Wire mesh deflection prevention component

Abstract

The present invention provides a wire mesh deflection prevention member that can be easily attached to the aforementioned steel support structure and, upon attachment, automatically ensures the horizontal alignment so as to prevent any significant step difference with the upper surface of the ground-side flange, and is superior in terms of workability, economy, and quality. [Solution] A deflection prevention member 10 for a wire mesh K provided on the upper surface of the ground-side flange J of a tunnel steel support structure S, etc., is composed of an attachment member 1 etc. that hooks onto the ground-side flange J, etc., and a rod-shaped member 2 or 34 etc. that is integrally provided with the attachment member 1 etc. and extends in the direction of the tunnel entrance without creating a step difference with the upper surface of the ground-side flange J, etc. The rod-shaped member 2 or 34 is a deformed steel bar or a round steel bar. The attachment member 1 etc. is detachably provided on the ground-side flange J.

Description

Technical Field

[0001] The present invention belongs to the technical field of steel support members arranged in a substantially arch shape in the hollow cross-section of a tunnel. More specifically, it relates to a member for preventing the deflection of a wire mesh provided on the upper surface of the steel support member.

Background Art

[0002] In steel support members arranged in a substantially arch shape in the hollow cross-section of a tunnel, in order to reinforce them, such as suppressing cracking of the secondary shotcrete layer to be constructed later, a wire mesh is usually provided (spanned) between the upper surfaces of adjacent steel support members in the front and rear. Since the installation interval between adjacent steel support members in the front and rear is about 1 m, the wire mesh spanned between adjacent steel support members in the front and rear is likely to deflect downward due to its own weight.

[0003] Therefore, Patent Document 1 discloses a support member 16 that suppresses the deflection of the wire mesh 15 by supporting the deflection of the wire mesh 15 caused by its own weight from below, as shown in FIG. 12 of the same Document 1. As described in detail in paragraphs

[0060] to

[0064] of Document 1, the support member 16 is mainly composed of a support anchor 161, a spacer 162, and a fixture 163.

[0004] According to the support member 16 according to Patent Document 1, since the downward deflection of the wire mesh 15 can be suppressed by the supporting effect of the support anchor 161 on the wire mesh 15, it is possible to construct a secondary shotcrete with better quality, such as suppressing cracking of the secondary shotcrete layer to be constructed later.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the support member 16 described in Patent Document 1 requires the support anchor 161 to be firmly fixed to the web of the steel support structure by means of welding or other means, which is time-consuming and troublesome, requiring skilled workers. Furthermore, a fixing device 163 is also required to ensure the verticality (horizontality) of the support anchor 161, requiring precise work. The installation of the spacer 162 also requires fixing at key points, and overall, the support member 16 described in Patent Document 1 has the problem of being time-consuming and very troublesome.

[0007] It is clear that having a wire mesh deflection prevention member that can be easily attached to the steel support structure and, when attached, automatically ensures the horizontal level so as not to create a step difference with the upper surface of the ground-side flange would be more beneficial, such as significantly improving workability.

[0008] Therefore, the present invention was devised in view of the problems of the background technology described above, and its objective is to provide a wire mesh deflection prevention member that can be easily attached to the steel support structure and, when attached, automatically ensures the horizontal level so as not to create a step difference with the upper surface of the ground-side flange, and is excellent in terms of workability, economy, and quality. [Means for solving the problem]

[0009] As a means to solve the above-mentioned problems, the wire mesh deflection prevention member according to claim 1 is a wire mesh deflection prevention member provided on the upper surface of the ground-side flange of a tunnel steel support structure, characterized in that it comprises an attachment member that is hooked onto the ground-side flange and a rod-shaped member that is integrally provided with the attachment member and extends in the direction of the tunnel entrance without substantially creating a step difference with the upper surface of the ground-side flange.

[0010] The invention described in claim 2 is characterized in that, in the wire mesh deflection prevention member described in claim 1, the rod-shaped member is a deformed steel bar or a round steel bar.

[0011] The invention described in claim 3 is characterized in that, in the wire mesh deflection prevention member described in claim 1, the mounting member is detachably provided on the ground-side flange.

