A self-anchoring interface for drag pipes

Abstract

This utility model discloses a self-anchoring interface for dragging pipes, including a spigot, a pipe body, and a socket. The spigot is coaxially connected to one end of the pipe body and inserted into the socket. The outer diameter of the spigot is larger than the outer diameter of the pipe body. The self-anchoring interface also includes a protrusion, at least two arc-shaped first half-flanges, and at least two arc-shaped second half-flanges. The protrusion is fixedly installed on the outer wall of the pipe body. The first half-flanges are spliced ​​into a ring covering the end face of the socket. The second half-flanges cover the splicing gaps, which are the joints of two adjacent first half-flanges. The first half-flanges extend beyond the inner wall of the socket. The first half-flanges, the protrusion, and the spigot contact each other sequentially to transmit thrust, which enables the sequential dragging of adjacent pipes. This utility model enables the sequential dragging of pipes and allows deflection between adjacent pipes. The required components are simple, the installation is simple, the overall cost is low, and the interface strength is high.

Description

Technical Field

[0001] This utility model belongs to the field of pipe technology, specifically a self-anchoring interface for drag pipes. Background Technology

[0002] Pipe-pulling technology is a trenchless underground pipeline laying method. Its core process includes: drilling holes along a designed trajectory using a directional drill bit; progressively enlarging the hole diameter using a reamer; and finally, connecting the pipe to the reamer's tail and pulling it back into the hole. This process is repeated, with subsequent pipes being pulled into the hole by the preceding ones. Connecting adjacent pipes requires utilizing the pipe's structure and other components to form self-anchoring interfaces, enabling the sequential pulling of adjacent pipes. However, if the self-anchoring interface fails during pulling, causing adjacent pipes to detach, the pipes already pulled into the hole must be pulled out again, reconnected, and the pulling process restarted. This significantly reduces construction efficiency and increases costs. Furthermore, the connection of adjacent pipes is carried out and completed on-site, where equipment and personnel have limited technical expertise; therefore, it is best to keep the connection of adjacent pipes simple. Utility Model Content

[0003] To address the aforementioned problems in existing technologies, the purpose of this utility model is to provide a self-anchoring interface for dragging pipes. This interface allows for sequential dragging of pipes, with the protrusion welded to the pipe body. The spigot, being an integral part of the pipe body, possesses high strength, thereby improving the overall strength and reliability of the self-anchoring interface. The second and first half-flanges also exhibit high overall strength. Deflection between adjacent pipes is permitted. The self-anchoring interface requires simple components, is easy to install, has low overall cost, and boasts high interface strength, significantly reducing the probability of rework due to interface detachment during construction. It also requires less expertise in installation equipment and personnel, making it suitable for on-site installation.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0005] A self-anchoring interface for dragging pipes includes a spigot, a pipe body, and a socket. The spigot is coaxially connected to one end of the pipe body and inserted into the socket. The outer diameter of the spigot is larger than the outer diameter of the pipe body. The self-anchoring interface also includes a protrusion, at least two arc-shaped first half-flanges, and at least two arc-shaped second half-flanges. The protrusion is fixedly installed on the outer wall of the pipe body. Each first half-flange is spliced ​​into a ring and covers the end face of the socket. Each second half-flange covers each splicing gap. The splicing gap is the joint of two adjacent first half-flanges. The first half-flanges extend beyond the inner wall of the socket. The first half-flanges, the protrusion, and the spigot contact each other in sequence to transmit thrust. This thrust is an axial thrust, enabling the sequential dragging of adjacent pipes.

[0006] As a further improvement to the above technical solution:

[0007] The protrusion extends radially beyond the socket.

[0008] The inner wall of the socket is provided with a first clearance groove, a blocking part, a sealing groove and a second clearance groove in sequence from the end face away from the end face of the socket. The inner diameter of the socket at the first clearance groove is larger than the inner diameter of the socket at the blocking part. The inner diameter of the socket at the sealing groove, the inner diameter of the socket at the second clearance groove and the inner diameter of the pipe body decrease in sequence. The first clearance groove is used to avoid the protrusion so that the protrusion can enter the socket.

