Method for rehabilitating existing pipes and anti-floating device for rehabilitated pipes

Abstract

To dispense with an arrangement of a timbering for preventing a float of a regeneration pipe at the charge of a back-filling material in the regeneration pipe, and suppress a fluctuation in diameter of the regeneration pipe in a pipe axis direction, in a regeneration method of an existing pipe.SOLUTION: An existing pipe regeneration method sequentially executes the processes of: installing a float prevention device 1 at an upper wall face of an existing pipe 5; lining a regeneration pipe 6 at the inside of the existing pipe 5; and charging a gap between the existing pipe 5 and the regeneration pipe 6 with a back-filling material 7. The installation process of the float prevention device 1 includes teh steps of: temporarily holding an oblong float prevention member 10 extending in a pipe axis direction of the existing pipe 5 by using an anchor 20; positioning the float prevention member 10, and making a position adjustment member 30 interposed in a clearance when the clearance is formed between the float prevention member 10 and the upper wall face of the existing pipe 5 in the positioned state; and authentically fixing the float prevention member 10 to the existing pipe 5 by caulking the float prevention member 10 toward the upper wall face of the existing pipe 5 by using the anchor 20.SELECTED DRAWING: Figure 6A

Description

Technical Field

[0001] The present invention relates to a method for rehabilitating an existing pipe by lining a rehabilitation pipe inside the existing pipe and then filling a backfilling material, and an anti-floating device for the rehabilitation pipe used in this rehabilitation method.

Background Art

[0002] In order to rehabilitate an aging existing pipe such as a sewer pipe buried underground, it is known to line a rehabilitation pipe inside the existing pipe. After lining the rehabilitation pipe, a backfilling material such as mortar is filled between the existing pipe and the rehabilitation pipe. When filling this backfilling material, the rehabilitation pipe receives buoyancy from the backfilling material, but it is necessary to prevent the rehabilitation pipe from floating in order to ensure the flow path gradient.

[0003] In the method for rehabilitating an existing pipe disclosed in Patent Document 1, after lining the rehabilitation pipe inside the existing pipe, a number of anti-floating supports are installed at intervals in the axial direction of the pipe inside the rehabilitation pipe. Each support has a straight support member extending in the vertical direction and a jack provided at the lower end of this support member. With a belly-up member extending in the axial direction of the pipe bottom of the rehabilitation pipe installed, by operating the jack placed on this belly-up member, the support member passes through the through hole formed at the pipe top of the rehabilitation pipe and hits the pipe top of the existing pipe. Since the pipe bottom of the rehabilitation pipe is pressed against the pipe bottom of the existing pipe, it is possible to prevent the rehabilitation pipe from floating when the backfilling material is filled between the existing pipe and the rehabilitation pipe.

[0004] In the method of Patent Document 1, it is necessary to form a through hole at the pipe top of the rehabilitation pipe, and it is necessary to seal the through hole after the backfilling material is filled and hardened. In addition, since many supports are arranged inside the rehabilitation pipe, when constructing with water flowing inside the rehabilitation pipe, the supports become an obstacle to the flow and cause the water level to rise. When a local heavy rainstorm occurs and the water level rises rapidly, the water level rises further due to the flow obstruction of the supports, and there is a risk that the supports will flow out. Also, when lining the rehabilitation pipe and installing the supports simultaneously, there is a risk that the lining member will also flow out.

[0005] Various methods have been developed to resolve or mitigate the above-mentioned problems. In the method disclosed in Patent Document 2, a flexible cylindrical member is placed along the pipe axis on the upper wall surface of the existing pipe, and the rehabilitation pipe is lined with it. After lining, cement is filled into the cylindrical member to expand its diameter. After the cement hardens, backfill material is filled between the existing pipe and the rehabilitation pipe. During this filling, the cylindrical member filled with hardened cement, placed between the upper wall of the existing pipe and the upper wall of the rehabilitation pipe, prevents the rehabilitation pipe from floating.

[0006] In the method disclosed in Figure 21 of Patent Document 3, prior to the lining process of the rehabilitated pipe, an elongated spacer extending in the direction of the pipe axis is fixed to the upper wall surface of the existing pipe with anchors or the like. When filling the space between the existing pipe and the rehabilitated pipe with backfill material after lining the rehabilitated pipe, the spacer prevents the rehabilitated pipe from floating up. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2019-25839 [Patent Document 2] Japanese Patent Publication No. 2009-133477 [Patent Document 3] Japanese Patent Publication No. 2014-104615 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] In the method described in Patent Document 2, because the cylindrical member is flexible, it does not restrict the rehabilitated pipe during lining. Therefore, if there is localized corrosion on the inner wall surface of the existing pipe, the cross-sectional shape of the rehabilitated pipe will not be constant in the direction of the pipe axis. As a result, discrepancies with the cross-sectional shape designed for strength are likely to occur, and safety cannot be reliably guaranteed.

[0009] In the method described in Patent Document 3, the spacer has a fixed cross-sectional shape, and if there is corrosion on the inner wall surface of the existing pipe, the radial position of the spacer changes, resulting in the same problems as in Patent Document 2. [Means for solving the problem]

[0010] To solve the above problems, the present invention provides a method for rehabilitating an existing pipe, which sequentially includes the steps of: installing an anti-float device on the upper wall surface of an existing pipe; lining the inside of the existing pipe with a rehabilitated pipe; and filling the space between the existing pipe and the rehabilitated pipe with backfill material. The installation process for the float prevention device is characterized by comprising: a temporary holding step in which a float prevention member extending in the axial direction of the existing pipe is temporarily held by an anchor so as to be adjustable in the radially outward direction of the existing pipe, with the float prevention member aligned in the axial direction along the upper wall surface of the existing pipe; a position adjustment step in which the float prevention member is positioned by a positioning means so as to prevent the rehabilitation pipe having a predetermined diameter from floating up from the bottom of the existing pipe, and if a gap is formed between the float prevention member and the upper wall surface of the existing pipe in this positioned state, a position adjustment member is interposed in this gap; and a final fixing step in which the float prevention member is permanently fixed to the existing pipe by tightening the float prevention member toward the upper wall surface of the existing pipe with the anchor.