[0012] The invention described in claim 4 is a wire mesh deflection prevention member described in claim 1, wherein the mounting member has a plate member with a hook portion that can be hooked onto the face-side end of the ground-side flange, and with the hook portion hooked onto the face-side end, a bolt is inserted through the plate member vertically and vertically to a positioning member provided below the tunnel-side end of the ground-side flange so as to partially overlap with the tunnel-side end, and a nut is screwed on, thereby moving the positioning member up and down, and thus exhibiting a structure that can be hooked onto the ground-side flange.

[0013] The invention described in claim 5 is a wire mesh deflection prevention member described in claim 1, wherein the mounting member has a U-shaped plate member that opens downward so as to sandwich both widthwise ends of the ground-side flange from above, and has a structure that allows it to be hooked onto the ground-side flange by inserting a bolt that passes vertically through the plate member and screwing a nut onto the two positioning members which are provided below the face-side end and the tunnel-mouth-side end of the ground-side flange, respectively, and which partially overlap with the face-side end and the tunnel-mouth-side end, respectively, and moving the two positioning members up and down.

[0014] The invention described in claim 6 is a wire mesh deflection prevention member as described in claim 1, wherein the mounting member has a plate member with a hook portion that can be hooked onto the face-side end of the ground-side flange, and a hanging portion extending from the tunnel-side end of the plate member through which one end of the rod-shaped member, which has a threaded end, is horizontally passed, and the tip of the one end is formed into a notch portion that can receive and support the tunnel-side end of the ground-side flange by cutting out the upper half in a stepped manner, and the hook portion can be hooked onto the ground-side flange by tightening or loosening a nut that is screwed into the one end via the hanging portion while the hook portion is hooked onto the tunnel-side end.

[0015] The invention described in claim 7 is a wire mesh deflection prevention member described in claim 1, wherein the mounting member has a plate member with a hook portion that can be hooked onto the tunnel entrance end of the ground-side flange, and the support member is bent in a substantially L shape with a horizontal portion that abuts against the lower surface of the face-side end of the ground-side flange and a rising portion that passes through the plate member and is fastened with a nut, and is characterized in that it has a structure that can be hooked onto the ground-side flange. [Effects of the Invention]

[0016] According to the wire mesh deflection prevention member of the present invention, the mounting member of the wire mesh deflection prevention member, which has a simple structure, can be easily and reliably attached to the ground-side flange of a tunnel steel support structure. Furthermore, when attached, the wire mesh can be positioned with almost no deflection due to the support effect of the rod-shaped member integrally provided with the mounting member. Thus, a wire mesh deflection prevention member with excellent constructability, economy, and rationality can be realized. [Brief explanation of the drawing]

[0017] [Figure 1] This is a front view showing a wire mesh deflection prevention member according to Embodiment 1 of the present invention. [Figure 2] This is a plan view of Figure 1. [Figure 3] It is a front view showing the usage state of the wire mesh deflection prevention member according to FIG. 1. [Figure 4] It is a plan view of FIG. 3. [Figure 5] It is a front view showing the wire mesh deflection prevention member according to Example 2 of the present invention. [Figure 6] It is a plan view of FIG. 5. [Figure 7] It is a front view showing the usage state of the wire mesh deflection prevention member according to FIG. 5. [Figure 8] It is a plan view of FIG. 7. [Figure 9] It is a front view showing the wire mesh deflection prevention member according to Example 3 of the present invention. [Figure 10] It is a plan view of FIG. 9. [Figure 11] It is a front view showing the usage state of the wire mesh deflection prevention member according to FIG. 9. [Figure 12] It is a plan view of FIG. 11. [Figure 13] It is a front view showing the wire mesh deflection prevention member according to Example 4 of the present invention. [Figure 14] It is a plan view of FIG. 13. [Figure 15] It is a front view showing the usage state of the wire mesh deflection prevention member according to FIG. 13. [Figure 16] It is a plan view of FIG. 15.

Mode for Carrying Out the Invention

[0018] The present invention is based on the technical idea of a wire mesh deflection prevention member that can be realized with a simple structure, can be easily and reliably attached to the ground-side flange of a tunnel steel support, and can automatically position the wire mesh (welded wire mesh) almost without causing deflection when attached. Hereinafter, examples of the wire mesh deflection prevention member according to the present invention will be described based on the drawings.

