JP6812045B1 - How to repair the manhole pipe connection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a repair method for efficiently stopping repair work of a pipe connection portion of a manhole by stopping the groundwater contained in the ground outside the pipe attachment portion of the manhole by a simple method. SOLUTION: An injection hole 32 leading to the ground 100 outside the manhole 10 is locally formed from the inside of the manhole 10 to the outer peripheral portion of the existing pipe 14 in the pipe connecting portion 12 by using a drilling machine. Next, the injection tool 44 is inserted into the injection hole 32, the water blocking agent is injected from the injection tool 44 into the ground, and the water blocking agent is solidified around the existing pipe 14 to stop water. After that, the outer peripheral portion of the existing pipe 14 in the pipe connecting portion 12 is removed. [Selection diagram] Fig. 4

Description

The present disclosure relates to a method of repairing a pipe connection portion of a manhole.

Existing pipes forming underground pipelines such as sewers are connected to the peripheral walls of manholes provided at a predetermined distance. Since the manhole and the existing pipe are rigidly joined with concrete, they behave differently when an earthquake occurs. As a result, when bending displacement or extraction displacement occurs between the manhole and the existing pipe, cracks occur at the joint between the two, and in some cases, they are destroyed. If this happens, the function of the underground pipeline cannot be maintained.

Therefore, a method for improving seismic resistance has been proposed for the pipe connection portion to which the existing pipe is connected in the peripheral wall of the manhole. For example, in the repair method of Patent Document 1, a penetrating portion is formed by removing the outer peripheral portion of the existing pipe at the pipe connecting portion from the inside of the manhole, and a flexible water blocking member is embedded in the penetrating portion to stop water. By connecting the manhole and the existing pipe using a member, the pipe connection portion is prevented from being destroyed.

Japanese Unexamined Patent Publication No. 2003-74078

By the way, since the groundwater level is high depending on the place where the manhole is provided, the groundwater may also exist in the ground outside the existing pipe. In this case, since earth and sand tend to flow in the ground containing groundwater, if the above-mentioned repair method is performed on the pipe connection part of the manhole, when a penetration part is formed on the peripheral wall of the manhole, the groundwater penetrates together with the earth and sand. There is a risk of a large amount of water flowing into the manhole through the manhole. When a large amount of groundwater and earth and sand flow into the manhole, it becomes difficult to repair the pipe connection.

Therefore, it is necessary to investigate the groundwater level outside the manhole in advance. When the water level is high, an injection hole is formed on the paved road surface around the opening of the manhole before the penetration portion is formed on the peripheral wall of the manhole, and a liquid water blocking agent for solidifying the earth and sand from the injection hole. It is conceivable that the groundwater around the pipe connection part of the manhole is solidified together with earth and sand to stop the water by injecting.

However, when water is stopped around the pipe connection of the manhole in this way, if a buried pipe of another company is installed around the manhole, the buried pipe will be used when forming an injection hole on the paved road surface. May damage. After digging up the ground around the manhole and grasping the position of the buried pipe around the manhole, if the dug up ground is to be backfilled, the repair work of the pipe connection part of the manhole will be large-scale and the construction period will be prolonged. Will be invited.

The object of the present disclosure is to stop the groundwater contained in the ground around the pipe connection portion of the manhole by a simple method, and to improve the efficiency of the repair work of the pipe connection portion of the manhole.

The technique of the present disclosure is intended for a method of repairing a pipe connection portion to which an existing pipe buried in the ground is connected to the peripheral wall of a manhole.

The first aspect of the present disclosure is a first step of locally forming an injection hole leading to the ground outside the manhole from the inside of the manhole to the outer peripheral portion of the existing pipe at the pipe connection portion by using a drilling machine, and injection. The second step and the second step of inserting the injection tool into the hole, injecting a liquid water stop agent into the ground from the injection tool, and solidifying the water stop agent around the existing pipe are performed. This is a method for repairing a manhole pipe connection portion, which includes a third step of removing the outer peripheral portion of the existing pipe at the pipe connection portion. Then, in the first step, the injection hole is formed at a position where the distance from the existing pipe is 200 mm or more and 350 mm or less.

According to this first aspect, an injection hole is formed from the inside of the manhole to the outer peripheral portion of the existing pipe at the pipe connection portion, but since the injection hole is locally formed, even if the groundwater level outside the manhole is high, It is possible to limit the amount of groundwater and earth and sand that flow into the manhole through the injection hole. Then, before removing the outer peripheral portion of the existing pipe at the pipe connection portion, the water blocking agent is injected into the ground from the injection tool inserted into the injection hole to solidify the water blocking agent around the existing pipe to stop the water. , It is possible to prevent a large amount of groundwater and earth and sand from flowing into the manhole when the outer peripheral portion of the existing pipe at the pipe connection portion is removed.

According to this first aspect, since the injection hole is formed at a position where the distance from the existing pipe is 200 mm or more, the existing pipe can be prevented from being damaged by the formation of the injection hole by the drilling machine. Further, since the injection hole is formed at a position where the distance from the existing pipe is 350 mm or less, the water blocking agent injected through the injection hole is suitably wrapped around the existing pipe in the ground around the pipe connection portion to be installed. It can be infiltrated all around the tube.

