Method for installing drainage pipe of tunnel invert

Abstract

To provide a method for installing a drainage pipe of a tunnel invert, which does not require the labor of supplying and discharging a filler, installing a support material, etc., and does not require handling of a heavy object.SOLUTION: The other end 24 of a guide pipe 2 of a certain length is inserted into an opening 11 of a drainage pipe 1 buried in an existing invert concrete Y1 in a tunnel, and a required number of new pipe bodies 12 of a certain length are fitted onto an outer circumference of the guide pipe 2 from one end 22 of the guide pipe 2 to connect it to the existing drainage pipe 1. With one end 22 of the guide pipe 2 held and positioned by a removable holding device 3, new invert concrete Y2 is poured around the pipe bodies 12.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a method for installing drainage pipes in tunnel inverts. [Background technology]

[0002] A drainage pipe extending in the longitudinal direction of the tunnel may be installed in the center of the tunnel invert. In this case, the drainage pipe is laid in advance to be buried in the concrete before the invert concrete is poured into the concrete pouring space dug downward in an arc shape. However, compared to the concrete to be poured, the specific gravity of the drainage pipe made of resin pipe or the like is very small, so there is a problem that the drainage pipe floats when the concrete is poured.

[0003] In the past, anchors and the like have been used to prevent drainage pipes from floating up, but in Patent Document 1, for example, a long bag such as a rubber tube with a closed end is inserted into the drainage pipe using a rod or the like, and a hose is inserted into the base end opening of the bag to fill the bag with a filler with a high specific gravity such as water to act as a floating prevention device and prevent the drainage pipe from floating up when concrete is poured. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6932283 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the above drain pipe installation method has problems in that it takes time to supply and discharge the filler to the bag inserted in the drain pipe, and also takes time to install a support material to adjust the height of the drain pipe. It has also been proposed to use a heavy steel pipe or the like as a floating prevention body, but in this case, the problem of difficulty in handling the heavy object arises.

[0006] Therefore, the present invention is intended to solve such problems and aims to provide a method for installing drainage pipes for tunnel inverts that does not require the effort of supplying and discharging filler, installing support materials, etc., and does not require handling of heavy objects. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, in the first invention, the other end (24) of a guide rod (2) of a certain length is inserted into the opening (11) of a drainage pipe (1) buried in the existing invert concrete (Y1) in the tunnel, and the required number of new pipe bodies (12) of a certain length are fitted from one end (22) of the guide rod (2) to the outer periphery of the guide rod (2) to connect it to the existing drainage pipe (1). With one end (22) of the guide rod (2) held and positioned by a removable holding means (3), new invert concrete (Y2) is poured around the pipe bodies (12).

[0008] In the first invention, when the invert concrete is poured, a large buoyancy acts on the pipe body, but since the pipe body is fitted into the guide rod and positioned, and one end of the guide pipe is positioned by the holding means and the other end is inserted into the existing drainage pipe and positioned, the pipe body is reliably positioned against the buoyancy of the poured invert concrete. The first invention does not require the trouble of supplying and discharging filler and installing support materials as in the past, and since there is no need to make the guide rod itself heavier than necessary, there is no need to handle heavy objects.

[0009] In the second invention, a guide pipe (2) having an outer diameter slightly smaller than the inner diameter of the existing drain pipe (1) is used as the guide rod.

[0010] In the second aspect of the present invention, a lightweight guide rod of the required diameter can be realized.

[0011] In the third invention, the holding means has a holding cart (34) provided with a holding space (HS) into which the outer periphery of the other end of the guide rod is inserted, and by moving the holding cart (34) forward and backward, one end (22) of the guide rod (2) is moved relatively forward and backward into and out of the holding space (HS).

[0012] In the third aspect of the present invention, the other end of the guide rod can be held simply and reliably.

[0013] In the fourth aspect of the invention, a weight (36) of a predetermined weight is placed on the holding carriage (34).

[0014] In the fourth invention, a sufficient load capable of resisting the buoyancy force during pouring of invert concrete can be applied to the guide rod without excessively increasing the weight of the guide rod itself.