[0011] According to the above method, since the anti-float device is placed between the upper wall of the existing pipe and the rehabilitated pipe, it is not necessary to place numerous support structures inside the rehabilitated pipe to prevent float formation, and even when construction is carried out in a water-filled environment, the rise in water level can be avoided or suppressed. Furthermore, it is not necessary to form holes in the rehabilitated pipe to penetrate these support structures. Moreover, regardless of the corrosion of the existing pipe, the anti-float member can be accurately positioned to prevent the rehabilitated pipe of a predetermined diameter from floating, thereby suppressing fluctuations in the diameter of the rehabilitated pipe in the axial direction.

[0012] Preferably, the anchor has a male threaded portion and a head provided at one end of the male threaded portion, and in the temporary holding step, the male threaded portion of the anchor is shallowly screwed into the upper wall surface of the existing pipe, and the head engages with the float prevention member, thereby temporarily holding the float prevention member in a suspended state, and in the permanent fixing step, the anchor is further screwed into the upper wall surface of the existing pipe, so that the head presses the float prevention member toward the upper wall surface of the existing pipe. According to the method described above, an anchor with a relatively simple configuration can be provided.

[0013] In one embodiment, the position adjustment member consists of an adjustment plate, and in the position adjustment step, if a gap is formed between the positioned anti-float member and the upper wall surface of the existing pipe, the adjustment plate is inserted in the number of pieces necessary to fill this gap. According to the method described above, the position of the anti-float member can be adjusted with simple work.

[0014] In other embodiments, the position adjustment member consists of a screw member threaded onto the anti-float member, and in the position adjustment step, if a gap is formed between the positioned anti-float member and the upper wall surface of the existing pipe, the screw member is advanced toward the upper wall surface of the existing pipe so that it protrudes from the anti-float member by an amount corresponding to the gap, and its tip touches the upper wall surface of the existing pipe. According to the method described above, the position of the anti-float member can be adjusted with simple work.

[0015] Preferably, the positioning means consists of a positioning member having a reference length, and in the position adjustment step, the anti-float member is positioned by positioning one end of the positioning member on the anti-float member and the other end on the lower wall surface of the existing pipe facing the anti-float member in the diametrical direction. According to the above method, the anti-float member can be easily positioned.

[0016] More preferably, the positioning member is made of a rigid reference rod that extends in a straight line. According to the above method, the anti-float member can be temporarily held in a positioned state by the reference rod, making it easier to interpose the position adjustment member between the upper wall of the existing pipe and the rehabilitated pipe, as well as to permanently fix it in place.

[0017] Preferably, the positioning means consists of a reference frame that is an annular shape or a semicircular or more arc shape having an outer diameter equal to the outer diameter of the rehabilitated pipe, and in the position adjustment step, the positioning is performed by placing the reference frame on the lower wall surface of the existing pipe and applying the anti-float member to the outer circumferential surface of the reference frame. According to the above method, the anti-float member can be positioned easily and accurately.

[0018] Another aspect of the present invention is a device installed on the upper wall surface of an existing pipe, which prevents the rehabilitation pipe from floating when filling backfill material between the existing pipe and a rehabilitation pipe lined inside the existing pipe, The invention is characterized by comprising: an anti-float member extending in the axial direction of the existing pipe; a position adjustment member interposed between the anti-float member and the upper wall surface of the existing pipe so as to position the anti-float member in a position that prevents the rehabilitation pipe having a predetermined diameter from floating; and an anchor provided on the upper wall surface of the existing pipe, which can temporarily hold the anti-float member in a position that can be adjusted radially outward from the existing pipe, and which permanently fixes the anti-float member to the existing pipe by tightening the anti-float member toward the upper wall surface of the existing pipe while the position adjustment member is interposed between the existing pipe and the anti-float member.

[0019] Preferably, the anchor has a male threaded portion that penetrates the anti-float member and can be screwed into the existing pipe, and a head provided at one end of the male threaded portion for locking the anti-float member.

[0020] Preferably, the anti-floating member has a first wall on the existing pipe side, a second wall on the side opposite to the existing pipe, and a pair of side walls. The male screw portion of the anchor penetrates the first wall and the head portion is locked to the first wall, and the head portion of the anchor and the position adjusting member do not protrude from the second wall in the fully fixed state of the anti-floating member. According to the above configuration, since the head portion of the anchor and the position adjusting member do not protrude from the second wall of the anti-floating member, the rehabilitation pipe is not damaged.

[0021] In one embodiment, the position adjusting member is composed of at least one adjusting plate having a main plate portion and a sub-plate portion and forming an L shape. In the main plate portion, a slit extending in a direction orthogonal to the sub-plate portion and opened at the side edge opposite to the sub-plate portion is formed. The adjusting plate is attached to the anti-floating member in a state where the male screw portion of the anchor is passed through the slit, the main plate portion is along the first wall of the anti-floating member, and the sub-plate portion is along the side wall of the anti-floating member. According to the above configuration, the position adjusting plate can be stably attached to the anti-floating member.

[0022] In another embodiment, a nut is disposed in the internal space of the anti-floating member, and the position adjusting member is composed of a screw member screwed into the nut. The screw member protrudes from the first wall and abuts against the upper wall surface of the existing pipe. According to the above configuration, the position can be adjusted simply and reliably.

[0023] Preferably, a deflection preventing spacer is provided between the anti-floating member and the existing pipe, near the anchor and on one or both sides in the pipe axis direction. The deflection preventing spacer prevents the deflection of the anti-floating member when the anchor is tightened. More preferably, the position adjusting member also serves as the deflection preventing spacer.

