JP2013164103A - Embedded pipe structure and method for constructing embedded pipe structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a newl embedded pipe structure capable of effectively preventing an embedded pipe from being uplifted and sinked by simple work, and to provide a method for constructing the embedded pipe structure.SOLUTION: A through-hole 5 penetrating a pipe wall of an embedded pipe 4 is formed from the inside of the embedded pipe 4 and thereafter a tubular nozzle for injecting grout material is inserted into a base material 2 or a backfilling material 3 which is present around the embedded pipe 4, via the through-hole 5. The grout material is injected to the base material 2 or the backfilling material 3 through a nozzle provided in the nozzle for injecting the grout material while the nozzle for injecting the grout material is pulled out, and thus a lumped body 6 produced by the solidification of the grout material is formed around the embedded pipe 4.

Description

  The present invention relates to a buried pipe structure and a buried pipe structure construction method for preventing the buried pipe from floating when land where the buried pipe exists is liquefied.

  A buried pipe buried underground such as a shaft or pipe may surface if the land where the buried pipe is liquefied due to an earthquake. When the buried pipe is lifted, the road is markedly uneven, and the evacuation route is blocked, the range of dispatch of fire engines and ambulances is limited, and the transportation of support supplies becomes difficult.

  Therefore, at present, as a countermeasure against the levitation of the buried pipe, “consolidation” is to refill while compacting with high-quality soil, “backfill with crushed stone” and the like to refill deeper than the groundwater level with highly permeable material (crushed stone), and groundwater Three methods of “solidification” have been proposed in which the deeper than that is filled with cement-improved soil (for example, refer to Non-Patent Document 1 below).

“Guidelines and explanations for seismic measures for sewer facilities”, Japan Sewerage Association

  The buried pipe structure constructed by the three construction methods prevents the floating of the buried pipe by changing the properties of the base material and the backfill material existing around the buried pipe. Since the structure remains the same, it did not affect the buoyancy of the buried pipe itself during the liquefaction phenomenon.

  In addition, the above three methods can be said to be effective means for newly laying buried pipes, but when performing on existing buried pipes, excavation work that excavates the ground and exposes the buried pipes is necessary. Become.

  The present invention has been developed to solve the above technical problem, and is a novel buried pipe structure capable of effectively preventing the buried pipe from rising by a simple operation, and the buried pipe structure. An object of the present invention is to provide a new buried pipe structure construction method for constructing the structure.

  The buried pipe structure of the present invention includes a buried pipe, a base material or a backfill material existing around the buried pipe, one or a plurality of through holes provided through a pipe wall of the buried pipe, A lump attached to the periphery of the buried pipe, and the lump is formed by solidifying a grout material that has permeated the base material or the backfill material through the through hole. (Hereinafter referred to as the structure of the present invention).

  In the structure of the present invention, the buried pipe is a pipe line connecting a plurality of pipe bodies, and the through hole is 45 ± along the circumferential direction of the pipe body from the top of the pipe body. A preferred embodiment is one formed at any position selected from positions at a phase of 10 degrees, 135 ± 10 degrees, 225 ± 10 degrees, or 315 ± 10 degrees.

  In the structure of the present invention, it is preferable that the buried pipe has a diameter of 800 mm or more and the through hole has a diameter of 30 to 100 mm.

  In the structure of the present invention, it is preferable that the massive body is extended in a direction substantially orthogonal to the tangential direction of the buried pipe at the position where the through hole is provided.

  In the structure of the present invention, it is preferable that the lump is formed by inserting and arranging a support rod made of a metallic or plastic rod-shaped body or pipe-shaped body.

  In the structure of the present invention, a preferred embodiment is one that further comprises a lid member that closes the through hole.

  The buried pipe structure construction method of the present invention is a method for constructing the structure of the present invention, and includes a through hole forming step of forming a through hole penetrating the tube wall of the buried pipe from the inside of the buried pipe. , A nozzle insertion step for inserting a tubular grout material injection nozzle through the through-hole into the base material or backfill material existing around the buried pipe, and the base material or backfill material inserted into the nozzle By performing a grout material injection step of injecting the grout material toward the base material or backfill material through the nozzle port provided in the grout material injection nozzle while pulling back the grout material injection nozzle, A lump formed by solidifying the grout material is formed around the buried pipe (hereinafter referred to as the method of the present invention).

