Emergency bridge construction method

Abstract

To provide a construction method for an emergency bridge that can be constructed simply and quickly. [Solution] A method for constructing an emergency bridge by erecting bridge girders spanning both banks, comprising: a base frame laying process in which a base frame composed of vertical steel frames that are long in the erection direction of the bridge girders and horizontal steel frames that are long in the direction perpendicular to the erection direction is laid on at least one bank; a bridge girder assembly process in which multiple bridge girder pieces composed of multiple main girder piece steel members that are long in the erection direction and arranged parallel in the direction perpendicular to the erection direction, and horizontal girder steel members that are long in the direction perpendicular to the erection direction and suspended across the multiple main girder piece steel members, with counterweights placed on the base frame, are connected in a stepped pattern starting from the base frame to assemble the bridge girder; and a process in which the counterweights are removed after the bridge girder assembly process is completed.

Description

[Technical Field]

[0001] The present invention relates to a method for constructing an emergency bridge. [Background technology]

[0002] Conventionally, when general traffic is interrupted due to the collapse of roads or bridges during disasters such as typhoons, heavy rains, earthquakes, etc., and a traffic route must be secured urgently, a temporary bridge is erected at the disaster site to secure the traffic route. For example, the technology described in Patent Document 1 is known as a method for constructing such a temporary bridge. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-259017 Summary of the Invention [Problem to be solved by the invention]

[0004] In the case of constructing such emergency bridges, the urgency is particularly high, so it is essential that the construction can be carried out easily and quickly. The present invention has been made in view of the above circumstances, and aims to provide a method for constructing an emergency bridge that can be constructed easily and quickly. [Means for solving the problem]

[0005] The first method is A method for constructing an emergency bridge by erecting bridge girders across both banks, a base frame laying step of laying a base frame on at least one bank, the base frame being composed of vertical steel frames that are long in the erection direction of the bridge girder and horizontal steel frames that are long in a direction perpendicular to the erection direction; a bridge girder assembly process in which a bridge girder is assembled by connecting a plurality of bridge girder pieces, each of which comprises a plurality of main girder piece steel materials that are long in the erection direction and arranged parallel in a direction perpendicular to the erection direction, and cross girder steel materials that are long in the direction perpendicular to the erection direction and suspended across the plurality of main girder piece steel materials, in a stepped manner starting from the base frame with a counterweight placed on the base frame; and a step of removing the counterweight after the bridge girder assembly step is completed. This is a construction method for emergency bridges characterized by the following.

[0006] The second means is the first means, In the base frame laying step, the base frame is laid on the one bank; a bridge girder erection process in which the bridge girder is rotated around a predetermined fulcrum by removing the counterweight, and the tip of the bridge girder is landed on the opposite bank to erect the bridge girder; It is characterized by:

[0007] The third means is the second means, characterized in that each of the vertical frame steel, the horizontal frame steel, the main girder piece steel and the cross girder steel is composed of a main retaining material.

[0008] The fourth means is the third means, If the number of the bridge girder pieces to be connected from the starting point is n (n is a natural number), and the main girder piece steel material and the cross girder steel material that make up the nth bridge girder piece from the starting point are the nth main girder retaining main material and the nth cross girder retaining main material, respectively, The first bridge girder piece is configured to include a first main girder retaining main material whose base end side is superimposed on the vertical frame steel material that constitutes the base frame, and a first cross girder retaining main material that is placed on the first main girder retaining main material, The second and subsequent bridge girder pieces are superimposed at their base ends on the (n-1) main girder retaining material. Nth main girder retaining material and an nth cross girder retaining main material placed on the nth main girder retaining main material, It is characterized by:

[0009] The fifth means is the fourth means, The first horizontal girder retaining main material of the first bridge girder piece is provided on the vertical frame steel material and the first main girder retaining main material, The nth cross girder retaining main material of the second and subsequent bridge girder pieces is (n-1) Main girder retaining material and n It is characterized by being installed on top of the main girder retaining material.

[0010] A sixth means is the fifth means, characterized in that the cross beam steel material is an H-beam steel and is arranged with the flanges facing up and down.

[0011] A seventh means is the sixth means, characterized in that the upper surfaces of the upper flanges of the cross beam steel materials of the plurality of bridge beam pieces are flush with each other.

[0012] An eighth means is the seventh means, characterized in that after the bridge girder erection step, a covering plate is placed between adjacent cross girder steel members to form a bridge deck.

