JP2024056308A - Earthquake-resistant structure of pipelines - Google Patents

Abstract

An earthquake-resistant structure capable of improving the earthquake resistance of a pipeline is provided.
[Solution] An earthquake-resistant structure 10 for a pipeline 1 connected to a manhole, comprising a concave guide groove 20 formed circumferentially on the inner surface of the pipeline 1 and formed so that at least a portion of it is discontinuous in the circumferential direction, a flexible water-stopping body 31 covering the guide groove 20 from the inside of the pipeline 1, and an expansion section 32 that expands the water-stopping body 31 from the inside of the pipeline 1 and presses it against the inner surface of the pipeline 1.
[Selected figure] Figure 2

Description

The present invention relates to technology for earthquake-resistant structures of pipelines connected to manholes.

Technology for earthquake-resistant structures of pipelines connected to manholes has been publicly known. For example, see Patent Document 1.

The technology described in Patent Document 1 improves the earthquake resistance of the joint between the manhole and the sewer main pipe by attaching an earthquake-resistant joint to the base (joint) of the sewer main pipe that is joined to the side wall of the manhole.

However, when an earthquake or other disaster occurs, damage (such as cracks) can occur not only at the joint between the manhole and the sewer main pipe, but also in the middle of the pipe, such as the sewer main pipe, which can lead to water leakage from the pipe or soil intrusion into the pipe. Therefore, technology that can improve the earthquake resistance of pipes is desired.

JP 2011-241617 A

One aspect of the present disclosure has been made in consideration of the above-mentioned circumstances, and the problem it aims to solve is to provide an earthquake-resistant structure that can improve the earthquake resistance of pipelines.

The problem that one aspect of this disclosure aims to solve is as described above, and the means for solving this problem will be described next.

In one aspect of the present disclosure, the earthquake-resistant structure for a pipeline connected to a manhole includes a concave damage inducement portion formed along the circumferential direction on the inner surface of the pipeline and formed so that at least a portion of the concave damage inducement portion is discontinuous in the circumferential direction, a flexible covering member that covers the damage inducement portion from the inside of the pipeline, and an expansion member that expands the covering member from the inside of the pipeline and presses it against the inner surface of the pipeline.

In one aspect of the present disclosure, the breakage inducer includes a plurality of recesses formed in a circumferential arrangement on the inner surface of the pipeline.

In one aspect of the present disclosure, the breakage inducer includes a pair of recesses formed on either side of the center of the pipe cross section.

In one aspect of the present disclosure, the breakage inducer includes a pair of recesses formed above and below the center of the pipe cross section.

In one aspect of the present disclosure, the pair of recesses are formed asymmetrically with respect to the center of the pipe cross section.

In one aspect of the present disclosure, the circumferential length of the lower recess of the pair of recesses is longer than the circumferential length of the upper recess.

In one aspect of the present disclosure, the breakage inducer includes a recess formed on the inner circumferential surface of the pipeline so as to extend circumferentially around at least half of the inner circumferential surface.

In one aspect of the present disclosure, the earthquake-resistant structure further includes a lining material provided on the inner peripheral surface of the pipeline, and the damage inducer is formed to penetrate the lining material.

According to one aspect of the present disclosure, it is possible to improve the earthquake resistance of pipelines.

1 is a side cross-sectional view showing a pipeline and a manhole to which an earthquake-resistant structure according to one embodiment of the present invention is applied. FIG. 2 is an enlarged view of part A in FIG. FIG. FIG. 4 is a front cross-sectional view showing guide grooves according to the first pattern. 13A is a front cross-sectional view showing the guide groove according to the second pattern, and FIG. 13B is a front cross-sectional view showing the guide groove according to the third pattern. 13A is a front cross-sectional view showing a guide groove according to a fourth pattern, and FIG. 13B is a front cross-sectional view showing a guide groove according to a fifth pattern. 13A is a front cross-sectional view showing a guide groove according to a sixth pattern, and FIG. 13B is a front cross-sectional view showing an example of a guide groove in a pipeline provided with a lining material.

In the following explanation, the directions indicated by arrows U, D, F, B, L, and R in the figure are defined as upward, downward, forward, backward, leftward, and rightward, respectively.

