Pipe joint of pipe jacking tunnel convenient to jacking and sealing waterproof

Abstract

The application provides a pipe joint of pipe jacking tunnel, which is convenient for jacking and sealing waterproof, a steel plate is fixedly covered on the outer wall of the pipe joint body, the coverage of the steel plate is 80%-95%, the outer wall of the steel plate is flush with the outer wall of the pipe joint body which is not covered by the steel plate, annular grooves are arranged on the front side wall and the rear side wall of the pipe joint body, the grooves are continuous structures and the overall shape of the grooves is consistent with the shape of the pipe joint, the positions of the two grooves correspond to each other, a male sealing strip is arranged in the groove of the front side wall, and a female sealing strip is arranged in the groove of the rear side wall. The pipe joint can further reduce the friction between the pipe joint and the soil layer, and is convenient for jacking operation. Meanwhile, the waterproof structure of the pipe joint adopts hot melt adhesive which is coated on the metal plate and filled in the gap between the two sealing strips, so that a dense waterproof sealing layer is formed, and excellent waterproof effect can be achieved.

Description

Technical Field

[0001] This invention provides a pipe section for use in pipe jacking tunnels that is easy to jack and waterproof, belonging to the field of tunnel waterproofing structure technology. Background Technology

[0002] With the rapid pace of urban construction, the number of municipal pipelines is increasing. Direct excavation has a significant environmental impact and poor social benefits. Pipe jacking, as a trenchless technology, has been widely used in municipal pipeline construction. Pipe jacking technology requires no ground excavation or demolition, does not disrupt traffic, causes minimal environmental damage, and offers good social and economic benefits. Pipe jacking involves using the jacking force generated by jacking equipment within a working pit to overcome the friction between the pipeline and the surrounding soil, pushing the pipeline into the ground at the designed slope. The excavated soil is then removed. After one section of pipe is pushed into the soil, the second section is lowered and the process continues. The principle is based on the thrust from the main jacking cylinder and the pipeline itself, as well as intermediate sections, to advance the tool pipe or tunneling machine from the working pit through the soil to the receiving pit, where it is then lifted. The pipeline follows closely behind the tool pipe or tunneling machine and is buried between the two pits.

[0003] During pipe jacking, because the diameter of the end drill bit is larger than the diameter of the pipe, a certain gap exists between the pipe and the surrounding soil. Injecting thixotropic mud into this gap reduces the friction between the pipe section and the soil layer, facilitating the jacking operation. The grouting process is repeated throughout the entire jacking process. If the grouting effect is poor, such as failing to form a complete and effective mud sleeve in time, it may lead to increased pipe thrust, resulting in significant deformation later. In long-distance or ultra-long-distance pipe jacking, due to the long construction period, the loss of water in the mud will cause the thixotropic mud to become ineffective. Therefore, it is necessary to set grouting holes at regular intervals along the pipeline and from the tool pipe to replenish the thixotropic mud in a timely manner. Furthermore, after the pipeline is laid and the tunnel is completed, the thixotropic mud will lose water, shrink, and solidify, potentially causing continuous surface subsidence later. Therefore, replacement grouting is required after the pipe jacking tunnel is completed, with timely injection of cement grout to replace or fill the thixotropic mud used during construction, consolidating the tunnel and the strata. Therefore, how to ensure that the thixotropic mud and cement grout fill the gap between the pipe section and the soil layer as quickly and uniformly as possible during the injection process is an urgent problem to be solved in this field.

