JP3449534B2 - Propulsion tube transmission collar - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-open cutting propulsion method for burying a fluid transportation pipe used for water supply, gas, sewerage, etc. underground to transmit propulsive force by inserting it between front and rear pipes. The present invention relates to a propulsion force transmission collar used for that purpose.

[0002]

2. Description of the Related Art As a construction method for burying a fluid transportation pipe such as a ductile cast iron pipe, there are a so-called pipe-in-pipe construction method and a two-step propulsion construction method. These construction methods are methods of inserting a new pipe into an existing old pipe, and are widely adopted because they do not require excavation.

A conventional pipe joint in the pipe-in-pipe method is shown in FIG. 9, for example. This joint 100 is called a PII type joint,
The receiving port 101, the insertion port 102, the lock ring 103, the set bolt 104, the rubber ring 105, and the like.

FIG. 10 shows an outline of the above conventional pipe-in-pipe construction method. A new pipe having a smaller diameter than the existing pipe P'which is buried between the starting pit S and the reaching pit R is shown in FIG. Insert P. A hydraulic jack J is installed at the start pit, the rear portion of the hydraulic jack abuts against the reaction force receiver H, and the front portion presses the new pipe P via the pushing angle B. The new pipe P is sequentially joined by inserting the insertion opening 102 at the tip end thereof into the receiving opening 101 at the rear end portion of the preceding new pipe, and is pushed into the existing pipe. A leading sled K is attached to the front end of the new pipe.

The new pipes P, ... Are joined in the following manner. First, the lock ring 103 and the rubber ring 105
To the inside of the mouth. After that, the hydraulic jack J is operated, the insertion port 102 is inserted into the receiving port 101, and the set bolt is tightened. As a result, the succeeding new pipe is joined to the rear part of the preceding new pipe whose rear end faces the start pit. When the following new pipe is joined, press it with the hydraulic jack J,
A series of joined pipes is advanced toward the reaching pit.
The propulsive force of the hydraulic jack is
It is transmitted by contact with the end surface of the lock ring groove 107. Although the figure shows an example in which a new pipe is inserted into an existing pipe, a two-step propulsion method in which a new pipe is inserted by a pipe-in-pipe method into a sheath for propulsion work is also performed.

[0006]

In the case of the PII type ductile pipe for the pipe-in-pipe construction method, after the pipe-in is completed, the lock ring 103 and the end face of the lock ring groove 107 are in contact with each other as shown in FIG. Therefore, the insertion opening 102 cannot move in the direction in which the insertion opening 102 enters the receiving opening 101. Therefore, there is a problem that the joint does not completely satisfy the performance as a seismic resistant pipe that needs to expand and contract in both directions. Note that when a large pulling force acts on the joint due to an earthquake or the like, the lock ring 103 and the lock ring groove 107 engage with each other to exert a separation preventing force.

When a large compressive force is applied to the joint portion of the propulsion pipe due to an earthquake or the like, the joint portion can be contracted to some extent to prevent damage to the joint portion. A technique has been proposed in which a liner capable of transmitting a propulsive force and removable after the completion of propulsion is provided in between (Japanese Patent Laid-Open No. 10-148290). This liner has a plurality of main body portions arranged in the circumferential direction,
An elastic body provided between adjacent main body portions, the diameter of which is reduced by compressive deformation of the elastic body, and the elastic body is removed from between the distal end portion of the insertion opening and the rear end surface of the receiving opening into the pipe. It is a thing. If you remove each liner after the end of the pipe promotion,
It is said that a pushing margin amount corresponding to the front and rear width of the liner can be obtained between the front and rear pipes.

However, the liner that can be removed after the completion of the above-mentioned propulsion can secure a margin for pushing by the removal, but it is necessary to remove the liner over the entire pipeline after laying the pipe, so the number of steps is reduced. In addition to the problem that the number of pipes increases, in the case of a pipe having a diameter of less than Φ800, there is a problem that the workable diameter of the pipe is limited because the pipe cannot be inserted into the pipe to work. Therefore, it is an object of the present invention to provide a propulsive force transmitting collar that can transmit a sufficient propulsive force when the pipe is propelled and can easily secure a pushing margin after the end of the propulsion.

[0009]

In order to solve the above problems, the present invention employs the following configurations. That is, the propulsive force transmitting collar according to the present invention is a propulsive force transmitting collar for advancing while burying a plurality of pipes and burying the pipe underground. It is characterized in that an annular brittle molded body which is crushed by its own expansion pressure after being embedded is interposed between the annular plate bodies.

The brittle compact is one that is crushed by itself after laying a pipe and drops from between the insertion port and the receiving port. For example, a static crushing agent that expands by a hydration reaction in an appropriate place of a concrete annular body. It is possible to adopt the one in which is embedded.