The following describes the earthquake-resistant structure 10 of the pipeline 1 according to one embodiment of the present invention.

The earthquake-resistant structure 10 shown in FIG. 1 induces damage to the pipeline 1 connected to the manhole 2 at a midpoint, and prevents water leakage from the damaged portion. In this embodiment, the pipeline 1 is assumed to be a pipe made of reinforced concrete. The earthquake-resistant structure 10 mainly comprises an induction groove 20 and a water stop section 30.

The guide groove 20 shown in FIG. 2 is for guiding breakage when a load is applied to the pipeline 1 due to an earthquake or the like. The guide groove 20 is formed in a concave shape on the inner peripheral surface of the pipeline 1. The guide groove 20 is formed along the circumferential direction of the inner peripheral surface of the pipeline 1. The guide groove 20 is formed in the middle of the pipeline 1 (more specifically, in the vicinity of the manhole 2). The guide groove 20 can be formed by processing the inner peripheral surface of the pipeline 1 using an appropriate tool. By forming the guide groove 20 in the pipeline 1, the strength of the pipeline 1 can be locally reduced. An example of a specific shape of the guide groove 20 will be described later.

The water stop section 30 shown in Figures 1 to 3 is for stopping water in the pipeline 1 where damage such as cracks has occurred in the guide groove 20. Specifically, the water stop section 30 can prevent water leakage from the pipeline 1 and the intrusion of water and soil into the pipeline 1 from the outside. The water stop section 30 mainly comprises a water stop body 31 and an expansion section 32.

The water stop body 31 is a member that is arranged so as to be in contact with the inner peripheral surface of the pipeline 1. The water stop body 31 is formed of an elastic body (rubber, etc.). The water stop body 31 is formed in a circular ring shape. The outer diameter of the water stop body 31 is formed so as to be approximately the same as the inner diameter of the pipeline 1. The water stop body 31 is arranged so as to cover the guide groove 20 formed in the pipeline 1 from the inside of the pipeline 1.

The expansion section 32 is a member for pressing the water stopper 31 against the inner surface of the pipeline 1. The expansion section 32 is formed in an annular shape. The expansion section 32 is formed by combining multiple divisions 32a (four in the illustrated example) that are divided in the circumferential direction. The diameter of the expansion section 32 can be changed (e.g., expanded) by moving adjacent divisions 32a relative to each other in the circumferential direction. In addition, the expansion section 32 can be maintained at any diameter by fixing adjacent divisions 32a together.

Two expansion sections 32 are provided for one water stop body 31. The expansion sections 32 are arranged at positions sandwiching the guide groove 20 (on both sides of the guide groove 20) in the direction in which the pipeline 1 extends (longitudinal direction). The expansion sections 32 are arranged so as to be in contact with the inner surface of the water stop body 31. The expansion sections 32 are held in a state in which their diameter is expanded so as to press the water stop body 31 against the inner surface of the pipeline 1.

The earthquake-resistant structure 10 configured in this manner can prevent water leakage from the pipeline 1 if the pipeline 1 is damaged by an earthquake or other event.

Specifically, when a load is applied to the pipeline 1 due to an earthquake or the like, damage such as cracks occurs in the portion where the guide groove 20, which has a lower strength than other portions, is formed. In other words, damage can be intentionally caused in the guide groove 20. Since the guide groove 20 is covered by the water stop body 31, even if a crack or the like occurs in the guide groove 20, the water stop body 31 can prevent water leakage, etc.

The following describes a method for forming (constructing) the above-mentioned earthquake-resistant structure 10 on a pipeline 1 (existing pipe) installed underground.

First, a process of forming the guide groove 20 on the inner circumferential surface of the pipeline 1 (guide groove forming process) is performed. At this time, the inner circumferential surface of the pipeline 1 is processed using a tool corresponding to the shape of the guide groove 20, such as a cutter or a drill. It is desirable that the guide groove 20 is formed in the pipeline 1 near the manhole 2.

The guide groove 20 may be filled with a filler (e.g., rubber, synthetic resin, etc.) to fill the internal space of the guide groove 20.