The second aspect of the present disclosure is the method of repairing the pipe connection portion of the manhole of the first aspect, in the first step, at least one outer peripheral portion on the left half of the existing pipe and one outer peripheral portion on the right half of the existing pipe. This is a method of repairing a manhole pipe connection that forms an injection hole.

According to this second aspect, since injection holes are formed in the outer peripheral portion of the left half of the existing pipe and the outer peripheral portion of the right half of the existing pipe, each injection hole is used to stop water on the ground outside the pipe connection portion. By injecting the agent, it is possible to prevent the permeation of the water blocking agent from being biased to the ground on one side in the left-right direction of the existing pipe. As a result, the groundwater contained in the ground around the pipe connection can be solidified together with the earth and sand on both the left and right sides of the existing pipe.

The third aspect of the present disclosure, the repair method of the pipe connection between Nhoru the first or second aspect, in the first step, the injection hole is formed below and 40mm or more in diameter 30 mm, the tube connection portion of the manhole It is a repair method of.

According to this third aspect, since the injection hole is formed to have a diameter of 30 mm or more, a required amount of water blocking agent can be injected into the ground through the injection hole in a relatively short time. Further, since the injection hole is formed to have a diameter of 40 mm or less, the amount of groundwater and earth and sand flowing into the manhole through the injection hole can be suitably limited.

A fourth aspect of the present disclosure is a method for repairing a pipe connection portion of a manhole according to any one of the first to third aspects, in which a main agent solution and a curing agent solution are mixed as a water blocking agent in the second step. This is a method of repairing a manhole pipe connection using a two-component curing type water blocking agent. In the second step, as an injection tool, an injection tool having a merging head for merging the main agent liquid and the curing agent liquid and an injection nozzle for discharging a water blocking agent composed of the main agent liquid and the curing agent liquid merging at the merging head. Is used. Then, in the second step, the injection nozzle is inserted into the injection hole, the main agent solution and the curing agent solution are mixed by a 1.5 shot method, and the water blocking agent is injected into the ground.

According to this fourth aspect, by using an injection tool having a merging head and an injection nozzle, the injection nozzle is inserted into the injection hole, and the main agent liquid and the curing agent liquid are merged by the merging head, so that both liquids are combined into 1 Since the water blocking agent mixed by the 5. shot method is injected into the ground, a two-component curing type water blocking agent that cures in a relatively short time can be used. This is advantageous for streamlining the repair work of the pipe connection part of the manhole.

A fifth aspect of the present disclosure is a first step of locally forming an injection hole leading to the ground outside the manhole from the inside of the manhole to the outer peripheral portion of the existing pipe at the pipe connection portion by using a drilling machine, and injection. The second step and the second step of inserting the injection tool into the hole, injecting a liquid water stop agent into the ground from the injection tool, and solidifying the water stop agent around the existing pipe are performed. This is a method for repairing a manhole pipe connection portion, which includes a third step of removing the outer peripheral portion of the existing pipe at the pipe connection portion. In the second step, a two-component curing type water blocking agent obtained by mixing a main agent solution and a curing agent solution is used as the water blocking agent. In the second step, the injection tool has a merging head for merging the main agent liquid and the curing agent liquid, and an injection nozzle for discharging a water blocking agent composed of the main agent liquid and the curing agent liquid merging at the merging head. An injection tool is used in which the nozzle is provided with a plug portion having a tapered shape in which the tapered side faces the discharge port side of the water blocking agent . Then, mixing in a second step, Rutotomoni is inserted an injection nozzle into the injection hole, the tapered surface of the plug portion is brought into contact with the periphery of the opening of the injection hole, and a main agent solution and the curing agent solution with 1.5 shot method Then inject a water blocking agent into the ground .

According to this fifth aspect, when the injection nozzle is inserted into the injection hole, the tapered surface of the plug portion is brought into contact with the peripheral edge of the opening of the injection hole, so that the plug portion of the injection nozzle can close the injection hole. As a result, it is possible to suppress or prevent the water blocking agent injected into the ground from the injection nozzle from flowing into the manhole through the injection port together with the groundwater and earth and sand. As a result, the water blocking agent injected into the ground can be suitably permeated into a predetermined range around the existing pipe. This is advantageous for streamlining the repair work of the pipe connection part of the manhole.

A sixth aspect of the present disclosure is the injection method in which the pipe connection portion of the manhole of the fifth aspect is repaired. In the second step, the injection tool is composed of a tubular accessory whose plug portion is inserted into the injection nozzle. This is a method of repairing a manhole pipe connection using a tool. The attachment has a variable fixed position with respect to the injection nozzle.

According to this sixth aspect, since the plug portion of the injection nozzle is composed of the accessory and the fixing position of the accessory to the injection nozzle is variable, the injection of the injection nozzle is performed by changing the fixing position of the accessory to the injection nozzle. The length inserted into the hole can be changed according to the thickness of the peripheral wall of the manhole. As a result, the injection nozzle can reach the ground around the existing pipe even when the peripheral wall of the manhole is relatively thick. Further, even when the peripheral wall of the manhole is relatively thin, the plug portion can suppress or prevent the inflow of groundwater and earth and sand into the manhole through the injection hole.