[0013] The ninth means is the eighth means, characterized in that after the bridge girder erection process, a temporary guardrail based on the main earth retaining material is installed. [Effects of the Invention]

[0014] According to the present invention, the bridge girder is assembled by connecting the bridge girder pieces in a stepped manner, so that the emergency bridge can be constructed easily and quickly. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a perspective view of an emergency bridge according to an embodiment. [Figure 2] FIG. 10 is a front view illustrating the steps of the construction method for an emergency bridge. [Figure 3] FIG. [Figure 4] 1 is a perspective view showing the connection structure between the base frame and the bridge girder and the connection structure between the bridge girder pieces. FIG. [Figure 5] FIG. 1 is a front view showing the mounting structure of the cross beam retaining main material. [Figure 6]FIG. 10 is a perspective view of a tilted base. [Figure 7] FIG. 1 is a perspective view of a Z-joint. [Figure 8] FIG. 1 is a perspective view of an L-shaped joint. [Figure 9] FIG. [Figure 10] FIG. [Figure 11] FIG. 10 is a diagram showing the mounting structure of the scaffolding. [Figure 12] An enlarged perspective view of part of the completed emergency bridge. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, a construction method for an emergency bridge according to an embodiment of the present invention will be described.

[0017] FIG. 1 is a perspective view of an emergency bridge 100 according to an embodiment, and FIG. 2 is a front view for explaining the steps of a construction method for the emergency bridge 100. As shown in FIG. The construction of this emergency bridge 100 is broadly divided into a base frame installation process A (Fig. 2(A)), a bridge girder assembly process B (Fig. 2(B)), a bridge girder erection process C (Fig. 2(C)), and a bridge deck and guardrail installation process D (Fig. 2(D)).

[0018] (Base frame installation process A) The base frame installation step A is a step of installing the base frame 10 on one side of the river. FIG. The base frame 10 is formed by connecting main earth retaining members (H-beams) in a ladder-like manner. That is, the base frame 10 is composed of two parallel vertical frames 11, 11 and several horizontal frames 12 suspended between the two vertical frames 11, 11. Each of the vertical frames 11 and horizontal frames 12 is composed of a main earth retaining material (H steel). The base frame 10 is laid on one side of the shore, and the two vertical frames 11, 11 extend toward the opposite shore.

[0019] The vertical frame 11 is constructed by stacking main earth retaining members in two layers, and comprises a lower frame 11a and an upper frame 11b superimposed on the lower frame 11a. The lower frame 11a is made up of multiple main earth retaining members connected lengthwise with flanges at the top and bottom. Adjacent main earth retaining members in the lower frame 11a are connected by bolting the end plates of the main earth retaining members together. The main earth retaining members of the upper frame 11b are superimposed on the main earth retaining members of the lower frame 11a, with the flanges facing up and down. Adjacent main earth retaining members of the upper frame 11b are arranged across a gap where the horizontal frames 12 fit together. The main retaining member of the upper frame 11b is connected to the main retaining member of the lower frame 11a by bolting the lower flange to the upper flange of the main retaining member of the lower frame 11a.

[0020] A horizontal frame 12 with its flange positioned horizontally spans the gap in the upper frame 11b. The main earth retaining member of this horizontal frame 12 is connected to the main earth retaining member of the upper frame 11b by bolting the flange to the end plate of the main earth retaining member of the upper frame 11b.

[0021] At the opposite bank end of the base frame 10, a portion of the main retaining wall material 13a of the lower frame 11a protrudes toward the opposite bank beyond the end of the main retaining wall material 13b of the upper frame 11b.

[0022] The bolt connections between the main earth retaining members are made using bolt holes pre-formed in the main earth retaining members. The assembly of the base frame 10 may be carried out on-site, or all or part of it may be carried out in a factory.

[0023] (Bridge girder assembly process B) A bridge girder 20 is connected to the opposite bank end of the base frame 10. Fig. 4 is a perspective view showing the connection structure between the base frame 10 and the bridge girder 20 and the connection structure of the bridge girder pieces 20a. With a counterweight CW placed on the base frame 10, the bridge girder 20 starts from the point where the cross girder main retaining member (H-steel) 22 is installed on the main retaining member 13a and extends in a stepped manner upward toward the opposite bank.