  According to the present invention, it is possible to effectively prevent the buried pipe from floating during the liquefaction phenomenon with a simple operation.

1A is a front sectional view showing the structure of the present invention, and FIG. 1B is a side sectional view showing the structure of the present invention. 2 (a) to 2 (d) are front cross-sectional views showing a situation where the method of the present invention is performed. FIG. 3 (a) is a schematic diagram showing a situation in which an external pressure test (flat test) is performed on a tubular body constituting an embedded pipe, and FIG. 3 (b) shows the circumference of the tubular body in the external pressure test. It is the graph obtained by measuring the distortion of a direction. FIGS. 4A and 4B are front sectional views showing another example of the structure of the present invention. FIG. 5 is a front sectional view showing still another example of the structure of the present invention.

  Hereinafter, although an embodiment of the present invention is described based on a drawing, the present invention is not limited to this embodiment.

<Embodiment 1>
[Invention Structure 1]
FIG. 1 shows the structure 1 of the present invention. The structure 1 of the present invention includes an embedded pipe 4 embedded with a base material 2 and a backfill material 3, a plurality of through holes 5 provided through the tube wall of the embedded pipe 4, and the embedded pipe 4. And a lump 6 attached to the periphery of the.

  The buried pipe 4 is a pipe constructed by connecting a pipe body (FRPM pipe (reinforced plastic composite pipe)) 41 having a diameter of 1500 mm and a pipe length of 4 m, excavating the ground to form the groove floor 7, The tube 41 is placed on the base floor 21 formed by uniformly spreading the foundation material 2 made of sand on the bottom of the groove floor 7 so that its axis is parallel to the floor surface of the base floor 21. The base material 2 is poured and compacted until the tube top portion of the tubular body 41 is filled, and then the backfill material 3 made of high-quality soil is added and compacted. It is.

  The through-hole 5 has 45 degrees, 135 degrees, and 225 along the circumferential direction of the tubular body 41 with reference to the top of each tube at the position closer to the receiving end of the tubular body 41 and the position closer to the insertion opening. , And at a position at a phase of 315 degrees (eight convenient positions per tube 41), and the diameter of each through-hole 5 is set to 50 mm.

  The mass 6 is formed by solidifying the grout material that has penetrated the base material 2 or the backfill material 3 through the through-hole 5. Therefore, the lump 6 is partially formed around the tube 41 constituting the buried tube 4. In other words, the massive body 6 is formed radially toward the periphery of the tubular body 41 with the respective positions where the through holes 5 are provided as the base ends.

  Since the structure 1 of the present invention having such a configuration is obtained by adding the weight of the lump 6 to the buried pipe 4, when the land where the buried pipe 4 exists is liquefied, the buried pipe 4. Even when buoyancy occurs in the tube body 41 constituting the structure, the weight of the massive body 6 becomes a resistance force to the buoyancy, and the floating of the embedded tube 4 is preferably prevented.

  In the present embodiment, since the massive body 6 is arranged radially around the tubular body 41 constituting the embedded pipe 4, the bulk of the massive body 6 is increased during the liquefaction phenomenon. The resistance in the direction in which the buried pipe 4 is lifted up, and the floating of the buried pipe 4 during the liquefaction phenomenon is further preferably prevented.

  In addition, in the case of ordinary buried pipes that are not made into the structure 1 of the present invention, an example in which the buried pipe sinks in addition to the floating of the buried pipe during the liquefaction phenomenon has been reported. In the embodiment, since the massive body 6 is arranged radially around the tubular body 41 constituting the buried pipe 4, the bulk of the massive body 6 becomes a resistance in the direction in which the buried pipe 4 sinks. The subsidence of the buried pipe 4 during the liquefaction phenomenon is also suitably prevented.

