JP7537751B2 - Short pipe installation method - Google Patents

Description

The present invention relates to a technology for treating flow paths that are formed by drilling equipment through concrete structures in an uninterrupted flow state, for example in pipeline expansion work for existing reinforced concrete reservoirs such as purified water reservoirs and wastewater reservoirs, or in pipeline construction associated with the construction of new reinforced concrete reservoirs.

As a technique for drilling a flow path in a concrete structure under uninterrupted flow conditions, for example, there is a method for drilling a concrete structure disclosed in Patent Document 1. In this drilling method, a gate valve is attached to a planned drilling location on the outer surface of the concrete structure via a short pipe with an inner diameter that allows the cylindrical cutter of the drilling device to move in and out, and a drilling device is attached to this gate valve. Then, the gate valve is opened and the cylindrical cutter of the drilling device is fed through the gate valve and the inside of the short pipe to form a flow path through the planned drilling location of the concrete structure.
After drilling, the cylindrical cutter of the drilling device is returned to the initial standby position through the short pipe and the inside of the gate valve, the gate valve is closed, and the drilling device is removed from the gate valve. Then, piping work for branching is carried out on the gate valve.

JP 2014-218036 A

In the above-mentioned drilling method, the perforation opening of the structure drilled by the cylindrical cutter of the drilling device is used as a flow path as is, so if cracks or the like occur on the inner surface of the flow path of the structure due to the rotary cutting force or vibration of the cylindrical cutter during drilling, there is the inconvenience that fluid will leak through these cracks to the outer surface of the structure.
Furthermore, if part of a reinforcing bar placed in a concrete structure is located on the drilling path of the cylindrical cutter, the cut end surface of the cut reinforcing bar will be exposed to the flow path, which can cause corrosion to progress from the cut end surface due to contact with the fluid.

In view of this situation, the main objective of the present invention is to provide a method for covering the flow passage of a concrete structure, which can suppress fluid leakage due to cracks on the inner surface of the flow passage caused by the rotary cutting force and vibrations during drilling, and the progression of corrosion from the cut end surface of the cut rebar, and which can efficiently cover the inner surface of the flow passage for this purpose, and a covering cylinder used therein.

The first characteristic feature of the present invention is a method for covering an inner circumferential surface of a flow passage formed in a concrete structure by a drilling device in an uninterrupted flow state, comprising:
a mounting step of mounting a covering cylinder capable of covering an inner peripheral surface of the flow path on an insertion device attached to an outer surface side of the structure in a state facing the flow path;
an insertion step of inserting a covering cylinder of the insertion device into the flow path in an uninterrupted state;
a sealing process for sealing a set sealing region between an outer circumferential surface of the inserted covering cylinder and an inner circumferential surface of the flow passage with a sealing means;
a removal step of removing the insertion device;
The present invention is characterized in that the above-mentioned is carried out.

According to the above configuration, in the installation step after drilling with the drilling device, the covering cylinder is installed on the insertion device replaced with the drilling device, and in the insertion step, the covering cylinder is inserted into the flow path of the structure with the insertion device in an uninterrupted flow state. The inserted covering cylinder can substantially cover the inner surface of the flow path in an unsealed state. Next, in the sealing process, a set sealing area in an annular space of small radial width between the outer surface of the inserted covering cylinder and the inner surface of the flow path is sealed. This sealing process can suppress fluid leakage due to cracks and corrosion of the cut end surface of the rebar, even if cracks or the like occur on the inner surface of the flow path of the structure, or even if the rebar in the structure is cut and exposed to the inner surface of the flow path of the structure.

This makes it possible to suppress fluid leakage due to cracks on the inner surface of the flow path caused by the rotary cutting force and vibrations during drilling, as well as the progression of corrosion from the cut end surface of the cut rebar. Moreover, by simply inserting the covering cylinder into the flow path, the inner surface of the flow path can be substantially covered in a non-sealed state, so that it is only necessary to seal the set sealing area in the small radial width annular space between the outer surface of the covering cylinder and the inner surface of the flow path. This allows efficient coating of the inner surface of the flow path.

The second characteristic feature of the present invention is to execute a removal control process in which the removal movement of the covering cylinder inserted into the flow path is controlled by a removal control means.

According to the above configuration, a moving force toward the detachment side due to fluid pressure acts on the covering cylindrical body inserted into the flow path of the structure, but by executing the detachment prevention process, the detachment movement of the covering cylindrical body inserted into the flow path can be reliably restricted by the detachment prevention means.
Therefore, the covering cylinder can be maintained inserted in the flow path, so that the set sealing area between the outer peripheral surface of the inserted covering cylinder and the inner peripheral surface of the flow path can be reliably sealed.

The third characteristic feature of the present invention is that the sealing means is composed of a seal material that is placed in a pressure-contact state between the outer circumferential surface of the covering cylinder and the inner circumferential surface of the flow path as the covering cylinder is inserted in the insertion step, and the removal prevention means is composed of the seal material of the sealing means.

According to the above configuration, the sealing material of the sealing means is pressed between the outer circumferential surface of the covering cylinder and the inner circumferential surface of the flow path as the covering cylinder is inserted in the insertion step, and the set sealing area between the outer circumferential surface of the covering cylinder and the inner circumferential surface of the flow path can be appropriately sealed. Moreover, the frictional resistance of the sealing material pressed between the outer circumferential surface of the covering cylinder and the inner circumferential surface of the flow path can suppress the covering cylinder inserted into the flow path from moving out of the flow path.
Therefore, the removal restriction means can be configured advantageously in terms of structure and cost by utilizing the sealing material of the sealing means.

The fourth characteristic feature of the present invention is that the sealing means is composed of a plurality of seal materials that are placed in a pressure-contact state between the outer circumferential surface of the covering cylinder and the inner circumferential surface of the flow path as the covering cylinder is inserted in the insertion step, and a filler material that is injected into the sealed area between the outer circumferential surface of the covering cylinder sealed with the seal materials and the inner circumferential surface of the flow path, and the removal prevention means is composed of the seal materials and the filler material of the sealing means.