Example

[0019] FIGS. 1 to 4 show the prevention member 10 of the wire mesh K according to Example 1. The deflection prevention member 10 for the wire mesh K according to this embodiment 1 is a deflection prevention member 10 for the wire mesh K that is provided on the upper surface of the ground-side flange J of a tunnel steel support structure (H-shaped steel formed in an arch shape) S, and is composed of an attachment member 1 that is hooked onto the ground-side flange J, and a rod-shaped member 2 that is integrally provided with the attachment member 1 and extends in the direction of the tunnel entrance Y without creating a step difference with the upper surface of the ground-side flange J. The rod-shaped member 2 is made of a deformed steel bar 2, but it can also be made of a round steel bar, etc. In short, any member that can stably support the wire mesh K without causing it to bend significantly is acceptable. In this embodiment, the mounting member 1 is detachably attached to the ground-side flange J. In the diagram, the symbol K may represent the entire wire mesh or the individual wires that make up the mesh. Furthermore, the symbol X indicates the direction towards the tunnel face (face side), and the symbol Y, as mentioned above, indicates the direction towards the tunnel entrance (entrance side). Additionally, when illustrating the entire wire mesh, for illustrative purposes, the wire mesh K is shown as a dashed line (see Figure 4). The same applies to the other embodiments 2-4.

[0020] Specifically, with respect to the deflection prevention member 10 of the wire mesh K according to Embodiment 1, the mounting member 1 has a plate member 11 equipped with a hook portion 11a that can be hooked onto the face-side end of the ground-side flange J, and with the hook portion 11a hooked onto the face-side end (see Figure 3), a bolt 13 that passes through the plate member 11 vertically is inserted into a positioning member 12 provided below the tunnel-side end of the ground-side flange J so as to partially overlap with the tunnel-side end, and a nut 14 is screwed in, and the positioning member 12 is moved up and down by tightening and loosening the nut 14, thereby exhibiting a structure that can be hooked onto the ground-side flange J.

[0021] The procedure for attaching the deflection prevention member 10 of the wire mesh K according to the above-described embodiment 1 to the tunnel steel support structure (hereinafter referred to as steel support structure as appropriate) S is as follows, as an example only. In other words, first, the wire mesh K is positioned at a predetermined location on the upper surface of the ground-side flange J of the steel support structure S. Next, the plate member 11 is placed on the upper surface of the ground-side flange J via the wire mesh (or wire) K by hooking the hook portion 11a from above toward the face-side end of the ground-side flange J. Next, a bolt (headed bolt) 13 is suspended and supported in a through hole that penetrates vertically and horizontally, pre-drilled near the tunnel entrance end of the plate member 11 of the deflection prevention member 10. The positioning member 12, which has a bolt hole drilled in it, is then passed through the bolt 13, and a nut 14 is screwed on to attach the positioning member 12 to the bolt 13. In this embodiment, a rectangular thin plate member is used as the positioning member 12, but the design can be appropriately changed as long as it is such that it partially overlaps with the tunnel entrance end of the ground-side flange J when viewed from the planar direction. Subsequently, the process of screwing in the nut 14 is continued until it abuts against the lower end of the hanging portion 11b that hangs vertically from the tunnel entrance end of the plate member 11, thereby creating a configuration in which the ground-side flange J of the steel support structure S is held (held) from above by the plate member 11, the hook portion 11a, the hanging portion 11b, and the positioning member 12, as if they were arms. The rod-shaped member (deformed steel bar) 2 is joined to the outer surface of the hanging portion 11b in a substantially horizontal manner by joining means such as welding. The bolt 13, the positioning member 12, and the nut 14, which are components of the mounting member 1 of the deflection prevention member 10, are preferably attached to the plate member 11 in advance, taking into consideration the prevention of loss of the components and work efficiency. Thus, by following the procedure described above, the steel support structure S, to which the deflection prevention member 10 is attached via the wire mesh K, can simultaneously perform the support structure erection work by heavy machinery (robot) and the installation of the wire mesh K. Finishing work (adjustment work) for setting the wire mesh K, such as securing key points with binding devices like binding wire, can be performed by workers as needed.