[0009] The width of the protrusion is less than the width of the first clearance groove. The width of the protrusion refers to its axial dimension, and the width of the first clearance groove refers to its axial dimension in the socket.

[0010] When the spigot and socket are coaxial, neither the first half flange nor the second half flange will contact the pipe body.

[0011] Neither the first half flange nor the second half flange extends beyond the outer wall of the socket radially.

[0012] The first and second half flanges are fixed to the socket by fasteners.

[0013] In the overlapping portion of the first and second half flange plates, the fastener passes through the second and first half flange plates in sequence and is then inserted into the socket from the socket end face. For the first half flange plate not covered by the second half flange plate, the fastener passes through the first half flange plate and is then inserted into the socket from the socket end face.

[0014] The socket is provided with a blind fastening hole for fasteners to be inserted, and the fastening hole is formed by recessing from the end face of the socket.

[0015] Two adjacent pipes can deflect relative to each other. When the maximum deflection angle is α, the following condition is satisfied:

[0016] h>D1+(2t2+2L1+S1)sinα-d2 cosα

[0017] B>bcosα+(D2+2h)sinα

[0018]

[0019] Where h is half the difference between the outer and inner diameters of the protrusion, D1 is the outer diameter of the socket, t2 is the axial distance between the connection between the sealing groove and the second clearance groove and the bottom of the fastening hole, L1 is the length of the fastening hole, S1 is the thickness of the first half flange, d2 is the minimum inner diameter of the socket at the second clearance groove, B is the dimension of the first clearance groove in the direction parallel to the central axis of the pipe, b is the width of the protrusion, D2 is the outer diameter of the pipe body, and H is half the difference between the inner diameter of the socket at the first clearance groove and the outer diameter of the pipe body.

[0020] The beneficial effects of this utility model are:

[0021] (1) The first half flange, the protrusion, and the spigot sequentially contact and transmit force, enabling the pipe to be pulled sequentially. The protrusion is welded to the pipe body, and the spigot, as part of the main body of the pipe, has high strength. The force is ultimately transmitted to the main body of the pipe, thereby improving the overall strength and reliability of the self-anchoring interface, which is suitable for pulling large-diameter pipes. In addition, the outer diameter of the spigot is smaller than the outer diameter of the protrusion but larger than the inner diameter of the protrusion. This means that the spigot contacts a part of one end face of the protrusion near the central axis, which is equivalent to providing a counterweight for the part of the protrusion near the central axis. When two adjacent pipes deflect relative to each other, the above-mentioned arrangement of the protrusion makes the torque required for the protrusion to rotate greater, and the interface strength greater.

[0022] (2) The second half flange is stacked on the first half flange and covers the gap between two adjacent first half flanges, which greatly improves the overall strength of the second half flange and the first half flange.

[0023] (3) There are gaps between the second half flange and the first half flange and the coaxial pipe body, gaps between the protrusion and the wall of the first clearance groove, and gaps between the spigot and the socket outside the sealing ring. This allows the adjacent pipes to deflect, so that the pipes can deflect under external force during construction and use, thus improving the flexibility and applicability of the pipes.

[0024] (4) The second half flange and the first half flange do not extend beyond the outer wall of the socket in the radial direction, and will not be subject to forward resistance during construction, thus minimizing other external forces borne by the second half flange and the first half flange; the fasteners inserted into the blind holes in the socket will not be subject to the resistance of the pipe during construction because they pass through the socket.

[0025] (5) The self-anchored interface requires simple components and is easy to install. The overall cost is low and the interface strength is high, which greatly reduces the probability of rework due to interface detachment during construction. It has low requirements for installation equipment and personnel technical level and is suitable for on-site installation. Attached Figure Description

[0026] Figure 1This is a schematic diagram of the pipe structure according to an embodiment of the present invention.

[0027] Figure 2 This is a schematic diagram of a self-anchoring interface according to an embodiment of the present invention.

