JP2000266261A - Aseismatic propulsion construction method and pipe joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aseismatic pipe joint and its propulsion construction method capable of inserting a pipe and the joint in a condition ensuring a sufficient shrinkage amount which is the most important matter of aseismatic property regardless of a bore. SOLUTION: A plurality of propulsive force transmitting disk springs 3 arranged so as to stop a deflection amount to within a prescribed range even by receiving propulsive force are interposed between the external periphery of a spigot 1 of a connecting ductile cast iron pipe 10A and a side end face 21 of a socket 2 of the following pipe 10B, as mixing of sediment is prevented, the propulsive force is transmitted from the following pipe to the leading pipe by utilizing a spring constant, to press-in the pipe to be advanced together, even when all the pipes are loaded with excessive external force by an earthquake or the like by repeating connecting and pressing, by providing an annular space S in all joints of a pipe line after burying, needless to say, in a direction extracting the pipe also in a press-in direction, construction is executed by a procedure formed with the pipe line having aseismatic property of the highest level. Strength is changed by adjusting series/parallel arrangement of the disk spring interpolated corresponding to the propulsive force changed with a progress of construction, the pipe is propelled while maintaining always a fixed annular space in the joint.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-step propulsion method or a pipe-in-pipe method for laying a pipe for fluid transport used for water supply, gas, sewerage and the like without cutting, and a seismic propulsion pipe joint thereof.

[0002]

2. Description of the Related Art Conventionally, for laying ducts such as ductile cast iron pipes, a digging method in which the ground is cut and laid is generally used. Due to the increase, it is becoming difficult to cut off traffic due to the excavation method. Therefore, only the starting shaft and the reaching shaft are excavated, and a fume pipe or steel pipe is propelled as a sheath pipe, then a two-step propulsion method of inserting ductile cast iron pipe is used. A propulsion method such as a pipe-in-pipe method in which a pipe is inserted to update a pipe line is generally used. On the other hand, even when an unsteady external force directly hits the pipeline due to lessons learned from the Great Hanshin Earthquake, seismic pipelines that have joints that can expand and contract on both the pull-out side and the push-in side of the joint have been required.

As a seismic joint used in the pipe-in-pipe method, there is a PII type joint for a pipe-in-pipe method as shown in FIG. Insert 10
1, socket 102, rubber ring 103, lock ring 104,
The pipe-in-pipe method uses the existing pipe 203 buried as shown in FIG.
And a new pipe 204 having a smaller diameter
This is a construction method in which the hydraulic jack 205 is used to insert the shaft up to the reaching shaft 202. The hydraulic jack 205 has a rear portion against which a reaction force receiver 206 abuts, and a front portion which presses the new pipe 204 via a push angle 207. In addition, Shinkan 204
Is a leading sled 208 for reducing insertion resistance.
Is installed.

[0004] The joining method of a new pipe is as follows.
4 and the rubber ring 103 are mounted on the inner surface of the receiving port, the hydraulic jack 205 is operated, the insertion port 101 is inserted into the receiving port 102, and the set bolt 105 is tightened. Are joined, and the side of the lock ring 104 of the joined new tube and the insertion port 1 are joined.
The propulsion force is transmitted at the side end surface 107 of the lock ring groove 106 provided in the lock ring 01. In this figure, a new pipe is inserted into the existing pipe to update it.
Further, a two-stage propulsion method of inserting a new pipe into the sheath pipe by a pipe-in-pipe method is also usually performed.

[0005]

In the construction of the PII type joint for the pipe-in-pipe method, after the propulsion work is completed,
As shown in FIG.
01 is in a state where the side end faces 107 of the lock ring groove 106 are in contact with each other, that is, in a state where the joint is pushed in, so only the pull-out allowance is secured, but in a direction in which the insertion port enters the receiving port. Since it does not move, there is a problem that the joint only partially fulfills the performance as a seismic pipe joint which needs to expand and contract in both directions.

[0006] As a conventional pipe joint used in the propulsion method, a conventional technique for maintaining a constant interval so as to be able to move to both the contraction side and the extension side is shown in FIGS. 11 (A), (B) and (C). JP-A-3-39594 is known. The gist of the present invention is that a removable spacer jig 303 is interposed between the insertion port 301 and the receiving port 302 of the propulsion pipe to transmit a propulsive force, and after propulsion to a predetermined position, the spacer jig 303 is removed. A predetermined interval is formed.

However, in this method, a load for mounting the spacer jig between the opening and the receiving port and a large amount of spacer jigs are required in the starting pit, and after the installation is completed, all the spacer jigs are removed over the entire pipeline. Specifically, special tools and cumbersome operations are required, such as removing the body frame 303 after contracting the diameter-increased surface pressure jack 304 to reduce its diameter. First, since the worker cannot infiltrate into the pipe unless the pipe diameter is at least φ800 mm or more, this is the greatest restriction in implementation.