Next, a process of providing the water stop portion 30 in the pipeline 1 (water stop portion installation process) is performed. At this time, the water stop body 31 is first provided so as to cover from the inside the guide groove 20 formed on the inner surface of the pipeline 1. Next, two expansion portions 32 are provided inside the water stop body 31. The expansion portions 32 are expanded using an appropriate tool, and the water stop body 31 is expanded from the inside and pressed against the inner surface of the pipeline 1. In this state, the expansion portions 32 are fixed.

In this way, an earthquake-resistant structure 10 is formed inside the pipeline 1. Note that, in this embodiment, an example of forming an earthquake-resistant structure 10 on an existing pipe is described, but the present invention is not limited to this, and it is also possible to apply the structure to a newly installed pipeline 1 (newly constructed pipe).

The following describes the shape of the guide groove 20 formed in the pipeline 1.

The guide groove 20 according to this embodiment is formed in a concave shape along the circumferential direction. The guide groove 20 according to this embodiment is also formed in a concave shape that is at least partially discontinuous in the circumferential direction so that damage does not occur even in unintended situations (for example, when a small load is applied). By forming the guide groove 20 so that it is partially discontinuous in this manner, it is possible to ensure a certain degree of strength for the pipeline 1. Below, multiple patterns of the shape of the guide groove 20 as described above will be described.

The guide groove 20 according to the first pattern shown in FIG. 4 includes a plurality of recesses 21 formed at equal intervals along the circumferential direction of the inner peripheral surface of the pipeline 1. The recesses 21 are round holes (holes having a circular cross section) formed to an appropriate depth on the inner peripheral surface of the pipeline 1. The recesses 21 can be formed, for example, by drilling or core punching. In this way, the recesses 21 can be formed relatively easily.

In the illustrated example, twelve recesses 21 are formed around the circumferential direction of the pipeline 1, but the number of recesses 21 is not limited to this and can be changed as desired depending on the strength required for the pipeline 1.

In addition, while the illustrated example shows the recesses 21 formed at equal intervals on the inner peripheral surface of the pipeline 1, the intervals between the recesses 21 do not necessarily have to be equal. For example, by forming the recesses 21 at unequal intervals, it is possible to form a pipeline 1 that is easily damaged by a load in a specific direction (in other words, strong against loads in other directions).

The shape of the recesses 21 (inner diameter, depth, etc.) can be changed as desired. The shapes of the multiple recesses 21 do not necessarily have to be the same, and they can be formed into different shapes.

The guide groove 20 according to the second pattern shown in FIG. 5(a) includes a plurality of recesses 22 formed at equal intervals along the circumferential direction of the inner circumferential surface of the pipeline 1. The recesses 22 are formed in an arc shape in a cross section perpendicular to the longitudinal direction of the pipeline 1 (front cross section). The recesses 22 are formed to an appropriate depth on the inner circumferential surface of the pipeline 1. The recesses 22 can be formed, for example, by cutting the inner circumferential surface of the pipeline 1 with a substantially circular cutter C having an outer diameter corresponding to the shape of the desired recesses 22. In this way, the recesses 22 can be formed relatively easily by using a cutter C having an outer diameter corresponding to the shape of the desired recesses 22.

In the illustrated example, six recesses 22 are formed around the circumferential direction of the pipeline 1, but the number of recesses 22 is not limited to this and can be changed as desired depending on the strength required for the pipeline 1.

In addition, while the illustrated example shows the recesses 22 formed at equal intervals on the inner peripheral surface of the pipeline 1, the intervals between the recesses 22 do not necessarily have to be equal. The shape of the recesses 22 (inner diameter, depth, etc.) can be changed as desired. The shapes of the multiple recesses 22 do not necessarily have to be the same, and they can be formed into different shapes.

The guide groove 20 according to the third pattern shown in FIG. 5(b) includes one recess 23 formed to extend along the circumferential direction of the inner circumferential surface of the pipeline 1. The recess 23 is formed to extend over more than half the circumference of the inner circumferential surface of the pipeline 1. Specifically, the recess 23 is formed in a range excluding the upper end of the inner circumferential surface of the pipeline 1. Both ends of the recess 23 are formed with a predetermined interval so that they are not continuous with each other. The recess 23 is formed on the inner circumferential surface of the pipeline 1 to an appropriate depth. The recess 23 can be formed, for example, by cutting the inner circumferential surface of the pipeline 1 along the circumferential direction with a substantially circular cutter C having an outer diameter according to the desired recess 23.

