and suppresses the rotation of the anchor material 6 around the axis of the insertion portion 61. As shown in FIG. 3(a), the fixing means 7 is fixed to the corner portion between the insertion portion 61 of the anchor material 6 and the embedding portion 62. The fixing means 7 includes a base portion 71, a female screw portion 72, and a fixing bolt 73.

[0027] As shown in FIG. 3(a), the base portion 71 is made of a rectangular steel plate. As shown in FIGS. 2(a) and (b), when the overturning prevention member 4 is installed on the steel support 3, the base portion 71 is welded to the outer surface of the anchor material 6 so as to abut against the flange 31 of the steel support 3 to which the sheath pipe 5 is fixed. The shape and dimensions of the base portion 71 are not limited, but when the overturning prevention member 4 is installed on the steel support 3, one end is located on the web 32 side of the sheath pipe 5, and the other end has a length protruding toward the shaft mouth side from the end surface of the flange 31. The thickness of the base portion 71 is set to be slightly separated from the surface of the flange 31 when the insertion portion 61 is inserted into the sheath pipe 5.

[0028] The female screw portion 72 is fixed to the base portion 71. In the present embodiment, the female screw portion 72 is a nut welded to the other end portion of the base portion 71 (the portion protruding toward the shaft mouth side from the end surface of the flange 31). The female screw portion 72 is fixed to the base portion 71 such that the central axis is orthogonal to the end surface of the flange 31. Note that the material constituting the female screw portion 72 is not limited, and for example, it may be a steel plate in which a bolt hole (a through hole with female screw processing on the inner surface) is formed.

[0029] The fixing bolt 73 is a bolt that is screwed into and out of the female screw portion 72 in a retractable manner. The tip of the fixing bolt 73 is flat and can abut against the end face of the flange 31.

[0030] In the step of fixing the anti - tipping member, as shown in FIGS. 2(a) and (b), first, the insertion portion 61 of the anchor member 6 is inserted into the sheath pipe 5. At this time, the flange 31 and the base 71 are separated by the clearance between the sheath pipe 5 and the insertion portion 61, making it easier to insert. Next, the fixing bolt 73 is rotated so that its tip abuts against the end face of the flange 31. When the fixing bolt 73 is further rotated (screwed in) with its tip abutting against the end face of the flange 31, the insertion portion 61 in contact with the lower inner surface in the sheath pipe 5 moves (ascends) along the arc surface in the sheath pipe, and thus the base 71 adheres closely to the flange 31. As a result, the rotation of the anchor member 6 is suppressed, and the friction force between the base 71, the fixing bolt 73, and the flange 31 also prevents the member from coming out of the sheath pipe 5. A plurality of anti - tipping members 4 are installed at a predetermined interval with respect to the steel support 3. Note that the number and the breaking pitch of the anti - tipping members 4 are not limited.

[0031] In the erection process, the steel support 3 is erected in an arch shape using a heavy machine. First, in the vicinity of the face K, the steel support 3 with the anti - tipping member 4 fixed along the surface of the primary sprayed concrete 21 (or the natural ground surface Gs) is erected by a heavy machine (erector). At this time, as shown in FIG. 1(a), a pair of left - and - right steel supports 3, 3 are connected at the top to be assembled in an arch shape. Next, the heavy machine is operated to position the steel support 3.

[0032] In the secondary spraying process (spraying process), secondary sprayed concrete 22 is sprayed onto the primary sprayed concrete 21 (ground surface Gs). In the secondary spraying process, first, while holding the steel support 3 built in an arch shape by a heavy machine, fixing sprayed concrete 23 (a part of the secondary sprayed concrete 22) is sprayed so as to entangle the fixing member 63 (preliminary spraying work). In the present embodiment, at this time, the sprayed concrete 2 is also sprayed onto the legs of the steel support 3 to solidify the legs. When a predetermined strength is developed in the secondary sprayed concrete 22 sprayed by the preliminary spraying work, the secondary sprayed concrete 22 is sprayed onto the area other than the area where the secondary sprayed concrete 22 was sprayed in the preliminary spraying work with the holding of the steel support 3 by the heavy machine released (main spraying work). Note that the spraying thickness of the secondary sprayed concrete 22 is determined according to the state of the ground, and the minimum thickness is 5 cm.