[0024] The bridge girder 20 is configured to include a plurality of main earth retaining members (H-beams) of the same length. Excluding the starting point of the cross girder retaining main member 22, the bridge girder 20 is constructed by connecting multiple bridge girder pieces 20a, each with one cross girder retaining main member 22 suspended across the middle of the length of two parallel main girder retaining main members 21, 21, facing the opposite bank so that some of the pieces overlap. Here, for convenience of explanation, the number of bridge girder pieces 20a from the starting point is set to n (n=1 to 18 in the embodiment), and the n-th bridge girder piece 20a is set to the bridge girder piece 20a. n , and bridge girder piece 20a n The main girder retaining member 21 and the cross girder retaining member 22 that constitute the main girder retaining member 21 are n and main crossbeam retaining material 22 n If so, the bridge girder piece 20a is configured as follows. In the embodiment of the bridge girder 20, the main girder retaining member 21 and the cross girder retaining member 22 are arranged so that their flanges are positioned above and below. In addition, in order to distinguish the cross girder retaining member 22 at the starting point position from the other cross girder retaining member 22, it will be represented as the cross girder retaining member 220.

[0025] First, the main crossbeam retaining member 220 that constitutes the starting point will be described. The main crossbeam retaining member 220, which constitutes the starting point, is installed on top of the main crossbeam retaining member 13a of the sill 11a. As shown in Fig. 5, a sloping base 23 is installed below this main crossbeam retaining member 220, with the upper surface having a predetermined upward gradient toward the opposite bank. Fig. 6 is a perspective view of the base 23. The base 23 is bolted onto the main earth retaining member 13a. This bolting may be performed on-site or in advance at a factory.

[0026] The cross beam earth retaining main material 220 is connected to the middle of the length of the earth retaining main material 13a using a Z-joint 24. FIG. Specifically, the cross beam main retaining member 220 is connected to the main retaining member 13a by bolting one leaf of the Z-type joint 24 to the upper flange of the main retaining member 13a at the base end side of the main retaining member 13a, and by fastening the other leaf together with the lower flange of the cross beam main retaining member 220 to the base 23.

[0027] Adjustment pieces 25a, 25a are bolted to both sides in the bridge width direction on the upper surface of the crossbeam retaining main material 220. This bolting may be performed on-site or may be performed in advance in a factory.

[0028] Next, the bridge girder piece 20a1 connected to the base frame 10 will be described. Returning to Figure 4, on the opposite bank side of the cross girder main earth retaining material 220, the base end side of the main girder earth retaining material 211 is superimposed on the main earth retaining material 13a. The tip side of the main girder earth retaining material 211 protrudes further toward the opposite bank side than the end of the main earth retaining material 13a. The main girder retaining member 211 is connected to the retaining member 13a by bolting the lower flange to the upper flange of the retaining member 13a. The cross girder retaining main material 220 and the main girder retaining main material 211 are connected by an L-shaped joint 26, as shown in Fig. 5. Fig. 8 is a perspective view of the L-shaped joint 26. Specifically, the main girder retaining member 220 is connected to the main girder retaining member 211 by bolting one leaf of the L-shaped joint 26 to the end plate of the main girder retaining member 211, and by fastening the other leaf together with the bottom flange of the main girder retaining member 220 to the base 23. The other leaf and the bottom flange of the main girder retaining member 220 together to the base 23 may be fastened on-site or may be fastened in advance at a factory. A pivot piece (retaining part) 27a, which has been fixed to the abutment in advance, is connected to the bottom of the tip of the main girder retaining member 211 by bolting using existing bolt holes. Figure 9 is a perspective view of the pivot piece 27a. This bolting can be done on-site or in advance at a factory.

[0029] A cross girder main retaining material 221 is connected to the middle of the length of the main girder main retaining material 211. On the opposite side of the cross girder main retaining material 221, the base end side of a main girder main retaining material 212 is placed overlapping on top of the main girder main retaining material 211. The tip side of the main girder main retaining material 212 protrudes further toward the opposite side than the end of the main girder main retaining material 211. The main girder retaining member main material 211 and the main girder retaining member main material 212 are connected by bolting the opposing flanges together. Furthermore, the connection between the cross girder main retaining material 221 and the main girder main retaining material 211 or the main girder main retaining material 212 is performed using the base 23, Z-joint 24, and L-joint 26, similar to the case of connecting the cross girder main retaining material 220. In this case, the connection between the cross girder main retaining material 221 and the main girder main retaining material 211 may be performed on-site or may be performed in advance at a factory. In addition, a corner piece 28 is provided at the lower step between the main girder retaining main member 211 and the main girder retaining main member 212, and the end piece of the main girder retaining main member 211 and the bottom flange of the main girder retaining main member 212 are connected to the corner piece 28 by bolting. In this case, the bolting between the corner piece 28 and either the end piece of the main girder retaining main member 211 or the bottom flange of the main girder retaining main member 212 may be performed in advance at the factory. Figure 10 is a perspective view of the corner piece 28.