[0028] Figure 3 yes Figure 2 Another perspective structural diagram.

[0029] Figure 4 This is a schematic diagram of the relative deflection of the socket and the insert of the self-anchoring interface according to an embodiment of the present invention.

[0030] Figure 5 This is a schematic diagram of the socket end dimensions of one embodiment of the present invention.

[0031] Figure 6 yes Figure 4 Enlarged diagram of F1.

[0032] Figure 7 yes Figure 4 Enlarged diagram at F2.

[0033] Figure 8 yes Figure 4 Enlarged diagram at F3.

[0034] Reference numerals: 1. socket, 2. spigot, 21. first clearance groove, 22. blocking part, 23. sealing groove, 24. fastening hole, 25. second clearance groove, 3. pipe body, 4. protrusion, 5. first half flange, 6. second half flange, 7. fastener, 8. sealing ring, 9. gasket, 10. socket reinforcing ring. Detailed Implementation

[0035] The specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of this utility model.

[0036] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0037] A self-anchoring interface for drag pipes, such as Figure 1 As shown, the pipe is a socket-type pipe, comprising a spigot 1, a pipe body 3, and a socket 2 connected coaxially in sequence. The outer diameter of the spigot 1 is larger than the outer diameter of the pipe body 3, meaning the spigot 1 protrudes from the outer surface of the pipe body 3, forming a stepped structure. The end face of the spigot 1 furthest from the pipe body 3 is the end face of the spigot 1, and the end face or side face of the spigot 1 connected to the pipe body 3 is the stepped surface. That is, the stepped surface is formed by the spigot 1 protruding from the surface of the pipe body 3, and the plane containing the stepped surface is parallel to the radial direction of the spigot 1.

[0038] A reinforcing ring 10 is fitted inside the socket 1 to enhance its strength. The reinforcing ring 10 can be integrally formed with the socket 1, essentially making them two layers of the same or different metal materials. Alternatively, the reinforcing ring 10 can be installed separately. When installed separately, the reinforcing ring 10 is annular, typically made of stainless steel, and possesses a certain degree of ductility and rigidity. The initial outer diameter of the reinforcing ring 10 is smaller than the inner diameter of the socket 1. During installation, the reinforcing ring 10 is placed inside the socket 1, and then its diameter is expanded using an expanding device until it is tightly pressed against the inner wall of the socket 1. The reason why the spigot reinforcing ring 10 can be pressed tightly against the inner wall of the spigot 1 is that during the expansion process, the inner wall of the spigot 1 will be subjected to radial pressure from the expansion equipment. After the pressure is removed (the expansion is completed), the spigot 1 and the spigot reinforcing ring 10 will have a certain elastic recovery. Since the spigot 1 has a large wall thickness and is connected to the pipe body, the elastic recovery is greater than that of the spigot reinforcing ring 10. After the recovery, the spigot reinforcing ring 10 is pressed tightly against the inner wall of the spigot.

[0039] A protrusion 4 is fixedly installed on the outside of the tube body 3. The protrusion 4 contacts the stepped surface of the socket 1 and protrudes from the outer surface of the socket 1. The outer surface of the socket 1 refers to the curved outer wall of the socket 1.

[0040] In this embodiment, the protrusion 4 is a ring-shaped structure made of metal, and is coaxially and fixedly sleeved on the outside of the tube body 3. The inner surface of the protrusion 4 contacts the outer surface of the tube body 3, and one end face of the protrusion 4 contacts the stepped surface of the socket 1. The outer diameter of the protrusion 4 is larger than the outer diameter of the socket 1.

[0041] In this embodiment, the protrusion 4 is welded onto the tube body 3.

[0042] When two adjacent pipes are connected, the spigot 1 of one pipe is inserted into the socket 2 of the other pipe, and with the cooperation of other auxiliary parts, the self-anchoring interface is formed.

[0043] The self-anchoring interface is as follows: Figure 2 and 3 As shown, it includes a spigot 1, a pipe body 3, a socket 2, a protrusion 4, a first half flange 5, a second half flange 6, a fastener 7, a sealing ring 8, a gasket 9, and a spigot reinforcing ring 10.