[Method of the present invention]
In constructing the structure 1 of the present invention by the method of the present invention, first, a through hole forming step for forming the through hole 5 penetrating the tube wall of the buried pipe 4 from the inside of the buried pipe 4 is executed. . In the present embodiment, a worker S enters the buried pipe 4 and a predetermined portion of the pipe wall of the tubular body 41 constituting the buried pipe 4 using a drilling tool D such as a drill or a hole cutter. The through hole forming step was performed by drilling holes (from the eight locations) from the inside (see FIG. 2A).

  After the through hole 5 is formed at a predetermined location, the nozzle piercing the tubular grout material injection nozzle 8 through the through hole 5 into the base material 2 or the backfill material 3 existing around the buried pipe 4. An insertion process is performed (refer FIG.2 (b)). In this embodiment, the grout material injection nozzle 8 is moved to the base material 2 or the backfill material until the nozzle port 81 provided at the tip of the grout material injection nozzle 8 is 1 m away from the through hole 5. Stabbed into 3 The grout material injection nozzle 8 is connected to a grout material injection plant (not shown) disposed on the ground via a tube 82, and the grout material transported from the grout material injection plant is connected to the nozzle port. It is a mechanism that can be injected through 81. In addition, the jet agitation method of the grout material is not particularly limited, and for example, a one-phase flow method called a grout injection system, a two-phase flow method called an air grout injection system, or water A known jet stirring method such as a three-phase flow method called an air-grout injection system can be appropriately selected and used.

  After inserting the grout material injection nozzle 8 to a predetermined depth, the grout material sprays the grout material toward the base material 2 or the backfill material 3 through a nozzle port 81 provided in the grout material injection nozzle 8. An injection process is performed. In the grout material injection step, the grout material is injected while slowly pulling back the grout material injection nozzle 8 inserted in the base material 2 or the backfill material 3 at a constant speed (see FIG. 2C). ). As a result, a layer in which the grout material is permeated into the base material 2 or the backfill material 3 is formed by the depth at which the grout material injection nozzle 8 is inserted. Thereafter, when the grout material is solidified, the lump 6 is formed in a state of adhering to the outer peripheral surface of the buried pipe 4 (see FIG. 2D).

  If the nozzle insertion step and the grout material injection step are executed for each of the plurality of through-holes 5 formed in the through-hole forming step, the mass bodies 6 are respectively formed at the positions where the through-holes 5 are provided. Thus, the structure 1 of the present invention is constructed (see FIG. 1).

  In the present invention, it is preferable that the through hole 5 is closed from the inner wall side of the tube body 41 with a lid material (not shown) after the execution of the grout material injection step.

  By the way, in the method of the present invention, since it is necessary to form the through-hole 5 from the buried pipe 4 in the through-hole forming step, the pipe body 41 constituting the buried pipe 4 is not covered by an operator. It is preferable that the diameter is sufficient to enter. Specifically, the diameter of the buried pipe 4 is preferably 800 mm or more, and more preferably 1000 mm or more.

  Further, in the present embodiment, in the through hole forming step, the through hole 5 with respect to the embedded tube 4 is arranged along the circumferential direction of the tube body 41 constituting the embedded tube 4 with the tube top as a base point. Are provided at positions that are in a phase of 45 degrees, 135 degrees, 225 degrees, and 315 degrees (eight convenient positions per one of the tube bodies 41). This is because the tube body 41 is always loaded with a pressure that flattens the tube body 41 from the tube top side toward the tube bottom side.

  That is, the formation of the through-hole 5 in the buried pipe 4 means that the physical strength of the buried pipe 4 is reduced. If the physical strength of the buried pipe 4 is reduced, the pressure is reduced. The generated deformation stress may cause damage such as cracks starting from the through hole 5. In this regard, the present inventor conducted an external pressure test (flat test) shown in FIG. 3A on the pipe body 41 constituting the buried pipe 4. The strain generated in the tube body 41 by the pressure applied toward the bottom is large in the tube top portion, tube bottom portion, and both tube side portions, between the tube top portion and both tube side portions of the tube body 41, and It was confirmed that the strain generated between the tube bottom portion of the tube body 41 and both tube side portions was relatively small (see FIG. 3B).