[0015] The reference characters in parentheses indicate, for reference, the correspondence with specific means described in the embodiments described later. Effect of the Invention

[0016] According to the method for installing a drainage pipe for a tunnel invert of the present invention, the time-consuming task of supplying and discharging filler, installing support materials, etc., as in the conventional method, is not required, and there is no need to handle heavy objects. [Brief description of the drawings]

[0017] [Figure 1] 1 is a longitudinal cross-sectional view of a tunnel showing the steps of the method of the present invention. FIG. [Diagram 2] 1 is a longitudinal cross-sectional view of a tunnel showing the steps of the method of the present invention. FIG. [Diagram 3] FIG. [Figure 4] 1 is a longitudinal cross-sectional view of a tunnel showing the steps of the method of the present invention. FIG. [Diagram 5] 1 is a longitudinal cross-sectional view of a tunnel showing the steps of the method of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] It should be noted that the embodiment described below is merely an example, and various design improvements made by those skilled in the art without departing from the gist of the present invention are also included in the scope of the present invention.

[0019] Figure 1 is a longitudinal section of a tunnel, with the left side of the drawing being the tunnel face and the right side being the tunnel mouth (the same applies to the following drawings). At the center of the cross section of the excavated tunnel invert X is an existing drainage pipe 1 that is buried in the invert concrete Y1 and extends toward the tunnel mouth, with one end 11 facing the tunnel face opening outside the concrete Y1. The drainage pipe 1 is made by connecting resin pipes 12, for example, with a hollow spiral structure.

[0020] The installation method for the existing drainage pipe 1 is the same as the installation method described in detail below, but the drainage pipe to be installed in the first concrete pouring span on the tunnel entrance side is installed using conventional anchors, etc. to prevent it from floating up when the concrete is poured, since there is no existing drainage pipe.

[0021] The installation method of the present invention will be described below. In this embodiment, the guide rod used in the installation method of the present invention is a cylindrical guide pipe 2 in which three steel pipes 21 of a certain length are connected to ensure the required length. The outer diameter of such a guide pipe 2 is slightly smaller than the inner diameter of the tubular body 12 constituting the drainage pipe 1, and one end 22 is closed and a wire locking part 23 is provided thereon. The guide pipe 2 is positioned along the longitudinal direction of the tunnel with the one end 22 facing the face side, and then the other end 24 facing the mouth side is inserted into the one end opening 11 of the existing drainage pipe 1 buried in the invert concrete Y1 as shown by the arrow in FIG. 1. The guide pipe does not necessarily have to be made of a steel pipe 21, and may be made of resin or the like. The guide rod does not have to be a pipe, and may be a solid rod body.

[0022] After this, a holding device 3 serving as holding means is placed inside the tunnel invert X on the face side, away from the existing drainage pipe 1 by the required distance (Fig. 2). The holding device 3 is equipped with parallel rails 32 for position adjustment on long base plates 31 of a fixed length on the left and right (Fig. 3), and a holding cart 34 is provided on the parallel rails 32 so as to be movable by front, rear, left and right wheels 33. A rail clamp 35 (Fig. 2) is provided on the front (face side) wheel 33 of the holding cart 34, and the holding cart 34 can be fixed and positioned on the parallel rails 32 by operating the rail clamp 35 at an appropriate position on the parallel rails 32.

[0023] Left and right leg frames 37 (Figure 3) and upper and lower cross frames 38 that connect these leg frames 341 are provided at the front and rear positions of the holding cart 34. The upper cross frame 38 is supported by the front, rear, left and right leg frames 37, and a weight 36 of a predetermined weight is placed on the cross frame 38.

[0024] The vertical guide 341 and horizontal guide 342 located on the rear side (the tunnel mouth side) of the holding cart 34 form a rectangular holding space HS as shown in Fig. 3. The vertical guide 341 and horizontal guide 342 which form the holding space HS are each provided with a guide roller 343 in the center, and the intervals between the top and bottom and left and right guide rollers 343 are adjustable so that they are approximately equal to the outer diameter of the guide pipe 2 and can hold the tip 22 of the guide pipe 2 in a state where it has passed through. Also, a winch 37 is provided on the stays provided between the leg frames 37 located on the front side (the face side) of the holding cart 34.