[0033] According to the support erection method of the first embodiment, the fall prevention member 4 is fixed to the steel support 3, and the fall prevention member 4 functions as an anchor by being embedded in the sprayed concrete 2. Therefore, there is no need to separately provide a member for preventing the steel support 3 from falling. Therefore, it is not necessary to enter the exposed ground before the support 1 is completed or directly below the primary sprayed concrete 21 to perform the work of installing the connecting material manually.

[0034] The fall prevention member 4 is installed using the sheath pipe 5 provided in advance on the steel support 3, so the attachment work is easy. Specifically, since the fall prevention member 4 is fixed to the steel support 3 only by inserting the insertion portion 61 into the sheath pipe 5 and tightening the fixing bolt 73, it has excellent workability.

[0035] Since the fixing member 63 is made of a flat mesh material, it is not necessary to make the thickness of the sprayed concrete 2 thicker than necessary for the purpose of embedding the fixing member 63. Therefore, the labor (time) and cost required for the construction (including curing) of the sprayed concrete 2 can be minimized. In addition, since the fixing member 63 is integrated with the sprayed concrete over the entire surface, it has excellent fixing strength.

[0036] <Second Embodiment> In the second embodiment, as in the first embodiment, the case of tunnel construction by NATM will be described. The tunnel construction is carried out by excavating the ground G to form an excavation hole (tunnel T), and forming the support 1 along the ground surface Gs exposed by excavating the ground G (see Fig. 1).

[0037] The support 1 of the second embodiment includes a shotcrete 2, a steel support 3 provided at a predetermined interval in the tunnel axis direction, and a fall prevention member 40 attached to the steel support 3. The construction (support assembly method) of the support 1 of this embodiment includes a primary shotcrete step, a fall prevention member fixing step, an erection step, and a secondary shotcrete step (shotcrete step).

[0038] In the primary shotcrete step, the primary shotcrete 21 is sprayed onto the ground surface Gs exposed by excavating the ground G. The primary shotcrete 21 is sprayed not only on the wall surface (side surface) of the tunnel T but also on the face K. The spraying thickness of the primary shotcrete 21 may be determined as appropriate, for example, 5 cm.

[0039] In the fall prevention member fixing step, the fall prevention member 40 is fixed to the steel support 3 before erection (see Fig. 4). The timing of implementing the fall prevention member fixing step is not limited as long as it is before the erection step. For example, it may be implemented before the primary shotcrete step or in parallel with the primary shotcrete step.

[0040] The fall prevention member 40 prevents the steel support 3 from falling. The steel support 3 is formed by processing a so-called H-shaped steel composed of a pair of flanges 31, 31 and a web 32 horizontally mounted on the pair of flanges 31, 31, as shown in Fig. 4(b). A sheath pipe 5 is fixed to the corner of the outer (ground side) flange 31 and the web 32 of the steel support 3.

[0041] The fall prevention member 40 is attached to the steel support 3 by using the sheath pipe 5 provided on the steel support 3. As shown in Fig. 5(a), the fall prevention member 4 of the present embodiment has an anchor member 6 and a fixing means 70.

[0042] The anchor member 6 includes an insertion portion 61 to be inserted into the sheath pipe 5 (see Fig. 4) provided on the steel support 3, an embedding portion 62 that extends in the tunnel axis direction from one end of the insertion portion 61 and is embedded in the sprayed concrete 2, and a net-shaped fixing member 63 fixed to the embedding portion 62. Note that since the details of the anchor member 6 (the insertion portion 61, the embedding portion 62, and the fixing member 63) are the same as those described in the first embodiment, detailed description thereof is omitted.

[0043] The fixing means 70 prevents the insertion portion 61 from coming out of the sheath pipe 5 and suppresses the rotation of the anchor member 6 about the insertion portion 61. As shown in Figs. 5(a) to 5(c), the fixing means 70 is fixed to the corner portion between the insertion portion 61 and the embedding portion 62 of the anchor member 6. The fixing means 70 includes a base portion 74, a female screw portion 72, and a fixing bolt 73.