According to the above configuration, the set sealed area between the outer circumferential surface of the covering cylinder and the inner circumferential surface of the flow path can be more appropriately sealed by the multiple seal materials that are pressed between the outer circumferential surface of the covering cylinder and the inner circumferential surface of the flow path as the covering cylinder is inserted in the insertion step, and the filler material that is injected into the sealed area sealed by the multiple seal materials. Moreover, by utilizing the multiple seal materials and filler material of the sealing means, the separation prevention means can be configured more advantageously in terms of structure and cost.

The fifth characteristic feature of the present invention is that the insertion device is detachably attached to the outer surface of the structure via a short pipe and a gate valve, the detachment restriction means is composed of an engagement means having an engagement portion provided on the covering cylinder and an engaged portion provided on the inner peripheral surface of the short pipe, and the engagement portion and the engaged portion are configured to be freely switched between a detachment restriction state in which the covering cylinder is engaged in the flow path axial direction to restrict the detachment movement of the covering cylinder and a disengaged state in which relative movement in the flow path axial direction is permitted by rotating the covering cylinder relative to the short pipe.

According to the above configuration, when the covering cylinder is inserted into the flow path of the structure using the insertion device, the relative position between the short tube and the covering cylinder in the rotational direction is set to a disengaged state that allows the engaging portion of the covering cylinder to move through the engaged portion of the short tube in the flow path axial direction, so that the insertion operation of the covering cylinder into the flow path can be performed reliably and smoothly without being hindered by the engaged portion of the short tube.
When the engaging portion of the covering cylinder passes through the engaged portion of the short tube and is inserted into the flow path, the covering cylinder is rotated relative to the short tube to change it from a disengaged state to a disengagement restricted state, so that when a moving force in the disengagement direction due to fluid pressure acts on the covering cylinder inserted into the flow path, the engaging portion of the covering cylinder engages with the engaged portion of the short tube from the axial direction of the flow path, thereby reliably preventing the covering cylinder from moving away from the flow path.

Therefore, by simply providing an engaging portion on the covering cylinder and an engaged portion on the inner surface of the short tube, it is possible to reliably and smoothly insert the covering cylinder into the flow path while reliably preventing the covering cylinder from moving out of the flow path.

The sixth characteristic feature of the present invention is that the engaged portion of the engaging means is configured as an insertion guide protrusion that slides against the outer circumferential surface of the covering cylinder and guides the covering cylinder into the flow path in a concentric or nearly concentric state.

According to the above configuration, when the covering cylinder is inserted into the flow path by the insertion device, the covering cylinder can be smoothly inserted and guided in a concentric or nearly concentric state with respect to the flow path while the load of the covering cylinder is supported by the insertion guide protrusions provided on the inner peripheral surface of the short tube. Moreover, since the insertion guide protrusions for this purpose can constitute the engaged portion of the engaging means, the removal restriction means can be constructed more advantageously in terms of structure and cost.

The seventh characteristic feature of the present invention is that the flange abutment portion at the periphery of the opening of the flow passage on the outer surface of the structure, where the connecting flange of the short pipe abuts from the flow passage axial direction, is smoothed, and then the connecting flange of the short pipe is fixed to the flange abutment portion with a bolt with an elastic sealant interposed between the flange abutment portion and the connecting flange of the short pipe.

Conventional short pipe installation processes include a chipping process in which the outer surface of the structure is chipped to expose some of the internal rebars, a short pipe fixing process in which one end of multiple connecting rebars is welded to multiple axial and circumferential locations on the outer surface of the short pipe and the other end of the multiple connecting rebars is welded to the exposed rebars on the structure, and a waterproof mortar application process in which waterproof mortar is applied to the chipped locations on the outer surface of the structure. Therefore, in conventional short pipe installation processes, each of the chipping process, short pipe fixing process, and waterproof mortar application process requires a lot of effort.

However, according to the above-mentioned configuration of the present invention, the flange abutment portion on the outer surface of the concrete structure, where the connecting flange of the short pipe abuts from the axial direction of the flow path, is smoothed, so that the unevenness of the flange abutment portion on the outer surface of the structure can be corrected. Therefore, a simple elastic sealant can be used to waterproof the area between the flange abutment portion on the outer surface of the structure and the connecting flange of the short pipe.
Therefore, it is only necessary to bolt the connecting flange of the short pipe to the smooth flange abutment portion of the structure with an elastic sealant interposed between them, and the short pipe installation work can be carried out efficiently.

The covering cylinder used in the flow passage covering method for a concrete structure described in any one of the first to seventh characteristic configurations above is characterized in that a flange portion is formed at one end of the covering cylinder, which can abut against the opening periphery of the flow passage on the outer surface of the structure, and the outer peripheral surface of the covering cylinder is provided with a plurality of sealing materials of the sealing means that seal between the outer peripheral surface of the covering cylinder and the inner peripheral surface of the flow passage.

According to the above configuration, when the covering cylinder is inserted into the flow path of the structure by the insertion device, it is only necessary to insert the covering cylinder to a position where the flange portion formed on one end of the covering cylinder abuts against the opening periphery of the flow path on the outer surface of the structure, which simplifies the insertion operation of the covering cylinder. Moreover, when the covering cylinder is inserted into the flow path, the set sealing area between the outer surface of the covering cylinder and the inner surface of the flow path can be appropriately sealed by the multiple seal materials provided on the outer surface of the covering cylinder.

The ninth characteristic feature of the present invention is that the length from the tip of the outer circumferential surface of the covering cylinder to the flange portion is configured to be the same as or greater than the axial length of the flow path.

According to the above configuration, when the length from the tip to the flange portion on the outer peripheral surface of the covering cylinder is configured to be the same as the axial length of the flow path, even if the covering cylinder inserted into the flow path moves slightly toward the removal side due to fluid pressure, the set sealing area on the inner peripheral surface of the flow path can be kept sealed approximately properly.
Furthermore, when the length from the tip to the flange portion on the outer peripheral surface of the covering cylinder is configured to be longer than the axial length of the flow path, even if the covering cylinder inserted into the flow path moves slightly toward the removal side due to fluid pressure, the set sealing area on the inner peripheral surface of the flow path can be reliably maintained sealed.