According to the present invention, since the propulsive force can be transmitted to the preceding pipe through the propulsive force transmitting collar during the propulsion work, the pipe can be efficiently propelled.
After the propulsion is completed, the brittle molded body of the propulsive force transmitting collar crushes and falls off by itself, and there is a margin to push in as much as the brittle molded body is in the fitting portion between the insertion opening and the receiving opening. Will be secured, and it will have a function as a seismic resistant joint.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described more specifically based on the embodiments of the present invention shown in the drawings.

FIG. 1 exemplifies a propulsive force transmitting collar according to the present invention. This propulsive force transmitting collar (abbreviated as "color") 1 has a pair of annular plate members 2 and 2 predetermined. The outer frame body 5 is made to face each other at an interval of 2 and is joined to each other by the support members 3 provided on the outer periphery thereof, and the annular brittle molded body 10 is interposed between the annular plate bodies 2 and 2. Composed of.

The annular plate body 2 is formed by forming a plate material such as a steel plate having a sufficient strength (for example, SS material, SUS material, etc.) into a donut shape in a front view. In a state where they face each other, they are fixed and integrated with each other by a plurality of supporting members 3 ,. The support member 3 is
When the collar 1 is transported or propelled, deviation of the brittle molded body 10 inside is prevented, and after the brittle molded body has fallen off, when a compressive force due to an earthquake acts, the annular plates on both sides are buckled or damaged. The strength is such that the bodies 2 and 2 can approach each other. For example, a metal plate (several mm in width, several mm in thickness) or a bar material such as a steel rod having an appropriate thickness (diameter several mm to several tens m).
m) may be fixed by welding or the like. A bolt may be used as the support member 3 and a nut may be used for fastening.

The brittle compact 10 is made of concrete, for example.
It is made of materials such as ceramics that have appropriate brittleness and rigidity. As shown in FIG. 5, the brittle molded body 10 has an insertion hole 11 formed at an intermediate portion in a thickness direction thereof, the insertion holes 11 penetrating forward and backward along the circumferential direction at an appropriate interval (L). The insertion hole is filled with the static crushing agent 12. The relationship between the diameter d of the insertion hole 11 and the hole interval L is, for example, L = 8.
It is preferably about d.

The static crushing agent 12 is capable of crushing the brittle compact itself after the completion of the propulsion. The static crushing agents include lime-based ones containing calcium oxide (CaO) as a main component, 3CaO / 3Al ₂ O ₃ CaSO.
There are two types of calcium-sulfo-aluminate (CSA) based on ₄ , ₄ , CaSO _4, and CaO. Lime-based CaO produces fine colloidal calcium hydroxide Ca (OH) ₂ by hydration reaction. This Ca (OH) ₂ grows into a long anisotropic hexagonal plate crystal with the passage of time. As a result, a crystal pressure is generated by pressing against each other, and an expansion pressure is generated on the constraining wall. Further, in the case of CSA type as well, due to the general hydration reaction as shown below, needle-like crystals called ettringite are grown, so that an expansion pressure to the constraining wall is generated as in the case of lime type. . These expansion pressures act on the filling hole, and compressive stress is generated in the peripheral portion around the hole, so that tensile stress is generated in the direction perpendicular to the compressive stress.

[0017]

[Chemical 1]

When the tensile stress exceeds the tensile strength of the brittle compact 10, a crack is generated, and the expansion of the static crushing agent is continued, so that the crack propagates. Therefore, a large number of cracks are formed both in the circumferential direction and in the axial direction of the brittle molded body 10 and crushing is performed. As described above, since the above-mentioned two types of main components both have the effect of crushing the propulsive force transmitting collar in both the lime type and the CSA type, either component may be used. Moreover, if the object of the present invention is achieved,
Components other than these two types may be used. In the case of the pipe-in-pipe construction method, since there is a gap between the sheath pipe (outer pipe) and the propulsion pipe (inner pipe), the fragments generated by this crushing fall into this void portion, and the insertion port 2 and the receiving port 3 Is removed from between. For this reason, the joint can be contracted by the amount separated by the collar 25. Further, in the case of the propulsion method, the compressive strength of the propulsive force transmitting collar 25 becomes close to 0, so that the joint can be contracted accordingly. In the case of the pipe-in-pipe method, there is a gap between the sheath pipe (outer pipe) and the propulsion pipe (inner pipe). Removed from between. Therefore, the pair of annular plate bodies 2, 2 are supported only by the supporting members 3, ... Which have relatively low strength, and when the pressing force exceeds these compressive strengths, the supporting members are buckled or damaged. It is possible to approach until both annular plate bodies are almost in close contact. Therefore, the amount of shrinkage of the joint can be secured.

