Steel pipe pile for retaining fall prevention wire terminal, bridge, and method for retaining fall prevention wire

Abstract

To provide a facility and a construction method for retaining a terminal of a fall prevention wire for preventing a road accessory such as a fence provided on a bridge from falling at a low cost in a short construction period.SOLUTION: A steel pipe pile 1 for retaining a terminal of a fall prevention wire comprises: a buried part 12 buried in the ground; a head part 11 projecting on the ground surface; a hole part formed in the head part 11, into which a terminal part of a fall prevention wire 2 is inserted; and a locking part 13 for locking the terminal part inserted into the hole part, wherein the terminal of the fall prevention wire 2 is retained, so as to a reduce a cost and a construction period.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a steel pipe pile for retaining the end of a fall prevention wire installed on a bridge, a bridge using the same, and a method for retaining a fall prevention wire. [Background technology]

[0002] Bridges are equipped with road accessories such as falling object prevention fences to prevent vehicle cargo from falling off the bridge and soundproof fences to prevent noise, and fall prevention wires are provided to prevent these road accessories from falling off the bridge. Patent Document 1 discloses a technique related to such a fall prevention wire. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-328677 Summary of the Invention [Problem to be solved by the invention]

[0004] In the middle of the bridge, fall prevention wires are secured to the outer surface of the balustrade using metal fittings, as shown in Figure 8 of Patent Document 1. However, at both ends of the bridge, it is sometimes not possible to secure the wire to the balustrade, and in such cases, concrete foundations are poured into the slopes near both ends of the bridge, and the wires are secured to the concrete foundations using metal fittings. However, there are problems with the cost and time required for pouring and curing the concrete, and this is especially time-consuming when doing this on sloping ground such as a slope.

[0005] In view of the above, the present invention relates to a facility and construction method for securing the ends of fall prevention wires used to prevent road accessories such as fences installed on bridges from falling, at low cost and in a short construction period. [Means for solving the problem]

[0006] (Configuration 1) A steel pipe pile for retaining the end of a fall prevention wire to prevent road accessories such as fences installed on bridges from falling, characterized in that it comprises: an embedded portion that is buried in the ground; a head portion that protrudes above the ground surface; a hole portion formed in the head portion through which the end portion of the fall prevention wire is inserted; and a locking portion that locks the end portion inserted into the hole portion.

[0007] (Configuration 2) A steel pipe pile for retaining a wire terminal for fall prevention, as described in configuration 1, characterized in that a plurality of the hole portions are formed, or the hole portion is formed as a long hole, and the engaging portion can be selected from a plurality of engaging members having different contact angles with the head, thereby making it possible to change the attachment angle of the terminal portion.

[0008] (Configuration 3) A steel pipe pile for retaining a wire terminal to prevent falling, as described in configuration 1 or 2, characterized in that the engaging portion comprises a first washer member provided on the side that enters the hole portion when the terminal portion is inserted, and a second washer member provided on the side that exits the hole portion.

[0009] (Configuration 4) A steel pipe pile for retaining a wire terminal for fall prevention, as described in configuration 3, characterized in that the first washer member and the second washer member have a plate portion for engaging the terminal portion, and a spacer portion arranged between the plate portion and the head portion.

[0010] (Configuration 5) A steel pipe pile for retaining the end of a wire to prevent a fall, as described in configuration 4, characterized in that the head is a cylindrical member, and the contact surface of the spacer portion that comes into contact with the head has a curved portion that follows the cylindrical shape.

[0011] (Configuration 6) A steel pipe pile for retaining a wire end for fall prevention, as described in any one of configurations 1 to 5, characterized in that a lower flange portion is formed at a position below the engaging portion.

[0012] (Configuration 7) The steel pipe pile for retaining a wire end for fall prevention according to configuration 6, characterized in that an upper flange portion is formed at a position above the engaging portion.

[0013] (Configuration 8) A bridge characterized in that the end of a fall prevention wire is retained by the steel pipe pile for retaining the end of a fall prevention wire as described in any one of configurations 1 to 7.