[0030] Similarly, the main girder retaining material 21 n In the middle of the length of (2≦n≦18), the main material of the horizontal beam retaining wall 22 n are connected. Main crossbeam retaining member 22 n On the opposite side of the river, there is a main girder retaining member 21 n On top of that, n=1 Except for the case of 8, the main girder retaining material 21 n+1 The base end side of the main girder retaining member 21 is provided so as to overlap. n+1 The tip side of the main girder retaining material 21 n It protrudes further to the opposite bank than the end of the river. Main girder retaining material 21 n and main girder retaining material 21 n+1 The connection is made by bolting the flanges together. Also, the main crossbeam retaining material 22 n and the main girder retaining material 21 nOr main girder retaining material 21 n+1 The connection to the main beam retaining member 221 is performed using the base 23, Z-joint 24, and L-joint 26, in the same manner as in the case of connecting the main beam retaining member 221. n and main girder retaining material twenty one n The connection can be made on-site or in advance at the factory. In addition, the main girder retaining material 21 n and main girder retaining material 21 n+1 The corner pieces (retaining parts) 28 provided at the lower step of the main girder retaining member 21 are bolted together using the existing bolt holes. n End pieces and main girder retaining members 21 n+1 The lower flange of the In addition, bridge girder piece 20a n Main crossbeam retaining material 22 n is the main girder retaining material 21 n―1 and main girder retaining material 21 n It is placed on top of.

[0031] In this way, a bridge girder 20 of a predetermined length is assembled. In this case, the members are transported by a lafter crane or the like. In addition, the main girder retaining material 21 n As shown in FIG. 11, a scaffolding 29 consisting of a roller 29a and a column 29b is provided via clamps on the exposed underside of the bridge girder 20 (2≦n). This scaffolding 29 is also stepped. In FIG. 2, this scaffolding 29 is shown by a thick line. This scaffolding 29 is attached to the main girder retaining member 21. n It is preferable to attach it to (2≦n) in advance. In addition, the upper surfaces of all the cross beam retaining main members 22 are arranged to be flush.

[0032] (Bridge girder erection process C) The counterweight CW is removed by an uplift release device (not shown), and the base frame 10 and the bridge girder 20 are gently rotated around the pivot piece (support point) 27a. 16The lower flange of the bridge is connected to the pivot piece 27b, which has been fixed to the abutment in advance, by bolting. At this time, the footing 29 at the landing portion is removed. Furthermore, if necessary, a portion of the base frame 10 is removed after the bridge girder 20 is erected. In this case, the uplift is opened by a lafter crane or the like.

[0033] (Bridge deck installation process and guardrail installation process) FIG. 12 is an enlarged perspective view of a portion of the completed emergency bridge 100. In this bridge deck installation process, FRP (Fiber Reinforced Plastics) lining plates 30 are placed between adjacent cross girder retaining main materials 22 and bolted together. Here, four FRP lining plates 30 are bolted together in the width direction of the bridge, with the length direction of the FRP lining plates 30 aligned in the length direction of the bridge. After that, temporary guardrails 32 are installed on both sides of the bridge width, with the base being made of main retaining members (H-beams) 31 with flanges positioned horizontally.

[0034] Finally, slopes 33a and 33b are formed at both ends of the bridge girder in the bridge length direction, thereby completing the emergency bridge 100. In this case, the materials are transported using a lafter crane or the like.

[0035] (Effects of the embodiment) According to the construction method of the emergency bridge 100 of this embodiment, the following effects can be obtained. In other words, according to the construction method of the emergency bridge 100 of the embodiment, the bridge girder pieces 20a are extended in a stepped manner from one bank and the bridge girder 20 can be erected simply by rotating them around the fulcrum 27a, so that the emergency bridge 100 can be constructed easily and quickly. Furthermore, even if there is a difference in height between the two banks, the emergency bridge 100 can be constructed easily and quickly. Furthermore, since the main retaining wall materials and retaining wall parts are mainly used and bolt connections are made using existing bolt holes, procurement is easy and the work of processing is eliminated, which also makes construction simple and quick.

[0036] <<Variation>> Although the embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to the above embodiments and that various modifications are possible without departing from the spirit of the present invention.

[0037] For example, in the above embodiment, temporary guardrails 32 are installed as a passage safety facility, but instead of or in addition to the temporary guardrails 32, passage safety facilities such as handrails may be installed.

[0038] In the above embodiment, main earth retaining members and earth retaining parts are mainly used, but steel materials other than main earth retaining members and earth retaining parts can also be used. For example, a steel material in which two bar-shaped steel materials are integrated in a stepped shape can be used as a member to which a pivot piece is attached.