[0004] Meanwhile, pipe segment connection is also a technical challenge in pipe jacking projects, often resulting in connection failures or severe water leakage. In existing technologies, pre-adhesive neoprene rubber is often used as the primary waterproofing measure between pipe segments, supplemented by a comprehensive waterproofing scheme involving grouting. This involves pre-adheding a ring of neoprene rubber on the outer side of the tail of the preceding pipe segment, with the socket plate of the subsequent pipe segment exerting a certain pressure on this rubber ring, thus forming the first layer of waterproofing. Grouting holes are pre-reserved within the pipe segment structure to fill the gaps between the socket plate of the subsequent pipe segment and the preceding pipe segment structure, forming the second layer of waterproofing. In practical applications, existing technologies have the following problems: the "pressure effect" between the socket plate of the subsequent pipe segment and the neoprene rubber of the preceding pipe segment is difficult to control; construction deviations during pipe segment jacking can easily cause uneven and uncertain "pressure effects"; differential settlement between pipe segments in the later stages causes the "pressure effect" to change over time, leading to voids and leakage points; due to process limitations, the grouting holes are blocked after the first grouting, making long-term, repeated grouting impossible. Therefore, how to solve the problem that the waterproofing measures between pipe jacking sections cannot guarantee their long-term effectiveness has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] This invention addresses the shortcomings of existing technologies by providing a pipe jacking tunnel segment that is easy to jack and provides a waterproof seal. This segment utilizes steel plates combined with magnetic thixotropic mud and magnetic mortar. During grouting, the magnetic thixotropic mud quickly and evenly fills the gaps, reducing friction. Simultaneously, the metallic material of the steel plates further reduces friction between the segment and the soil layer, facilitating jacking operations. Furthermore, the waterproof structure of this segment employs hot-melt adhesive to coat the metal plates and fill the gaps between the two sealing strips, forming a dense waterproof seal layer that provides excellent waterproofing.

[0006] The technical solution adopted to achieve the above-mentioned objectives of this invention is as follows:

[0007] A pipe jacking tunnel segment that is easy to jack and waterproof includes at least a cylindrical pipe segment body. The outer wall of the pipe segment body is fixedly covered with a steel plate, and the coverage of the steel plate is 80% to 95%. The outer wall of the steel plate is flush with the outer wall of the pipe segment body that is not covered with a steel plate. The area of ​​the outer wall of the pipe segment body that is not covered with a steel plate is located at the front and rear ends. The inner wall of the steel plate is provided with concave and convex textures. The steel plate and the pipe segment body are tightly fixed by concrete pouring.

[0008] Both the front and rear sidewalls of the pipe section body are provided with annular grooves. The grooves are continuous structures and their overall shape is consistent with the shape of the pipe section. The two grooves are in corresponding positions. A male sealing strip is provided in the groove of the front sidewall and a female sealing strip is provided in the groove of the rear sidewall.

[0009] The male sealing strip includes a first hot-melt rubber strip and a strip-shaped metal plate. The lower part of the metal plate is fixed inside the first hot-melt rubber strip, and the upper part of the metal plate extends from the top surface of the first hot-melt rubber strip. Two connection points are provided at the bottom of the metal plate. The female sealing strip is composed of a second hot-melt rubber strip, and the second hot-melt rubber strip has the same structure as the first hot-melt rubber strip.

[0010] Two terminal blocks are provided in the groove of the front sidewall. The terminal blocks correspond to the connection points on the metal plate and are electrically connected. A wire is pre-embedded in the pipe section body. One end of the wire is connected to the terminal block, and the other end of the wire is located on the inner wall of the pipe section body near the front sidewall.

[0011] Furthermore, the pipe section body is provided with grouting holes and grout discharge holes, and openings are provided on the steel plate at positions corresponding to the grouting holes and grout discharge holes.

[0012] Furthermore, the surface of the metal plate is provided with an uneven pattern to increase the bonding strength between the metal plate and the hot melt rubber.

[0013] Furthermore, both the first and second hot melt rubber strips have porous structures, and the melting point of the first hot melt rubber strip is higher than that of the second hot melt rubber strip.

[0014] Furthermore, the cross-section of the groove is a trapezoid with a larger inner diameter and a smaller outer diameter. The cross-sectional structure of the first and second hot-melt rubber strips is also trapezoidal, and their thickness is greater than the depth of the groove.

[0015] Furthermore, the top edge of the metal plate is sharp.