[0014] (Configuration 9) A construction method for securing the ends of fall prevention wires that are used to prevent road accessories such as fences installed on bridges from falling, characterized in that the method includes the steps of driving steel pipe piles near both ends of the bridge, and fastening the ends of the fall prevention wires to the heads of the steel pipe piles. [Effects of the Invention]

[0015] The steel pipe pile for retaining the end of a fall prevention wire of the present invention makes it possible to retain the end of a fall prevention wire, which is used to prevent road accessories such as fences installed on bridges from falling, at low cost and in a short construction period. [Brief explanation of the drawings]

[0016] [Figure 1] Schematic diagram showing a bridge according to an embodiment of the present invention. [Figure 2] A diagram showing the head part of a steel pipe pile for anchoring wire terminals to prevent falling [Figure 3] A diagram showing the head part of a steel pipe pile for anchoring wire terminals to prevent falling [Figure 4] A diagram showing the locking member (first washer portion, second washer portion) [Figure 5] A diagram showing another locking member (first washer portion, second washer portion) [Figure 6] A diagram showing the head part of a steel pipe pile for anchoring wire terminals to prevent falling [Figure 7] Schematic diagram illustrating a test method for a performance test of a steel pipe pile for anchoring a wire end for fall prevention according to an embodiment. [Figure 8] Photo showing the performance test [Figure 9] Photo showing the performance test DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the following embodiments are merely examples of how the present invention can be realized, and are not intended to limit the scope of the present invention.

[0018] FIG. 1 is a schematic diagram showing parts of a bridge according to an embodiment of the present invention that are relevant to the present invention. The bridge 100 of this embodiment comprises a balustrade 3, which is a concrete protective fence to prevent vehicles from falling, a falling object prevention fence 4 attached to the balustrade 3 to prevent objects from falling from the bridge, a fall prevention wire 2 to prevent the falling object prevention fence 4 from falling, and steel pipe piles 1 for retaining the end of the fall prevention wire, which are driven into the vicinity of both ends of the bridge to retain the end of the fall prevention wire 2. The term "bridge" in this application includes river bridges, land bridges, viaducts, overpasses, railway bridges, sea bridges, pedestrian bridges, etc., but the structure of the bridge other than the steel pipe pile 1 for retaining the end of a fall prevention wire is the same as conventional (it may be any structure), so detailed explanation will be omitted here. In the following, the longitudinal direction of the bridge (the left-right direction in Figure 1) will be referred to as the "bridge extension direction."

[0019] The steel pipe pile 1 for retaining the wire end for fall prevention is a buried portion 12 that is buried in the ground by being driven as a steel pipe pile; A head 11 protruding from the ground surface; Holes H1 and H2 (see Figures 2 and 3) formed in the head 11 and through which the terminals of the fall prevention wire 2 are inserted; a locking portion 13 for locking the terminal portion inserted into the hole portions H1 and H2; a lower flange portion 14A formed at a position lower than the locking portion 13; an upper flange portion 14B formed at a position above the locking portion 13; Equipped with. The steel pipe pile 1 for anchoring a fall-prevention wire end of this embodiment is, in its basic form, a single cylindrical steel pipe pile in which the head portion 11 and the buried portion 12 are continuous.

[0020] FIG. 2 is a partial cross-sectional view for explaining the head portion 11 (particularly the locking portion 13) of the steel pipe pile 1 for anchoring the end of a fall-prevention wire. The fall prevention wire 2 has a threaded end 21 (a metal fitting that is fastened by crimping to the end of the rope, turning the rope end into a screw) attached to it as its end treatment, and a threaded rod 23 is further connected to it with a coupler 22. This forms the end of the fall prevention wire 2. In this embodiment, the configuration of the end of the fall prevention wire 2 is as described above, but it is not limited to this and may be any configuration that can be fixed to the locking portion 13 (plate portion 131 of washer member 13A) described below.

