JP2000266260A - 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 propulsion force transmitting coil spring 3 having a spring constant stopping a deflection amount to within a prescribed range even by receiving propulsive force is interposed between the external periphery of a spigot 1 of a connecting pipe 10A and a side end face 21 of a socket 2 of the following pipe 10B, as mixing of sediment is prevented, propulsive force is transmitted from the following pipe to the leading pipe by using the spring constant to press-in the pipe in an axial line direction to be advanced together, even when all the pipes are loaded with excessive external force by an earthquake or the like, 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 of an interpolation spring is changed corresponding to the propulsive force changed in accordance with a progress of construction work, 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 is based on 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.

As a conventional technique for maintaining a constant interval so that it can move to both the contraction side and the extension side as a pipe joint used in the propulsion method, as shown in FIGS. 9A, 9B, and 9C, FIG. 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 newly establish a 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. In the meantime, a propulsion force transmitting coil spring 3 having a spring constant whose deflection amount remains within a predetermined range even when receiving the propulsion force is interposed to prevent earth and sand from being mixed into the propulsion force transmitting coil spring 3. Meanwhile, utilizing the spring constant, the driving force is transmitted from the succeeding tube to the preceding tube and pushed in the axial direction to advance together, repeating the joining and pressing to push each tube to a predetermined position, If excessive external force due to an earthquake or the like is applied to the pipe Also, of course in the direction to pull out the tube all the joints of the pipe after embedding, in 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 an outer peripheral surface 12 of the insertion port 1 and one end is fixed to a top surface of the pressing flange 11. Prevention cover 31 protruding like an eaves, a propulsion force transmitting coil spring 3 built into an annular space between the inner peripheral surface of the contamination prevention cover 31 and the outer peripheral surface 12 of the insertion opening 1, The propulsion force transmitting coil spring 3 is formed by selecting a substantially constant allowable bending amount in accordance with the propulsion force that fluctuates with the progress of the propulsion process. The above problem was solved by adjusting the constants and arranging them.

[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 coil spring 3 is interposed between the pressing flange 11 fixed on the outer peripheral surface of the insertion port 1 and the open side end face 21 of the receiving port 2. And is enclosed in an annular space in which the earth and sand and moisture from the outside are prevented from being mixed by the mixing preventing rubber 32. The requirement for the coil spring 3 for transmitting the propulsion force is that the propulsion method bends only within a predetermined allowable range during the propulsion method during the entire construction period, and almost loses the initially set length of the annular space in the tube axis direction. Instead, an annular space that can be extended and contracted over the entire length of the completed pipe line is formed in all the pipe joints.

In forming the pipeline, the resistance near the head is small because the propulsion force is small in view of the frictional resistance of the preceding pipe due to its own weight with the existing pipe and the sheath pipe. Withstands enough pushing force and secures pushing allowance. In the middle, since the number of preceding tubes increases, it is necessary to replace the coil spring with a stronger spring constant to endure the increased pushing force and secure the pushing allowance. In the final pipe, the propulsion force is maximized due to the frictional resistance due to the weight of all the pipes, and the pushing force is considerably larger than the joint near the head. It can withstand the force and secure the pushing force. As described above, it is necessary to enhance the spring constant of the coil spring as the subsequent joint is completed, to make fine adjustments, and to take measures to ensure a substantially constant pushing allowance for the propulsion force.

FIG. 2 is an overall view of the construction according to the present invention, and FIG.
FIG. 2B is a sectional view taken along line 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. 4A to 4C 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 coil spring 3 is fitted between the outer peripheral surface 12 of the insertion port 1 and the mixing prevention cover 31. In FIG. (C), the insertion port 1 is inserted into the reception port 2 and joined.

FIGS. 5A and 5B show the secured joint expansion and contraction amount in this embodiment. Since the connection of all the pipes is completed while the propulsive force transmitting coil spring 3 maintains a constant annular space, a pushing allowance L1 is provided on the side where the joint is pushed, and a drawing 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 pull-out force is applied, the insertion port projection 13 and the lock ring 5 finally engage with each other, so that the structure is resistant to the pull-out force. In addition, since all means to secure pipe joint and joint expansion and contraction are performed from the pipe outer surface side in the start pit,
The present invention is also applicable to small and medium bores having a bore diameter of less than φ800 mm, in which a worker cannot enter the pipe.

FIG. 6 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 due to the high compressive strength of the grout material. 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. .

[0019]

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 greatly due to an earthquake or the like, the joints can follow the ground fluctuations, 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 can be maximized. It is possible. In addition, the means for securing the joint expansion / contraction amount is performed in the start pit at the same time as the propulsion work.
Even pipes of less than 800 mm can be used as seismic pipe joints for propulsion methods, and do not impair the function of existing pipe joints since no function is added to the water-contacting portion 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 sectional view showing the entire construction method.

FIG. 3 is a sectional view taken along the line AA in FIG.
It is an arrow view (B) of a section.

FIGS. 4A to 4C are cross-sectional views showing a joining procedure of the pipe joint according to the present invention by (A) to (C).

FIGS. 5A and 5B are a cross-sectional view and a cross-sectional view illustrating a secured pushing margin and a secured pull-out margin in the present embodiment, respectively.

FIG. 6 is a cross-sectional view showing another embodiment of the present invention.

FIG. 7 is a partial front sectional view of the prior art.

FIG. 8 is a front sectional view showing a pipe-in-pipe method.

FIG. 9 is a partial front sectional view (A) showing another conventional technique, a side view (B) and a front view (C) of a main part.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insertion port 2 Reception port 3 Coil spring for transmitting propulsion force 10 Ductile 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. (Reference) 2D063 BA26 BA27 BA31 3H104 JA08 JB02 JC08 JC09 JD09 JD06 JD09 KA04 KB03 KB06 KB11 KB12 KC01 KC06 LF02

Claims (3)

[Claims] 1. A two-step propulsion method and a pipe-in-pipe method in which pipes are successively joined to the rear 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 propulsion force transmitting coil spring 3 having a spring constant that stays within the range is interposed to prevent the intrusion of earth and sand into the propulsion force transmitting coil spring 3 and use the spring constant to advance from a subsequent pipe. An annular space S which transmits a propulsive force to the pipes, pushes the pipes in the axial direction, advances together, repeats joining and pressing, pushes each pipe to a predetermined position, and can be pushed into all joints of the buried pipe. And can be extended and retracted in two directions: pull-out and push-in An earthquake-resistant propulsion method characterized by having excellent earthquake resistance. 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 propulsion force transmitting coil spring 3 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 propulsion force transmitting coil spring 3 is selected and arranged so as to always stay within a substantially constant allowable bending amount corresponding to the propulsion force that fluctuates with the progress of the propulsion process. A pipe joint for an earthquake-resistant propulsion method. 3. A pipe joint for an earthquake-resistant propulsion method according to claim 2, wherein an annular cushion material 33 is provided around the back surface 14 of the pressing flange 11 of the insertion port 1.