[0022] Here, the components of the deflection prevention member 10 according to this embodiment 1, and the size of the wire mesh K and steel support structure S used, will be described as merely an example. The aforementioned mounting member 1 (plate member 11) has a plate thickness of approximately 4.5 mm and a width of approximately 30 mm. The length in the lateral direction is changed according to the size of the steel support structure S to which it is applied, but in this embodiment, it is made to be approximately 240 mm to match the size of the H-200 steel support structure (H-beam) S. The aforementioned rod-shaped member (deformed steel bar) 2 has a diameter (D) of approximately 13 to 16 mm, and its lateral length is approximately 600 mm, which is considered an appropriate length for stably supporting the wire mesh (welded wire mesh) K to be applied with almost no bending. Therefore, the total length of the deflection prevention member 10 of the wire mesh K in this embodiment 1 is approximately 840 mm. Of course, the total length of the deflection prevention member 10 is set to a short length that does not interfere with the installation interval (usually about 1 m) of the steel shoring S that are erected sequentially. As an example, the positioning member 12 is a rectangular, thin plate member with a width of approximately 30 mm (the same as the mounting member 1 (plate member 11)), a length of approximately 50 mm, and a plate thickness of approximately 4.5 mm. The wire mesh K is formed in a grid pattern, for example, and in this embodiment, one mesh (one square) of the wire mesh K is approximately 150 x 150 mm. The wire mesh K is stretched over the entire length of the arch-shaped steel support structure (H-beam) S. Experiments conducted by the applicant have shown that if the deflection prevention members 10 according to this embodiment are installed at approximately equal intervals of 1.0 to 1.5 m pitch along the axial direction of the arch-shaped steel support structure (H-beam) S, and a total of about 14 to 20 such members are installed over approximately the entire length (most of the upper half of the spring line), the wire mesh (welded wire mesh) K can be stably supported with almost no deflection. In this embodiment, the wire mesh K is constructed so that approximately 5 meshes (5 squares) protrude laterally (to the right in the illustrated example) from the tunnel entrance end of the ground-side flange J, while approximately 1 mesh (1 square) protrudes laterally (to the left in the illustrated example) from the face-side end of the opposite ground-side flange J. However, the design can be appropriately modified according to the structural design. The 1 mesh of wire mesh K that protrudes laterally (to the left) from the face-side end is used to form an overlap with the end (right end) of the wire mesh K that protrudes laterally (to the right) from the tunnel entrance end of the steel support structure S that is to be erected next.

[0023] Therefore, the deflection prevention member 10 of the wire mesh K described above provides the following effects. (1) The mounting member 1 of the deflection prevention member 10, which has a simple structure, can be easily and reliably attached to the ground-side flange J of the steel support structure S, and a mounting structure can be realized that restrains the wire mesh K provided on the upper surface of the ground-side flange J by embracing it from above, thereby suppressing the displacement movement of the wire mesh K. Thus, a deflection prevention member 10 for the wire mesh K that is economical and easy to install can be realized. (2) The rod-shaped member (deformed steel bar) 2, which is integrally attached to the mounting member 1 by joining means such as welding in a substantially horizontal manner, has a shape in which the upper surface of the ground-side flange J and the top of the rod-shaped member 2 are aligned in a substantially straight line, as can be clearly seen in Figure 3. Therefore, the wire mesh K provided on the upper surface of the ground-side flange J can be stretched from the ground-side flange J toward the tunnel entrance Y with almost no deflection due to the support effect of the rod-shaped member 2. In other words, when the mounting member 1 is attached to the ground-side flange J, the wire mesh K can be automatically positioned with almost no deflection. Thus, a wire mesh deflection prevention member 10 with excellent workability and rationality can be realized. [Examples]

[0024] Figures 5 to 8 show the deflection prevention member 20 of the wire mesh K according to Example 2. The deflection prevention member 20 of the wire mesh K in this embodiment 2 differs from that of embodiment 1 in that the hook portion 11a is replaced by the bolt 13 (reference numeral 24 in embodiment 2), the positioning member 12 (reference numeral 23), and the nut 14 (reference numeral 25).

[0025] Specifically, the mounting member 21 of the deflection prevention member 20 of the wire mesh K according to this embodiment 2 has a U-shaped plate member 22 that opens downward so as to sandwich both widthwise ends of the ground-side flange J from above, and is provided below the face-side end and the tunnel-side end of the ground-side flange J, respectively, and partially overlaps with the face-side end and the tunnel-side end, respectively. By inserting a bolt 24 that passes vertically through the plate member 22 and screwing a nut 25 onto the two positioning members 23, the two positioning members 23 are moved up and down, thereby providing a structure that can be hooked onto the ground-side flange.