According to the technique of the present disclosure, the groundwater contained in the ground around the pipe connection portion of the manhole can be stopped by a simple method, and the repair work of the pipe connection portion of the manhole can be made more efficient.

FIG. 1 is a cross-sectional view schematically showing the configuration of a pipe connection portion of a manhole in the embodiment. FIG. 2 is a cross-sectional view showing a state of the first step in the method of repairing the pipe connection portion of the manhole in the embodiment. FIG. 3 is a cross-sectional view showing the peripheral wall of the manhole in which the injection hole was formed in the first step in the method of repairing the pipe connection portion of the manhole in the embodiment. FIG. 4 is a cross-sectional view showing a state of the second step in the method of repairing the pipe connection portion of the manhole in the embodiment. FIG. 5 is a plan view showing a main part of the injection tool used in the second step in the method of repairing the pipe connection portion of the manhole in the embodiment. FIG. 6 is a cross-sectional view showing a range in which the ground is improved in the second step in the method of repairing the pipe connection portion of the manhole in the embodiment. FIG. 7 is a cross-sectional view showing a range in which the ground is improved in the second step in the method of repairing the pipe connection portion of the manhole in the embodiment. FIG. 8 is a cross-sectional view showing a state in which a water blocking agent is injected into the ground around the pipe connection portion in the second step of the method for repairing the pipe connection portion of the manhole in the embodiment. FIG. 9 is a cross-sectional view showing a state in which the outer peripheral portion of the pipe connecting portion is removed in the third step of the method for repairing the pipe connecting portion of the manhole in the embodiment. FIG. 10 is a plan view showing a main part of the injection device used in the second step in the method of repairing the pipe connection portion of the manhole in the modified example of the embodiment. FIG. 11 is a cross-sectional view of an accessory of the injection device used in the second step in the method of repairing the pipe connection portion of the manhole in the modified example of the embodiment. FIG. 12 is a cross-sectional view showing a state in which a water blocking agent is injected into the ground around the pipe connection portion in the second step of the method for repairing the pipe connection portion of the manhole in the modified example of the embodiment. FIG. 13 is a cross-sectional view showing the peripheral wall of the manhole in which the injection hole was formed in the first step in the method of repairing the pipe connection portion of the manhole in another embodiment.

Hereinafter, exemplary embodiments will be described in detail with reference to the drawings.

<< Embodiment >>
In this embodiment, the method of repairing the pipe connection portion of the manhole according to the technique of the present disclosure will be described by exemplifying the repair method for making the pipe connection portion of the manhole earthquake-resistant.

-Manhole pipe connection-
The repair method of this example targets the pipe connection portion 12 of a general manhole 10 as shown in FIG. Since the water level GL of the groundwater is high depending on the place where the manhole 10 is provided, the groundwater may also exist in the ground 100 outside the existing pipe 14.

The pipe connecting portion 12 of the manhole 10 is a portion of the manhole 10 to which the existing pipe 14 buried in the ground is connected. The manhole 10 is a hole through which a person can enter and exit, which is used for inspection and management of an underground pipeline formed by an existing pipe 14. For example, the manhole 10 is provided for applications such as sewer pipes, water pipes for digestion, and gas pipes. The manhole 10 is opened in a pavement plate 16 made of asphalt or the like provided on the roadbed. The opening of the manhole 10 is closed with an iron lid 18 so as to be openable and closable.

The manhole 10 is a so-called assembled manhole, and is constructed by stacking cylindrical precast concrete blocks 20. For example, the manhole 10 includes a skeleton block 20a and a slanted wall block 20b provided on the skeleton block 20a as the precast concrete block 20. The manhole 10 may further include a straight wall block provided between the skeleton block 20a and the slanted wall block 20b, or may include an annular adjusting ring provided on the slanted wall block 20b.

The skeleton block 20a is provided on the concrete bottom plate block 22. An invert block 24 made of concrete, mortar, or the like is provided on the bottom plate block 22 in the skeleton block 20a. The invert 26 is formed in the invert block 24 with both ends open to the outer peripheral side. Connection holes 30 are formed in the portions of the peripheral wall 28 of the manhole 10 corresponding to both open ends of the invert 26.

The end of the existing pipe 14 is inserted into each connection hole 30. The end of the existing pipe 14 is fixed to the manhole 10 by being wound with a filler such as concrete in the gap in the connection hole 30 of the skeleton block 20a. As described above, in the pipe connecting portion 12 of the manhole 10, the existing pipe 14 is rigidly joined to the peripheral wall 28. The existing pipe 14 is a pipe body made of concrete such as a Hume pipe.

-How to repair the pipe connection of the manhole-
The method of repairing the pipe connecting portion 12 of the manhole 10 is a water stopping method in which the groundwater contained in the ground 100 outside the manhole 10 is solidified together with earth and sand and then repaired. The method of repairing the pipe connecting portion 12 of the manhole 10 includes a first step, a second step, and a third step.

<First step>
In the first step, the injection hole 32 is formed in the peripheral wall 28 of the manhole 10. The injection hole 32 is a hole that penetrates the peripheral wall 28 for injecting a liquid water blocking agent into the ground 100 outside the manhole 10.