[0016] Furthermore, a pre-reserved slot is provided on the top surface of the female sealing strip at the center line position to facilitate the insertion of the metal plate.

[0017] Furthermore, the connection point is a two-conical protrusion structure, and the terminal block is funnel-shaped with a larger outer surface and a smaller inner surface. The connection point extends from the bottom surface of the first hot melt rubber strip and is inserted into the terminal block, thereby electrically connecting with the wires in the pipe section.

[0018] Furthermore, a plastic tube is pre-embedded in the pipe section, through which the wire passes. The plastic tube has an arc-shaped or bent structure, with one end connected to the terminal block and the other end leading to the inner wall of the pipe section.

[0019] Furthermore, the two connection points on the metal plate are located on the bottom edge of the metal plate and near the two ends.

[0020] Compared with the prior art, the pipe jacking tunnel section provided by the present invention, which is easy to jack up and is sealed and waterproof, has the following advantages:

[0021] 1. In this application, a steel plate is fixedly wrapped around the outer wall of the pipe section body. The steel plate is cast and fixed to the pipe section body through the concave and convex grooves on the bottom, and the outer wall of the steel plate is flush with the outer wall of the end of the pipe section body. Therefore, the connection between the steel plate and the pipe section body is very strong. During jacking, since the jacking pressure mainly comes from the friction between the pipe section and the soil layer, the steel plate wrapped around the outer wall of the pipe section in this application facilitates jacking operations because the friction between the steel plate and the soil layer is much smaller than the friction between concrete and soil layer.

[0022] 2. Since the steel plate on the pipe section body in this application is ferromagnetic, when injecting thixotropic grout, magnetic thixotropic grout with added iron rubidium boron magnetic powder can be used. When the magnetic thixotropic grout is injected into the gap between the pipe section body and the soil layer, it can quickly and evenly fill the internal gap under the action of magnetic force, shorten the grouting time, and avoid causing voids.

[0023] 3. In this application, the steel plate on the pipe section body is ferromagnetic. After the entire pipe section is jacked in, magnetic powder is added to the injected cement mortar, and the magnetic mortar is injected to replace the magnetic thixotropic mud. Due to the magnetic force between the magnetic mortar and the steel plate, the contact between the mortar and the pipe section body is closer, and after curing, it can provide better support for the pipe section.

[0024] 4. This application creatively employs an electrothermal melting method for waterproofing. The melting point of rubber is typically between 90-140℃, varying depending on the material. When electricity is applied to the metal plate via pre-installed wires, the heat generated raises the temperature around the metal plate above the rubber's melting point. The rubber around the metal plate gradually melts. As the power is turned off and the temperature decreases, the melted rubber adheres to the metal plate. The patterned design on the metal plate surface enhances the adhesion between the rubber and the metal plate. Simultaneously, the melted rubber gradually penetrates into the gaps between the male and female sealing strips, sealing them. It also seals the gaps where the male and female sealing strips meet. Combined with the sealing effect of the metal plate, this effectively isolates the external environment from the tunnel interior, preventing water leakage. Furthermore, because the melted rubber coats the metal plate, it not only waterproofs but also prevents corrosion and rust from water or seawater, resulting in a more stable waterproofing effect and a longer service life. Attached Figure Description

[0025] Figure 1 A cross-sectional schematic diagram of a pipe jacking tunnel section that is easy to jack up and is sealed and waterproof, provided by the present invention;

[0026] Figure 2 A schematic diagram of the overall structure of a pipe jacking tunnel section that is easy to jack up and waterproof, provided by the present invention;

[0027] Figure 3 This is a schematic diagram of the connection status of adjacent pipe sections in an embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram of the male and female sealing strips.

[0029] Figure 5 for Figure 3 A magnified view of the local structure;

[0030] In the diagram: 1-pipe section body, 2-steel plate, 3-groove, 4-first hot melt rubber strip, 5-metal plate, 6-connection point, 7-second hot melt rubber strip, 8-connection socket, 9-wire, 10-plastic pipe, 11-grouting hole, 12-grout discharge hole. Detailed Implementation

[0031] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. However, the scope of protection of the present invention is not limited to the following embodiments.