[0026] The deflection prevention member 20 for the wire mesh K according to this embodiment 2 is a deflection prevention member 20 for the wire mesh K that is provided on the upper surface of the ground-side flange J of the tunnel steel support structure (H-shaped steel formed in an arch shape) S, similar to embodiment 1 above, and consists of an attachment member 21 that is hooked onto the ground-side flange J, and a rod-shaped member 2 that is integrally provided with the attachment member 21 and extends in the direction of the tunnel entrance Y without creating a step difference with the upper surface of the ground-side flange J. Further supplementary explanations, such as the fact that the rod-shaped member 2 is made of deformed steel bar 2, are as described in paragraph

[0019] above.

[0027] The procedure for attaching the deflection prevention member 20 of the wire mesh K according to this embodiment 2 to the steel support structure S is as follows, as is merely one example. In other words, first, the wire mesh K is positioned at a predetermined location on the upper surface of the ground-side flange J of the steel support structure S. Next, the plate member 22 is placed on top of the ground-side flange J. Next, bolts (headed bolts) 24 are suspended and supported in through holes that are pre-drilled vertically at positions near the tunnel entrance end and the tunnel face end of the plate member 22 of the deflection prevention member 20. The positioning member 23, which has a bolt hole drilled in it, is then passed through the bolt 24, and a nut 25 is screwed on to attach the positioning member 23 to the bolt 24. In this embodiment, the positioning member 23 is a rectangular thin plate member, similar to Embodiment 1 above, but the design can be appropriately modified as long as it is such that it can partially overlap with the ground-side flange J when viewed from the planar direction. Subsequently, the process of screwing in the nut 25 is continued until it abuts against the lower end of the hanging portion that hangs vertically from both the left and right ends of the plate member 22, thereby creating a configuration in which the plate member 22 and the positioning members 23, 23 seem to be embracing the ground-side flange J of the steel support S from above with both arms. The rod-shaped member (deformed steel bar) 2 is joined approximately horizontally to the outer surface of the hanging portion Y on the tunnel entrance side of the plate member 22 by welding or other joining means. The bolt 24, the positioning member 23, and the nut 25, which are components of the mounting member 22 of the deflection prevention member 20, are preferably attached to the plate member 22 in advance, taking into consideration the prevention of loss of components and work efficiency. Thus, by following the procedure described above, the steel support structure S, to which the deflection prevention member 20 is attached via the wire mesh K, can simultaneously perform the support structure erection work using heavy machinery (robots) and the installation of the wire mesh K. Finishing work (adjustment work) for setting the wire mesh K, such as securing key points with binding devices like binding wire, can be performed by workers as needed.

[0028] The components of the deflection prevention member 20 according to this embodiment 2, and the size of the wire mesh K and steel support structure S used, will not be explained (see paragraph

[0022] above for details).

[0029] Therefore, with the above-described deflection prevention member 20 for the wire mesh K, similar to Embodiment 1, the mounting member 21 of the deflection prevention member 20, which has a simple structure, can be easily and reliably attached to the ground-side flange J of the steel support structure S. This enables a mounting structure that restrains the wire mesh K by embracing it from above on the upper surface of the ground-side flange J, thereby suppressing the displacement movement of the wire mesh K. Thus, similar to Embodiment 1, a deflection prevention member 20 for the wire mesh K that is economical and easy to install can be realized. Furthermore, the rod-shaped member (deformed steel bar) 2, which is integrally attached to the mounting member 21 in a substantially horizontal manner by joining means such as welding, exhibits a shape in which the upper surface of the ground-side flange J and the top of the rod-shaped member 2 are aligned in a substantially straight line, as can be clearly seen in Figure 7. Therefore, the wire mesh K provided on the upper surface of the ground-side flange J can be stretched from the ground-side flange J toward the tunnel entrance Y with almost no deflection due to the support effect of the rod-shaped member 2. In other words, when the mounting member 21 is attached to the ground-side flange J, the wire mesh K can be automatically positioned with almost no deflection. Thus, similar to the above embodiment 1, a wire mesh deflection prevention member 20 with excellent workability and rationality can be realized. [Examples]

[0030] Figures 9 to 12 show the deflection prevention member 30 of the wire mesh K according to Example 3. The deflection prevention member 30 of the wire mesh K in this embodiment 3 differs from that of embodiment 1 in that, instead of using the bolts 13, positioning members 12, and nuts 14 as mounting means, it is implemented using a rod-shaped member 34 which is a modified version of the rod-shaped member 2.