Specifically, the lid 19 of the iron lid 18 is lifted to open the manhole 10, and as shown in FIG. 2, the worker WK enters the manhole 10, and the pipe connection portion 12 of the manhole 10 is connected from the inside of the manhole 10. An injection hole 32 leading to the ground 100 outside the manhole 10 is locally formed in the outer peripheral portion of the existing pipe 14 by using a drilling machine 34. As the drilling machine 34, an electric drilling tool such as a diamond core drill or a rotary hammer drill is preferably used.

In the first step, a plurality of injection holes 32 are formed at intervals in the circumferential direction of the pipe connecting portion 14. The plurality of injection holes 32 are preferably formed separately in the outer peripheral portion of the left half of the existing pipe 14 and the outer peripheral portion of the right half of the existing pipe 14. As shown in FIG. 3, in this example, a portion of the outer peripheral portion of the left half of the existing pipe 14 located above the invert block 24 and a portion of the outer peripheral portion of the right half of the existing pipe 14 above the invert block 24. Injection holes 32 are formed one by one at the locations located on the upper side.

The formation position of the injection hole 32 is based on the ease of penetration of the water blocking agent into the ground 100, the time required to distribute the water blocking agent to the required range Rg of the ground 100, and the number of injection holes 32 required. Is set. In this example, the position where the two injection holes 32 are formed is set at an angle a (10 ° or more and 130 ° or less) on the upper side of the virtual line L1 connecting the center of each injection hole 32 and the center C of the existing pipe 14. In the illustrated example, the angle is 120 °), and the positions are symmetrical with respect to the vertical line L2 passing through the center C of the existing pipe 14.

Here, if the distance d between each injection hole 32 and the existing pipe 14 is less than 150 mm, the position of the injection hole 32 and the position of the existing pipe 14 are relatively close to each other. Therefore, when the injection hole 32 is formed, the drilling machine 34 If the posture is shaken, the existing pipe 14 may be damaged. Further, when the distance d between each injection hole 32 and the existing pipe 14 exceeds 350 mm, the water blocking agent injected through the injection hole 32 is discharged around the existing pipe 14 in the ground 100 around the pipe connection portion 14 during the gel time. It becomes difficult to get around. For this reason, the number of injection holes 32 required for the water blocking agent to permeate the entire circumference of the existing pipe 14 in the ground 100 outside the pipe connecting portion 12 is relatively large. In that case, it takes time and effort to form the injection hole 32, and the total amount of groundwater and earth and sand flowing into the manhole 100 through the injection hole 32 increases, which may hinder the second step to be performed later.

For these reasons, in the first step, each injection hole 32 is formed at a position where the distance d from the existing pipe 14 is 150 mm or more and 350 mm or less. For the reasons described above, the formation position of each injection hole 32 is preferably a position where the distance d from the existing pipe 14 is 200 mm or more and 300 mm or less. The distance d of each injection hole 32 from the existing pipe 14 may be set shorter as the inner diameter of the existing pipe 14 is smaller and longer as the inner diameter of the existing pipe 14 is larger.

The diameter of each injection hole 32 is set based on the ease of injecting the water blocking agent into the ground 100 and the amount of groundwater or earth and sand flowing into the manhole 10 from the individual injection holes 32.

If the diameter of each injection hole 32 is less than 30 mm, the time required to inject the required amount of water blocking agent into the ground 100 through the injection hole 32 becomes relatively long. Therefore, it takes time to stop the water in the repair work of the pipe connecting portion 12 of the manhole 10. Further, when the diameter of each injection hole 32 exceeds 40 mm, the amount of groundwater and earth and sand flowing into the manhole 10 through the individual injection holes 32 becomes relatively large. If there is a lot of groundwater or earth and sand flowing into the manhole 10, it is difficult to repair the pipe connection portion 12.

For these reasons, in the first step, each injection hole 32 is formed to have a diameter of 30 mm or more and 40 mm or less. As a specific method, for example, each injection hole 32 is formed by using an electric drilling tool to which a drill bit having a diameter of 32 mm is attached.

After forming each injection hole 32, it is confirmed that the injection hole 32 penetrates depending on whether or not the state of the ground 100 can be seen through the injection hole 32. At this time, if there is an outflow of groundwater or earth and sand from the injection hole 32, it is confirmed that the injection hole 32 has penetrated. When the amount of groundwater or earth and sand flowing from the injection hole 32 into the manhole 10 is large, the injection hole 32 is temporarily cured with a stopper such as a cork.

<Second step>
The second step is performed after the first step. As shown in FIG. 4, in the second step, a liquid water blocking agent is injected into the ground 100 using each injection hole 32 formed in the peripheral wall 28 of the manhole 10.

As the water blocking agent, a two-component curing type water blocking agent obtained by mixing a main agent solution and a curing agent solution is used. The water blocking agent of this example is a water blocking agent for improving the geology of a water glass system. The main agent solution used for the water blocking agent is a sol solution in which sodium silicate (sodium silicate) as the main agent and water are mixed. The curing agent solution used for the water blocking agent is a solution in which an alkaline inorganic agent as a curing agent and water are mixed. The gel time of the water blocking agent is, for example, 5 seconds or more and 15 seconds or less.