[0024] Preferably, a slit is formed in the second wall of the anti-float member along its entire length, and this slit divides the second wall into two wall sections, and the nut is welded to the two wall sections of the second wall. With the above configuration, anchor tightening and other operations can be performed smoothly through the slits in the anti-float member. In addition, since the nuts are welded to the two wall sections of the second wall, the open-section anti-float member can be reinforced. [Effects of the Invention]

[0025] According to the present invention, it is not necessary to place numerous supports inside the rehabilitated pipe to prevent the pipe from floating when filling with backfill material, and fluctuations in the diameter of the rehabilitated pipe in the pipe axis direction can also be suppressed. [Brief explanation of the drawing]

[0026] [Figure 1] The float prevention member used in the float prevention device for a rehabilitation pipe according to the first embodiment of the present invention is shown, where (A) is a side view, (B) is a top view, and (C) is a bottom view. [Figure 2] The main parts of the above-mentioned anti-float member are shown enlarged together with the anchor, with (A) being a vertical cross-sectional view, (B) a top view, (C) a bottom view, and (D) a cross-sectional view taken along the DD line in (A). [Figure 3] The position adjustment plates used in the anti-float device are shown, with (A) being a cross-sectional view and (B) being a bottom view. [Figure 4A] This is a cross-sectional view showing the step in the installation process of the anti-float device in which the anti-float member is temporarily held to the existing pipe with an anchor. [Figure 4B] This is a longitudinal cross-sectional view showing the temporary holding step. [Figure 5A] This is a cross-sectional view showing the step of adjusting the position of the anti-float member in the installation process of the anti-float device. [Figure 5B] This is a longitudinal cross-sectional view showing the same position adjustment step. [Figure 6A]This is a cross-sectional view showing the step of permanently fixing the buoyancy prevention member in the installation process of the buoyancy prevention device. [Figure 6B] This is a longitudinal cross-sectional view showing the same fixing step. [Figure 7] This is a cross-sectional view showing the lining process of a rehabilitation pipe. [Figure 8] This is a cross-sectional view showing the backfill material filling process. [Figure 9] This is an enlarged cross-sectional view of the main parts showing the installation process of the anti-float device in order, where (A) shows the temporary holding step, (B) shows the position adjustment step, and (C) shows the final fixing step. [Figure 10] This is a cross-sectional view showing the position adjustment step in a second embodiment of the present invention. [Figure 11] This is a cross-sectional view showing the position adjustment step in the third embodiment of the present invention. [Figure 12] This is a cross-sectional view showing the position adjustment step in the fourth embodiment of the present invention. [Figure 13] This shows a float prevention device according to a fifth embodiment of the present invention, where (A) is a top view, (B) is an enlarged cross-sectional view of the main part showing the state before the position adjustment step is performed, and (C) is an enlarged cross-sectional view of the main part showing the state after the position adjustment step has been performed. [Figure 14] This is a cross-sectional view showing the fixing step in the fifth embodiment. [Figure 15] This is a cross-sectional view showing a state in which a bracing member is installed after the lining process of the rehabilitated pipe and prior to the filling of the backfill material, according to the sixth embodiment of the present invention. [Figure 16] Figures (A) to (C) are longitudinal cross-sectional views showing the deflection prevention structure of the anti-float member, respectively. [Figure 17] The image shows a float prevention member used in the seventh embodiment of the present invention, where (A) is a bottom view, (B) is a cross-sectional view showing a reinforcing structure of the float prevention member, and (C) is a cross-sectional view showing another reinforcing structure of the float prevention member. [Figure 18] This is a bottom view showing long and short anti-float members used in the eighth embodiment of the present invention. [Figure 19]This is an enlarged view of the main part of the long anti-float member of the same embodiment, where (A) is a bottom view, (B) is a top view, and (C) is a side view. [Figure 20] (A) is an end view along line AA in Figure 19(B), (B) is an end view along line BB in Figure 19(B), and (C) is an end view along line CC in Figure 19(B). [Figure 21] This is a longitudinal cross-sectional view showing the installation state of the anti-float member when there is a step misalignment in the existing pipe. [Modes for carrying out the invention]

[0027] The first embodiment of the present invention will be described below with reference to Figures 1 to 9. First, the components of the rehabilitation pipe flotation prevention device 1 (hereinafter simply referred to as the flotation prevention device; see Figures 5 to 8) will be described. The flotation prevention device 1 comprises a flotation prevention member 10 shown in Figures 1 and 2, an anchor 20 shown in Figure 2, and a position adjustment plate 30 (position adjustment member) shown in Figure 3.

[0028] The anti-float member 10 is made of a long, slender rigid material and has the same cross-sectional shape along its entire length. Specifically, the anti-float member 10 is made of a long, slender, hollow rectangular steel with a flattened rectangular cross-section, and has a length of, for example, 1 to several meters, with a height of 16 mm, a width of 40 mm, and a thickness of 1.6 mm. When the existing pipe 5, which will be described later, is constructed by connecting concrete pipes, it is preferable to make the length of the anti-float member 10 equal to the length of the concrete pipe. This allows the anti-float member 10 to be installed while avoiding the joints of the concrete pipe. The anti-float member 10 can also be cut to size as needed.

[0029] The anti-float member 10 has a wide first wall 11 and a second wall 12 that are parallel to each other and face each other, and a pair of side walls 13 that are parallel to each other and face each other. The first wall 11 has through holes 15, which are elongated holes extending in the longitudinal direction, formed at a predetermined pitch in the longitudinal direction. The second wall 12 has operating holes 16 formed at the same pitch in the longitudinal direction. The operating holes 16 are elliptical in shape and are sized to encompass the through holes 15 when viewed from a direction perpendicular to the walls 11 and 12. The pair of side walls 13 have through holes 17 formed at a shorter pitch than the through holes 15 and operating holes 16.