FIG. 2 is a partially cutaway side view showing the installation process of the flow passage covering method for the concrete structure according to the first embodiment of the present invention; Enlarged cross-sectional side view of the insertion device 3 is a cross-sectional view taken along line III-III of FIG. 1 in a disengaged state; Partially cutaway side view showing the installation process 5 is a cross-sectional view taken along line V-V of FIG. 4 in a state in which the release is restricted; A partially cutaway side view of the insertion device when it is moved back to the initial position FIG. 1 is an enlarged cross-sectional side view of the covering cylinder when it is inserted into the flow path. An enlarged cross-sectional side view of the covering cylinder when it is removed FIG. 13 is a partially cutaway side view showing a flow passage covering treatment method for a concrete structure according to a second embodiment of the present invention, in which a flow passage blocking jig is attached to an insertion device. FIG. 13 is a partially cutaway side view of the passage blocking jig of the insertion device inserted into the passage blocking position in the covering cylinder. Enlarged cross-sectional side view when filling material is injected Enlarged cross-sectional side view after filling material injection is completed FIG. 11 is an enlarged partially cutaway cross-sectional side view showing a third embodiment of the present invention.

First Embodiment
1 to 8 show a first embodiment of a flow channel covering method for a concrete structure and a covering cylinder 4 used therein. In this flow channel covering method, the inner peripheral surface 1a of a flow channel 1 formed by a drilling device (not shown) below the water level of the reservoir, which is a concrete wall W of a reinforced concrete reservoir, which is an example of a concrete structure, is covered in an uninterrupted water state (uninterrupted flow state).
The above-mentioned flow channel covering treatment method uses a short pipe (flange short pipe) 2 fixed to the opening peripheral portion of the flow channel 1 on the outer surface Wa of the concrete wall W, a check valve 3 connected to the connecting flange 2B on the downstream side of the short pipe 2, a cylindrical covering cylinder 4 capable of covering the inner surface 1a of the flow channel 1, an insertion device 5 that can freely detachably attach the covering cylinder 4 and is connected to the check valve 3 in a state facing the flow channel 1, a sealing means 6 that seals a set sealing area L4 between the outer surface 4a of the covering cylinder 4 inserted into the flow channel 1 by the insertion device 5 and the inner surface 1a of the flow channel 1, and a detachment control means 7 that controls the detachment movement of the covering cylinder 4 inserted into the flow channel 1.

The short pipe 2 and gate valve 3 were used during drilling work using the drilling device, and are also used as is in the flow path covering treatment method. Of these, the connecting flange 2A on the upstream side of the short pipe 2 is fixed in a watertight manner to the outer surface Wa of the concrete wall W with multiple bolts 10 and nuts 11, as shown in Figures 7 and 8. In addition, the connecting flange 2B on the downstream side of the short pipe 2 and the connecting flange 3A on the upstream side of the gate valve 3 are fixed and connected in a watertight manner with bolts 15 and nuts 16.

At least the flange abutting portion of the outer surface Wa of the concrete wall W with which the upstream connecting flange 2A of the short pipe 2 abuts is formed with a smoothing layer 12 that has been smoothed by grinding, filling with putty, adjusting the base surface, etc., as shown in Figures 7 and 8. In this embodiment, the range of the smoothing layer 12 is set to a range that extends from the opening edge of the flow path 1 radially outward beyond the connecting flange 2A of the short pipe 2.
The space between the smoothing layer 12 of the smoothed concrete wall W and the connecting flange 2A of the short pipe 2 is watertight sealed by a ring-shaped elastic sealant (such as a rubber ring) 13 installed in the seal mounting groove on the abutting surface side of the connecting flange 2A.
A chemical anchor bolt is used as the bolt 10 for fixing the connecting flange 2A of the short pipe 2, and the chemical anchor bolt is fixed with a chemical reaction adhesive in a bolt mounting hole 14 formed by a drill at the flange fixing portion of the concrete wall W.

As shown in Figures 1 and 5, first insertion guide protrusions 20 are fixed to two circumferential positions on the inner surface of the short pipe 2 in the lower half of the short pipe 2. The first insertion guide protrusions 20 are fixed along the flow path axis direction and slide against the outer surface of the cylindrical cutter of the drilling device or the outer surface 4a of the covering cylinder 4 to guide the cylindrical cutter or the covering cylinder 4 in a concentric or approximately concentric state with respect to the drilling center of the concrete wall W or the center of the flow path 1.
One end of this first insertion guide protrusion 20 is positioned as close as possible to the upstream end of the short pipe 2, and the other end of the first insertion guide protrusion 20 is positioned to protrude into the upstream portion of the check valve 3.
Furthermore, short ridges 21 are fixed to two circumferential positions on the inner peripheral surface of the upper half of the short tube 2, and extend along the axial direction of the flow passage, with one end located at the same position as one end of the first insertion guide projection 20. One end 21a of this ridge 21 and one end 20a of the first insertion guide projection 20 are an example of a removal restriction means 7, which will be described later, that restricts the covering cylindrical body 4 inserted into the flow passage 1 from moving away from the flow passage 1 beyond a certain level, and form one engaged portion 7B of the engaging means.

As shown in Figures 1 to 3, the covering cylinder 4 consists of a metal covering cylinder portion 4A with excellent corrosion resistance formed in a cylindrical shape with an outer diameter smaller than the inner diameter of the flow path 1, and a flange portion 4B integrally formed at one end of the covering cylinder portion 4A in a state capable of abutting the opening peripheral portion of the flow path 1 on the outer surface Wa of the concrete wall W from the flow path axial direction.
As shown in Figures 1 and 2, the cylindrical length L1 from the tip of the outer peripheral surface 4a of the covering cylinder 4 to the flange portion 4B is configured to be the same as the axial length L2 of the flow path 1, and annular seal members (O-rings, etc.) 6a and 6b, which are components of the sealing means 6 and seal the annular space between the inner peripheral surface 1a of the flow path 1 and the outer peripheral surface 4a of the covering cylinder 4, are provided at two locations in the axial direction of the flow path on the outer peripheral surface 4a of the covering cylinder 4.

As shown in Figure 7, the installation distance L3 between the two sealing materials 6a, 6b in the flow path axial direction is set to be greater than the set sealing area L4 including the reinforcing bar 19 in the concrete wall W in the flow path axial direction. Therefore, as shown in Figure 8, even if the covering cylinder 4 moves to the detachment side within the flexibility range of the detachment prevention means 7 due to water pressure (fluid pressure), at least the set sealing area L4 on the inner surface 1a of the flow path 1 can be reliably maintained sealed.