[0031] Specifically, the mounting member 31 of the deflection prevention member 30 of the wire mesh K according to this embodiment 3 has a plate member 32 equipped with a hook portion 32a that can be hooked onto the face-side end of the ground-side flange J, and a hanging portion 33a extending from the tunnel-side end of the plate member 32 through which one end of the rod-shaped member 34, which has one end threaded, is horizontally passed, and the tip of the one end is formed into a notched portion 34a that can receive and support the tunnel-side end of the ground-side flange J by cutting out the upper half in a stepped manner, and the hook portion 32a is hooked onto the face-side end, and the nut 35 screwed into the one end via the hanging portion 33a can be tightened or loosened to hook onto the ground-side flange J.

[0032] The deflection prevention member 30 for the wire mesh K in this embodiment 3 is, similar to embodiment 1, a deflection prevention member 30 for the wire mesh K provided on the upper surface of the ground-side flange J of the tunnel steel support structure (H-shaped steel formed in an arch shape) S, and is composed of an attachment member 31 that is hooked onto the ground-side flange J, and a rod-shaped member (deformed steel bar) 34 that is integrally provided with the attachment member 31 and extends in the direction of the tunnel entrance Y without creating a step difference with the upper surface of the ground-side flange J. The rod-shaped member 34 can be made of round steel as well as deformed steel, but the rod-shaped member (deformed steel bar) 34 in this embodiment 3 differs from the rod-shaped member 2 in embodiments 1 and 2 in that, as described above, one end of the rod-shaped member 34, which is threaded, is positioned to penetrate horizontally into the U-shaped sagging portion 33a on the tunnel entrance side Y.

[0033] The procedure for attaching the deflection prevention member 30 of the wire mesh K according to this embodiment 3 to the steel support structure S is as follows, and is merely one example. In other words, first, the wire mesh K is positioned at a predetermined location on the upper surface of the ground-side flange J of the steel support structure S. Next, the plate member 32 is placed on the upper surface of the ground-side flange J via the wire mesh (or wire) K by hooking the hook portion 32a from above toward the face-side end of the ground-side flange J. Next, the end of the rod-shaped member 34, which has one end threaded (processed), is horizontally passed through the through hole pre-drilled in the drooping portion 33a of the U-shaped tunnel entrance side Y, and the notch 34a formed at the tip of the end of the rod-shaped member supports the edge of the tunnel entrance side Y of the ground-side flange J, and by supporting it in this way, the rod-shaped member 34 can be reliably maintained in a substantially horizontal position. After that, by further screwing in the nut 35 that is screwed into the end of the rod-shaped member 34, the mounting member 31 of the deflection prevention member 30 can be firmly fixed to the ground-side flange J. Therefore, the ground-side flange J of the steel support structure S is held in place by the plate member 32, the hook portion 32a, and the rod-shaped member 34 (its tip) as if it were being embraced from above by both arms. Thus, by following the procedure described above, the steel support structure S, to which the deflection prevention member 30 is attached via the wire mesh K, can simultaneously perform the support structure erection work using heavy machinery (robots) and the installation of the wire mesh K. Finishing work (adjustment work) for setting the wire mesh K, such as securing key points with binding devices like binding wire, can be performed by workers as needed.

[0034] The components of the deflection prevention member 30 according to this embodiment 3, and the size of the wire mesh K and steel support structure S used, will not be explained (see paragraph

[0022] above for details).

[0035] Therefore, as with the above-described deflection prevention member 30 for the wire mesh K, the mounting member 31 of the deflection prevention member 30, which has a simple structure, can be easily and reliably attached to the ground-side flange J of the steel support structure S, and a mounting structure can be realized that restrains the wire mesh K by embracing it from above on the upper surface of the ground-side flange J, thereby suppressing the displacement movement of the wire mesh K. Thus, as with the above-described embodiments 1 and 2, a deflection prevention member 30 for the wire mesh K that is economical and easy to install can be realized. Furthermore, as described above, the rod-shaped member (deformed steel bar) 34 can reliably maintain a substantially horizontal position, and as can be clearly seen in Figure 11, the top of the rod-shaped member 34 is aligned in a substantially straight line with the upper surface of the ground-side flange J. Therefore, the wire mesh K provided on the upper surface of the ground-side flange J can be stretched from the ground-side flange J toward the tunnel entrance Y with almost no deflection due to the support effect of the rod-shaped member 34. In other words, when the mounting member 31 is attached to the ground-side flange J, the wire mesh K can be automatically positioned with almost no deflection. Thus, similar to embodiments 1 and 2 above, a wire mesh deflection prevention member 30 with excellent workability and rationality can be realized. [Examples]

[0036] Figures 13 to 16 show the deflection prevention member 40 of the wire mesh K according to Example 4. The deflection prevention member 40 of the wire mesh K in this embodiment 4 differs from that of embodiments 1 and 3 in that the hook portions 11a and 32a are located on the opposite side, and the means of attachment to the ground-side flange J is different. The rod-shaped member 2 is the same, so its explanation is omitted.