[0030] The anchor 20 is made of a concrete screw and has a male threaded portion 21 and a head 22 provided at one end of the male threaded portion 21. The outer diameter of the male threaded portion 21 is smaller than the width of the insertion hole 15 of the anti-float member 10. The head 22 is larger than the width of the insertion hole 15 and smaller than the width of the operating hole 16. As a result, the anchor 20 is inserted into the anti-float member 10 from the operating hole 16, the male threaded portion 21 is inserted through the insertion hole 15, and the head 22 is locked to the first wall 11.

[0031] The position adjustment plate 30 has an L-shape, comprising a rectangular main plate portion 31 and a rectangular sub-plate portion 32 that is narrower than the main plate portion 31 and perpendicular to it. The main plate portion 31 has a slit 35 that extends in a direction perpendicular to the sub-plate portion 32 and reaches the opposite side edge of the sub-plate portion 32. The width of the slit 35 is greater than the diameter of the male screw portion 21 of the anchor 20 and smaller than the head 22.

[0032] Next, the rehabilitation work of the aging sewer pipes 5 will be explained in order of steps, referring to Figures 4 to 9. The existing pipes 5 extend over two manholes and, in this embodiment, are made of concrete. Installation process of anti-float device In the installation process of the float prevention device 1, the following steps are performed in this order: a temporary holding step of the float prevention member 10, a position adjustment step of the float prevention member 10, and a permanent fixing step of the float prevention member 10. Each step will be explained below.

[0033] <Temporary holding step> As shown in Figures 4A and 4B, a number of anti-float members 10 extending in the direction of the pipe axis are temporarily held in place on the upper wall surface of the existing pipe 5, at positions a predetermined angle to the left and right from the top of the pipe, and arranged in a nearly straight line. It is preferable that the anti-float members 10 be continuous along the pipe axis, but if the existing pipe 1 is made up of connected concrete pipes, they may be spaced 100 mm or less in the direction of the pipe axis to avoid joints, etc. The temporary holding positions described above form angles of less than 90° to the left and right, with the top of the pipe being 0°, and preferably 45° or less as shown in the figure. It is most preferable to bring the angle as close to 45° as possible in order to minimize the stress on the existing pipe 5 when soil pressure is applied.

[0034] Each anti-float member 10 is temporarily held in place at least at two locations by anchors 20, with the first wall 11 facing the upper wall surface of the existing pipe 5. As shown in Figure 9(A), a pilot hole 5a is drilled in the upper wall surface of the existing pipe 5 corresponding to the insertion hole 15 of the first wall 11, and the male threaded portion 21 of the anchor 20 passes through this insertion hole 15 and is lightly screwed into the pilot hole 5a. The tool used for this screwing operation is inserted through an operating hole 16 formed in the second wall 12 of the anti-float member 10 and engages with the head 22 of the anchor 20. The anti-float member 10 is temporarily held in a suspended state, with its first wall 11 being locked to the heads 22 of multiple anchors 20, allowing its position to be adjusted upward (radially outward from the existing pipe 5).

[0035] <Position adjustment step> In the next position adjustment step, a rigid, linearly formed reference rod 40 (positioning member; positioning means) is prepared, as shown in Figures 5A and 5B. This reference rod 40 has a reference length corresponding to the outer diameter of the planned rehabilitated pipe 6. That is, this reference length is set to be equal to the distance between the position where the anti-float member 10 contacts the outer circumference of the rehabilitated pipe 6 and the lower wall surface of the existing pipe 5 facing the diametrically opposed pipe, assuming that the rehabilitated pipe 6, which has the planned outer diameter, rests on the bottom of the existing pipe 5. When the temporary holding position is close to the top of the existing pipe 5, the reference length is approximately equal to the outer diameter of the rehabilitated pipe 6, and as the temporary holding position moves away from the top of the existing pipe 5, the reference length becomes larger than the outer diameter of the rehabilitated pipe 6.

[0036] As shown in Figure 5B, the reference rod 40 is slightly offset from the anchor 20 in the direction of the pipe axis, and positioned so as to pass almost through the pipe axis of the existing pipe 50 as shown in Figure 5A. One end of the rod is placed against the lower wall surface of the existing pipe 5, and the other end is placed against the second wall 12 of the anti-float member 10. As a result, the anti-float member 10 is lifted by the reference rod 40, and as shown in Figure 9(B), the first wall 11 of the anti-float member 10 moves away from the head 22 of the anchor 20. In this way, the anti-float member 10 is positioned.

[0037] With the anti-float member 10 positioned as described above, if a gap is formed between the first wall 11 of the anti-float member 10 and the upper wall surface of the existing pipe 5, the necessary number of position adjustment plates 30 are inserted to fill this gap. That is, the main plate portion 31 of the first position adjustment plate 30 is inserted from a direction perpendicular to the longitudinal direction of the anti-float member 10, so that the slit 35 is inserted into the male screw portion 21 of the anchor 20. This places the main plate portion 31 on the first wall 11 and the sub-plate portion 32 against the higher side wall 13. If necessary, additional position adjustment plates 30 are inserted between the previously inserted position adjustment plates 30 and the upper wall surface of the existing pipe 5 in the same manner as described above. The main plate portions 31 of the position adjustment plates 30 overlap, and the sub-plate portions 32 overlap each other. The inserted position adjustment plate 30 maintains a stable attachment state to the anti-float member 10 because it is inserted into the slit 35 by the male screw portion 21 and the sub-plate portion 32 rests on the higher side wall 13.