[0044] The base portion 74 is made of an L-shaped steel material in cross section composed of a first piece 75 and a second piece 76 as shown in Fig. 5(c). As shown in Fig. 5(a), the base portion 74 is fixed to the anchor member 6 by welding the first piece 75 to the inner surfaces (inner corners) of the insertion portion 61 and the embedding portion 62.

[0045] The contact portion of the first piece 75 with the anchor member 6 is processed into a shape (curved shape) corresponding to the shape of the anchor member 6. Further, a through hole is formed in the central portion of the first piece 75 so that the fixing bolt 73 can be inserted therethrough.

[0046] The second piece 76 is made of a rectangular steel plate as shown in Fig. 5(b). The width (length in the tunnel axis direction) of the second piece 76 is larger than the width of the first piece 75, and the tip has a length that protrudes from the insertion portion 61 of the anchor member 6. Note that a notch process (defect portion 77) is performed on the corner portion of the second piece 76 on the side of the insertion portion 61 (the side on the face side and the side on the ground side) so as not to contact the insertion portion 61.

[0047] The female screw part 72 is fixed to the base part 74. The female screw part 72 is a nut welded to the outer surface (the surface on the base metal side) of the first piece 75 so as to communicate with the through-hole of the first piece 75. The female screw part 72 is fixed to the first piece 75 such that the central axis is orthogonal to the inner surface of the flange 31. Note that the material constituting the female screw part 72 is not limited. For example, when the base part 74 is a steel plate having sufficient strength (thickness), it may be a bolt hole formed by performing female screw machining on the inner surface of the through-hole of the first piece 75.

[0048] As shown in FIG. 5(c), the fixing bolt 73 is a bolt that is screwed into the female screw part 72 so as to be able to advance and retract. The tip of the fixing bolt 73 is flat and can abut against the end face of the flange 31.

[0049] In the anti-tip member fixing step, as shown in FIGS. 4(a) and (b), first, the insertion part 61 of the anchor member 6 is inserted into the sheath pipe 5. At this time, with the insertion part 61 and the sheath pipe 5 as a fulcrum, the second piece 76 of the base part 74 comes into contact with the web 32. Next, the fixing bolt 73 is rotated so that the tip abuts against the inner surface of the flange 31. When the fixing bolt 73 is further rotated (screwed in) with the tip of the fixing bolt 73 abutting against the inner surface of the flange 31, the second piece 76 is pressed against the web 32 with the insertion part 61 and the sheath pipe 5 as a fulcrum. That is, since the fixing means 7 is in close contact at three locations: the fixing bolt 73 that abuts against the inner surface of the flange 31, the second piece 76 (base part 74) that abuts against the web 32, and the fulcrum of the insertion part 61 and the sheath pipe 5, the rotation of the anchor member 6 is suppressed, and the base part 74 and the fixing bolt 73 are also prevented from coming out of the sheath pipe 5 due to the frictional force. A plurality of anti-tip members 4 are installed at a predetermined interval with respect to the steel support 3. Note that the number and the breaking pitch of the anti-tip members 4 are not limited.

[0050] In the erection process, a steel shoring 3 is erected in an arch shape using heavy machinery. In the vicinity of the face K, a steel shoring 3 with a fall prevention member 40 fixed along the natural ground surface Gs is erected by a heavy machine. At this time, as shown in Fig. 1(a), a pair of left and right steel shorings 3, 3 are connected at the top to be assembled in an arch shape.

[0051] In the secondary spraying process (spraying process), secondary sprayed concrete 22 is sprayed onto the primary sprayed concrete 21 (natural ground surface Gs). In the secondary spraying process, first, while holding the steel shoring 3 erected in an arch shape by a heavy machine, fixed spraying concrete 23 (a part of the secondary sprayed concrete 22) is sprayed so as to entangle the fixing member 63 (preliminary spraying work). In the present embodiment, at this time, spraying concrete 2 is also sprayed onto the legs of the steel shoring 3 to solidify the legs. When a predetermined strength is developed in the secondary sprayed concrete 22 sprayed by the preliminary spraying work, the secondary sprayed concrete 22 is sprayed onto the range other than the range where the secondary sprayed concrete 22 was sprayed in the preliminary spraying work with the holding of the steel shoring 3 by the heavy machine released (main spraying work). The spraying thickness of the secondary sprayed concrete 22 is determined according to the state of the natural ground, and the minimum thickness is 5 cm.