3 and 5, the flange portion 4B of the covering cylinder 4 is formed with recesses 4b through which the first insertion guide projections 20 and the ribs 21 of the short tube 2 can pass from the flow path axial direction. An intermediate flange portion 4c of the flange portion 4B located between adjacent recesses 4b in the circumferential direction engages with an engaged portion 7B constituted by one end 21a of the ribs 21 and one end 20a of the first insertion guide projection 20 from the flow path axial direction, thereby forming the other engaging portion 7A of the engaging means that prevents the covering cylinder 4 inserted into the flow path 1 from moving out of the flow path beyond a certain point.
The engaging portion 7A and the engaged portion 7B of the engaging means are configured to be freely switched between a disengagement restriction state in which they engage in the flow path axial direction to prevent the covering cylinder 4 from moving away from the short pipe 2, and a disengaged state in which they allow the covering cylinder 4 to move through the short pipe 2 in the flow path axial direction, by rotating the covering cylinder 4 relative to the short pipe 2.

As shown in Figures 1 and 2, the insertion device 5 is composed of a cylinder attachment part 30 that holds the covering cylinder 4 in an exterior state so that it can be freely attached and detached, an insertion operation part 40 that inserts the cylinder attachment part 30 into the flow path 1 in the concrete wall W, and a work case 50 that can store the cylinder attachment part 30 together with the covering cylinder 4 and has a connecting flange 50A that is fixedly connected to the connecting flange 3B downstream of the gate valve 3 in a watertight manner with bolts 15 and nuts 16.

As shown in FIG. 2, the cylindrical body mounting portion 30 mainly comprises a mounting cylinder 31 having a diameter smaller than the inner diameter of the covering cylinder 4 and a length smaller than the length of the covering cylinder 4 in the flow path axial direction, and an extrusion member 32 that fits freely into the base end of the mounting cylinder 31 in the flow path axial direction.
The extrusion member 32 is provided with a pressing flange portion 32A that abuts against the flange portion 4B of the covering cylinder 4 from the flow path axial direction, and an engaging cylinder portion 32B that slidably engages with a small diameter portion 31a formed on the bottom plate 31A of the mounting cylinder 31.
An annular support protrusion 31B is integrally formed with the tip end portion of the outer peripheral surface of the mounting cylinder 31, which contacts and supports the tip end portion of the inner peripheral surface of the covering cylinder 4 from the radial direction, and an annular step surface of the small diameter portion 31a of the mounting cylinder 31 and the tip surface of the mating cylinder portion 32B of the extrusion member 32 are provided between the annular step surface of the small diameter portion 31a of the mounting cylinder 31 and the tip surface of the mating cylinder portion 32B of the extrusion member 32. The annular rubber elastic body 33 is elastically deformable and capable of expanding radially outwardly to support and press the base end portion of the inner peripheral surface of the covering cylinder 4 in a radially tensioned state.

When the expansion nut 44 of the insertion operation unit 40 is rotated toward the expansion side, the elastic body 33 is deformed by expanding radially outward as the mounting cylinder 31 and the extrusion member 32 move closer to each other, and is placed in a holding state in which it supports the base end portion of the inner surface of the covering cylinder 4 in a tensioned state. Conversely, when the expansion nut 44 of the insertion operation unit 40 is rotated toward the contraction side, the elastic body 33 contracts radially inward due to elastic restoring force as the mounting cylinder 31 and the extrusion member 32 move away from each other, and is placed in a holding release state in which it is smaller than the inner diameter of the covering cylinder 4.

1 and 2, the insertion operation unit 40 is configured as an inner/outer double shaft structure with an outer shaft 41 and an inner shaft 42 having a length capable of feeding the cylindrical body mounting unit 30 in the working case 50 into the flow path 1 in the concrete wall W via the insides of the gate valve 3 and the short pipe 2. The outer shaft 41 is supported through the bottom plate 50B of the working case 50 in a watertight manner so as to slide freely, and a first screw shaft portion 41a at the tip side of this outer shaft 41 is screwed and connected to the connecting cylindrical portion 32C of the extrusion member 32 of the cylindrical body mounting unit 30. On the other hand, a first screw shaft portion 42a at the tip side of the inner shaft 42 is screwed and connected to the bottom plate 31A of the mounting cylindrical body 31 of the cylindrical body mounting unit 30.
As shown in FIG. 2, an expansion nut 44 is screwed onto a second screw shaft portion 42b formed on the base end portion of the inner shaft 42, which is the operating side, and is capable of pressing an end face of the base end portion of the outer shaft 41 in the axial direction via a thrust bearing 43.
The outer shaft 41 is made up of a plurality of split outer shafts that can be jointed together, and the inner shaft 42 is also made up of a plurality of split inner shafts that can be jointed together.

As shown in Figures 1 and 3, a second insertion guide protrusion 51 is fixed to the inner circumferential surface of the lower half of the work case 50 at two circumferential locations, and is in sliding contact with the outer circumferential surface of the cylindrical cutter of the drilling device or the outer circumferential surface 4a of the covering cylinder 4, and is aligned along the flow path axis direction to guide the cylindrical cutter or covering cylinder 4 in a concentric or nearly concentric state with respect to the drilling center of the concrete wall W or the center of the flow path 1.

Next, a first embodiment of a method for covering a flow passage of a concrete structure using the covering cylinder 4 and the insertion device 5 and other devices constructed as described above will be described.
[1] Regarding the mounting process:
1 to 3 show a mounting process for mounting a covering cylinder 4 capable of covering the inner surface of a flow passage 1 to an insertion device 5 attached to the outer surface Wa of a concrete wall W in a state facing the flow passage 1 formed through the concrete wall W by a drilling device.
In this installation process, as shown in FIG. 1, the connecting flange 50A of the work case 50 of the insertion device 5, on which the covering cylindrical body 4 is attached, is fixedly connected in a watertight manner to the connecting flange 3B downstream of the gate valve 3, which is in a closed state with the drilling device removed.
2, the covering cylinder 4 is fitted over the mounting cylinder 31 of the cylinder mounting portion 30 of the insertion device 5 and the pusher member 32. In this fitted state, the flange portion 4B of the covering cylinder 4 abuts against the pressing flange portion 32A of the pusher member 32 from the axial direction of the flow passage.