[0038] It is preferable to set the height of the anti-float member 10 to be equal to the gap formed between the outer surface of the rehabilitated pipe 6 and the upper wall surface of the existing pipe 5 when the rehabilitated pipe 6 of the planned outer diameter is resting on the bottom of the existing pipe 5. In this way, in areas where there is no corrosion on the upper wall surface of the existing pipe 5, the position adjustment plates 30 can be omitted, and in areas where there is corrosion, the number of position adjustment plates 30 will be interposed according to the depth of the corrosion.

[0039] <Main fixing step> Next, as shown in Figures 6A, 6B, and 9(C), the anchor 20 is rotated and screwed deeply into the upper wall surface of the existing pipe 5. This causes the head 22 of the anchor 20 to tighten together with the position adjustment plate 30 towards the upper wall surface of the existing pipe 5. As described above, the anti-float member 10 is permanently fixed to the upper wall surface of the existing pipe 5. In this state, the position adjustment plate 30 is sandwiched between the first wall 11 of the anti-float member 10 and the upper wall surface of the existing pipe 5, so that the mounting state can be maintained more stably. As shown in Figure 9(C), in this fixed state, the head 22 of the anchor 20 is positioned inside the anti-float member 10 and does not protrude radially inward from the second wall 12. Also, since the width of the sub-plate portion 32 of the position adjustment member 30 is the same as or narrower than the height of the anti-float member 10, the position adjustment member 30 also does not protrude from the second wall 12.

[0040] After the above-mentioned final fixing, the reference rod 40 is removed from between the lower wall surface of the existing pipe 5 and the second wall 12 of the anti-float member 10. The reference rod 40 allows the anti-float member 10 to be maintained in a positioned state from the position adjustment step to the final fixing step, thus enabling the work to proceed smoothly.

[0041] Rehabilitation pipe lining process Next, as shown in Figure 7, the rehabilitated pipe 6 is lined inside the existing pipe 5. The rehabilitated pipe 6 is constructed by spirally winding a strip-shaped member made of synthetic resin such as polyvinyl chloride resin and fitting the edges of adjacent winding portions together, but the rehabilitated pipe 6 may also be manufactured using other pipe manufacturing methods. The anti-float member 10 is positioned such that the distance between the second wall 12 of the anti-float member 10 and the lower wall surface of the existing pipe 5 facing it in the diametrical direction is equal to the standard length of the standard rod 40. Therefore, by manufacturing the rehabilitated pipe 6 so that it is almost inscribed within the second wall 12 of the anti-float member 10, the rehabilitated pipe 6 can be manufactured with the planned diameter along the pipe axis, and diameter fluctuations can be suppressed. As a result, the strength design can be performed accurately.

[0042] If the rehabilitation pipe 6 deforms and a gap is created between it and the anti-float member 10, the anchor 20 may be loosened to lower the anti-float member 10 and insert an additional position adjustment plate 30, or a bracing member may be placed inside the rehabilitation pipe 6 and the shape may be corrected by bracing the rehabilitation pipe 6 radially until it contacts the anti-float member 10.

[0043] Backfill material filling process Next, as shown in Figure 8, a backfill material 7 made of mortar or the like is filled between the existing pipe 5 and the rehabilitated pipe 6. The filling of this backfill material 7 creates buoyancy in the rehabilitated pipe 6, but the upper wall of the rehabilitated pipe 6 comes into contact with the second wall 12 of the anti-float member 10, preventing the rehabilitated pipe 6 from floating. Numerous through holes 17 are formed in the side wall 13 of the anti-float member 10, and air is released from the through holes 17 as the backfill material 7 enters from the openings at both ends of the anti-float member 10. In addition, the backfill material 17 enters the internal space through the through holes 17. As a result, the backfill material 17 can be reliably filled into the internal space of the anti-float member 10, and the anti-float member 10 and the backfill material 7 can be integrated. As described above, the head 22 of the anchor 20 and the position adjustment member 30 do not protrude from the second wall 12, so the rehabilitated pipe 6 is not damaged. In this embodiment, the anti-buoyancy member 10 is positioned to the left and right of the top of the existing pipe 5, so that the rehabilitated pipe 6 is held stably without rotating even when subjected to buoyancy.

[0044] Other Embodiments Next, other embodiments of the present invention will be described. In the following embodiments, components corresponding to those in the prior embodiments will be denoted by the same numbers, and their detailed descriptions will be omitted. In the second embodiment shown in Figure 10, a flexible reference strip 41 such as a wire or thread is used as a positioning member (positioning means). This reference strip 41 has a reference length, similar to the first embodiment. With one end against the lower wall surface of the existing pipe 5 and the other end against the anti-float member 10, the anti-float member 10 is lifted so that the reference strip 41 extends almost straight along the pipe axis. In this state, similar to the first embodiment, if there is a gap between the anti-float member 10 and the upper wall surface of the existing pipe 5, the position adjustment plate 30 is inserted and then permanently fixed.

[0045] In the third embodiment shown in Figure 11, a ring-shaped reference frame 43 having the same outer diameter as the intended outer diameter of the rehabilitated pipe 6 is used as the positioning means. In the position adjustment step, with the reference frame 43 placed on the bottom of the existing pipe 5, the float prevention member 10 is positioned by bringing the outer surface of the reference frame 43 into contact with the second wall 12 of the float prevention member 10. This reference frame 43 allows the float prevention member 10 to be positioned easily and accurately. The reference frame 43 may also be in the shape of an arc with a circumference of a semicircle or longer.

[0046] In the fourth embodiment shown in Figure 12, a measuring device, such as a laser distance meter 45, is used as the positioning means. That is, the laser distance meter 45 is installed on the lower wall surface of the existing pipe 5, and the laser 45a is directed onto the second wall 12 of the anti-float member 10 so as to pass through the pipe axis of the existing pipe 5. The anti-float member 10 is lifted so that the measured distance corresponds to the reference length of the first and second embodiments, and the position adjustment plate 30 is inserted as needed in that position.