The present invention can be used for the two-step propulsion method and the pipe-in-pipe method to solve the above-mentioned problems. It is an object of the present invention to provide an earthquake-resistant pipe joint capable of inserting a pipe and a joint in a state where the amount is secured, and a method of propulsion thereof.

[0009]

In the seismic propulsion method according to the present invention, pipes are joined one after another from the starting shaft excavated from the ground to the rear of the preceding pipe, and are pressed in the axial direction to form a new pipe without cutting. Alternatively, a two-step type propulsion method and a pipe-in-pipe method to be renewed, in which the pressing flange 11 provided outside the insertion port 1 of the pipe 10A to be joined and the side end face 21 of the opening of the receiving port 2 of the other pipe 10B. A plurality of propulsion force transmitting springs 3 arranged so that the amount of deflection stays within a predetermined range even if the propulsion force is received in between. Even if the external force due to an earthquake or the like is applied to all the pipes by transmitting the propulsion force and pushing in the axial direction to advance together, repeating the joining and pressing, pushing each pipe to the predetermined position, Direction of pulling out pipes to all joints of buried pipeline Not to mention also the pushing direction has solved the above problems by providing an annular space S.

As a seismic pipe joint used in the two-step propulsion method and the pipe-in-pipe method, a pressing flange 11 fixed to the outer peripheral surface 12 of the insertion port 1 and one end is fixed to the top surface of the pressing flange 11. Mixing cover 31 projecting like an eaves, and a propulsion force transmitting flat spring 3 built into an annular space between the inner peripheral surface of the mixing prevention cover 31 and the outer peripheral surface 12 of the insertion opening 1. The thrust spring 3 for transmitting the propulsion force is adjusted so as to always stay within a substantially constant allowable bending amount in accordance with the propulsion force fluctuating with the progress of the propulsion process. The above-mentioned problem was solved by arranging in the above manner.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings, in which a ductile cast iron pipe is applied. FIG.
FIG. 1 is a sectional view showing the structure of a seismic pipe joint according to the present invention. The joint type is an NS type joint which is generally used as a seismic joint of water supply, and has an insertion port 1 and a receiving port 2. The insertion port 1 is provided with an insertion projection 13 integrally on the outer peripheral surface of the distal end portion of the ductile cast iron pipe 10A, and the insertion projection 13 is formed in a ring shape on the outer peripheral surface 12 of the insertion port 1. . A pressing flange 11 is integrally provided on the outer peripheral surface of the insertion port 1 on the rear side. This pressing flange 11
A back-up reinforcing rib 15 is provided at an appropriate interval on the back surface 14 of the base member, and the pressing flange 11 and the reinforcing rib 15 are made of metal and attached by a method such as welding.

A rubber ring groove 41 for accommodating the rubber ring 4 for sealing and a lock ring groove 51 are provided on the inner peripheral surface 22 of the receiving port 2. The groove 51 is provided with a lock ring centering rubber 52 formed of a single annular body.
When the lock ring 5 and the insertion port projection 13 are subjected to a large withdrawal force due to an earthquake or the like, the lock ring 5 and the insertion port projection 13 engage with each other to prevent the lock ring 5 from being detached.

The propulsion force transmitting spring 3 is interposed between the pressing flange 11 fixed on the outer peripheral surface of the insertion opening 1 and the open side end surface 21 of the receiving opening 2.
1 and is enclosed in an annular space in which the intrusion of earth and sand or moisture from the outside is prevented by the intrusion prevention rubber 32. The requirement of the thrust spring 3 for transmitting the propulsion force is that the propulsion during the entire construction period of the propulsion method causes deflection only within a predetermined allowable range during the propulsion and almost loses the initially set length of the annular space in the tube axis direction. Instead, an annular space that can expand and contract over the entire length of the completed pipe is formed in all the pipe joints.

As an embodiment of the present invention, a flat spring having a specific spring constant is applied, and a method of converting the spring constant in accordance with a change in external force by adjusting the arrangement of the flat springs is adopted. 2 (A), 2 (B) and 2 (C) show characteristics of flat springs (Kyoritsu Publishing Co., Ltd., handbook of mechanical design charts). As shown in FIG. Some of them are superimposed and others are superimposed in series as shown in FIG. When superimposed in parallel,
As shown in FIG. 3 (C), the load required to produce a constant amount of deflection of 1 mm increases in proportion to the number of sheets, whereas in the case of series connection, the amount of deflection is constant for a constant load of 4 × 10 ³ kgf, for example. It increases from 1 mm to 4 mm in proportion to the number of stacked sheets. In the present invention, basically, the flat springs are calculated and arranged in series so as not to bend at about the initial propulsion,
In the following, in order to cope with the increasing propulsion force at the same time as the construction progresses, it will be strengthened in parallel in order to keep the amount of flexure below a certain level and to be able to expand and contract inside the pipe joint even under the maximum propulsion force at the final stage. It is necessary to secure space.