Furthermore, in this mounting process, the expansion nut 44 of the insertion operation unit 40 is rotated to the expansion side, and the movement of the mounting cylinder 31 and the extrusion member 32 toward each other due to this rotation operation changes the elastic body 33 to a state in which it is bulged outward in the radial direction. Therefore, the base end side portion of the inner surface of the covering cylinder 4 is supported by the bulged elastic body 33 in a radially stretched state, and the tip side portion of the inner surface of the covering cylinder 4 is supported by the annular support protrusion 31B integrally formed with the tip side portion of the outer surface of the mounting cylinder 31 in the radial direction. This allows the covering cylinder 4 to be reliably and satisfactorily held in a specified mounting position at two points, the elastic body 33 and the annular support protrusion 31B.

1 and 2, annular seal members (O-rings or the like) 6a and 6b, which are components of the sealing means 6 and seal the annular space between the inner peripheral surface 1a of the flow passage 1 and the outer peripheral surface 4a of the covering cylinder 4, are provided at two locations in the axial direction of the flow passage on the outer peripheral surface 4a of the covering cylinder 4. The attachment interval L3 between these seal members 6a and 6b in the axial direction of the flow passage is set to be larger than a set sealing area L4 including a reinforcing bar area of the reinforcing bars 19 in the concrete wall W in the axial direction of the flow passage, as shown in Figs.
In addition, both sealing materials 6a, 6b of the covering cylinder 4 are in slidable contact with second insertion guide projections 51 fixed to two circumferential positions on the lower half of the inner surface of the work case 50 in the flow path axial direction.

The two second insertion guide protrusions 51 on the inner surface of the work case 50 and the two first insertion guide protrusions 20 fixed to two circumferential locations on the lower half of the inner surface of the short pipe 2 form two straight guide rails in the flow path axial direction.
Furthermore, as shown in Figures 1 and 3, the recesses 4b formed at four circumferential positions on the flange portion 4B of the covering cylindrical body 4 are arranged in the same phase facing the two second insertion guide protrusions 51 of the work case 50, the two first insertion guide protrusions 20 of the short tube 2, and the protrusions 21 fixed to the inner surface of the upper half of the short tube 2 at two circumferential positions in the flow path axis direction.
Therefore, as shown in Figure 3, the recess 4b of the flange portion 4B of the covering cylinder 4 is in a state in which it can move through and pass along both second insertion guide protrusions 51 of the work case 50 and both first insertion guide protrusions 20 and protrusions 21 of the short tube 2.

[2] Regarding the insertion process and the sealing process,
FIG. 4 shows an insertion process in which the covering cylinder 4 of the insertion device 5 is inserted into the flow path 1 of the concrete wall W under an uninterrupted water supply state, and a sealing process in which the set sealing area L4 between the outer peripheral surface 4a of the inserted covering cylinder 4 and the inner peripheral surface 1a of the flow path 1 is sealed with a sealing means 6.
In the insertion process, the valve body 3C of the gate valve 3 is opened, and the insertion operation part 40 of the insertion device 5 is pushed in. During this pushing operation, the two seal materials 6a, 6b on the outer circumferential surface 4a side of the covering cylindrical body 4 attached to the cylindrical body attachment part 30 of the insertion device 5 are guided in sliding contact with the two second insertion guide projections 51 of the working case 50 and the two first insertion guide projections 20 and the ridges 21 of the short pipe 2.

As shown in FIG. 4, the maximum insertion state is when the flange portion 4B of the covering cylinder 4 abuts against the periphery of the opening of the flow passage 1 on the outer surface Wa of the concrete wall W in the flow passage axial direction. As the covering cylinder 4 is inserted into the flow passage 1, the two seal materials 6a, 6b on the outer surface 4a of the covering cylinder 4 enter the flow passage 1 while being compressed to a smaller diameter by abutting against the inner surface 1a of the flow passage 1. Therefore, the two seal materials 6a, 6b on the outer surface 4a of the covering cylinder 4 are pressed against the inner surface 1a of the flow passage 1 and are sealed, and this sealed state is maintained.

[3] Regarding the removal control process,
4 and 5 show a detachment restricting step in which the detachment movement of the covering cylindrical body 4 inserted into the flow passage 1 is restricted by the detachment restricting means 7. FIG.
The separation prevention means 7 in this separation prevention step is composed of two components. One of the components is composed of both seal materials 6a, 6b of the sealing means 6. In this case, the frictional resistance of both seal materials 6a, 6b pressed between the outer circumferential surface 4a of the covering cylinder 4 and the inner circumferential surface 1a of the flow path 1 can suppress the separation movement of the covering cylinder 4 from the set insertion area.

Another component of the separation restriction means 7 is composed of an engagement means having an engagement portion 7A provided on the covering cylinder 4 and an engaged portion 7B provided on the inner circumferential surface of the short pipe 2. The engagement portion 7A and the engaged portion 7B of the engagement means are configured to be freely switched, by rotating the covering cylinder 4 relative to the short pipe 2, between a separation restriction state in which they engage in the flow path axial direction to restrict separation movement of the covering cylinder 4, and a disengaged state in which relative movement in the flow path axial direction is permitted.
In this embodiment, the engaging portion 7A is configured by an intermediate flange portion 4c located between adjacent recesses 4b in the circumferential direction of the flange portion 4B of the covering cylindrical body 4. On the other hand, the engaged portion 7B is configured by one end 21a of the protrusion 21 and one end 20a of the first insertion guide projection 20.

As described in the above insertion process, when inserting the covering cylinder 4 into the flow path 1 by the insertion device 5, the relative positions of the short tube 2 and the covering cylinder 4 in the rotation direction are set to a disengaged state as shown in FIG. 3. In other words, by setting the intermediate flange portion 4c of the flange portion 4B constituting the engaging portion 7A on the covering cylinder 4 side to a disengaged state in the flow path axial direction, which is not engaged with one end 21a of the protrusion 21 constituting the engaged portion 7B on the short tube 2 side and one end 20a of the first insertion guide protrusion 20, the covering cylinder 4 can be inserted into the flow path 1 reliably and smoothly without being hindered by the engaged portion 7B of the short tube 2.