In the illustrated example, the recess 23 is formed in an area excluding the upper end of the inner circumferential surface of the pipeline 1, but the area in which the recess 23 is formed is not limited to this and can be changed as desired. For example, the recess 23 can be formed in an area excluding any part of the inner circumferential surface of the pipeline 1, such as the lower end, left end, or right end.

In the illustrated example, the recess 23 is formed over a range that extends over almost the entire circumference of the inner circumferential surface of the pipeline 1, excluding the upper end portion, but the range (circumferential length) over which the recess 23 is formed is not limited to this and can be changed as desired. For example, the recess 23 can be formed over a length that is less than half the circumference of the inner circumferential surface of the pipeline 1.

The guide groove 20 according to the fourth pattern shown in FIG. 6(a) includes a pair of recesses 24 formed on either side of the center of the pipeline 1 in a front cross-sectional view. The recesses 24 are formed on the top and bottom of the inner peripheral surface of the pipeline 1. The recesses 24 are formed so as to extend in the circumferential direction of the inner peripheral surface of the pipeline 1. The recesses 24 are formed on the inner peripheral surface of the pipeline 1 to an appropriate depth. In the illustrated example, the pair of recesses 24 are formed so as to have a shape that is symmetrical above and below the center of the cross section of the pipeline 1. The pair of recesses 24 are formed with a predetermined interval between their ends so that they are not continuous with each other. By forming the recesses 24 in this way, the guide groove 20 is formed in a range excluding both left and right ends of the inner peripheral surface of the pipeline 1. The recesses 24 can be formed, for example, by cutting the inner peripheral surface of the pipeline 1 in the circumferential direction with a substantially circular cutter C having an outer diameter according to the desired recess 24.

The guide groove 20 according to the fifth pattern shown in FIG. 6(b) includes a pair of recesses 25 formed on the left and right sides of the center of the pipeline 1 in a front cross-sectional view. By forming the recesses 25 in this manner, the guide groove 20 is formed in an area excluding both the upper and lower ends of the inner circumferential surface of the pipeline 1. Note that the recesses 25 according to the fifth pattern have a shape obtained by rotating the recesses 24 according to the fourth pattern (see FIG. 6(a)) by 90 degrees with respect to the center of the pipeline 1, and therefore a detailed description thereof will be omitted.

As in the example shown in Figure 6, by forming a pair of recesses 24, 25 on either side of the center of the pipeline 1, damage to the pipeline 1 can be suppressed when a load is applied in a direction in which the recesses 24, 25 are not formed. For example, in the fourth pattern shown in Figure 6(a), damage to the pipeline 1 can be induced relatively easily by a load in the vertical direction, while damage to the pipeline 1 can be suppressed when a load is applied in the horizontal direction.

In this way, by arbitrarily setting the direction in which the recesses 24 and 25 are formed, it is possible to create an earthquake-resistant structure 10 that suits the ground environment of the pipeline 1 (the direction in which loads are likely to be applied) and the purpose. For example, if an earthquake occurs and the ground liquefies, a large buoyancy will be generated in the manhole 2, and it is expected that a load will be applied to the pipeline 1 in the vertical direction. Therefore, by forming guide grooves 20 on the top and bottom as in the fourth pattern shown in Figure 6 (a), it is possible to effectively guide damage to the pipeline 1 in the event of an earthquake. On the other hand, if a load is applied to the pipeline 1 in the horizontal direction due to factors other than an earthquake, damage to the pipeline 1 can be suppressed.

In the example shown in FIG. 6, the guide groove 20 is formed in an area excluding both the left and right ends or both the top and bottom ends, but the area in which the guide groove 20 is formed is not limited to this and can be changed as desired, for example, to an area excluding both diagonal ends (e.g., the upper right end and the lower left end).