FIG. 3 shows an example of an embodiment in which the spring constant is adjusted along with the progress of the propulsion method. FIG. 3 (A) shows a leading portion, an intermediate portion, and a trailing portion when a pipe is inserted.
(B) and (C) respectively. Figure (A ')
(B ′) and (C ′) are enlarged views in the vicinity of the respective propulsion force transmitting springs. Considering that the resistance near the head is the frictional resistance between the existing pipe and the sheath pipe due to the weight of the preceding pipe, the propulsion force is small, so if the springs are arranged in series as shown in FIG. It can withstand the force and secure the pushing allowance. In the middle, since the number of preceding tubes increases, by overlapping the flat springs in parallel as shown in FIG. (B), it is possible to withstand the pushing force and secure the pushing allowance. In the last tube, the frictional resistance due to the weight of all the tubes is added, so the propulsion force is maximized, and the pushing force is considerably larger than the joint near the head. Therefore, as shown in FIG. By doing so, it can withstand the pushing force and secure the pushing force. As described above, fine adjustment can be performed by changing the number of superposed springs as the subsequent joint is formed, and a substantially constant pushing allowance for the propulsion force can be secured. In this embodiment, the initial series structure was strengthened by adding a partial parallel structure.
It goes without saying that different arrangements can be adopted to form the most reasonable seismic structure by appropriately combining the parallel systems.

FIG. 4 is an overall view of the construction according to the present invention, and FIG.
4B is a cross-sectional view taken along the lines AA and BB in FIG. The ductile cast iron pipe 10 is inserted into the sheath pipe 6 from the X direction to the Y direction by a hydraulic jack, and is propelled by repeating joining and insertion sequentially. The sheath tube 6 is a ductile cast iron tube 1
In order to lay 0, it is a newly propelled pipe or an aging pipe, such as a fume pipe or a steel pipe. The pipe-in-pipe method roller 7 is usually used in the pipe-in-pipe method, and is set in the gap between the sheath pipe and the propulsion pipe to perform centering. ). In this figure, the ductile iron pipe provided with the inlet is successively joined and inserted repeatedly as a subsequent pipe, and is promoted.However, the ductile iron pipe provided with the insertion port is promoted as the subsequent pipe,
That is, it is also possible to propel from the Y direction to the X direction.

FIGS. 6A to 6C are cross-sectional views showing a procedure for carrying out the present invention. In FIG. The rubber ring 4, the lock ring 5, and the lock ring centering rubber 52 are mounted on the inner peripheral surface 22 of the mouth 2. In FIG. 2B, the propulsion force transmitting spring 3 is fitted between the outer peripheral surface 12 of the insertion opening 1 and the mixing prevention cover 31. In FIG. (C), the insertion port 1 is inserted into the reception port 2 and joined.

FIGS. 7A and 7B show the secured joint expansion and contraction amount in this embodiment. Since the connection of all the pipes is completed while the propulsion force transmitting spring 3 maintains a constant annular space, a pushing allowance L1 is provided on the side where the joint is pushed, and a pull-out allowance L2 is provided on the side where the joint is pulled out. Once it has been secured, secure the push-in and pull-out allowances of 1% or more of the pipe length as prescribed by the National Land Development Technology Center "Technical Standards for Seismic Joints for Underground Pipes" (draft) (draft). Is also easy. When a pulling force is applied, the insertion projection 13 and the lock ring 5
, The structure withstands the pulling force. Further, since the means for joining the pipes and securing the amount of expansion and contraction of the joints are all performed from the outer surface side of the pipes in the starting pit, the present invention can be applied even to small and medium-sized bores having a diameter of less than φ800 mm, in which a worker cannot enter the pipes.

FIG. 8 shows another embodiment. When a large force acts on the joint due to an earthquake or the like, there is a possibility that the joint is not freely expanded and contracted by the pressing flange 11 because the compressive strength of the grout material is high. Can be considered. Therefore, as shown in the figure, by connecting a cushion material 33 such as a sponge to the back side surface 14 of the pressing flange 11 and the pressing flange 11, the joint can be reliably expanded and contracted even when the grout material has a high compressive strength. .