[0037] Specifically, the mounting member 41 of the deflection prevention member 40 of the wire mesh K according to this embodiment 4 has a plate member 42 equipped with a hook portion 42a that can be hooked onto the tunnel entrance end of the ground-side flange J, and a support member 43 that is bent into a substantially L shape, having a horizontal portion 43a that abuts against the lower surface of the face-side end of the ground-side flange J and a rising portion 43b that passes through the plate member 42 and is fastened with a nut 44, and is characterized in that it has a structure that can be hooked onto the ground-side flange J.

[0038] The deflection prevention member 40 for the wire mesh K according to this embodiment 4 is a deflection prevention member 40 for the wire mesh K that is provided on the upper surface of the ground-side flange J of the tunnel steel support structure (H-shaped steel formed in an arch shape) S, similar to embodiment 1 above, and is composed of an attachment member 41 that is hooked onto the ground-side flange J, and a rod-shaped member (deformed steel bar) 2 that is integrally provided with the attachment member 41 and extends in the direction of the tunnel entrance Y without creating a step difference with the upper surface of the ground-side flange J. Further supplementary explanations, such as the fact that the rod-shaped member 2 is made of deformed steel bar 2, are as described in paragraph

[0019] above.

[0039] The procedure for attaching the deflection prevention member 40 of the wire mesh K according to this embodiment 4 to the steel support structure S is as follows, as is merely one example. In other words, first, the wire mesh K is positioned at a predetermined location on the upper surface of the ground-side flange J of the steel support structure S. Next, the plate member 42 is placed on the upper surface of the ground-side flange J via the wire mesh (or wire) K by hooking the hook portion 42a from above toward the tunnel entrance end of the ground-side flange J. Next, by utilizing the through-holes that penetrate vertically and horizontally, which are pre-drilled near the face-side end of the plate member 42 of the deflection prevention member 40, the rising portion 43b of the substantially L-shaped bent support member 43 is fastened with a nut 44 via the plate member 42, thereby creating a structure in which the support member 43 receives and supports the face-side edge X of the ground-side flange J. Subsequently, by further screwing in the nut 44, the mounting member 41 of the deflection prevention member 40 can be securely fixed to the ground-side flange J. Therefore, the ground-side flange J of the steel support structure S is held in place by the plate member 42, the hook portion 42a, and the support member 43 in a manner that resembles being embraced from above by two arms. Thus, by following the procedure described above, the steel support structure S, to which the deflection prevention member 40 is attached via the wire mesh K, can simultaneously perform the support structure erection work using heavy machinery (robots) and the installation of the wire mesh K. Finishing work (adjustment work) for setting the wire mesh K, such as securing key points with binding devices like binding wire, can be performed by workers as needed. The rod-shaped member (deformed steel bar) 2 is joined approximately horizontally to the approximate center of the outer surface of the hook portion 42a by joining means such as welding. The support member 43 and the nut 44, which are components of the mounting member 41 of the deflection prevention member 40, are preferably attached to the plate member 42 in advance, taking into consideration the prevention of loss of the components and work efficiency.

[0040] The components of the deflection prevention member 40 according to this embodiment 4, and the size of the wire mesh K and steel support structure S used, will not be explained (see paragraph

[0022] above for details).

[0041] Therefore, with the above-described deflection prevention member 40 for the wire mesh K, similar to embodiments 1 to 3, the mounting member 41 of the deflection prevention member 40, which has a simple structure, can be easily and reliably attached to the ground-side flange J of the steel support structure S. This enables a mounting structure that restrains the wire mesh K by embracing it from above on the upper surface of the ground-side flange J, thereby suppressing the displacement movement of the wire mesh K. Thus, similar to embodiments 1 to 3, a deflection prevention member 40 for the wire mesh K that is economical and easy to install can be realized. Furthermore, the rod-shaped member (deformed steel bar) 2, which is integrally attached to the mounting member 41 in a substantially horizontal manner by joining means such as welding, exhibits a shape in which the upper surface of the ground-side flange J and the top of the rod-shaped member 2 are aligned in a substantially straight line, as can be clearly seen in Figure 15. Therefore, the wire mesh K provided on the upper surface of the ground-side flange J can be stretched from the ground-side flange J toward the tunnel entrance Y with almost no deflection due to the support effect of the rod-shaped member 2. In other words, when the mounting member 41 is attached to the ground-side flange J, the wire mesh K can be automatically positioned with almost no deflection. Thus, similar to the above embodiment 1, a wire mesh deflection prevention member 40 with excellent workability and rationality can be realized.