[0052] According to the shoring assembly method of the second embodiment, the same operational effects as those of the shoring assembly method of the first embodiment can be obtained.

[0053] The embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and each of the above-described components can be appropriately changed without departing from the spirit of the present invention. For example, the fixing member may be installed as needed.

[0054] Also, in the above-described embodiment, the case where the spraying concrete 2 is sprayed in two stages before and after the erection process has been described, but the spraying concrete 2 may be sprayed once after the erection process.

[0055] The position of the sheath tube 5 fixed to the support worker 1 is not limited. For example, in the first embodiment, the case where the sheath tube 5 is fixed to the end of the flange 31 has been described, but the sheath tube 5 may be fixed near the center of the flange 31. In this case, the fixing bolt may be screwed into the female screw portion 72 formed in the base portion 71 so that the tip can abut against the inner surface of the flange 31 in a retractable manner.

Explanation of Signs

[0056] 1 Support worker 2 Sprayed concrete 21 Primary sprayed concrete 22 Secondary sprayed concrete 3 Steel support worker 31 Flange 32 Web 4,40 Anti-tip member 5 Sheath tube 6 Anchor material 61 Insertion part 62 Embedded part 63 Fixing member 7,70 Fixing means 71 Base 72 Female screw part 73 Fixing bolt 74 Base T Tunnel

Claims

1. An anti - tipping member attached to a steel support worker to prevent the tipping of the steel support worker, comprising an L - shaped anchor member having an insertion portion to be inserted into a sheath pipe provided on the steel support worker, and an embedding portion extending in the tunnel axis direction from one end of the insertion portion and to be embedded in the shotcrete; and fixing means fixed to a corner portion between the insertion portion and the embedding portion to prevent the insertion portion from coming out of the sheath pipe and to suppress the rotation of the anchor member about the insertion portion. The anti - tipping member is characterized by the above - mentioned structure.

2. The fixing means includes a base portion that abuts against a flange of the steel support worker to which the sheath pipe is fixed, a female screw portion fixed to the base portion, and a fixing bolt that is screwed into the female screw portion so as to be able to advance and retreat and whose tip can abut against the end face of the flange. The anti - tipping member according to claim 1 is characterized by the above - mentioned structure.

3. The fixing means includes a base portion that abuts against a web of the steel support worker to which the sheath pipe is fixed, a female screw portion fixed to the base portion, and a fixing bolt that is screwed into the female screw portion so as to be able to advance and retreat and whose tip can abut against the flange of the steel support worker. The anti - tipping member according to claim 1 is characterized by the above - mentioned structure.

4. The anti - tipping member according to any one of claims 1 to 3 further includes a net - shaped fixing member fixed to the embedding portion.

5. An anti - tipping member fixing step of fixing the anti - tipping member according to any one of claims 1 to 3 to a steel support worker, an erection step of erecting the steel support worker in an arch shape using a heavy machine, and a spraying step of spraying shotcrete onto the ground surface. A method for assembling a support worker, characterized in that the spraying step includes a preliminary spraying operation of spraying shotcrete so as to entangle the embedding portion while holding the steel support worker by the heavy machine, and a main spraying operation of spraying shotcrete after releasing the holding of the steel support worker by the heavy machine after the preliminary spraying operation.

6. An anti - tipping member fixing step of fixing the anti - tipping member according to claim 4 to a steel support worker, an erection step of erecting the steel support worker in an arch shape using a heavy machine, and a spraying step of spraying shotcrete onto the ground surface. A method for assembling a support worker, comprising: The spraying step includes a preliminary spraying operation of spraying sprayed concrete so as to entangle the fixing member while the steel shoring is held by the heavy machine, and a main spraying operation of spraying sprayed concrete in a state where the holding of the steel shoring by the heavy machine is released after the preliminary spraying operation. A shoring assembly method characterized by comprising the above.

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