Then, in the separation prevention process, as shown in Figure 5, when the engaging portion 7A on the covering cylinder 4 side passes through the engaged portion 7B on the short pipe 2 side and is inserted into the flow path 1, in other words, when the flange portion 4B of the covering cylinder 4 abuts against the opening peripheral portion of the flow path 1 on the outer surface Wa of the concrete wall W from the flow path axial direction, the insertion operating portion 40 of the insertion device 5 is rotated to change the relative position in the rotational direction between the short pipe 2 and the covering cylinder 4 from the disengaged state to the separation prevention state.
Therefore, as shown in Figure 8, even if the covering cylinder 4 inserted into the flow path 1 moves out of the flow path due to water pressure (fluid pressure), the intermediate flange portion 4c of the flange portion 4B that constitutes the engaging portion 7A on the covering cylinder 4 side engages with one end portion 21a of the protrusion 21 that constitutes the engaged portion 7B on the short tube 2 side and one end portion 20a of the first insertion guide protrusion 20 in the flow path axial direction, thereby reliably preventing the covering cylinder 4 from moving out of the flow path.

As shown in FIG. 7, the installation distance L3 between the two sealing materials 6a, 6b in the axial direction of the flow channel is set to be greater than the set sealing area L4 including the reinforcing bar area of the reinforcing bars 19 in the concrete wall W in the axial direction of the flow channel. Therefore, as shown in FIG. 8, even if the covering cylinder 4 moves to the detachment side within the flexibility range of the detachment prevention means 7 due to water pressure (fluid pressure), at least the set sealing area L4 on the inner surface 1a of the flow channel 1 can be reliably maintained sealed.

[4] Regarding the removal process:
FIG. 6 shows a removal step for removing the insertion device 5 .
4, in the removal process, the expansion nut 44 of the insertion operation unit 40 is rotated back to the contracting side after the removal restriction process in which the covering cylinder 4 is inserted and held in a sealed state in the flow passage 1 of the concrete wall W. This rotation back operation causes the elastic body 33 to contract radially inward due to elastic restoring force as the mounting cylinder 31 and the pusher member 32 move away from each other, and the elastic body 33 enters a hold-release state in which the elastic body 33 is smaller than the inner diameter of the covering cylinder 4.
Therefore, even if the insertion operation portion 40 of the insertion device 5 is pulled out, the covering cylinder 4 remains inserted and held in the flow path 1 of the concrete wall W, and only the cylinder mounting portion 30 of the insertion device 5 is pulled out from the covering cylinder 4.

Then, as shown in FIG. 6, when the tube mounting portion 30 of the insertion device 5 is moved back into the work case 50, the valve body 3C of the gate valve 3 is closed, and the work case 50 of the insertion device 5 is removed from the connecting flange 3B downstream of the gate valve 3.

Second Embodiment
9 to 12 show a second embodiment of the method for covering a flow passage of a concrete structure.
In the flow path covering treatment method of this second embodiment, after carrying out the mounting process, insertion process, sealing process, removal prevention process, and removal processes of the first embodiment described above, a flow path blocking process is carried out in which a flow path blocking position on the upstream side within the covering cylinder 4 is temporarily watertightly sealed with a flow path blocking jig 60, a filler injection process is carried out in which cement milk 76, an example of a solidifying filler, is injected with a filling device 70 into the sealed area between the outer surface 4a of the covering cylinder 4 sealed with both sealing materials 6a, 6b of the sealing means 6 and the inner surface 1a of the flow path 1, and a jig removal process is carried out in which the flow path blocking jig 60 is removed.

As shown in FIG. 9 , the flow path blocking jig 60 is detachably attached to the tip of the insertion operating portion 40 of the insertion device 5. When inserting the flow path blocking jig 60 into the covering cylinder 4 attached to the flow path 1 of the concrete wall W, the insertion operating portion 40 of the insertion device 5 is pushed into the work case 50.
The flow path blocking jig 60 is composed of a first pressure plate 60A that is detachably connected to the tip of the outer shaft 41, a second pressure plate 60B that is detachably connected to the tip of the inner shaft 42, and a rubber flow path blocking body 60C that elastically bulges and deforms radially outward as the first pressure plate 60A moves closer to the second pressure plate 60B, thereby blocking the flow path 1.

As shown in FIG. 11, the filling device 70 is composed of a pressure delivery unit 71 that pressure-feeds cement milk 76, which is a mixture of cement-based materials and water, an inlet 73 on the lower side of the covering cylinder 4 to which a hose 72 of the pressure delivery unit 71 is connected, an outlet 74 on the upper side of the covering cylinder 4 from which the cement milk 76 that fills the sealed area flows out, and a plug 75 that closes the inlet 73 and outlet 74 in a sealed state after the cement milk 76 is filled.

As shown in FIG. 11, the covering cylinder 4 has annular seals 6a and 6b, which are components of the sealing means 6, at two locations on its outer circumferential surface 4a in the axial direction of the flow path and seal at least the set sealing area L4 in the annular space between the inner circumferential surface 1a of the flow path 1 and the outer circumferential surface 4a of the covering cylinder 4, and an inlet 73 and an outlet 74 are formed between the seals 6a and 6b in the covering cylinder portion 4A.

Next, a flow passage blocking step and a filler injection step of the flow passage covering method according to the second embodiment using the flow passage blocking jig 60 and the filling device 70 configured as described above will be described.
[5] Regarding the flow path blocking step,
As shown in Figure 9, the connecting flange 50A of the work case 50, to which the flow path blocking jig 60 and the insertion operation unit 40 are attached, is fixedly connected in a watertight manner to the connecting flange 3B downstream of the gate valve 3 in a closed state.

10, the valve body 3C of the gate valve 3 is opened, and the insertion operation unit 40 is pushed in to send the flow path blocking jig 60 to the flow path blocking position in the covering cylinder 4. When the expansion nut 44 of the insertion operation unit 40 is rotated to the expansion side in this state, the rubber flow path blocking body 60C is elastically expanded and deformed radially outward as the first pressing plate 60A moves closer to the second pressing plate 60B, and the entire circumference of the flow path blocking body 60C is changed to a flow path blocking state in which it is pressed against the entire circumference of the inner circumferential surface of the covering cylinder 4 in a watertight manner.
An upstream sealing material 6a is placed at a portion of the covering cylinder 4 corresponding to the flow path blocking position of the flow path blocking jig 60, and this upstream sealing material 6a can firmly support the flow path blocking portion of the covering cylinder 4, where the entire circumference of the flow path blocking body 60C is pressed in a watertight state, from the outside in the diameter direction.