The injection device 36 is used for injecting the water blocking agent into the ground 100. The injection device 36 includes a stirring mixer 38, an injection pump 39, a generator 40, and an injection tool 44. The stirring mixer 38 stirs and mixes sodium silicate and water, and a curing agent and water in separate tanks to generate a main agent solution and a curing agent solution separately and independently. The injection pump 39 sends the main agent solution and the curing agent solution generated by the stirring mixer 38 to the injection tool 44 using separate hoses 46. The generator 40 is a power supply device that supplies electric power to the stirring mixer 38 and the injection pump 39.

As the injection tool 44, a metal machine tool made of a Y-shaped tube component shown in FIG. 5 is used. The injection tool 44 has a merging head 48 and an injection nozzle 50. The merging head 48 is composed of two inflow pipes 52, a merging pipe 54 connecting the ends of the two inflow pipes 52, and an outflow pipe 56 extending from the central portion of the merging pipe 54. .. Each inflow pipe portion 52 has an inflow port 58 on the side opposite to the confluence pipe portion 54. A hose 46 for transferring the main agent liquid is connected to one of the inflow ports 58. A hose 46 for transferring the curing agent liquid is connected to the other inflow port 58.

Each inflow pipe portion 52 is provided with an on-off valve 62 with a handle 60. The on-off valve 62 is opened and closed by operating the handle 60. The amount of the solution flowing through the inflow pipe portion 52 per unit time can be changed according to the opening degree of the on-off valve 62. The injection tool 44 merges the main agent liquid and the curing agent liquid flowing into the different inflow pipe portions 52 at the merging pipe portion 54. The outflow pipe portion 56 has an outflow port 64 on the side opposite to the confluence pipe portion 54. The water blocking agent formed by mixing the main agent liquid and the curing agent liquid merged at the merging pipe portion 54 flows out from the outflow port 64 through the outflow pipe portion 56.

The injection nozzle 50 is made of a straight tube. The base end portion of the injection nozzle 50 is connected to the outlet 64 of the outflow pipe portion 56. The tip of the injection nozzle 50 has a sharpened shape as if the pipe body is cut in an oblique direction, and has a discharge port 51 for discharging a water blocking agent. The water blocking agent flowing out from the outlet 64 of the merging head 48 is discharged from the discharge port 51 of the injection nozzle 50.

The worker WK carries the injection tool 44 into the manhole 10 and inserts the injection nozzle 50 into the injection hole 32 in the horizontal direction. Then, by operating both handles 60, the main agent solution and the curing agent solution are mixed by a 1.5 shot method, and the water blocking agent is injected from the injection nozzle 50 into the ground 100 outside the manhole 10. As shown in FIGS. 6 and 7, the required range Rg of the ground 100 for spreading the water blocking agent is, for example, a vertical width H of 1100 mm or more and 1400 mm or less, and a horizontal width W of 1100 mm or more in the left-right direction centering on the existing pipe 14. Moreover, the range is 1400 mm or less, and the depth width D is 400 mm or more and 600 mm or less.

The injection amount of the water blocking agent for each injection hole 32 is set so that the water blocking agent is distributed over the required range Rg of the ground 100 outside the pipe connecting portion 12. Specifically, the injection amount of the water blocking agent is based on the following formula, where the injection amount of the water blocking agent is Q (kl), the amount of soil to be injected is V (m3), and the injection rate is λ. Set.

Q = V × λ
Here, the injection rate λ is obtained by the product (λ = n × α) of these gap rates n and the filling rate α, where n is the gap rate of the ground 100 and α is the filling rate. The injection rate λ may be set based on the N value of the target ground 100. Further, the amount of soil V to be injected is set based on the volume of the required range Rg of the ground 100 in which the water blocking agent is distributed.

For example, since it is assumed that the ground 100 around the manhole 10 is backfilled with sandy soil, the pore space n is considered to be 45% and the filling factor is considered to be 90%, so the injection rate λ is 40.5. Set to%. When the vertical width H is 1250 mm, the horizontal width W is 1250 mm, and the depth width D is 500 mm, the amount of soil to be injected V is set to 0.781 m3 with respect to the required range Rg of the ground 100 for spreading the water blocking agent. In this case, the injection amount Q of the water blocking agent is 0.316 kl according to the above formula, so it is set to approximately 320 liters. When there are two injection holes 32 as in this example, the injection amount of the water blocking agent for each injection hole 32 is set to 160 liters.

As shown in FIG. 8, when the water level GL of the groundwater outside the manhole 10 is high, when the water blocking agent is injected into the ground 100 outside the manhole 10 by using the injection tool 44, the groundwater forms the injection hole 32 together with the earth and sand. It flows into the manhole 10 through it, but since the injection hole 32 is local, the amount of groundwater and earth and sand flowing into the manhole 10 is limited. In the second step, in order to further reduce the amount of groundwater and earth and sand flowing into the manhole 10, a cloth is wrapped around the injection nozzle 50, and when the injection nozzle 50 is inserted into the injection hole 32, the cloth is inserted into the injection hole 32. It may be closed by addressing the opening.

When a curing agent is added, sodium silicate, which is the main agent of a water blocking agent, undergoes a chemical reaction such as dehydration and polymerization, and silicic acid (SiO2) gels, that is, colloidal particles lose their fluidity due to interaction. And solidify. The gelled silicic acid has adhesiveness, solidifies the ground 100, and exhibits water stopping property on the ground 100. When the water blocking agent is injected into the ground 100, it permeates from the injection site to the periphery of the existing pipe 14 and solidifies in a predetermined time according to the gel time. As a result, the groundwater contained in the ground 100 outside the pipe connecting portion 12 of the manhole 10 is stopped.