[0032] The structure of the jacking tunnel segment provided in this embodiment, which is easy to jack up and waterproof, is as follows: Figure 1 and Figure 2 As shown, the outer wall of the pipe section body 1 is fixedly covered with a steel plate 2, with a coverage rate of 80% to 95%. The outer wall of the steel plate is flush with the outer wall of the pipe section body that is not covered with a steel plate. The areas of the outer wall of the pipe section body that are not covered with a steel plate are located at the front and rear ends. The inner wall of the steel plate is provided with concave and convex textures. The steel plate and the pipe section body are tightly fixed by concrete pouring. The pipe section body is provided with grouting holes 11 and grout discharge holes 12, and the steel plate is provided with openings at positions corresponding to the grouting holes and grout discharge holes. In this embodiment, the steel plate is fixed to the pipe section body by the concave and convex textures at the bottom, and the outer wall of the steel plate is flush with the outer wall of the end of the pipe section body. Therefore, the connection between the steel plate and the pipe section body is very strong. During jacking, since the jacking pressure mainly comes from the friction between the pipe section and the soil layer, the outer wall of the pipe section is covered with a steel plate in this application. Since the friction between the steel plate and the soil layer is much smaller than the friction between the concrete and the soil layer, the pipe section in this application can be easily jacked.

[0033] Both the front and rear sidewalls of the pipe section body are provided with annular grooves 3. The grooves are continuous structures and their overall shape is consistent with the shape of the pipe section. The two grooves are positioned correspondingly. A male sealing strip is installed in the groove on the front sidewall, and a female sealing strip is installed in the groove on the rear sidewall. This design is mainly to take into account that when the jacks in the working well are used for jacking, the rear end of the pipe section needs to bear the thrust of the jacks. If the male sealing strip is installed at the rear end, it will cause damage to the metal plate in the male sealing strip. Therefore, the female sealing strip is installed in the groove at the rear end of the pipe section.

[0034] The structures of the male and female sealing strips are as follows: Figure 4 As shown in the diagram, straight male and female sealing strips are installed in grooves on the front and rear side walls, respectively. Since both the male and female sealing strips are made of flexible material, and the metal plate within the male sealing strip is also elastic, installation simply involves inserting them along the direction of the groove. Typically, the first end of the male and female sealing strips is inserted from the bottom of the groove, then they are inserted around the groove once, and finally the last end is inserted to the bottom of the groove, forming a loop.

[0035] The sealing strip includes a first hot-melt rubber strip 4 and a strip-shaped metal plate 5, such as... Figure 4 As shown, the lower part of the metal plate is fixed inside the first hot-melt rubber strip, and the upper part of the metal plate extends from the top surface of the first hot-melt rubber strip. The surface of the metal plate is provided with an uneven pattern to increase the bonding strength between the metal plate and the hot-melt rubber. The female sealing strip is composed of a second hot-melt rubber strip 7, which has the same structure as the first hot-melt rubber strip. To make the connection between the male and female sealing strips and the groove more secure, in this embodiment, the cross-section of the groove is set as a trapezoid with a larger inner diameter and a smaller outer diameter. The cross-sectional structure of the first and second hot-melt rubber strips is also set as a trapezoid, and their thickness is greater than the depth of the groove. This setting method can firmly fix the male and female sealing strips in the groove. At the same time, considering that the metal plate and the first hot-melt rubber strip have already been bonded and fixed in the production process, the melting point of the first hot-melt rubber strip is set to be higher than that of the second hot-melt rubber strip. In this way, the second hot-melt rubber strip can melt first in the later stage of segment installation.