When the flow path 1 is blocked within the covering cylinder 4, as shown in FIG. 11, the outer shaft 41 and inner shaft 42 of the insertion operation part 40 are separated from the first pressure plate 60A and second pressure plate 60B of the flow path blocking jig 60, and the insertion operation part 40 is removed toward the work case 50 while the flow path blocking jig 60 in the flow path blocking state is left in the flow path blocking position within the covering cylinder 4. After that, the valve body 3C of the gate valve 3 is closed, and the work case 50 is removed from the connecting flange 3B downstream of the gate valve 3.

[6] Regarding the filler injection process,
As shown in Fig. 11, a hose 72 of a pumping unit 71 for pumping cement milk 76 is connected to an inlet 73 on the lower side of the covering cylinder 4, and the cement milk 76 is filled into the sealed area between the outer peripheral surface 4a of the covering cylinder 4 and the inner peripheral surface 1a of the flow path 1, which are sealed by both sealing materials 6a, 6b of the sealing means 6. The outflow of cement milk 76 from the outlet 74 on the upper side of the covering cylinder 4 is visually confirmed, and if there is any outflow of cement milk 76, it is determined that the sealed area is filled with cement milk 76, and the pumping of the cement milk 76 by the pumping unit 71 is stopped. Thereafter, as shown in Fig. 12, the inlet 73 and outlet 74 of the covering cylinder 4 are closed with plugs 75.

Then, as the cement milk 76 filled in the sealed area solidifies, the inner surface 1a of the flow path 1 in the concrete wall W and the outer surface 4a of the covering cylinder 4 are integrally fixed together via the cement milk 76.
Therefore, in the second embodiment of the flow path covering treatment method, the sealing means 6 for sealing at least the set sealing area L4 between the outer peripheral surface 4a of the covering cylinder 4 and the inner peripheral surface 1a of the flow path 1 is composed of two sealing materials 6a, 6b arranged in a pressed state between the outer peripheral surface 4a of the covering cylinder 4 and the inner peripheral surface 1a of the flow path 1, and cement milk 76, which is an example of a filler material injected into the sealing area sealed by the two sealing materials 6a, 6b.

Furthermore, in the flow passage covering method of the second embodiment, the separation prevention means 7 in the separation prevention step is composed of three components. The first component is composed of both seal materials 6a and 6b of the sealing means 6.
The second component is made up of cement milk 76, which is an example of a filler that is filled into the sealed area.
The third component is composed of an engagement means having an engagement portion 7A provided on the covering cylinder 4 and an engaged portion 7B provided on the inner circumferential surface of the short pipe 2. The engagement portion 7A and the engaged portion 7B of the engagement means are configured to be freely switched, by rotating the covering cylinder 4 relative to the short pipe 2, between a disengagement restricting state in which they engage in the flow path axial direction to restrict disengagement of the covering cylinder 4, and a disengaged state in which relative movement in the flow path axial direction is permitted.
This allows the sealing area between the outer surface 4a of the covering cylinder 4 and the inner surface 1a of the flow path 1 to be sealed more appropriately, and at the same time, the removal prevention means 7 can be configured to be more advantageous in terms of structure and cost by the multiple sealing materials 6a, 6b of the sealing means 6, cement milk 76 which is an example of a filler, the intermediate flange portion 4c between the recesses 4b in the flange portion 4B of the covering cylinder 4 which constitutes the engaging portion 7A of the engaging means, one end 21a of the protrusion 21 which constitutes the engaged portion 7B of the engaging means, and one end 20a of the first insertion guide protrusion 20.

[7] Regarding the jig removal process:
The connecting flange 50A of the working case 50 to which the insertion operation part 40 is attached is fixedly connected in a watertight manner to the connecting flange 3B downstream of the gate valve 3 in a closed state. Next, the valve body 3C of the gate valve 3 is opened, and the insertion operation part 40 attached to the working case 50 is pushed into the flow path blocking jig 60 that blocks the flow path blocking position in the covering cylinder 4, and the outer shaft 41 and the inner shaft 42 of this insertion operation part 40 are connected to the first pressing plate 60A and the second pressing plate 60B of the flow path blocking jig 60 (see FIG. 10 ).

Then, when the expansion nut 44 of the insertion operating unit 40 is rotated toward the reduced diameter side, as the first pressure plate 60A moves away from the second pressure plate 60B, the flow path blocking body 60C is contracted and deformed radially inward by the elastic restoring force, and the flow path blocking body 60C is changed to an unblocked state in which it is separated from the inner surface of the covering cylinder 4.
In this state, the insertion operating portion 40 of the insertion device 5 is pulled out, and the flow path blocking jig 60, which is in the unblocked state, is moved back into the work case 50 (see Figure 9), and then the valve body 3C of the gate valve 3 is closed, and the work case 50 is removed from the connecting flange 3B downstream of the gate valve 3.

The rest of the configuration is the same as that described in the first embodiment, so the same components are given the same numbers as in the first embodiment and the description is omitted.

Third Embodiment
13 shows a third embodiment of the covering cylinder 4 used in the flow passage covering method for a concrete structure. In this third embodiment, the cylinder length L1 from the tip of the outer circumferential surface 4a of the covering cylinder 4 to the flange portion 4B is configured to be longer than the axial length L2 of the flow passage 1 formed through the concrete wall W.
As shown in the upper half cross-sectional view of Figure 13, when the flange portion 4B of the covering cylinder 4 abuts against the opening peripheral portion of the flow passage 1 on the outer surface Wa of the concrete wall W from the flow passage axial direction, the tip of the covering cylinder 4 protrudes from the inner surface Wb of the concrete wall W.
Furthermore, as shown in the lower half cross-sectional view of Figure 13, when the intermediate flange portion 4c between the recesses 4b in the flange portion 4B of the covering cylinder 4 that constitutes the engaging portion 7A abuts against one end 21a of the protrusion 21 and one end 20a of the first insertion guide projection 20 that constitute the engaged portion 7B, the tip of the covering cylinder 4 is positioned flush or approximately flush with the inner surface Wb of the concrete wall W.
Therefore, even if the covering cylindrical body 4 inserted into the flow passage 1 moves slightly toward the removal side due to water pressure, the set sealing area L4 of the inner circumferential surface 1a of the flow passage 1 can be reliably maintained sealed.