[0020]

After the propulsion is completed, the annular space S is inserted into the pipe joint not only in the direction in which the pipe is pulled out but also in the direction in which the pipe is pushed in.
Since the joint expansion and contraction amount can be secured by maintaining
Even if the ground fluctuates significantly due to an earthquake or the like, the joints follow the ground deformation and prevent the destruction of the pipeline, and even if the pipeline is constructed by the pipe-in-pipe method or the two-step propulsion method, the seismic resistance of the pipeline Sex can be at the highest level. Also, the means for securing the joint expansion / contraction amount is performed in the starting pit at the same time as the propulsion work, so that even if the pipe has a diameter of less than φ800 mm, the worker cannot enter the pipe,
It can be used as a seismic pipe joint for the propulsion method, and does not impair the function of the existing pipe joint because it does not add a function to the water contact part on the inner surface of the pipe.

[Brief description of the drawings]

FIG. 1 is a sectional view of a pipe joint according to the present invention.

FIG. 2 is a diagram (C) showing a method of arranging the flat springs (A) in parallel, (B) in series, and a load-deflection diagram thereof.

FIG. 3 shows the propulsion at the beginning (A) and its enlarged view (A ′), the middle section (B) and its enlarged view (B ′), the last section (C) and its enlarged view (C ′) of the propulsion method. It is sectional drawing which illustrates adjustment of arrangement | positioning of a force transmission spring.

FIG. 4 is a sectional view showing the entire construction method.

FIG. 5 is a sectional view taken along line AA in FIG. 4 (A) and BB.
It is an arrow view (B) of a section.

FIGS. 6A to 6C are cross-sectional views showing a joining procedure of the pipe joint according to the present invention by FIGS.

FIGS. 7A and 7B are a cross-sectional view and a cross-sectional view, respectively, showing a secured push-in margin and a secured pull-out margin in the present embodiment.

FIG. 8 is a cross-sectional view showing another embodiment of the present invention.

FIG. 9 is a partial front sectional view of a conventional technique.

FIG. 10 is a front sectional view showing a pipe-in-pipe method.

FIG. 11 is a partial front sectional view (A), a side view (B) and a front view (C) of a main part showing another conventional technique.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 insertion port 2 receiving port 3 flat spring for transmitting propulsion force 10 ductile cast iron pipe 11 pressing flange 12 outer peripheral surface 21 side end surface 31 mixing prevention cover 32 mixing prevention rubber 33 cushion material S annular space

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yoshiki Okamoto 1-12-19 Kitahorie, Nishi-ku, Osaka-shi, Osaka F-term in Kurimoto Iron Works Co., Ltd. 2D063 BA26 BA27 BA31 3H104 JA08 JB02 JC08 JC09 KA04 KB03 LF16 LG02 MA08

Claims (4)

[Claims] 1. A two-step propulsion method and a pipe-in-pipe method in which pipes are successively joined to a rear part of a preceding pipe from a starting shaft excavated from the ground and pressed in the axial direction to newly establish or renew a pipe without cutting. In this case, the amount of flexure between the pressing flange 11 provided at the insertion port 1 of the pipe 10A to be joined and the side end face 21 of the opening of the receiving port 2 of the other pipe 10B is a predetermined amount even when the propulsion force is received. A plurality of propulsion force transmitting springs 3 arranged so as to stay within the range are interposed, and the propulsion force is transmitted from the succeeding tube to the preceding tube by utilizing the spring constant and pushed in the axial direction to advance together. Each pipe is pushed to a predetermined position by repeating joining and pressing, and an annular space S that can be pushed is provided in all joints of the buried pipe, and the seismic resistance can be extended and retracted in two directions of pulling and pushing. An earthquake-resistant propulsion method characterized by having a characteristic. 2. A pipe joint for a two-step propulsion method and a pipe-in-pipe method, wherein a pressing flange 11 fixed to an outer peripheral surface 12 of an insertion port 1 and one end is fixed to a top surface of the pressing flange 11 to form an eaves-like shape. , A thrust spring 3 for transmitting a propulsion force built into an annular space between the inner peripheral surface of the intrusion prevention cover 31 and the outer peripheral surface 12 of the insertion opening 1, and a connection between the annular space and the outside of the tube. The thrust spring 3 for transmitting the propulsion force is arranged and adjusted so as to always stay within a substantially constant allowable bending amount corresponding to the propulsion force fluctuating with the progress of the propulsion process. A pipe joint for an earthquake-resistant propulsion method. 3. The thrust spring 3 for transmitting a propulsion force according to claim 2, comprising a plurality of springs having the same spring constant. In the latter period, the propulsion force is strengthened, and the individual parts constituting the series are sequentially superimposed and strengthened in parallel, and when completed, the number of flat springs is serially and in parallel with the number of flat springs so that a constant annular space S is always secured at any joint. A pipe joint for an earthquake-resistant propulsion method characterized by adjusting the combination of 4. An annular cushion material 3 according to claim 2, wherein the back surface portion 14 of the pressing flange 11 of the insertion opening 1 is provided on the back surface portion 14.
3. A pipe joint for an earthquake-resistant propulsion method, wherein 3 is provided.