The guide groove 20 according to the sixth pattern shown in FIG. 7(a) includes a pair of recesses 26 formed above and below the center of the pipeline 1 in a front cross-sectional view. The guide groove 20 (recesses 26) according to the sixth pattern differs from the guide groove 20 according to the fourth pattern (see FIG. 6(a)) in that the pair of recesses 26 are formed asymmetrically.

Specifically, of the pair of upper and lower recesses 26, the circumferential length of the lower recess 26 is formed to be longer than the circumferential length of the upper recess 26. By configuring in this way, when an upward load is applied to both sides of the guide groove 20 in the longitudinal direction of the pipeline 1, it is possible to easily induce damage to the pipeline 1. Specifically, when an upward load is applied to both sides of the guide groove 20 in the longitudinal direction of the pipeline 1, a tensile load is applied to the lower side of the pipeline 1. Since a relatively large recess 26 is formed on the lower side of the pipeline 1, damage to the pipeline 1 can be effectively induced. On the other hand, when a downward load is applied to both sides of the guide groove 20 in the longitudinal direction of the pipeline 1, a tensile load is applied to the upper side of the pipeline 1, but since a relatively small recess 26 is formed on the upper side of the pipeline 1, damage to the pipeline 1 is less likely to occur than when an upward load is applied. In this way, by forming the guide groove 20 asymmetrically according to the load direction, damage to the pipeline 1 can be effectively induced for loads in any direction.

In the above example, the guide groove 20 is formed by directly processing the inner circumferential surface of the pipeline 1, but the present invention is not limited to this. For example, as shown in FIG. 7(b), when a lining material 3 is provided on the inner circumferential surface of the pipeline 1, it is also possible to form the guide groove 20 from above the lining material 3 so as to penetrate the lining material 3. FIG. 7(b) shows an example in which a guide groove 20 (recess 21) similar to the first pattern (see FIG. 4) is formed from above the lining material 3.

The lining material 3 is a member that is provided on the inner surface of the pipeline 1 for the purpose of reinforcing the strength of the existing pipe and preventing water leakage. Examples of the lining material 3 include a cylindrical member that is provided on the inner surface of the pipeline 1, and a band-shaped member that is provided in a spiral shape on the inner surface of the pipeline 1.

When providing a guide groove 20 in the pipeline 1 provided with the lining material 3 in this manner, the guide groove 20 can be filled with a filler such as synthetic resin to fill the gap between the inner surface of the pipeline 1 and the lining material 3 with the filler, thereby stopping water leakage.

As described above, the earthquake-resistant structure 10 according to this embodiment has the following features:
An earthquake-resistant structure 10 for a pipeline 1 connected to a manhole 2,
A concave guide groove 20 (breakage guide portion) formed along a circumferential direction on an inner circumferential surface of the pipeline 1 and formed so that at least a portion of the groove is discontinuous in the circumferential direction;
A water-stopping body 31 (covering member) having flexibility and covering the guide groove 20 from the inside of the pipeline 1;
an expansion portion 32 (expansion member) that expands the water stop body 31 from the inside of the pipeline 1 and presses it against the inner circumferential surface of the pipeline 1;
It is equipped with the following.

By configuring in this manner, the strength of the pipeline 1 can be ensured and earthquake resistance can be improved.
That is, when a large load is applied to the pipeline 1 due to an earthquake or the like, damage is induced to occur in the guide groove 20 covered with the water stop body 31, thereby preventing water leakage and the inflow of groundwater and soil into the pipeline 1. Also, by forming the guide groove 20 so that it is partially discontinuous in the circumferential direction, the strength of the pipeline 1 can be ensured compared to when it is formed over the entire circumference. This makes it possible to prevent damage to the guide groove 20 even in unnecessary cases (when a relatively small earthquake, impact, etc. occurs).

In addition, the guide groove 20 is
The pipe 1 includes a plurality of recesses 21, 22 formed in the inner peripheral surface thereof so as to be aligned in the circumferential direction (see Figs. 4 and 5(a)).