[0021] FIG. 3 is a diagram showing the head portion 11 of the steel pipe pile 1 for anchoring the end of a fall-prevention wire, and shows the holes H1 and H2 as viewed from the direction along the extending direction of the bridge. As shown in FIGS. 2 and 3, in this embodiment, the holes H1 and H2 are elongated holes and are disposed at both ends in the bridge extension direction. Holes H1 and H2 are formed with dimensions that allow θ in Fig. 2 to be in the range of 0° to 30° in relation to the diameter of the head 11. That is, the height dimensions of holes H1 and H2 are formed so that the angle θ of the end portion of the fall prevention wire 2 inserted through hole H1 on the insertion side (right side in Fig. 2) and hole H2 on the exit side (left side in Fig. 2) can be adjusted in the range of 0° to 30°, as shown in Fig. 2. Here, the hole H1 on the insertion side (right side in FIG. 2 ) and the hole H2 on the exit side (left side in FIG. 2 ) are shown as having the same dimensions, but only one of them may be an elongated hole and the other an approximately round hole. That is, in this embodiment, both holes H1 and H2 are elongated holes, so the vertical position of the terminal end of the fall prevention wire 2 inserted therethrough can be adjusted on both sides. Alternatively, only one of them may be an elongated hole that allows for vertical position adjustment, while the other may be an approximately round hole that does not allow for vertical position adjustment. By using the approximately round hole side as a fulcrum and adjusting the vertical position on the elongated hole side, the angle θ of the terminal end of the fall prevention wire 2 can be adjusted within a range of 0° to 30°. Strictly speaking, the fulcrum side is an elongated hole because it is necessary to allow the terminal end of the fall prevention wire 2 to be inserted within a range of 0° to 30°. In addition, although the example shown here is one in which the holes H1 and H2 are elongated holes, making it possible to adjust the vertical position of the terminal portion of the fall prevention wire 2, the present invention is not limited to this. For example, one or both of the holes H1 and H2 may be substantially circular holes formed in multiple positions in the vertical direction, and the vertical position of the terminal portion of the fall prevention wire 2 may be adjusted by selecting the hole to be inserted through.

[0022] 4A to 4C are diagrams (plan views) showing washer members (locking members) 13A that constitute the locking portion 13. FIG. The locking portion 13 has a first washer member provided on the hole H1 side through which the terminal portion of the fall prevention wire 2 is inserted, and a second washer member provided on the hole H2 side. In this embodiment, the first washer member and the second washer member are configured as the same washer member 13A shown in Fig. 4. The washer member 13A is used with the first washer member and the second washer member turned upside down. The washer member 13A includes a plate portion 131 for engaging the terminal portion of the fall prevention wire 2, and a spacer portion 132 disposed between the plate portion 131 and the head portion 11. A hole H3 is formed in the approximate center of the plate portion 131, through which the terminal portion of the fall prevention wire 2 is inserted. As shown in Figure 4(b), the contact surface of the spacer portion 132 that comes into contact with the head portion 11 has a curved portion that follows the cylindrical shape of the head portion 11. This prevents localized loads from being applied to the side surfaces of the head portion 11, and prevents the steel pipe from being locally depressed and buckled. In this embodiment, the outer shapes of the plate portion 131 and the spacer portion 132 are rectangular in plan view (see FIG. 4(a)), but may be any shape, such as circular.

[0023] Furthermore, the spacer portion 132 is a member that adjusts the relative angle between the plate portion 131 and the head portion 11. The washer member 13A shown in Fig. 4 is configured so that the plate portion 131 is inclined at an angle of 30° relative to the head portion 11. As can be seen from Fig. 2, the angle of the plate portion 131 relative to the head portion 11 is the same as the angle θ of the terminal portion of the fall prevention wire 2, and the spacer portion 132 determines the angle θ of the terminal portion of the fall prevention wire 2. A plurality of washer members (locking members) that make up the locking portion 13 are prepared, each with a different contact angle with respect to the head 11. Fig. 5 shows an example of such members. Fig. 5(a) shows washer member 13B in which the angle θ of the terminal end of the fall prevention wire 2 is 0°, and Fig. 5(b) shows washer member 13C in which the angle θ of the terminal end of the fall prevention wire 2 is 15°. Note that in this embodiment, three types of washer members, 0°, 15°, and 30°, are prepared as an example, but four or more types of washer members may be prepared, or only two or one type may be prepared.

[0024] The upper flange portion 14B and the lower flange portion 14A are each formed by fixing, by welding or the like, a ring-shaped member that fits onto the outer periphery of the head portion 11. In this embodiment, the upper flange portion 14B and the lower flange portion 14A have a rectangular outer shape in a plan view, but may have any shape, such as a circular shape. As shown in Figure 1, the lower flange portion 14A is formed at a position below the locking portion 13, and the upper flange portion 14B is formed at a position above the locking portion 13, so that the locking portion 13 is located between the upper and lower flanges. Where the flanges are formed, the thickness of the steel pipe can be considered to increase by the width of the flanges. This allows the deformation to be limited to the area between the upper and lower flanges, even if the force acting on the locking portion 13 due to the tension in the fall prevention wire causes the steel pipe to deform locally (the cross-sectional shape becomes non-circular). The flange portion contributes to improving the strength of the steel pipe and also has the effect of making the design of the steel pipe easier. By providing the lower flange portion 14A, when calculating the strength of the portion below the lower flange portion 14A, it is possible to consider the load acting at the position of the lower flange portion 14A as a fixed end moment (which simplifies the calculation), making it easier to design the steel pipe.