[0047] In the fifth embodiment shown in Figures 13 and 14, the anti-float member 10 is made of flattened rectangular steel, similar to the first embodiment, with an elongated insertion hole 15 formed in the first wall 11, an operating hole 16 (not shown in Figure 13) formed in the second wall 12, and a through hole 17 (not shown in Figure 13) formed in the side wall 13. In the fifth embodiment, the anti-float member 10 has a cylindrical nut 18 (female thread portion) positioned away from the insertion hole 15 and at the same pitch as the insertion hole 15. This nut 18 is welded to the first wall 11 and the second wall 12. A screw member 50 (position adjustment member) is screwed onto the nut 18. This screw member 50 is called a set screw, has a tool hook hole 51 on its base end face, and its tip face is flat or rounded and not pointed.

[0048] Before the position adjustment step, as shown in Figure 13(B), the screw member 50 is fitted into the nut 18 of the anti-float member 10. In the position adjustment step, after positioning is complete, if there is a gap between the first wall 11 of the anti-float member 10 and the upper wall surface of the existing pipe 5, the screw member 50 is screwed in until it touches the upper wall surface of the existing pipe 5. As a result, the portion of the screw member 50 protruding from the first wall 11 of the anti-float member 10 is interposed between the anti-float member 10 and the upper wall surface of the existing pipe 5, and the position adjustment is completed. Since the screw member 50 does not have a head, it can protrude significantly from the anti-float member 10. The temporary holding step and the final fixing step in this embodiment are the same as in the first embodiment, so their description is omitted. Figure 14 shows the final fixing state.

[0049] It is preferable that the length of the screw member 50 be equal to or shorter than the height of the anti-float member 10. Even if there is no gap between the first wall 11 of the anti-float member 10 and the upper wall surface of the existing pipe 5, and the screw member 50 does not protrude from the first wall 11, the screw member 50 does not protrude downward from the second wall 12, and the rehabilitated pipe 6 is not damaged when the backfill material is filled. If the upper wall surface of the existing pipe 5 is severely corroded locally, a threaded member 50 longer than the height of the anti-float member 10 may be used. Even in this case, care must be taken to ensure that the threaded member 50 does not protrude from the second wall 12 and damage the rehabilitated pipe 6 after adjustment. Since the tip surface of the screw member 50 is not sharp, even if buoyancy is applied to the rehabilitated pipe 6 while it is in contact with the upper wall surface of the existing pipe 5, it will not damage the existing pipe 5. Furthermore, when using screw members with a head, it is preferable to make the head as low as possible.

[0050] As in the embodiment described above, if at least one pair of anti-float members 10 are arranged on both sides in the circumferential direction, avoiding the top of the pipe, the rehabilitated pipe 6 will not rotate even if it is subjected to buoyancy when the backfill material 7 is filled. However, as in the sixth embodiment shown in Figure 15, the anti-float members 10 may be arranged at one location on the top of the pipe on the upper wall surface of the existing pipe 5. In this case, it is preferable to install a bracing member 60 inside the rehabilitated pipe 6 in order to prevent the rehabilitated pipe 6 from rotating around the anti-float member 10 when the backfill material 7 is filled. This bracing member 60 has, for example, a linearly extending main body 61, jacks 62 arranged above and below the main body 61, and a pressing member 63 that is held by the jacks 62 and contacts the inner surface of the rehabilitated pipe 6.

[0051] When the anti-float member 10 is permanently fixed to the existing pipe 5 by anchors 20, if the tightening force of the anchors 20 is too strong, the anti-float member 10 may deflect. To prevent this deflection, it is preferable to place deflection-preventing spacers near and on both sides of the anchors 20 (on both sides in the direction of the pipe axis of the existing pipe 5), as shown in Figure 16. The distance between the anchors 20 and the spacers (indicated by the symbol D in Figure 16) is preferably 100 mm or less.

[0052] In the deflection prevention structure shown in Figure 16(A), the position adjustment plate 30 (position adjustment member), similar to that in the first embodiment, also serves as a deflection prevention spacer. However, this position adjustment plate 30 does not have the slit 35 of the first embodiment. In the deflection prevention structure shown in Figure 16(B), the screw member 50 (position adjustment member), similar to that in the fifth embodiment, also serves as a deflection prevention spacer.

[0053] In the deflection prevention structure shown in Figure 16(C), a screw member 50 is used as a position adjustment member, similar to the fifth embodiment, and a deflection prevention spacer 70 is added separately from this screw member 50. This deflection prevention spacer 70 is made of a screw member with a smaller diameter than the screw member 50 and is screwed into the female screw portion 18A of the float prevention member 10. In the same manner as in the fifth embodiment, the anti-float member 10, whose position has been adjusted by the screw member 50, is maintained in that position, while the spacer 70 is extended from the anti-float member 10 until it hits the upper wall surface of the existing pipe 5.

[0054] Figure 17(A) shows the anti-float member used in the seventh embodiment. The second wall 12A of this anti-float member 10A has a slit 19 formed along its entire length, dividing the second wall 12A into two wall sections. The configuration of the first wall 11 and the side wall 13 is the same as in the previously described embodiment. The anti-float member 10A is formed from structural steel or by bending a long steel plate. Since the anti-float member 10A has a slit 19, it is not necessary to drill an operating hole 16 in the second wall 12 as in the first embodiment. In addition, it is possible to have more space for the work of fixing the anchor to the existing pipe.