By configuring in this manner, the guide groove 20 (recesses 21 and 22) can be formed relatively easily.
For example, the guide groove 20 (recesses 21 and 22) can be formed by cutting a plurality of locations on the inner peripheral surface of the pipeline 1 using a cutter, a drill, a core punch, etc. In this case, since it is not necessary to cut while moving the cutter or the like in the circumferential direction, the guide groove 20 can be formed relatively easily.

In addition, the guide groove 20 is
The pipe 1 includes a pair of recesses 24 and 25 formed on either side of the center of the cross section of the pipe 1 (see FIG. 6).

By configuring it in this way, damage can be induced relatively easily by a load in the direction in which the pair of recesses 24, 25 are formed, while damage to the pipeline 1 can be suppressed by a load in a direction in which the pair of recesses 24, 25 are not formed. As a result, by arbitrarily setting the direction of the pair of recesses 24, 25, it is possible to create an earthquake-resistant structure that suits the installation environment (the direction in which loads due to earthquakes, etc. are likely to be applied).

In addition, the guide groove 20 is
The pipe 1 includes a pair of recesses 24 formed above and below the center of the cross section of the pipe 1 (see FIG. 6(a)).

By configuring it in this way, damage can be induced relatively easily by applying load in the vertical direction.

In addition, the pair of recesses 26 are
The pipe 1 is formed asymmetrically across the center of the cross section (see FIG. 7(a)).

This configuration makes it easier to induce damage depending on the direction of the load. For example, by setting the asymmetric shape of the recess 26 so that damage is more likely to occur depending on the direction of the load applied to the pipeline 1, it is possible to efficiently induce damage.

In addition, of the pair of recesses 26,
The circumferential length of the lower recess 26 is
It is formed so as to be longer than the circumferential length of the upper recess 26 (see FIG. 7(a)).

This configuration makes it easier to induce damage when an upward load is applied to both sides of the guide groove 20.

In addition, the guide groove 20 is
The inner peripheral surface of the pipeline 1 includes a recess 23 formed so as to extend in the circumferential direction over at least half the circumference of the inner peripheral surface (see FIG. 5(b)).

By configuring it in this way, the recesses 23 can be formed over a relatively wide area, making it easier to induce damage regardless of the direction of the load.

In addition, the earthquake-resistant structure 10 is
The pipe further includes a lining material 3 provided on the inner peripheral surface of the pipe 1,
The guide groove 20 is
It is formed so as to penetrate the lining material 3 .

By configuring it in this way, even in a pipeline 1 provided with a lining material 3, the strength of the pipeline 1 can be ensured and earthquake resistance can be improved.

The guide groove 20 according to this embodiment is one embodiment of a damage inducing portion according to the present invention.
Moreover, the water stop body 31 according to this embodiment is one embodiment of a covering member according to the present invention.
The expansion section 32 according to this embodiment is one embodiment of an expansion member according to the present invention.

Although an embodiment of the present invention has been described above, the present invention is not limited to the above configuration, and various modifications are possible within the scope of the invention described in the claims.

For example, the shape and number of guide grooves 20 are not limited to those shown in Figs. 4 to 7, and can be changed as desired. For example, Fig. 5 shows an example in which an arc-shaped (R-shaped) guide groove 20 is formed according to the shape (outer diameter) of the cutter C, but the present invention is not limited to this. For example, it is also possible to form a guide groove 20 that is not a smooth arc shape, but is generally rectangular in cross section with corners.

The method of forming the guide groove 20 is not limited to using a cutter, drill, core punch, etc., and the guide groove 20 can be formed by any method.

The circumferential cross-sectional shape of the guide groove 20 (see FIG. 2) is not particularly limited. In the example shown in FIG. 2, the guide groove 20 is substantially rectangular, but it is also possible to form the guide groove 20 in a triangular (V-shaped) or semicircular shape, for example. Furthermore, it is also possible to make the circumferential cross-sectional shapes of the multiple recesses different from each other, thereby making them more susceptible to breakage.

The pipe 1 is not limited to being made of reinforced concrete, but may be made of synthetic resin, metal, etc.