[0044] The spigot 1 is coaxially connected to one end of the pipe body 3. The spigot 1 and the socket 2 of the self-anchoring interface are the spigot 1 and the socket 2 of two adjacent pipes, respectively. The spigot 1 is inserted into the socket 2, and at the same time, the protrusion 4 enters the socket 2.

[0045] The inner wall of the socket 2 of the same pipe material is provided with a first relief groove 21, a blocking part 22, a sealing groove 23, and a second relief groove 25 sequentially from the end face towards the pipe body 3. The first relief groove 21, the sealing groove 23, and the second relief groove 25 are all grooves provided on the inner wall of the socket 2, that is, they are formed by indentation from the inner wall of the socket 2. The blocking part 22 is the part that is not indented. Each groove is a groove that runs around the circumference of the inner wall of the socket 2. The inner diameter of the socket 2 at the sealing groove 23, the inner diameter of the socket 2 at the second relief groove 25, and the inner diameter of the pipe body 3 decrease sequentially. The inner diameter of the socket 2 at the first relief groove 21 is larger than the inner diameter of the socket 2 at the blocking part 22. The inner diameter of the socket 2 at the sealing groove 23 is larger than the inner diameter of the socket 2 at the blocking part 22. The inner diameter of the socket 2 at the second relief groove 25 is not smaller than the inner diameter of the socket 2 at the blocking part 22. The inner diameter of the socket 2 at the blocking part 22 is larger than the inner diameter of the pipe body 3. The first clearance groove 21 is used to avoid the protrusion 4, so that when the spigot 1 is inserted into the socket 2, the protrusion 4 enters the first clearance groove 21. The sealing groove 23 is used to install the sealing ring 8 to achieve a seal after the connection of two adjacent pipes. The sealing groove 23 is pressed between the spigot 1 and the socket 2. The inner diameter of the socket 2 at various points in the second clearance groove 25 may not be completely equal. Specifically, from the end face of the socket 2 toward the direction away from the end face of the socket 2, the inner diameter of the socket 2 gradually increases at various points in the second clearance groove 25.

[0046] Both the first half-flange 5 and the second half-flange 6 are arc-shaped structures. There are at least two first half-flanges 5 and at least two second half-flanges 6. The first half-flanges 5 are joined together to form a ring that covers the end face of the socket 2. Each second half-flange 6 covers its respective joint, which is the junction of two adjacent first half-flanges 5. In other words, the second half-flange 6 does not need to cover the entire first half-flange 5, but only the joint between two adjacent first half-flanges 5. All the second half-flanges 6 are on the same ring.

[0047] The above-mentioned arrangement of the first half flange 5 and the second half flange 6 improves the overall connection strength and reliability of the two, and minimizes the probability of the first half flange 5 and the second half flange 6 falling off and failing during construction.

[0048] The first half-flange 5 and the second half-flange 6 extend radially beyond the inner wall of the socket 2 end face until the first half-flange 5 contacts the end face of the protrusion 4 furthest from the spigot 1. That is, the inner diameter of the annulus formed by the splicing of the first half-flange 5 and the inner diameter of the annulus containing the second half-flange 6 are both smaller than the inner diameter at the socket 2 end face and the outer diameter of the protrusion 4. Specifically, the side of the first half-flange 5 furthest from the second half-flange 6 contacts the end face of the protrusion 4 furthest from the spigot 1. This is equivalent to the first half-flange 5 being blocked by the protrusion 4, and the protrusion 4 being blocked by the step formed by the spigot 1 protruding from the surface of the pipe body 3. This allows the first half-flange 5, the protrusion 4, and the spigot 1 to sequentially contact and transmit thrust. This thrust is axial, enabling the sequential axial dragging of adjacent pipes.