[0055] When the backfill material is filled, the anti-float member 10A is subjected to the buoyancy of the rehabilitated pipe. At this time, since the second wall 12A has an open cross-sectional shape, it is subjected to a force in the direction that causes the two separated wall sections to spread apart. Reinforcement structures to prevent this spreading are shown in Figures 17(B) and (C), respectively. Figure 17(B) shows a reinforcing structure when a position adjustment plate similar to that of the first embodiment is used, in which the reinforcing plate 80 is welded so as to straddle two parts of the second wall 12A. Multiple reinforcing plates 80 are arranged at positions offset in the axial direction from the insertion hole 15. Figure 17(C) shows a reinforcing structure using a nut 18 and screw member 50 similar to that of the fifth embodiment, in which the nut 18 is welded so as to straddle the two wall portions of the second wall 12A.

[0056] Figures 18 to 20 show an anti-float device used in the eighth embodiment of the present invention. In this embodiment, as shown in Figure 18, an anti-float member 10A corresponding to the length of a normal concrete pipe is used, but a shorter anti-float member 10A' is also used to correspond to a shorter concrete pipe used in the curved section of an existing pipe. The anti-float member 10A has a length of, for example, 2290 mm or 2420 mm. The anti-float member 10A' has a length of, for example, 300 mm.

[0057] As shown in Figure 20, the cross-sectional shape of the anti-float members 10A and 10A' is the same as that of the anti-float member 10A in the seventh embodiment, and has a first wall 11, a second wall 12A with a slit 19 formed along its entire length, and a pair of side walls 13. As shown in Figures 18 and 19, the anti-float member 10A has multiple through-holes 15 formed at intervals in the longitudinal direction (in the direction of the existing pipe axis), for example, five holes, for passing anchors through. Nuts 18 are positioned on one or both sides in the longitudinal direction near these through-holes 15.

[0058] As shown in Figure 20(A), the nut 18 is housed in the internal space of the anti-float member 10A and is welded to two walls of the second wall 12A. An opening 90 is formed in the first wall 11 corresponding to the screw hole of the nut 18. As shown in Figure 20(B), at the corner where the first wall 11 and the pair of side walls 13 intersect, air vents 95 are formed extending from the first wall 11 to the side walls 13, located on both sides of the insertion hole 15. As shown in Figure 20(C), reinforcing plates 80 are welded to both ends of the anti-float member 10A, straddling the two wall sections of the second wall 12A.

[0059] In this embodiment, the anti-float member 10A is temporarily held and permanently fixed by an anchor 20 passing through the insertion hole 15, and the position of the anti-float member 10A is adjusted by a screw member 50 screwed onto a nut 18, which is the same as in the previously described embodiment, so a description will be omitted. In this embodiment, deflection of the anti-float member 10A is prevented by a screw member 50 positioned near the anchor 20, and the open cross-sectional shape of the anti-float member 10A is reinforced by a nut 18 and a reinforcing plate 80 welded to the two wall portions of the second wall 12A.

[0060] In the backfill material filling process, as the backfill material enters the internal space from both longitudinal ends of the anti-float member 10A, air in the internal space is discharged from the air vent holes 95, allowing the backfill material to be smoothly filled into the internal space. Furthermore, if the anti-float member 10A is positioned on the left and right sides of the top of the existing pipe, as in the first embodiment, the anti-float member 10A will be in an inclined position, and the upper of the pair of air vent holes 95 formed at the corners will be located at the very top of the anti-float member 10A. Therefore, air venting can be performed even more effectively.

[0061] The shorter anti-float member 10A' has the same structure as the longer anti-float member 10A, but the number of through holes 15 is smaller, for example, one is formed there, and the nuts 18 are attached only in two places on either side of it. Reinforcing plates 80 are attached to both ends, and air vents (not shown) are formed at the corners corresponding to the through holes 15.

[0062] As mentioned above, if the existing pipe 5 has been rehabilitated by connecting it to a concrete pipe, it is preferable to move the anti-float member 10 axially by a distance of 100 mm or less to avoid the joint of the concrete pipe. As shown in Figure 21, if a step misalignment occurs at the joint, the anti-float member 10 may be moved by a longer distance D (however, 500 mm or less). In this case, it is preferable to adjust the amount of protrusion of the screw member 50 of the anti-float member 10 near the step (the amount of interposition of the position adjustment member) to tilt the anti-float member 10 with respect to the pipe axis in order to mitigate the step.

[0063] The present invention is not limited to the embodiments described above, and various modifications can be made as long as they do not contradict the spirit of the invention. The anchor may consist of two parts: a nut embedded in the existing pipe and a bolt with a head that screws onto this nut. Alternatively, it may consist of two parts: a rod-shaped bolt driven into the existing pipe and a nut that screws onto this anchor to secure the anti-float member. The anti-float member is not limited to a hollow rectangular material; various types can be used, such as a flat bar, a steel plate with a U-shaped or L-shaped cross-section, or a round bar. Furthermore, to improve integration with the backfill material, a perforated material or a deformed steel bar may be used. The existing pipes to be rehabilitated are not limited to sewer pipes; they may also include water supply pipes, other water conduits, etc. They may also include tunnels. [Industrial applicability]

[0064] This invention can be applied to the rehabilitation of sewer pipes and the like that buried underground. [Explanation of Symbols]

[0065] 1 Floating prevention device for rehabilitated pipes 5 Existing pipes 6 Rehabilitation pipe 7. Backing material 10,10A Anti-float member 11 1st wall 12 Second wall 13 Side wall 18. Nut (female threaded part) 19 slits 20 Anchors 21 Male threaded section 22 Head 30 Position adjustment plate (position adjustment member) 31 Main plate part 32 Sub plate part 35 slits 40 Reference rod (positioning member, positioning means) 41. Reference strip (positioning member, positioning means) 43 Reference frame (positioning means) 45. Laser distance meter (positioning means) 50 Screw component (position adjustment component)