REFERENCE SIGNS LIST 1 Pipe 2 Manhole 3 Lining material 10 Earthquake-resistant structure 20 Guide groove 30 Water stop section 31 Water stop body 32 Expansion section

In one aspect of the present disclosure, there is provided an earthquake-resistant structure for a pipeline connected to a manhole, comprising: a concave damage induction portion formed circumferentially on the inner surface of the pipeline and formed so that at least a portion of it is discontinuous in the circumferential direction; a flexible covering member that covers the damage induction portion from inside the pipeline; and an expansion member that expands the covering member from inside the pipeline and presses it against the inner surface of the pipeline , wherein the damage induction portion includes a plurality of concave portions formed in a line in the circumferential direction on the inner surface of the pipeline .

In one aspect of the present disclosure, there is provided an earthquake-resistant structure for a pipeline connected to a manhole, the structure comprising: a concave damage induction portion formed circumferentially on an inner surface of the pipeline and formed so that at least a portion of the concave damage induction portion is discontinuous in the circumferential direction; a flexible covering member that covers the damage induction portion from inside the pipeline; and an expansion member that expands the covering member from inside the pipeline and presses it against the inner surface of the pipeline, the damage induction portion including a pair of recesses formed on either side of a center of a cross section of the pipeline.

In one aspect of the present disclosure, an earthquake-resistant structure for a pipeline connected to a manhole includes a concave damage induction portion formed circumferentially on the inner surface of the pipeline and formed so that at least a portion of it is discontinuous in the circumferential direction, a flexible covering member that covers the damage induction portion from inside the pipeline, and an expansion member that expands the covering member from inside the pipeline and presses it against the inner surface of the pipeline, and the damage induction portion includes a pair of upper and lower recesses formed on either side of the center of the pipeline cross section.

In another aspect of the present disclosure, the earthquake-resistant structure further includes a lining material provided on an inner surface of the pipeline, and the damage induction portion is formed so as to penetrate the lining material.
In one aspect of the present disclosure, there is provided an earthquake-resistant structure for a pipeline connected to a manhole, comprising: a concave damage induction portion formed along a circumferential direction on an inner surface of the pipeline and formed so that at least a portion of the concave damage induction portion is discontinuous in the circumferential direction; a flexible covering member that covers the damage induction portion from the inside of the pipeline; and an expansion member that expands the covering member from the inside of the pipeline and presses it against the inner surface of the pipeline, wherein the damage induction portion includes a concave portion formed on the inner surface of the pipeline so as to extend in the circumferential direction over at least half the circumference of the inner surface, and further comprises a lining material provided on the inner surface of the pipeline, and the damage induction portion is formed to penetrate the lining material.

Claims (8)

An earthquake-resistant structure for a pipeline connected to a manhole,
a concave breakage induction portion formed along a circumferential direction on an inner circumferential surface of the pipeline and at least a portion of which is discontinuous in the circumferential direction;
a covering member having flexibility and covering the breakage induction portion from the inside of the pipeline;
an expansion member that expands the covering member from inside the pipeline and presses the covering member against an inner circumferential surface of the pipeline;
The earthquake-resistant structure of the pipeline is provided with the above. The damage induction portion is
The inner circumferential surface of the pipeline includes a plurality of recesses formed in a circumferential direction.
An earthquake-resistant structure for a pipeline according to claim 1. The damage induction portion is
A pair of recesses are formed on either side of the center of the pipe cross section,
An earthquake-resistant structure for a pipeline according to claim 1. The damage induction portion is
A pair of recesses is formed above and below the center of the pipe cross section,
An earthquake-resistant structure for a pipeline according to claim 1. The pair of recesses are
The pipe is formed asymmetrically across the center of the pipe cross section.
An earthquake-resistant structure for a pipeline according to claim 4. Of the pair of recesses,
The circumferential length of the lower recess is
The recess is formed so as to have a circumferential length longer than that of the upper recess.
An earthquake-resistant structure for a pipeline according to claim 5. The damage induction portion is
The inner circumferential surface of the pipeline includes a recess formed so as to extend in a circumferential direction over at least half of the inner circumferential surface.
An earthquake-resistant structure for a pipeline according to claim 1. Further comprising a lining material provided on an inner peripheral surface of the pipeline,
The damage induction portion is
Formed to penetrate the lining material;
An earthquake-resistant structure for a pipeline according to any one of claims 1 to 7.

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