[0049] Neither the first half flange 5 nor the second half flange 6 extends radially beyond the outer wall of the socket 2. That is, the outer diameter of the annulus formed by the splicing of the first half flanges 5 or the outer diameter of the annulus containing the second half flange 6 is less than or equal to the outer diameter at the end face of the socket 2. Thus, during construction, the first half flanges 5 and 6 will not experience the forward resistance from the surrounding soil or other factors, minimizing the external forces acting on them and improving their reliability.

[0050] In this embodiment, each of the second half flanges 6 is located on the same ring. The outer diameter of the ring is equal to the outer diameter of the ring formed by splicing the first half flanges 5, and the inner diameter of the ring is greater than the inner diameter of the ring formed by splicing the first half flanges 5.

[0051] When spigot 1 and socket 2 are coaxial, neither the first half-flange 5 nor the second half-flange 6 contacts the outer wall of the pipe body 3. That is, the inner diameter of the annulus formed by the splicing of the first half-flanges 5 or the inner diameter of the annulus containing the second half-flange 6 is greater than the outer diameter of the pipe body 3. The width of the protrusion 4 is less than the width of the first clearance groove 21. The width of the protrusion 4 refers to its axial dimension, and the width of the first clearance groove 21 refers to its axial dimension in the socket 2. The minimum inner diameter of the socket 2 is greater than the outer diameter of the spigot 1. In other words, when spigot 1 and socket 2 are coaxial, there are gaps between the first half-flange 5 and the second half-flange 6 and the pipe body 3, between spigot 1 and socket 2, and between the protrusion 4 and the wall of the first clearance groove 21. These gaps allow relative deflection between adjacent pipes to accommodate relative deflection caused by external forces during pipe construction or use. Figure 4 The dashed line shows the position of the spigot 1 and the pipe body 3 after the pipe containing the spigot 1 is rotated clockwise relative to the pipe containing the socket 2. After the counterclockwise rotation, the position is symmetrical about the axis.

[0052] In this embodiment, there are two first half flanges 5 and two second half flanges 6.

[0053] Multiple fasteners 7 are provided, and the first half flange 5 and the second half flange 6 are fixed to the socket 2 by the fasteners 7. The multiple fasteners 7 are arranged at intervals on the same ring. In the part where the first half flange 5 and the second half flange 6 are stacked, the fasteners 7 pass through the second half flange 6 and the first half flange 5 in sequence and are inserted into the socket 2 from the end face of the socket 2. In the part not covered by the second half flange 6, the fasteners 7 pass through the first half flange 5 and are inserted into the socket 2 from the end face of the socket 2.

[0054] Furthermore, the socket 2 is provided with blind fastening holes 24 for inserting fasteners 7, which are recessed from the end face of the socket 2. One fastener 7 is inserted into each fastening hole 24. The fastener 7 does not protrude beyond the socket 2 to avoid the fastener 7 being subjected to forward resistance during construction.

[0055] In this embodiment, the fastener 7 is a bolt, and a washer 9 is provided between the head of the fastener 7 and the first half flange 5 or between the second half flange 6.

[0056] In this embodiment, there are 12 fasteners 7.

[0057] In this embodiment, the outer surface of the socket 2 is a smooth connection and transition surface, and the outer diameter of the socket 2 gradually increases from the pipe body 3 toward the socket 2.

[0058] When installing two adjacent pipes, first insert the sealing ring 8 into the sealing groove 23 of the socket 2 of the first pipe, then insert the spigot 1 of the second pipe into the socket 2 of the first pipe, and the protrusion 4 enters the socket 2. Then, install the first half flange 5 and the second half flange 6 together with the fasteners 7 to complete the installation of the self-anchoring interface.