[0036] To enable the metal plate to generate heat when energized, two connection points 6 are provided on the bottom of the metal plate, as shown in the attached diagram. Figure 4 The two connection points are located on the bottom edge of the metal plate, near both ends, and are designed as two conical protrusions; simultaneously, two terminal blocks 8 are provided in the grooves where the male sealing strips are installed, such as... Figure 2 As shown, the terminal block is funnel-shaped, wider on the outside and narrower on the inside. The terminal block corresponds to the connection point on the metal plate. The connection point extends from the bottom of the first hot-melt rubber strip and is inserted into the terminal block, thus electrically connecting to the wire 9 in the pipe section. A wire is pre-embedded in the pipe section, with one end connected to the terminal block and the other end located on the inner wall of the pipe section. To facilitate production, a plastic tube 10 is pre-embedded during the segment casting process. The wire passes through the plastic tube, which protects the wire. The plastic tube has an arc or bent structure, with one end connected to the terminal block and the other end leading to the inner wall of the pipe section.

[0037] Since the pipe sections in this application are used continuously in actual construction, in practical applications, the male and female sealing strips in adjacent pipe sections are in contact with and inserted into each other, as shown in the reference. Figure 3 and Figure 5 Adjacent front and rear pipe sections are equipped with mating male and female sealing strips on their side walls. During the overall jacking process of the pipe sections, under the thrust of the jacks, the metal plate on the male sealing strip is inserted into the interior of the female sealing strip from the top surface. To facilitate the insertion of the metal plate into the female sealing strip, this can be achieved by making the top edge of the metal plate sharp and / or by providing a pre-reserved slot at the center line of the top surface of the female sealing strip to facilitate the insertion of the metal plate. The first and second hot-melt rubber strips are pressed against each other. Both the first and second hot-melt rubber strips have a porous structure to facilitate compression and enhance elasticity. (Refer to...) Figure 4 and Figure 5 After compression, the holes in the first and second hot melt rubber strips are flattened.

[0038] In this embodiment, the pipe section is manufactured in the factory by first binding the reinforcing bars and the end face groove molds, and simultaneously fixing the plastic pipes for passing through the wires, as well as the pipes corresponding to the grouting holes and grout drain holes, to their respective positions. Then, a steel plate is fitted onto the outer ring. The steel plate is made of thin steel sheet, bent end to end and welded into a cylindrical shape. Before bending and welding, the parts that need to be drilled should be cut. Finally, a special casting mold is fitted on and the concrete is poured. After the concrete solidifies, it is demolded to obtain the pipe section body provided in this application. The male and female sealing strips are also pre-prepared in the factory. Because they are made of flexible material, the male and female sealing strips can be wound into a single piece. The pipe section body and sealing strips are transported to the construction site for assembly. The male and female sealing strips are cut to length and inserted into the grooves. Before inserting the male sealing strip, the wires and terminals should be installed in the grooves on the front side wall.

[0039] During construction, as the jacking progresses, workers enter the pipe section to perform grouting operations, injecting thixotropic mud mixed with magnetic powder through the grouting holes. The magnetic thixotropic mud, injected into the gap between the pipe section and the soil layer, can quickly and evenly fill the internal gaps under magnetic force, shortening the grouting time and preventing voids. After all pipe sections have been jacked, workers enter the pipe section to energize the wire connectors on the inner wall. In this embodiment, the temperature of the metal plate and the melting degree of the hot-melt rubber strip are controlled by setting the material of the metal plate, the voltage intensity, and the energizing time. This process is common knowledge to those skilled in the art and will not be described in detail in this application. Rubber typically has a melting point between 90-140℃. When electricity is applied to the metal plate via pre-installed wires, the heat generated raises the temperature around the metal plate above the rubber's melting point. This causes the rubber in the first and second hot-melt rubber strips at their contact points with the metal plate to melt. As the electricity is removed and the temperature decreases, the molten rubber adheres to the metal plate. The patterned design on the metal plate's surface enhances the adhesion between the rubber and the metal. Simultaneously, the molten rubber gradually penetrates into the gaps between the first and second hot-melt rubber strips, sealing them. It also seals the gaps at the joints of the male and female sealing strips. Combined with the sealing effect of the metal plate, this effectively isolates the external environment from the tunnel's interior, preventing water leakage. Furthermore, because the molten rubber coats the metal plate, it not only provides waterproofing but also prevents corrosion and rust from water or seawater, resulting in a more stable waterproofing effect and a longer service life. After the electrofusion process is completed, the construction workers will inject cement mortar mixed with magnetic powder to replace the magnetic thixotropic mud. Due to the magnetic force between the magnetic mortar and the steel plate, the contact between the mortar and the pipe section body is tighter, and it can provide better support for the pipe section after curing.