[0025] FIG. 6 is a diagram illustrating a cap member fitted onto the tip of the head 11. As shown in FIG. As shown in the figure, a cap member 15 is provided at the tip of the head 11. The cap member 15 is formed with a leg portion 151 that is inserted into the inside of the head 11, and the cap member 15 is attached to the head 11 by passing a bolt through the leg portion 151 and the head 11.

[0026] Next, we will briefly explain the method for retaining the end of the fall prevention wire 2 using the fall prevention wire end retaining steel pipe pile 1. Note that for the bridge 100 excluding the fall prevention wire end retaining steel pipe pile 1, construction, including terminal processing of the fall prevention wire 2, has already been completed. First, steel pipe piles are driven into appropriate locations near both ends of the bridge 100. The steel pipe piles have holes H1 and H2 formed in the steel pipe, and the upper flange 14B and the lower flange 14A are welded together. Driving the steel pipe piles can be easily performed using a general pile driver. 2, the two washer members 13A are arranged upside down as the first and second washer members, and the end portion of the fall prevention wire 2 is inserted into the holes H1 and H2 and the hole H3 of the plate portion 131, and fastened with nuts N, thereby fastening the end portion of the fall prevention wire 2 to the head portion 11. The cap member 15 is also attached to the head portion 11. As described above, the end of the fall prevention wire 2 can be fastened with a relatively simple operation that takes a short time.

[0027] In addition, the angle of the fall prevention wire 2 (angle θ of the terminal part of the fall prevention wire 2) changes depending on factors such as differences in the position of the fall prevention wire 2 based on the structure of the bridge 100, and differences in the driving position of the steel pipe pile 1 for retaining the terminal of the fall prevention wire based on the site conditions. According to the steel pipe pile 1 for retaining the end of a fall prevention wire of this embodiment, the attachment angle of the end of the fall prevention wire 2 can be changed by selecting the most appropriate washer member from among the washer members 13A to 13C in relation to the angle θ of the end of the fall prevention wire 2, which is determined at the construction site. If there is a large discrepancy between the angle of the fall prevention wire 2 and the angle θ of the terminal portion, the wire will bend and stress will be applied at the joint between the fall prevention wire 2 and the screw end 21, which is undesirable.However, the steel pipe pile 1 for retaining the terminal of the fall prevention wire of this embodiment can suppress such problems.

[0028] As described above, the bridge 100 (steel pipe pile 1 for retaining the end of a fall prevention wire) of this embodiment can retain the end of a fall prevention wire, which is used to prevent road accessories such as fences installed on bridges from falling, at low cost and in a short construction period. Compared to pouring concrete foundations to retain a fall prevention wire, it is possible to retain the fall prevention wire in a smaller space. In addition, appropriate installation can be easily performed according to the angle of the fall prevention wire. In addition, the provision of the lower flange portion makes it easier to design the steel pipe, and the provision of the upper and lower flange portions improves the strength of the steel pipe.

[0029] Although the present embodiment is exemplified by an example in which there is one fall prevention wire, there may be multiple fall prevention wires. In this case, multiple fall prevention wires may be fastened to one steel pipe pile for retaining the end of the fall prevention wire, or a steel pipe pile for retaining the end of the fall prevention wire may be provided for each fall prevention wire (i.e., multiple steel pipe piles for retaining the end of the fall prevention wire are driven in).When multiple fall prevention wires are fastened to one steel pipe pile for retaining the end of the fall prevention wire, the head may be formed with multiple holes for inserting the fall prevention wires and multiple locking portions for locking the fall prevention wires.

[0030] In this embodiment, the fall prevention wire is used to prevent a falling object prevention fence from falling, but the fall prevention wire may also be used to prevent any other road accessories (such as a soundproof fence) from falling.

[0031] In this embodiment, the angle θ of the terminal portion of the fall prevention wire 2 is adjusted within the range of 0° to 30°, but it may be adjustable to other ranges. However, as the angle becomes larger, the vertical component of the applied load (i.e., the force to pull out the stake) increases, which is not preferable. From this perspective, it is preferable that the angle be ±30° or less with respect to the horizontal plane.