[0059] The deflection angle is the angle at which two adjacent pipes deflect relative to each other. When the deflection angle between the two adjacent pipes is at its maximum value, after deflection, both the first half flange 5 and the second half flange 6 of the self-anchoring interface contact the pipe body 3, and the spigot 1 contacts the socket 2 on the inner wall corresponding to the second clearance groove 25. Specifically, in Figure 4 In the cross-section shown, when the pipe containing spigot 1 is deflected clockwise relative to the pipe containing socket 2 to the maximum deflection angle α, as follows... Figure 6 As shown, after deflection, the end of the inner wall of the second half flange 6 furthest from the first half flange 5 contacts the pipe body 3 at point O1; the end of the inner wall of the first half flange 5 closest to the second half flange 6 contacts the pipe body 3 at point O2; and the contact point between the inner wall of the second half flange 6 and the first half flange 5 is point O3. Clearly, points O1, O2, and O3 are located at the three vertices of a right triangle, and... Among them, L 23 L is the distance between points O2 and O3. 13 This is the distance between points O1 and O3 (i.e., the thickness of the second half flange 6, or the dimension parallel to the axial direction of the pipe). The spigot 1 contacts the inner wall of the socket 2 at the point where the inner diameter of the second relief groove 25 is at its minimum.

[0060] For ease of explanation, assume that before deflection, the central axes of the two adjacent pipes coincide, and the stepped surfaces of the first half flange 5, the protrusion 4, and the spigot 1 contact each other in sequence; after deflection, the central axes of the two adjacent pipes intersect, as shown below. Figure 4 As shown. To ensure that the maximum deflection angle between two adjacent tubes reaches α, as... Figure 7 and 8 As shown, the thickness h of the protrusion 4 (i.e., half the difference between the outer diameter and the inner diameter of the protrusion 4), the dimension B of the first clearance groove 21 in the direction parallel to the central axis of the pipe, and half the difference H between the inner diameter of the socket 2 at the first clearance groove 21 and the outer diameter of the pipe body 3 satisfy the following:

[0061] h>h0 (1)

[0062] B>B0 (2)

[0063] H>H0 (3)

[0064] Wherein, h0 is the maximum vertical distance from the end of the inner wall of the first half flange 5 near the socket 1 to the deflected pipe body 3. B0 is the maximum axial distance from the end of the protrusion 4 near the first half flange 5 before deflection to the end of the protrusion 4 away from the first half flange 5 after deflection, where the axial direction refers to the axial direction of the protrusion 4 before deflection or the axial direction of the socket 2. H0 is the maximum radial distance between the outer wall of the pipe body 3 before deflection and the outer wall of the protrusion 4 after deflection, where the radial direction refers to the radial direction of the protrusion 4 before deflection or the socket 1.

[0065] Based on the above inequalities (1) to (3) and the geometric relationship before and after pipe deflection, we obtain:

[0066] h>D1+(2t2+2L1+S1)sinα-d2 cosα (4)

[0067] B>bcosα+(D2+2h)sinα (5)

[0068]

[0069] The meanings of each symbol are as follows:

[0070] D1 is the outer diameter of the socket 1, t2 is the axial (parallel to the central axis of the pipe) distance between the connection of the sealing groove 23 and the second relief groove 25 and the bottom of the fastening hole 24, L1 is the length of the fastening hole 24, that is, the dimension of the fastening hole 24 in the direction parallel to the central axis of the pipe, S1 is the thickness of the first half flange 5, that is, the dimension of the first half flange 5 in the direction parallel to the central axis of the pipe, d2 is the minimum inner diameter of the socket 2 at the second relief groove 25, b is the width of the protrusion 4, that is, the dimension of the protrusion 4 in the direction parallel to the central axis of the pipe, and D2 is the outer diameter of the pipe body 3.

[0071] It should be noted that the above formula does not limit the specific values ​​of each parameter. The specific values ​​of each parameter can be selected and calculated according to the application, but they must satisfy the above formula. For example, the outer diameter of the spigot 1 is selected according to the required specifications based on the application requirements, and the width b of the protrusion 4 is calculated based on the allowable tensile force, the allowable stress of the pipe, etc.

[0072] Finally, it is necessary to state that the above embodiments are only used to further illustrate the technical solution of this utility model in detail, and should not be construed as limiting the scope of protection of this utility model. Any non-essential improvements and adjustments made by those skilled in the art based on the above content of this utility model shall fall within the scope of protection of this utility model.