The hydration reaction for crushing the brittle compact is
For example, a method of stirring static crushing agent and water to fill the static crushing agent insertion hole before propulsion construction, reacting with water contained in the soil of the ground around the pipe after propelling without reacting with water It can be realized by a method of performing the above. If this is particularly urgent, water may be poured into this portion with a pipe or the like. The static crushing agent is a component similar to the swelling agent generally used for expansive concrete, and the excessive swelling agent promotes crushing of concrete or the like. Further, this static crushing agent is generally used for crushing rocks and concrete involved in construction work, and it is possible to crush concrete without generating vibration, noise, flying stones, etc. Moreover, since it does not contain harmful components, no adverse effect on the tubular body is expected.

Regarding the insertion shape of the static crushing agent, any shape other than the illustrated example may be used as long as it can achieve the purpose of crushing the brittle molded body and ensuring the expansion and contraction amount of the joint. Further, as in the illustrated example, the method is not limited to the method of filling the holes pierced in the brittle molded body 10 with the static crushing agent, and the collar itself may be made of concrete mixed with the static crushing agent as an admixture. it can. Also in this case, it can be crushed by a method of reacting with the water contained in the soil around the pipe after completion of the propulsion.

Next, a method of forming the brittle molded body 10 in the propulsive force transmitting collar 1 will be described. 3 and 4
Represents a centrifugal molding mold M for molding the brittle molded body 10. The molding mold M is an annular plate body 2,
2 and a plurality of exterior frame bodies 5 made up of support members 3 are arranged in series and can be held, and an outer cylinder 7 made of a steel plate and front and rear flanges 8 and 8 arranged at both front and rear ends of the outer cylinder. , And nuts 9a, ..., Which are inserted through the flanges 8, 8 and fasten them.
The outer cylinder 7 in the illustrated example is a two-piece structure in which a kamaboko-shaped member is vertically stacked to form a tubular shape, and the outer frame body 5 can be housed by being divided vertically. Other structures may be used as long as the outer frame can be housed and molded.

At the time of molding, as shown in FIG. 3, a plurality of outer frame bodies 5, ... Are housed in the outer cylinder 7 in a state of being stacked front and back, and the flanges on both sides are fastened and fixed with bolts 9. As a result, the internal exterior frame is firmly fixed. The mold M is attached to a known centrifugal molding device (not shown), and while rotating about the axis of the mold M, the molding material of the brittle molded body 10 is introduced into the outer cylinder 7 through the openings at both ends. Charge. The molding material is, for example, concrete that is kneaded with a statically crushed material as an admixture. The charged molding material is pressed against the inner wall side of the outer cylinder 7 by centrifugal force to be molded into a donut shape. In addition, the inner peripheral surface of the formed brittle molded body has an annular plate body 2 using a spatula or the like during rotation.
Level so that it is equal to the inner diameter of. By solidifying the molding material in this state, the desired color 1 can be obtained.

Next, how to use the propulsive force transmitting collar 1 will be described. FIG. 6 exemplifies a pipe joint equipped with this collar 1, and this pipe joint J is an NS type joint that is usually used as a seismic joint for waterworks, and has an insertion port 2
2 and the socket 23. The insertion opening 22 is integrally formed with an insertion projection 25 on the outer peripheral surface of the distal end portion of the ductile tube 24. When a large drawing force acts on the pipe joint due to an earthquake or the like, the insertion opening 22 and the receiving opening 23 are formed by the engagement of the insertion opening projection 25 and the lock ring 37 described later.
Is prevented from leaving.

The insertion port projection 25 is provided in a ring shape on the entire outer peripheral portion of the insertion port 22. A flange 27 is integrally provided at a position near the rear of the insertion slot 22.
28, ... Reinforcement ribs for backup provided on the back surface of the flange 27 at appropriate intervals. The flange 27 and the reinforcing rib 28 are made of metal and are inserted by welding or the like.
It is fixed on the outer peripheral surface of No. 2.

The receiving port 23 is formed by expanding the diameter of the rear part of the ductile tube 24 into a generally funnel shape, and a groove 30 for mounting a rubber ring and a lock ring groove 32 are provided on the inner surface part thereof. An inward flange 33 is formed at the rear end portion of the receiving port 23, and the end surface thereof is formed as a flat surface 33a perpendicular to the axial direction. A rubber ring 35 for sealing is fitted in the groove 30, and a lock ring 37 which is expanded in one piece in the lock ring groove 32 and freely formed is provided via a rubber ring 38 for centering the lock ring. Have been fitted. 40 is exterior concrete. Flange 2 of the insertion port 22
The propulsive force transmitting collar 1 of the present invention is interposed between the inwardly facing flange 33 of the receiving port 23 and the inwardly facing port 7.