Claims

1. In a method for rehabilitating an existing pipe, the steps of sequentially performing the steps of installing an anti-float device on the upper wall surface of the existing pipe, lining the inside of the existing pipe with a rehabilitated pipe, and filling the space between the existing pipe and the rehabilitated pipe with backfill material, The installation process of the aforementioned anti-float device is as follows: A temporary holding step involves temporarily holding the anti-float members, which extend in the axial direction of the existing pipe, along the upper wall surface of the existing pipe in the axial direction, and positioning them radially outward of the existing pipe using anchors, so as to be adjustable. The anti-float member is positioned by a positioning means so that the rehabilitated pipe having a predetermined diameter is prevented from floating up from the bottom of the existing pipe. If a gap is formed between the anti-float member and the upper wall surface of the existing pipe in this positioned state, a position adjustment step is made to interpose a position adjustment member in this gap. The anchor is used to tighten the anti-float member toward the upper wall surface of the existing pipe, thereby permanently fixing the anti-float member to the existing pipe in a final fixing step, A method for rehabilitating existing pipes, characterized by comprising the following:

2. The anchor has a male threaded portion and a head provided at one end of the male threaded portion. In the temporary holding step, the male threaded portion of the anchor is shallowly screwed into the upper wall surface of the existing pipe, and the head of the anchor locks onto the float prevention member, thereby temporarily holding the float prevention member in a suspended state. The method for rehabilitating an existing pipe according to claim 1, characterized in that the anchor is further screwed into the upper wall surface of the existing pipe, so that the head of the anchor presses the anti-floating member toward the upper wall surface of the existing pipe.

3. The method for rehabilitating an existing pipe according to claim 1 or 2, wherein the position adjustment member consists of an adjustment plate, and in the position adjustment step, if a gap is formed between the positioned anti-floating member and the upper wall surface of the existing pipe, the adjustment plate is inserted in the number of pieces necessary to fill the gap.

4. The method for rehabilitating an existing pipe according to claim 1 or 2, wherein the position adjustment member consists of a screw member screwed into the anti-float member, and in the position adjustment step, if a gap is formed between the positioned anti-float member and the upper wall surface of the existing pipe, the screw member is advanced toward the upper wall surface of the existing pipe so that it protrudes from the anti-float member by an amount corresponding to the gap, and its tip is brought into contact with the upper wall surface of the existing pipe.

5. The method for rehabilitating an existing pipe according to claim 1 or 2, characterized in that the positioning means comprises a positioning member having a reference length, and in the position adjustment step, the anti-float member is positioned by positioning one end of the positioning member on the anti-float member and the other end on the lower wall surface of the existing pipe facing the anti-float member in the diametrical direction.

6. The method for rehabilitating an existing pipe according to claim 5, characterized in that the positioning member consists of a rigid reference rod extending in a straight line.

7. The method for rehabilitating an existing pipe according to claim 1 or 2, characterized in that the positioning means consists of a reference frame having an outer diameter equal to the outer diameter of the rehabilitated pipe, and in the position adjustment step, the positioning is performed by placing the reference frame on the lower wall surface of the existing pipe and applying the anti-float member to the outer circumferential surface of the reference frame.

8. A device installed on the upper wall surface of an existing pipe, which prevents the rehabilitation pipe from floating when filling backfill material between the existing pipe and the rehabilitation pipe lined inside the existing pipe, A floating prevention member extending in the axial direction of the existing pipe, A position adjustment member is interposed between the float prevention member and the upper wall surface of the existing pipe so that the float prevention member is positioned to prevent the rehabilitation pipe having a predetermined diameter from floating. An anchor is provided on the upper wall surface of the existing pipe, which can temporarily hold the anti-float member in an adjustable position outward in the radial direction of the existing pipe, and which permanently fixes the anti-float member to the existing pipe by tightening the anti-float member toward the upper wall surface of the existing pipe while the position adjustment member is interposed between the existing pipe and the anti-float member, A device to prevent pipe buoyancy, characterized by having the following features.

9. The anti-float device for a rehabilitated pipe according to claim 8, characterized in that the anchor has a male threaded portion that penetrates the anti-float member and can be screwed into the existing pipe, and a head provided at one end of the male threaded portion for locking the anti-float member.

10. The floating prevention device for a rehabilitated pipe according to claim 9, wherein the floating prevention member has a first wall on the existing pipe side, a second wall in contact with the rehabilitated pipe, and a pair of side walls, the male threaded portion of the anchor penetrates the first wall and the head is locked to the first wall, and the head of the anchor and the position adjustment member do not protrude from the second wall when the floating prevention member is permanently fixed.

11. The position adjustment member consists of at least one adjustment plate that is L-shaped, having a main plate portion and a sub-plate portion, and the main plate portion has a slit that extends in a direction perpendicular to the sub-plate portion and is open at the side edge opposite to the sub-plate portion. The anti-float device for a rehabilitation pipe according to claim 10, characterized in that the adjustment plate is attached to the anti-float member with the male screw portion of the anchor passing through the slit, the main plate portion aligned along the first wall of the anti-float member, and the sub-plate portion aligned along the side wall of the anti-float member.

12. The floating prevention device for a rehabilitated pipe according to claim 10, wherein a nut is arranged in the internal space of the floating prevention member, the position adjustment member is made of a screw member that is screwed into the nut, and the screw member protrudes from the first wall and contacts the upper wall surface of the existing pipe.

13. The anti-float device for a rehabilitated pipe according to any one of claims 8 to 12, wherein a spacer for preventing deflection is provided between the anti-float member and the existing pipe near the anchor and on one or both sides in the axial direction of the pipe, and the spacer for preventing deflection prevents the anti-float member from deflecting when the anchor is tightened.

14. The anti-float device for rehabilitation pipes according to claim 13, characterized in that the position adjustment member also serves as the deflection prevention spacer.

15. The float prevention device for a rehabilitation pipe according to claim 12, characterized in that a slit is formed in the second wall of the float prevention member along the entire length of the float prevention member, the second wall is divided into two wall portions by this slit, and the nut is welded to the two wall portions of the second wall.

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