<Third step>
The third step is performed after the second step. As shown in FIG. 9, in the third step, a portion of the invert block 24 corresponding to the pipe connecting portion 12 is excavated and dug down, and a cutting device 66 is used to dig into the existing pipe 14 in the pipe connecting portion 12 of the manhole 10. Remove the outer peripheral part. The cutting device 66 is carried into the manhole 10 and supported by the horizontal frame 68 being stretched against the peripheral wall 28 of the manhole 10 by the extension force of the hydraulic cylinder 70.

The cutting device 66 includes a rotary drive unit 72 guided by a horizontal frame 68. A cutting blade unit 74 is attached to the rotary drive unit 72. The cutting blade unit 74 has a ring-shaped cutting blade 76 and is rotated by a hydraulic motor (not shown). The cutting device 66 moves the rotary drive unit 72 in the extending direction of the existing pipe 14 by the hydraulic cylinder 78, and presses the rotary drive unit 72 against the pipe connection portion 12 of the manhole 10 while rotating the cutting blade 76 to make the pipe connection portion 12 annular. The ground 100 outside the pipe connection portion 12 is excavated by cutting and drilling.

Next, the excavated portion of the ground 100 is filled with a filler such as mortar, and a flexible water blocking member is inserted into the perforated portion 80 of the peripheral wall 28 of the manhole 10. The water blocking member is made of a rubber material such as styrene-butadiene rubber (SBR), ethylene propylene diene rubber (EPDM), nitrile rubber (NBR), or natural rubber. The water blocking member may be made of a synthetic resin or an elastomer. After that, the perforated portion 80 of the peripheral wall 28 of the manhole 10 is filled with a filler, and the water blocking member is fixed to the pipe mounting portion 12.

As described above, the pipe connection portion 12 of the manhole 10 can be repaired.

-Features of the embodiment-
According to the method of repairing the pipe connecting portion 12 of the manhole 10 in this embodiment, the injection hole 32 is formed from the inside of the manhole 10 to the outer peripheral portion of the existing pipe 14 in the pipe connecting portion 12, but the injection hole 32 is locally formed. Therefore, even if the groundwater level outside the manhole 10 is high, the amount of groundwater and earth and sand flowing into the manhole 10 through the injection hole 32 can be limited. Then, before removing the outer peripheral portion of the existing pipe 14 in the pipe connecting portion 12, the water blocking agent is injected into the ground 100 from the injection tool 44 inserted into the injection hole 32 to solidify the water blocking agent around the existing pipe 14. As a result, water is stopped, so that it is possible to prevent a large amount of groundwater or earth and sand from flowing into the manhole 10 when the outer peripheral portion of the existing pipe 14 at the pipe connecting portion 12 is removed.

According to the method of repairing the pipe connecting portion 12 of the manhole 10 in this embodiment, injection holes 32 are formed in the outer peripheral portion of the left half of the existing pipe 14 and the outer peripheral portion of the right half of the existing pipe 14, respectively, and each injection hole 32 is formed. Since the water blocking agent is injected into the ground 100 outside the pipe connecting portion 12, it is possible to prevent the water blocking agent from being unevenly permeated into the ground 100 on one side in the left-right direction of the existing pipe 12. As a result, the groundwater contained in the ground 100 around the pipe connecting portion 12 can be solidified together with the earth and sand on both the left and right sides of the existing pipe 14.

According to the method of repairing the pipe connecting portion 12 of the manhole 10 in this embodiment, the injection hole 32 is formed at a position where the distance d from the existing pipe 14 is 150 mm or more, so that the injection hole 32 is formed by the drilling machine 34. The existing pipe 14 can be prevented from being damaged. Further, since the injection hole 32 is formed at a position where the distance d from the existing pipe 14 is 350 mm or less, the water blocking agent injected through the injection hole 32 is applied around the existing pipe 14 in the ground 100 around the pipe connection portion 12. It is possible to wrap around the existing pipe 14 and permeate it over the entire circumference of the existing pipe 14.

According to the method of repairing the pipe connecting portion 12 of the manhole 10 in this embodiment, since the injection hole 32 is formed to have a diameter of 30 mm or more, a required amount of water blocking agent can be injected into the ground 100 through the injection hole 32 in a relatively short time. .. Further, since the injection hole 32 is formed to have a diameter of 40 mm or less, the amount of groundwater and earth and sand flowing into the manhole 10 through the injection hole 32 can be suitably limited.

According to the method of repairing the pipe connection portion 12 of the manhole 10 in this embodiment, an injection tool 44 having a merging head 48 and an injection nozzle 50 is used to insert the injection nozzle 50 into the injection hole 32, and the main agent liquid and the curing agent liquid are inserted. By merging the two liquids with the merging head 50, a water blocking agent formed by mixing both liquids in a 1.5 shot method is injected into the ground 100, so that the two-component curing type water stopping is cured in a relatively short time. Agents can be used. This is advantageous for improving the efficiency of the repair work of the pipe connecting portion 12 of the manhole 10.