The construction method of the joint J will be described below. First, as shown in FIG. 7A, the propulsive force transmitting collar 1 is deposited in the outer peripheral portion of the insertion port 22. On the other hand, a rubber ring 35 and a lock ring 37 are attached to predetermined positions of the receiving port 23, and the insertion port 22 is inserted into the receiving port 23. After that, the pipe having the insertion port 22 inserted into the receiving port 23 is sequentially inserted into the sheath by the hydraulic jack by the hydraulic jack, and by the propulsion method, the pipes are sequentially inserted while excavating the leading pipe. . In the state of FIG. 7B, the propulsive force transmitting collar 1 is pinched by the flange 27 of the insertion port 22 and the inward flange 33 of the receiving port 23, and the propulsive force by the hydraulic jack is the same. 1 to the preceding tube.

The static crushing agent is set so as to expand and crush the brittle molded body 10 after completion of the propulsion,
As a result of the expansion, as shown in FIG.
As a result of 0 being cracked and crushed, the compressive strength of the brittle molded body 10 becomes almost 0, and the annular plate bodies 2, 2 on both sides are
The amount of expansion and contraction of the joint is secured by a distance close to the interval. In this case, even if a compressive force is applied to both annular plate members, a bent or damaged supporting member remains in the gap between the annular plate members, and that amount is excluded from the pushing margin. When the pipe is inserted into the sheath, the brittle molded body 10 with cracks falls off as fragments because there is a gap between the sheath and the inner peripheral surface of the inserted pipe as described above. FIG. 7D shows a state in which the brittle molded body 10 has fallen off and a pushing amount L1 ′ (ignoring the thickness of the residual support member) of the joint is secured.

FIG. 8 shows different forms of the static crushing agent to be inserted into the brittle molded body 10. In this form, the static crushing agent 12 is obliquely inserted between the outer peripheral surface side and the inner peripheral surface side of the thick portion of the propulsive force transmitting collar. For this reason, the crushed concrete fragments will surely fall off, and the joint expansion and contraction amount can be secured more reliably.

[0029]

As is apparent from the above description, the propulsive force transmitting collar of the present invention can transmit the propulsive force by being interposed in the pipe joint used in the propulsion method, and after the propulsion is completed, Since the brittle molded body is crushed by itself and removed from the joint, it is possible to secure a sufficient margin for pushing into the pipeline as a seismic resistant joint. In addition, since this brittle molded body is protected by the frame body, the collar is less likely to be damaged during transportation or handling during propulsion work, and there is no risk of problems due to reduced compression strength. . Further, even if crushing progresses as the material ages and a defect occurs on the load bearing surface during propulsion, since the plate material is applied to both surfaces, the propulsive force can be transmitted evenly. Further, since the space between the support members is a window-shaped space, most of the crushed fragments fall without remaining in the frame body, and as a result, a sufficient amount of expansion and contraction of the joint can be secured.

[Brief description of drawings]

FIG. 1 is a front sectional view of a propulsive force transmitting collar of the present invention (X
-X sectional view) (a) and a side view (b).

FIG. 2 is a front view (a) and a side view (b) of an annular frame.

FIG. 3 is a cross-sectional view of a molding mold for a brittle molded body.

FIG. 4 is a front view thereof.

FIG. 5 is a side sectional view (a) and a front sectional view (b) of a brittle molded body.

FIG. 6 is a cross-sectional view of a joint with a collar interposed.

FIG. 7 is an explanatory diagram of how to use the joint.

FIG. 8 is a side sectional view (a) and a front sectional view (b) of a brittle compact different from the above.

FIG. 9 is a sectional view of a conventional PII type pipe joint.

FIG. 10 is an explanatory diagram of a propulsion method.

[Explanation of symbols]

1 Propulsion force transmission collar 2 annular plate 3 Support members 5 Exterior frame 10 Brittle compact 12 Static crushing agent

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-56-25597 (JP, A) JP-A-4-312700 (JP, A) JP-A 2000-226986 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) E21D 9/06 311 F16L 1/024

Claims (3)

(57) [Claims] 1. A propulsive force transmitting collar for propelling a plurality of pipes while adhering to each other and burying the pipes underground, which is embedded between a pair of front and rear annular plate bodies arranged to face each other at a predetermined interval. A propulsion force transmission collar for a propulsion pipe, characterized in that an annular brittle molded body that is crushed later by its own expansion pressure is interposed. 2. The propulsive force transmitting collar for a propulsion pipe according to claim 1, wherein the brittle compact is a concrete annular compact containing a static crushing agent. 3. The propulsive force transmitting collar for a propulsion pipe according to claim 1, wherein the pair of front and rear annular plate members are fixed to each other by a plurality of supporting members.