[0025] When connecting a new pipe body 12 to an existing drainage pipe 1, as shown in FIG. 2, the tip hook of the wire 371 extending from the winch 37 of the holding device 3 is hooked on the wire locking part 23 of one end 22 of the guide pipe 2, and the guide pipe 2 is pulled out from the existing drainage pipe 1 by the required amount. Then, the wire 371 is removed, and a certain length of a new pipe body 12 is fitted around the outer periphery of the pulled-out guide pipe 2 (arrow in FIG. 2). After that, the wire 371 is hooked again, and the guide pipe 2 is further pulled out from the existing drainage pipe 1 by the winch 37 by the required amount (FIG. 4), and the wire 371 is removed, and the new pipe body 12 is further fitted around the outer periphery of the pulled-out guide pipe 2 (arrow in FIG. 4). At this time, it is recommended to temporarily use a sleeper 25 to support the pulled-out guide pipe 2.

[0026] If necessary, the entire holding device 3 is moved further toward the face using heavy machinery or the like (Fig. 5), the guide pipe 2 is pulled out further using a winch 37, and a third new pipe body 12 is fitted around the outer periphery of the guide pipe 2. The three pipe bodies 12 are connected to each other using a clamping jig or welding, and the pipe body 12 that was first fitted around the guide pipe 2 is also connected to the existing drainage pipe 1. In this way, a new drainage pipe 1n consisting of three more pipe bodies 12 is connected to the existing drainage pipe 1, and the entire drainage pipe is extended.

[0027] In this state, the gable formwork 4, supported at the back by a jack 41 and with the new drainage pipe 1n passing through it, is installed at a position a predetermined casting span P away from the existing invert concrete Y1. Then, the holding cart 34 of the holding device 3 is moved toward the pit mouth on the parallel rails 32, and the guide pipe 2 (and the new drainage pipe 1n in this embodiment) is relatively inserted between the top, bottom, left and right guide rollers 343 and held as shown in FIG.

[0028] After that, new invert concrete Y2 is poured between the existing invert concrete Y1 and the gable formwork 4. At this time, a large buoyancy acts on the new drainage pipe 1n, but the new drainage pipe 1n is fitted into the guide pipe 2 and positioned. One end 22 of the guide pipe 2 on the face side is held by the guide roller 343 to which the weight 36 is applied, and the other end 24 on the mouth side is located in the existing drainage pipe 1 buried in the existing invert concrete Y1, so that the new drainage pipe 1n can be reliably positioned by sufficiently countering the buoyancy of the poured invert concrete Y2.

[0029] After the poured invert concrete Y2 has cured, the above-mentioned process can be repeated to add a new drainage pipe, and the drainage pipe extending in the longitudinal direction of the tunnel can be quickly buried and installed at a specified depth in the center of the invert concrete X.

[0030] The holding means is not limited to the holding device exemplified in the above embodiment, and may be, for example, a pier or the like, as long as it can detachably hold and position the other end of the guide rod. [Explanation of symbols]

[0031] 1...existing drainage pipe, 11...opening, 12...pipe body, 2...guide pipe (guide rod), 22...one end, 24...other end, 3...holding device (holding means), 34...holding trolley, 36...weight, HS...holding space, Y1...existing invert concrete, Y2...newly constructed invert concrete.

Claims

1. A method for installing a tunnel invert drainage pipe, comprising: inserting the other end of a guide rod of a certain length into the opening of a drainage pipe buried in existing invert concrete in a tunnel; fitting the required number of new pipe bodies of a certain length from one end of the guide rod onto the outer periphery of the guide rod to connect it to the existing drainage pipe; and pouring new invert concrete around the pipe bodies while holding and positioning the other end of the guide rod with a removable holding means.

2. A method for installing a drainage pipe for a tunnel invert as described in claim 1, wherein the guide rod is a guide pipe having an outer diameter slightly smaller than the inner diameter of the existing drainage pipe.

3. A method for installing a drainage pipe for a tunnel invert as described in claim 1 or 2, wherein the holding means has a holding cart having a holding space into which the outer periphery of the other end of the guide rod is inserted, and by moving the holding cart forward and backward, one end of the guide rod is relatively advanced into or advanced out of the holding space.

4. 4. The method for installing a drainage pipe for a tunnel invert according to claim 3, wherein a weight of a predetermined weight is placed on the support cart.

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