  Therefore, in the present invention, 45 ± 10 degrees (preferably 45 ± 5 degrees), 135 ± 10 degrees (preferably 45 ± 5 degrees) along the circumferential direction of the tubular body 41 with the tube top portion of the tubular body 41 as a base point. 135 ± 5 degrees), 225 ± 10 degrees (preferably 225 degrees ± 5 degrees), or 315 ± 10 degrees (preferably 315 ± 5 degrees), the through hole 5 is provided It is preferable (this is not the case if the buried pipe 4 is installed with a shaft centered in the vertical direction such as a manhole).

  Moreover, in this embodiment, although the said through-hole 5 is provided in all the four places where the said deformation stress does not produce easily, this invention makes it essential to provide the said through-hole 5 in all the four places which concern. It is not a thing.

  For example, as shown in FIG. 4 (a), the through holes 5 may be provided at two locations on the tube bottom side of the embedded pipe 4, and as shown in FIG. 4 (b), the through holes 5 are provided. May be provided at two places on the top side of the buried pipe 4. It has been confirmed that when the through hole 5 is provided at two locations on the tube bottom side of the buried pipe 4 and the structure 1 of the present invention is constructed, the buried pipe 4 can be further prevented from sinking during the liquefaction phenomenon. On the other hand, when the structure 1 of the present invention is constructed by providing the through holes 5 at two locations on the tube bottom side of the embedded tube 4, it is confirmed that the embedded tube 4 can be prevented from being lifted during the liquefaction phenomenon. Has been. In addition, when providing the said through-hole 5, it is preferable to provide so that the said massive body 6 may become left-right symmetric in view of the weight balance by the said massive body 6 formed after that.

  Moreover, in this embodiment, although the said through-hole 5 is provided in eight places per said pipe body 41 which comprises the said embedment pipe 4, the number of the through-holes 5 which concern is not specifically limited. If a large number of the through holes 5 are provided, the total weight of the lump 6 finally formed becomes large, and the floating of the buried pipe 4 during the liquefaction phenomenon is further prevented. However, if a large number of the through holes 5 are provided, the physical strength of the pipe body 41 constituting the embedded pipe 4 is relatively reduced. Therefore, the through hole 5 has one pipe body 41 having a pipe length of 4 m. It is preferable to make it within a range of 2 to 16 locations (preferably within a range of 4 to 12 locations).

  Further, in the present embodiment, the diameter of the through hole 5 is 50 mm, but the number of the diameter of the through hole 5 is not particularly limited. If the diameter of the through-hole 5 is increased so that the grout material injection nose 8 having a large tube diameter can be inserted, the total weight of the mass 6 to be finally formed increases and a liquefaction phenomenon occurs. The floating of the buried pipe 4 at the time is further prevented. However, if the diameter of the through-hole 5 becomes too large, the physical strength of the buried pipe 4 is relatively reduced. Therefore, if the pipe body 41 has a diameter of 800 mm or more, the diameter of the through-hole 5 is , Preferably within a range of 30 to 100 mm (preferably within a range of 40 to 70 mm).

  In addition, in the present embodiment, in the nozzle insertion step, the grout material injection nozzle 8 is provided until the nozzle port 81 provided at the tip of the grout material injection nozzle 8 is 1 m away from the through-hole 5. Is inserted into the base material 2 or the backfill material 3. The deeper the piercing depth of the grout material injection nozzle 8 is, the larger the weight of the lump 6 finally formed becomes, and the floating of the buried pipe 4 during the liquefaction phenomenon is further prevented. Is done. However, it is difficult to insert the grout material injection nozzle 8 beyond the groove excavated for laying the buried pipe 4, and the grout material injection nozzle 8 is wasteful. The penetration depth is preferably 0.5 to 3 m. The grouting material injection nozzle 8 is inserted in a direction substantially perpendicular to the tangential direction of the buried pipe 4 at the position where the through hole 5 is provided (specifically, 90 ° ± 20 ° with the tangential direction). (Preferably, the direction intersecting at an intersection angle of 90 degrees ± 10 degrees). If the insertion direction of the grout material injection nozzle 8 is the direction, the mass 6 finally formed is substantially orthogonal to the tangential direction of the buried pipe 4 at the position where the through hole 5 is provided. It extends in the direction and becomes bulky, so that the buried pipe 4 is further prevented from floating during the liquefaction phenomenon.