Claims

1. A self-anchoring joint for pulling a pipe, comprising a spigot (1), a pipe body (3) and a socket (2), the spigot (1) being coaxially connected to one end of the pipe body (3), the spigot (1) being inserted into the socket (2), characterized in that, The outer diameter of the socket (1) is larger than the outer diameter of the pipe body (3). The self-anchoring interface also includes a protrusion (4), at least two arc-shaped first half flanges (5) and at least two arc-shaped second half flanges (6). The protrusion (4) is fixedly installed on the outer wall of the pipe body (3). Each first half flange (5) is spliced ​​into a ring and covers the end face of the socket (2). Each second half flange (6) covers each splicing gap. The splicing gap is the splicing point of two adjacent first half flanges (5). The first half flange (5) extends beyond the inner wall of the socket (2). The first half flange (5), the protrusion (4) and the socket (1) contact each other in sequence to transmit thrust. The thrust is an axial thrust, which realizes the sequential dragging of adjacent pipes.

2. The self-anchoring interface of claim 1, wherein: The protrusion (4) extends radially beyond the socket (1).

3. The self-anchoring interface of claim 1, wherein: The inner wall of the socket (2) is provided with a first clearance groove (21), a blocking part (22), a sealing groove (23), and a second clearance groove (25) in sequence from the end face away from the end face of the socket (2). The inner diameter of the socket (2) at the first clearance groove (21) is larger than the inner diameter of the socket (2) at the blocking part (22). The inner diameter of the socket (2) at the sealing groove (23), the inner diameter of the socket (2) at the second clearance groove (25), and the inner diameter of the pipe body (3) decrease in sequence. The first clearance groove (21) is used to avoid the protrusion (4) so ​​that the protrusion (4) can enter the socket (2).

4. The self-anchoring interface of claim 3, wherein: The width of the protrusion (4) is less than the width of the first clearance groove (21). The width of the protrusion (4) refers to the axial dimension of the protrusion (4), and the width of the first clearance groove (21) refers to the axial dimension of the first clearance groove (21) in the socket (2).

5. The self-anchoring interface of claim 1, wherein: When the spigot (1) and the socket (2) are coaxial, neither the first half flange (5) nor the second half flange (6) will contact the pipe body (3).

6. The self-anchoring interface of claim 1, wherein: Neither the first half flange (5) nor the second half flange (6) extends beyond the outer wall of the socket (2) in the radial direction.

7. The self-anchoring interface of claim 3, wherein: The first half flange (5) and the second half flange (6) are fixed to the socket (2) by fasteners (7).

8. The self-anchoring interface of claim 7, wherein: In the overlapping portion of the first half flange (5) and the second half flange (6), the fastener (7) passes through the second half flange (6) and the first half flange (5) in sequence and is then inserted into the socket (2) from the end face of the socket (2). For the first half flange (5) that is not covered by the second half flange (6), the fastener (7) passes through the first half flange (5) and is then inserted into the socket (2) from the end face of the socket (2).

9. The self-anchoring interface of claim 7, wherein: The socket (2) is provided with a blind fastening hole (24) for inserting a fastener (7), and the fastening hole (24) is formed by recessing from the end face of the socket (2).

10. The self-anchoring interface of claim 9, wherein: Two adjacent pipes can deflect relative to each other. When the maximum deflection angle is α, the following condition is satisfied: h>D1+(2t2+2L1+S1)sinα-d2 cosα B>bcosα+(D2+2h)sinα Where h is half the difference between the outer diameter and inner diameter of the protrusion (4), D1 is the outer diameter of the socket (1), t2 is the axial distance between the connection between the sealing groove (23) and the second relief groove (25) and the bottom of the fastening hole (24), L1 is the length of the fastening hole (24), S1 is the thickness of the first half flange (5), d2 is the minimum inner diameter of the socket (2) at the second relief groove (25), B is the dimension of the first relief groove (21) in the direction parallel to the central axis of the pipe, b is the width of the protrusion (4), D2 is the outer diameter of the pipe body (3), and H is half the difference between the inner diameter of the socket (2) at the first relief groove (21) and the outer diameter of the pipe body (3).

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