Claims

1. A pipe jacking tunnel section that is easy to jack and waterproof, comprising at least a cylindrical pipe section body, characterized in that: The outer wall of the pipe section body is fixedly covered with a steel plate, and the coverage rate of the steel plate is 80%~95%. The outer wall of the steel plate is flush with the outer wall of the pipe section body that is not covered with a steel plate. The area of ​​the outer wall of the pipe section body that is not covered with a steel plate is located at the front and rear ends. The inner wall of the steel plate is provided with concave and convex textures. The steel plate and the pipe section body are tightly fixed by concrete pouring. Both the front and rear sidewalls of the pipe section body are provided with annular grooves. The grooves are continuous structures and their overall shape is consistent with the shape of the pipe section. The two grooves are in corresponding positions. A male sealing strip is provided in the groove of the front sidewall and a female sealing strip is provided in the groove of the rear sidewall. The male sealing strip includes a first hot-melt rubber strip and a strip-shaped metal plate. The lower part of the metal plate is fixed inside the first hot-melt rubber strip, and the upper part of the metal plate extends from the top surface of the first hot-melt rubber strip. Two connection points are provided at the bottom of the metal plate, and the top edge of the metal plate is sharp. A pre-reserved slit is provided on the top surface of the female sealing strip at the center line position to facilitate the insertion of the metal plate. The female sealing strip is composed of a second hot-melt rubber strip, and the second hot-melt rubber strip has the same structure as the first hot-melt rubber strip. Both the first and second hot-melt rubber strips have porous structures, and the melting point of the first hot-melt rubber strip is higher than that of the second hot-melt rubber strip. The cross-section of the groove is a trapezoid with a larger inner diameter and a smaller outer diameter. The cross-sectional structure of the first and second hot-melt rubber strips is also trapezoidal, and their thickness is greater than the depth of the groove. Two terminal blocks are provided in the groove of the front sidewall. The terminal blocks correspond to the connection points on the metal plate and are electrically connected. A wire is pre-embedded in the pipe section body. One end of the wire is connected to the terminal block, and the other end of the wire is located on the inner wall of the pipe section body near the front sidewall.

2. The pipe jacking tunnel section according to claim 1, which is easy to jack and waterproof, is characterized in that: The pipe section body is provided with grouting holes and grout discharge holes, and the steel plate is provided with openings at positions corresponding to the grouting holes and grout discharge holes.

3. The pipe jacking tunnel section according to claim 1, which is easy to jack and waterproof, is characterized in that: The surface of the metal plate is provided with an uneven pattern to increase the bonding strength between the metal plate and the hot melt rubber.

4. The pipe jacking tunnel section according to claim 1, which is easy to jack and waterproof, is characterized in that: The connection point consists of two conical protrusions. The terminal block is funnel-shaped with a larger outer surface and a smaller inner surface. The connection point extends from the bottom surface of the first hot melt rubber strip and is inserted into the terminal block, thereby electrically connecting with the wires in the pipe section.

5. The pipe jacking tunnel section according to claim 1, which is easy to jack and waterproof, is characterized in that: A plastic tube is pre-embedded in the pipe section body, and the wire passes through the plastic tube. The plastic tube has an arc-shaped or bent structure, with one end connected to the terminal block and the other end leading to the inner wall of the pipe section body.

6. The pipe jacking tunnel section according to claim 1, which is easy to jack and waterproof, is characterized in that: The two connection points on the metal plate are located on the bottom edge of the metal plate and near the two ends.

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