  And in this invention, the total weight of the said lump 6 finally formed per said tube 41 is the buoyancy per said tube 41 (in the state which closed both ends, it is in water. The buoyancy generated in the above is preferably 90% or more (preferably 100 to 120%). The total weight of the mass 6 is adjusted by adjusting the number of the through holes 5, the diameter of the through holes 5, the penetration depth of the grout material injection nozzle 8, the pullback speed of the grout material injection nozzle 8, and the like. It can be determined by adjusting the injection amount of the grout material.

  By the way, although the said lump 6 is formed when the grout material penetrate | infiltrated into the said base material 2 or the backfilling material 3 solidifies, in the present invention, the said lump 6 is produced at the time of earthquake occurrence. As shown in FIG. 5, a metal or a fiber reinforced plastic such as stainless steel or a plastic such as a thermosetting resin is directed from the through-hole 5 toward the lump body 6 in order to make it difficult to cause cracks or cracks. It is preferable to insert and arrange a support rod 9 made of a rod-like body or a pipe-like body to improve the physical strength of the lump 6.

  The present invention can be implemented in various other forms without departing from the spirit or main features thereof. For this reason, the above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. The scope of the present invention is indicated by the claims, and is not restricted by the text of the specification. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  In particular, the present invention can be suitably used as a countermeasure against the liquefaction phenomenon for existing buried pipes.

1 Structure of the present invention (buried pipe structure)
2 Base material 21 Base floor 3 Backfill material 4 Buried pipe 41 Tube 5 Through hole 6 Mass 7 Groove floor 8 Grout material injection nozzle 81 Nozzle port 82 Tube 9 Support rod

Claims (7)

Buried pipe,
A base material or a backfill material existing around the buried pipe;
One or a plurality of through holes provided through the pipe wall of the buried pipe;
A lump attached to the periphery of the buried pipe;
Comprising
The buried pipe structure is characterized in that the lump is formed by solidifying a grout material permeated toward the base material or the backfill material through the through hole. The buried pipe structure according to claim 1,
The buried pipe is a pipe connecting a plurality of pipes;
The position where the through hole is in a phase of 45 ± 10 degrees, 135 ± 10 degrees, 225 ± 10 degrees, or 315 ± 10 degrees along the circumferential direction of the tubular body with the top of the tubular body as a base point A buried pipe structure formed at any position selected from The buried pipe structure according to claim 1 or 2,
The buried pipe has a diameter of 800 mm or more;
A buried pipe structure in which the diameter of the through hole is 30 to 100 mm. The buried pipe structure according to any one of claims 1 to 3,
A buried pipe structure in which the lump is extended in a direction substantially orthogonal to a tangential direction of the buried pipe at a position where the through hole is provided. The buried pipe structure according to any one of claims 1 to 4,
A buried pipe structure in which a metal or plastic support rod made of a rod-like body or a pipe-like body is inserted and arranged in the lump. The buried pipe structure according to any one of claims 1 to 5,
Furthermore, a buried pipe structure comprising a lid member that closes the through hole. An embedded pipe structure construction method for constructing an embedded pipe structure according to any one of claims 1 to 6,
A through hole forming step of forming a through hole penetrating the tube wall of the buried pipe from the inside of the buried pipe;
Nozzle insertion step of inserting a tubular grout material injection nozzle into the base material existing around the buried pipe or backfill material through the through-hole,
While pulling back the grout material injection nozzle stabbed in the base material or backfill material, the grout material is sprayed toward the base material or backfill material through a nozzle port provided in the grout material injection nozzle. A grout material injection process,
By running
A method for constructing a buried pipe structure, characterized in that a mass formed by solidifying the grout material is formed around the buried pipe.

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