[0039] In addition, in the above embodiment, a base frame is laid on one bank and the bridge girder pieces are connected to it in a stepped manner, but it is also possible to lay base frames on both banks and connect the bridge girder pieces to each of them in a stepped manner, and then connect the bridge girder pieces whose ends meet at the end of the bridge girder erection process.

[0040] Furthermore, in the above embodiment, the pedestal 23 has a low upper surface and is shaped to make it difficult to insert bolts, nuts, and tools inside the pedestal 23, but the upper surface may be made higher so that it is easy to insert bolts, nuts, and tools inside the pedestal 23. In this case, the pedestal 23 can be fixed without using the Z-joints 24 and L-joints 26, and can be joined directly to the main girder retaining member and the cross girder retaining member with bolts. [Explanation of symbols]

[0041] 10 base frame 11 Vertical frame 11a Bottom frame 11b Upper frame 12 Horizontal frame 13a,13b Yamadome main material 20 Bridge girder 20a Bridge girder piece 21 Main girder retaining material 22 Cross girder retaining main material (H steel) 23 Pedestal 24 Z-type joint 25a Adjustment piece 26 L-shaped joint 27a, 27b Pivot piece 28 Corner Piece 29 Scaffolding 30 FRP lining board 31 Yamadome main material 32 Temporary guardrail 33a, 33b Slope 100 Emergency Bridge

Claims

1. A method for constructing an emergency bridge by erecting bridge girders across both banks, a base frame laying step of laying a base frame on at least one bank, the base frame being composed of vertical steel frames that are long in the erection direction of the bridge girder and horizontal steel frames that are long in a direction perpendicular to the erection direction; a bridge girder assembly process in which a bridge girder is assembled by connecting a plurality of bridge girder pieces, each of which is composed of a plurality of main girder piece steel materials that are long in the erection direction and arranged parallel in a direction perpendicular to the erection direction, and cross girder steel materials that are long in the direction perpendicular to the erection direction and suspended across the plurality of main girder piece steel materials, in a stepped manner starting from the base frame with a counterweight placed on the base frame; and a step of removing the counterweight after the bridge girder assembly step is completed. A construction method for emergency bridges characterized by the above.

2. In the base frame laying step, the base frame is laid on the one bank; a bridge girder erection process in which the bridge girder is rotated around a predetermined fulcrum by removing the counterweight, and the tip of the bridge girder is landed on the opposite bank to erect the bridge girder; 2. The method for constructing an emergency bridge according to claim 1.

3. The construction method for an emergency bridge according to claim 2, characterized in that each of the vertical frame steel, the horizontal frame steel, the main girder piece steel and the cross girder steel is composed of a main retaining material.

4. Let the number of the bridge girder pieces to be connected from the starting point be n (n is a natural number), and let the main girder piece steel material and the cross girder steel material that make up the n-th bridge girder piece from the starting point be the n-th main girder retaining main material and the n-th cross girder retaining main material, respectively. The first bridge girder piece is configured to include a first main girder retaining main material whose base end side is superimposed on the vertical frame steel material that constitutes the base frame, and a first cross girder retaining main material that is placed on the first main girder retaining main material, The second and subsequent bridge girder pieces are composed of an nth main girder retaining main material whose base end side is superimposed on the (n-1)th main girder retaining main material, and an nth cross girder retaining main material placed on the nth main girder retaining main material.

4. The method for constructing an emergency bridge according to claim 3.

5. The first cross girder retaining main material of the first bridge girder piece is provided on the vertical frame steel material and the first main girder retaining main material, The construction method for an emergency bridge according to claim 4, characterized in that the nth cross girder retaining main material of the second or subsequent bridge girder pieces is provided on the (n-1)th main girder retaining main material and the nth main girder retaining main material.

6. 6. The method for constructing an emergency bridge according to claim 5, wherein the cross beam steel is an H-shaped steel beam and is oriented so that the flanges are at the top and bottom.

7. 7. The method for constructing an emergency bridge according to claim 6, wherein the upper surfaces of the upper flanges of the crossbeam steel members of the plurality of bridge girder pieces are flush with each other.

8. 8. The emergency bridge construction method according to claim 7, further comprising the step of forming a bridge deck by placing a covering plate between adjacent cross girder steel members after the bridge girder erection step.

9. 9. The method for constructing an emergency bridge according to claim 8, further comprising the step of installing a temporary guardrail based on the main earth retaining material after the bridge girder erection step.

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