<< Modification example >>
In the method of repairing the pipe connecting portion 12 of the manhole 10 in this modification, the configuration of the injection tool 44 used in the second step is different. As shown in FIG. 10, in the injection tool 44 of this modified example, the injection nozzle 50 is provided with a plug portion 82 having a tapered shape. The tapered side of the plug portion 82 faces the discharge port 51 side of the injection nozzle 50. In this example, the plug portion 82 is composed of a tubular accessory 84 inserted through the injection nozzle 50.

As shown in FIG. 11, the accessory 84 is a metal machine, and is composed of an insertion portion 86 having a tapered outer peripheral surface and a straight pipe portion 88 having the same outer peripheral surface. The straight pipe portion 88 is formed with a pair of mounting holes 90 at portions facing each other. An enamel set (potato screw) 92 is attached to each mounting hole 90. The accessory 84 is fixed to the injection nozzle 50 by tightening each enamel set 92, and can slide in the longitudinal direction with respect to the injection nozzle 50 by loosening each enamel set 92. As described above, the attachment 84 has a variable fixed position with respect to the injection nozzle 50.

In the second step, the accessory 84 is fixed to the injection nozzle 50 at a position where the injection nozzle 50 can be inserted into the injection hole 32 to reach the ground 100 according to the thickness of the peripheral wall 28 of the manhole 10. To do. Then, as shown in FIG. 12, when the injection nozzle 50 equipped with the accessory 84 is inserted into the injection hole 32, the insertion portion 86 of the accessory 84 is driven into the injection hole 32, and the injection nozzle 50 is inserted into the injection hole 32. The tapered surface 86a of the insertion portion 86 is brought into contact with the opening peripheral edge of the injection hole 32 to close the injection hole 32. By doing so, groundwater and earth and sand are suppressed or prevented from flowing into the manhole 10 through the injection port 32.

-Characteristics of the modified example-
According to the method of repairing the pipe connecting portion 12 of the manhole 10 in this modification, when the injection nozzle 50 is inserted into the injection hole 32, the tapered surface 86a of the plug portion 82 is brought into contact with the opening peripheral edge of the injection hole 32. Since the injection hole 32 is closed by the plug portion 82 of the injection nozzle 50, it is possible to suppress or prevent the water blocking agent injected from the injection nozzle 50 into the ground 100 from flowing into the manhole 10 together with the groundwater and earth and sand through the injection hole 32. .. As a result, the water blocking agent injected into the ground 100 can be suitably permeated into a predetermined range around the existing pipe 14. This is advantageous for improving the efficiency of the repair work of the pipe connecting portion 12 of the manhole 10.

According to the method of repairing the pipe connecting portion 12 of the manhole 10 in this modification, the plug portion 82 of the injection nozzle 50 is composed of the accessory 84, and the fixed position of the accessory 84 with respect to the injection nozzle 50 is variable. By changing the fixing position of the accessory 84 with respect to 50, the length inserted into the injection hole 32 of the injection nozzle 50 can be changed according to the thickness of the peripheral wall 28 of the manhole 10. As a result, the injection nozzle 50 can reach the ground 100 around the existing pipe 14 even when the peripheral wall 28 of the manhole 10 is relatively thick. Further, even when the peripheral wall 28 of the manhole 100 is relatively thin, the plug portion 82 can suppress or prevent groundwater and earth and sand from flowing into the manhole 10 through the injection hole 32.

<< Other Embodiments >>
In the above embodiment, in the first step, two injection holes 32 are formed, but the present invention is not limited to this. In the first step, only one injection hole 32 may be formed, or three or more injection holes 32 may be formed. For example, when the inner diameter of the existing pipe 14 is relatively small, such as 250 mm or less, in the first step, only one injection hole 32 is formed in the outer peripheral portion of the pipe connecting portion 12 of the manhole 10 directly above the existing pipe 14. You may. Further, when the inner diameter of the existing pipe 14 is relatively large, such as 500 mm or more, in the first step, as shown in FIG. 13, the injection hole 32 is formed in the outer peripheral portion of the left half of the existing pipe 14 and the existing pipe 14. It may be formed on the outer peripheral portion of the right half and the outer peripheral portion on the center C of the existing pipe 14, respectively.

In the above embodiment, in the first step, the two injection holes 32 are each formed in the upper half portion located above the invert block 24, but the present invention is not limited to this. For example, when the existing pipe 14 is connected to the peripheral wall 28 of the manhole 10 at a position spaced upward from the invert block 24, the injection holes 32 are placed on both the left and right sides so as to sandwich the center C of the existing pipe 14. It may be formed on the outer peripheral portion.

In the above embodiment, in the second step, a Y-shaped device is used as the injection tool 44, and the main agent solution and the curing agent solution are mixed by a 1.5 shot method and injected into the ground 100, but the present invention is limited to this. Absent. For example, in the second step, an apparatus having a double pipe structure may be used as the injection tool 44, and the main agent solution and the curing agent solution may be mixed in a two-shot method and injected into the ground 100.

In the above embodiment, the water blocking agent used in the second step is a water glass-based water blocking agent using sodium silicate as a main agent, and the gel time of the water blocking agent is 5 seconds or more and 15 seconds or less. This has been illustrated, but it is not limited to this. In the second step, a water blocking agent having a gel time of several tens of seconds may be used, and an arbitrary water blocking agent having a gel time set according to the permeation rate of the water blocking agent into the ground 100 can be used. ..