[0032] Any steel pipe can be used for the steel pipe piles used to anchor the end of fall prevention wires, as long as it meets the required strength. In other words, specifications such as length, thickness, diameter, and material can be selected appropriately within a range that satisfies the required strength. It is not limited to circular pipes, and square pipes can also be used. Furthermore, pipes filled with a filler such as cement milk or double-walled pipes are also acceptable.

[0033] Next, a performance test conducted on the steel pipe pile 1 for anchoring a wire end for fall prevention according to the embodiment will be described. An outline of the test method for this test is shown in Figure 7. As shown in Figure 7, a test was conducted in which a steel pipe pile 1 for anchoring the end of a fall-prevention wire, as described in the embodiment, was driven into the ground to anchor the wire rope 2, and a rotating support member was used to set the angle of the wire rope 2 at a predetermined angle, while a hydraulic jack (not shown) was used via a load cell to pull the wire rope 2. Table 1 shows the test conditions such as the steel pipe size of the steel pipe pile 1 and the specifications of the wire rope.

[0034] [Table 1]

[0035] The tension applied to the wire rope during the test was as follows: Working load (P) = Standard breaking load (RBS) kN / (Safety factor (F) x 2) φ6.3: Standard breaking load 19.9KN / (safety factor (F) x 2) = 9.95kN φ8.0: Standard breaking load 32.1KN / (safety factor (F) x 2) = 16.05kN φ12.0: Standard breaking load 72.3KN / (safety factor (F) x 2) = 36.15kN In Table 1, the "PL (angle) for the end of the fall prevention wire" indicates the washer member used, with 0° indicating washer member 13B (Figure 5(a)) and 30° indicating washer member 13A (Figure 4).

[0036] Tables 2 and 3 show the test results.

[0037] [Table 2]

[0038] [Table 3]

[0039] Figures 8 and 9 show some photographs showing how the test was carried out. Figure 8(a) shows the state before the test when the test conditions were steel pipe pile: φ114.3mm x t6mm x 2400mm, wire rope: φ6.3mm, wire rope installation angle: 24°, and Figure 8(b) is a photograph of the state after the test. Figure 9(a) shows the state before the test when the test conditions were steel pipe pile: φ114.3mm x t6mm x 2400mm, wire rope: φ6.3mm, wire rope installation angle: 0°, and Figure 9(b) is a photograph of the state after the test.

[0040] As a result of the test, under all conditions, the displacement and residual displacement of the piles against the tensile load of each wire rope were small and within the allowable range. It was shown that the steel pipe pile 1 for retaining wire ends to prevent falling has sufficient performance and exhibits performance equivalent to that of the conventional concrete foundation construction method. [Explanation of symbols]

[0041] 100...Bridge 1...Steel pipe pile for securing wire terminals to prevent falling 11...Head 12...Buried section 13...Latching part 13A...Washer member (locking member) 131...Plate section 132...Spacer part 14A...Lower flange 14B...Upper flange 1... 2. Fall prevention wire 4. Fences to prevent falling objects (road accessories) H...hole

Claims

1. A steel pipe pile for securing the end of a fall prevention wire to prevent road accessories attached to a wall parapet such as a fence installed on a bridge from falling, a buried portion buried in the ground; a head portion protruding from the buried portion to the ground surface and formed by a single continuous steel pipe; a hole formed in the head portion and through which an end portion of the fall prevention wire is inserted; a locking portion that locks the terminal portion inserted into the hole; a lower flange portion which is an annular member fitted onto the outer periphery of the head portion and fixed to the head portion at a position below the engaging portion and above the ground surface; A steel pipe pile for retaining a wire end for fall prevention, comprising:

2. A steel pipe pile for retaining wire terminals to prevent falls, as described in claim 1, characterized in that it is a ring-shaped member that fits around the outer periphery of the head and has an upper flange portion that is fixed to the head at a position above the engaging portion.

3. A bridge, characterized in that the end of the fall prevention wire is retained by the steel pipe pile for retaining the end of the fall prevention wire according to claim 1 or 2.

4. A construction method for retaining the end of the fall prevention wire using the steel pipe pile for retaining the fall prevention wire end according to claim 1 or 2, A step of driving steel pipe piles for retaining the fall prevention wire terminals near both ends of the bridge; fastening an end portion of the fall prevention wire to the head; A method for securing a fall prevention wire, characterized by having the following:

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