The rest of the configuration is the same as that described in the first embodiment, so the same components are given the same numbers as in the first embodiment and the description is omitted.

Other embodiments
(1) In the first embodiment described above, the detachment restriction means 7 for restricting the detachment movement of the covering cylinder 4 inserted into the flow path 1 is configured by a combination of the seal materials 6a and 6b of the sealing means 6 and the engaging portion 7A and the engaging portion 7B of the engaging means. Also, in the second embodiment described above, the detachment restriction means 7 is configured by a combination of the seal materials 6a and 6b of the sealing means 6, cement milk 76 which is an example of a filler, and the engaging portion 7A and the engaged portion 7B of the engaging means. However, the present invention is not limited to this configuration, and for example, when the water pressure acting on the covering cylinder 4 is small, the detachment restriction means 7 may be configured by only the seal materials 6a and 6b of the sealing means 6.
Furthermore, the length from the tip of the outer peripheral surface 4a of the covering cylinder 4 to the flange portion 4B may be made longer than the axial length of the flow path 1 formed through the concrete wall W, and the tip of the covering cylinder 4 protruding from the inner surface Wb of the concrete wall W may be expanded and deformed to a state that prevents it from coming off, whereby the expanded tip of the covering cylinder 4 may constitute the above-mentioned detachment prevention means 7.

(2) In the second embodiment described above, cement milk 76 is used as an example of the filler, but the filler may be a resin-based adhesive or a foaming resin that foams after filling.

(3) In each of the above-described embodiments, a pair of seal materials 6a, 6b are provided in a pressure-welded state between the outer circumferential surface 4a of the covering cylinder 4 and the inner circumferential surface 1a of the flow path 1. However, when the flange portion 4B of the covering cylinder 4 is in close contact with the opening periphery of the flow path 1 on the outer surface Wa of the concrete wall W, one seal material 6a may be disposed between the outer circumferential surface 4a of the covering cylinder 4 and the inner circumferential surface 1a of the flow path 1. Of course, three or more seal materials may be disposed between the outer circumferential surface 4a of the covering cylinder 4 and the inner circumferential surface 1a of the flow path 1.

(4) In each of the above-described embodiments, the engaged portion 7B of the engaging means is composed of the first insertion guide protrusions 20 fixed to two circumferential positions on the lower half of the inner surface of the short tube 2 and the short ridges 21 fixed to two circumferential positions on the upper half of the inner surface of the short tube 2, but the engaged portion 7B may be composed of either the first insertion guide protrusions 20 or the short ridges 21.

(5) In the above embodiment, the separation prevention means 7 is configured by at least one of the position holding means such as the seal materials 6a and 6b that hold the position of the covering cylinder 4 inserted into the flow path 1 of the concrete wall W, the fixing means such as the cement milk 76 that fixes the covering cylinder 4 inserted into the flow path 1 to the concrete wall W, and the engaging means that engages and prevents the covering cylinder 4 inserted into the flow path 1 from moving away from the flow path 1 beyond a certain level, but is not limited to this configuration. For example, a dedicated fixing means such as the solidifying filler 76 or a bolt that fixes the covering cylinder 4 inserted into the flow path 1 to the concrete wall W may be provided, and the separation prevention means 7 may be configured to specialize in the function of holding the position of the covering cylinder 4 until the covering cylinder 4 is fixed to the concrete wall W by the fixing means or engaging and preventing the covering cylinder 4 from moving away from the flow path 1 beyond a certain level.
As one example, the sealing means 6 is composed of a plurality of sealing materials 6a, 6b that are arranged in a pressed state between the outer peripheral surface 4a of the covering cylinder 4 and the inner peripheral surface 1a of the flow path 1 as the covering cylinder 4 is inserted in the insertion process, and a solidifiable filler 76 that is injected into the sealed area between the outer peripheral surface 4a of the covering cylinder 4 sealed with the sealing materials 6a, 6b and the inner peripheral surface 1a of the flow path 1, and the separation prevention means 7 is composed of an engagement means that engages with the covering cylinder 4 inserted into the flow path 1 in the axial direction of the flow path to prevent the covering cylinder 4 from moving away from the flow path beyond a certain extent.

REFERENCE SIGNS LIST 1 flow path 1a inner peripheral surface 2 short pipe 2A connecting flange 3 gate valve 4 covering cylinder 4B flange portion 4a outer peripheral surface 5 insertion device 6 sealing means 6a sealing material 6b sealing material 7 removal restriction means 7A engaging portion 7B engaged portion 10 bolt 13 elastic sealing material 20 insertion guide projection (first insertion guide projection)
76 Filler (cement milk)
L1: Cylinder length L2: Axial length of flow passage 1 L3: Installation interval L4: Set sealing area W: Structure (concrete wall)
Wa Outer surface

Claims (3)

A short pipe installation method for installing a connecting flange of a short pipe into which a cylindrical cutter of a drilling device can be inserted, on an outer surface of a concrete structure and on a peripheral edge of an opening of a flow path formed through the structure, comprising:
a flange abutment portion at the periphery of the opening of the flow path on the outer surface of the structure where the connecting flange of the short pipe abuts from the axial direction of the flow path is smoothed, an annular elastic seal material is fitted into a seal mounting groove formed on the abutment surface of the connecting flange of the short pipe, and the connecting flange of the short pipe is fixed to the flange abutment portion of the structure with an anchor bolt, thereby watertightly sealing the gap between the flange abutment portion of the structure and the connecting flange of the short pipe with the elastic seal material,
A short pipe installation method in which the opening edge of a flow path formed through the structure is positioned radially inward of the inner diameter of the connecting flange of the short pipe, and the smoothing treatment layer is set in a range extending radially outward from the opening edge of the flow path , which is positioned radially inward of the inner diameter of the connecting flange, to the outer diameter of the connecting flange. The short pipe installation method according to claim 1, in which the smoothing layer is formed by polishing, filling with putty, and adjusting the base material. The short pipe installation method according to claim 1 or 2, in which the anchor bolts are fixed with adhesive to bolt installation holes drilled at the flange fixing portions of the smoothed smoothing layer.

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