As described above, a preferred embodiment has been described as an example of the technique of the present disclosure. However, the technique of the present disclosure is not limited to this, and can be applied to embodiments in which changes, replacements, additions, omissions, etc. are made as appropriate. In addition, the components described in the attached drawings and the detailed description may include components that are not essential for solving the problem. Therefore, it should not be immediately determined that those non-essential components are essential by the fact that those non-essential components are described in the accompanying drawings and detailed description.

As described above, the technique of the present disclosure is useful for a method of repairing a pipe connection portion of a manhole.

GL Groundwater level WK Worker 10 Manhole 12 Pipe connection 14 Existing pipe 16 Paved plate 18 Iron lid 19 Lid 20 Precast concrete block 20a Skeleton block 20b Slope block 22 Bottom plate block 24 Invert block 26 Invert 28 Peripheral wall Injection hole 34 Drilling machine 38 Stirring mixer 39 Injection pump 40 Generator 44 Injection tool 46 Hose 48 Confluence head 50 Infusion nozzle 51 Discharge port 52 Inflow pipe part 54 Confluence pipe part 56 Outflow pipe part 58 Inflow port 60 Handle 62 Switching valve 64 Flow Outlet 66 Cutting device 68 Horizontal frame 70 Hydraulic cylinder 72 Rotating drive part 74 Cutting blade unit 76 Cutting blade 78 Hydraulic cylinder 80 Perforated part 82 Plug part 84 Accessories 86 Insertion part 86a Tapered surface 88 Straight pipe part 90 Mounting hole 92 Hollow set 100 ground

Claims (6)

It is a method of repairing the pipe connection part to which the existing pipe buried in the ground is connected to the peripheral wall of the manhole.
The first step of locally forming an injection hole leading to the ground outside the manhole from the inside of the manhole to the outer peripheral portion of the existing pipe at the pipe connection portion by using a drilling machine.
A second step of inserting an injection tool into the injection hole, injecting a liquid water blocking agent from the injection tool into the ground, and solidifying the water blocking agent around the existing pipe to stop water.
After the second step, seen including a third step of removing the outer peripheral portion of said existing pipe in the pipe connecting portion,
In the first step, a method for repairing a pipe connection portion of a manhole, characterized in that the injection hole is formed at a position where the distance from the existing pipe is 200 mm or more and 350 mm or less . In the method for repairing a manhole pipe connection according to claim 1,
In the first step, a method for repairing a pipe connection portion of a manhole, which comprises forming at least one injection hole on the outer peripheral portion of the left half of the existing pipe and one on the outer peripheral portion of the right half of the existing pipe. .. In the method for repairing a manhole pipe connection according to claim 1 or 2 .
In the first step, a method for repairing a pipe connection portion of a manhole, characterized in that the injection hole is formed to have a diameter of 30 mm or more and 40 mm or less. In the method for repairing a manhole pipe connection according to any one of claims 1 to 3 ,
In the second step,
As the water blocking agent, a two-component curing type water blocking agent obtained by mixing a main agent solution and a curing agent solution is used.
As the injection tool, an injection having a merging head for merging the main agent liquid and the curing agent liquid, and an injection nozzle for discharging the water blocking agent composed of the main agent liquid and the curing agent liquid merging at the merging head. Using the ingredients
Wherein the injection nozzle is inserted into the injection hole, the tube connecting the manhole to feature in that the main agent solution and said curing agent solution was mixed with 1.5 shot method injecting the water stop agent into the ground How to repair the department. It is a method of repairing the pipe connection part to which the existing pipe buried in the ground is connected to the peripheral wall of the manhole.
The first step of locally forming an injection hole leading to the ground outside the manhole from the inside of the manhole to the outer peripheral portion of the existing pipe at the pipe connection portion by using a drilling machine.
A second step of inserting an injection tool into the injection hole, injecting a liquid water blocking agent from the injection tool into the ground, and solidifying the water blocking agent around the existing pipe to stop water.
After performing the second step, the third step of removing the outer peripheral portion of the existing pipe at the pipe connecting portion is included.
In the second step,
As the water blocking agent, a two-component curing type water blocking agent obtained by mixing a main agent solution and a curing agent solution is used.
The injection tool includes a merging head that merges the main agent liquid and the curing agent liquid, and an injection nozzle that discharges the water blocking agent composed of the main agent liquid and the curing agent liquid that merge at the merging head. , Using an injection tool provided with a plug portion having a tapered side facing the discharge port side of the water blocking agent in the injection nozzle.
Wherein the injection nozzle is inserted into the injection hole Rutotomoni, wherein the tapered surface of the plug portion is brought into contact with the periphery of the opening of the injection hole, and mixing the curing agent solution with the base material liquid at 1.5 shot method A method for repairing a pipe connection portion of a manhole, which comprises injecting the water blocking agent into the ground . In the method for repairing a manhole pipe connection according to claim 5 ,
In the second step, as the injection tool, an injection tool having the plug portion inserted into the injection nozzle is used.
The accessory is a method for repairing a pipe connection portion of a manhole, characterized in that the fixed position with respect to the injection nozzle is variable.

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