[0042] Although embodiments have been described above with reference to the drawings, it should be noted that the present invention is not limited to the illustrated examples and includes design modifications and variations in application that are commonly practiced by those skilled in the art, without departing from the technical spirit thereof. [Explanation of symbols]

[0043] 1. Mounting component 2. Rod-shaped members (deformed steel bars) 10. Members to prevent bending of wire mesh 11 Plate members 11a Hook part 11b Hanging part 12 Positioning member 13 volts 14 nuts J Ground-side flange K Wire Mesh S Tunnel steel support structure X Tunnel face direction (face side) Y Tunnel entrance direction (entrance side) 20. Members to prevent bending of wire mesh 21 Mounting components 22 Plate members 23 Positioning member 24 volts 25 nuts 30 Wire mesh deflection prevention member 31 Mounting components 32 Plate members 32a Hook section 33a Hanging part 34. Rod-shaped members (deformed steel bars) 34a Notch 35 nuts 40. Member for preventing bending of wire mesh 41 Mounting components 42 Plate members 42a Hook section 43 Support member 43a Horizontal section 43b Rising section 44 nuts

Claims

1. A wire mesh deflection prevention member provided on the upper surface of the ground-side flange of a tunnel steel support structure, characterized in that it comprises an attachment member that is hooked onto the ground-side flange and a rod-shaped member integrally provided with the attachment member and extending in the direction of the tunnel entrance without creating a step difference with the upper surface of the ground-side flange.

2. The wire mesh deflection prevention member according to claim 1, characterized in that the rod-shaped member is a deformed steel bar or a round steel bar.

3. The wire mesh deflection prevention member according to claim 1, characterized in that the mounting member is detachably provided on the ground-side flange.

4. The mounting member has a plate member equipped with a hook portion that can be hooked onto the face-side end of the ground-side flange, and with the hook portion hooked onto the face-side end, a bolt is inserted through the plate member vertically and vertically to a positioning member provided below the tunnel-side end of the ground-side flange so as to partially overlap with the tunnel-side end, and a nut is screwed on, thereby moving the positioning member up and down, thus providing a structure that can be hooked onto the ground-side flange. This is the wire mesh deflection prevention member according to claim 1.

5. The mounting member has a U-shaped plate member that opens downward so as to sandwich both widthwise ends of the ground-side flange from above, and is provided below the face-side end and the tunnel-mouth-side end of the ground-side flange, respectively, and partially overlaps with the face-side end and the tunnel-mouth-side end, respectively. By inserting a bolt that passes vertically through the plate member and screwing a nut onto the two positioning members, the member is characterized in that it can be attached to the ground-side flange by moving the two positioning members up and down. This member is described in claim 1.

6. The mounting member has a plate member equipped with a hook portion that can be hooked onto the face-side end of the ground-side flange, and a hanging portion extending from the tunnel-side end of the plate member has one end of the rod-shaped member, which has a threaded end, horizontally passing through it, and the tip of the one end is formed into a notch portion that can receive and support the tunnel-side end of the ground-side flange by cutting out the upper half in a stepped manner, and the structure is such that the mounting member can be hooked onto the ground-side flange by tightening or loosening a nut screwed into the one end via the hanging portion while the hook portion is hooked onto the tunnel-side end, as described in claim 1.

7. The mounting member is a support member for preventing deflection of wire mesh as described in claim 1, characterized in that it has a plate member with a hook portion that can be hooked onto the tunnel entrance end of the ground-side flange, and when the hook portion is hooked onto the tunnel entrance end, it has a horizontal portion that abuts against the lower surface of the face-side end of the ground-side flange and a rising portion that passes through the plate member and is fastened with a nut, forming a substantially L-shape, and is structured to be hooked onto the ground-side flange.

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