High-efficiency construction device and construction method for muddy water balance jacking pipe to pass through railway roadbed

Abstract

The invention relates to the technical field of tunnel construction, in particular to an efficient construction device and method for a slurry balance jacking pipe to penetrate through a railroad bed, and the construction method comprises the steps of deep well construction, equipment installation and debugging, holing jacking, equipment overhauling, grouting reinforcement and holing, and a pipe jacking machine and first to third pipe joints behind the pipe jacking machine are connected together through pull rods to form a whole. After the three pipe joints completely go out of the hole together with the pipe jacking machine, the pipe jacking machine is detached and lifted out; the oil cylinder has the beneficial effects that the oil cylinder body is installed between the annular top plate and the rotating base, the annular top plate and the rotating base are connected with the end of the oil cylinder body through the connecting pins, the oil cylinder body can be conveniently detached, and the rotating base is rotationally installed on the side face of the installation base and driven by the driving worm to rotate; and the oil cylinder body in a fault state can be rotated to the highest position, so that an external crane can be conveniently hoisted and replaced, the shutdown time is shortened, and the construction efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel construction, and in particular to a high-efficiency construction device and a construction method for a slurry-balanced pipe jacking device crossing a railway roadbed. Background Art

[0002] As a trenchless construction method, pipe jacking construction has the following working principle: first, two foundation pits are dug at a certain distance on the ground, namely the pipe jacking launching well and the receiving well; then, in the launching well, with the help of the jacking force generated by the jacking equipment, the friction between the pipe and the surrounding soil is overcome, and the pipe is pushed into the soil according to the designed slope, and the earth is transported away until the tool or tunnel boring machine is pushed into the receiving well and lifted up.

[0003] A Chinese invention with publication number CN117386391A discloses a pipeline mud-water balance type pipe jacking construction device, which ensures that the pipeline is fed in a straight line by adjusting the horizontal and vertical positions of the device through vertical cylinders and transverse cylinders.

[0004] However, currently, equipment failure and downtime have a great impact on the overall construction period. The propulsion cylinder of traditional equipment is installed in a fixed position, which is not easy to hoist and replace when it fails and is damaged, resulting in long downtime and reduced construction efficiency. To this end, the present invention proposes an efficient construction device and construction method for mud-water balanced pipe jacking crossing railway roadbed to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide an efficient construction device and method for mud-water balanced pipe jacking crossing a railway roadbed, so as to solve the problems of long downtime and low construction efficiency of traditional equipment proposed in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solution: an efficient construction method for mud-water balanced pipe jacking crossing a railway roadbed, specifically comprising the following steps:

[0007] Step 1: Deep well construction, including deep well foundation pit excavation and well wall pouring and sinking;

[0008] Step 2: Equipment installation and commissioning: The pipe jacking machine is hoisted into the working well by a crane for assembly and commissioning, and the pipe jacking machine is pushed forward by the pipe jacking cylinder in the working well;

[0009] Step 3: Open the hole and jack up. The jacking machine head excavates along the predetermined trajectory. The front cutter cuts the soil and mixes it with mud and water, which is then transported to the ground by the mud discharge system. The pipe section at the rear of the jacking machine is pushed up by the jacking cylinder in the working well.

[0010] Step 4: Equipment maintenance: When the pipe jacking cylinder in the working well fails, adjust the position of the pipe jacking cylinder, and then use the crane outside the well to lift the pipe jacking cylinder out and replace it in time to reduce the downtime;

[0011] Step 5: Grouting reinforcement. Use a double slurry of cement slurry and water glass to grout and reinforce the railway subgrade around the pipe section. The grouting length is the full length along the direction of the pipe jacking for reinforcement.

[0012] Step 6: Exit the hole. The pipe jacking machine and the first to third pipe sections behind it are connected together with tie rods to form an integral body. After the three pipe sections completely exit the hole together with the pipe jacking machine, the pipe jacking machine is disassembled and hoisted out.

[0013] Preferably, in Step 1, the deep well foundation pit is excavated in layers. The soil is evenly and symmetrically excavated from the middle of the caisson towards the cutting edge. The thickness of each layer is controlled within 0.5 m. After the soil in the middle part of the caisson is excavated, a soil embankment with a width of 1.0 - 1.5 m is reserved around the cutting edge. The soil layer is symmetrically and evenly thinned towards the cutting edge in sections of every 2 - 3 m to ensure the stable sinking of the caisson. When the caisson sinks to about 1 m above the design elevation, the sinking speed is appropriately slowed down. At this time, the excavation depth of each layer should be controlled at about 0.2 m. When it is about 0.5 m away from the design elevation, stop excavating the soil, and let the caisson sink to the design elevation by its own weight to avoid over-sinking.

[0014] Preferably, in Step 1, the construction process of pouring the well wall twice and sinking once is adopted, including ground cushion construction, construction of the first section of the well wall, construction of the second section of the well wall, excavation of the foundation pit and sinking of the caisson, bottom sealing construction of the floor slab, roof construction, and brick capping and installation of the well cover.

[0015] Preferably, in Step 3, analyze the jacking speed, jacking force, lateral pressure of the soil in the cutter head soil bin, and cutter head torque. The jacking speed is determined according to the magnitude of the soil pressure in the cutter head soil bin. Jack strictly according to the predetermined soil pressure in the soil bin and cutter head torque, and prohibit the cutter head from operating under overload. At the same time, measure and correct the deviation during the jacking process on the ground. In addition, use an axial flow ventilator to conduct air exchange and ventilation in the pipeline.

[0016] Preferably, in Step 4, the pipe jacking cylinder includes a plurality of cylinder bodies distributed in a circular array. Both ends of the cylinder body are respectively connected with a rotating seat and an annular top plate. The rotating seat is rotatably installed on the side of the mounting seat, the mounting seat is fixed on the side of the rear seat wall, the side of the annular top plate is attached to the pipe section body, and the pipe section body is located above the bottom plate and supported by the guide rail.

[0017] Preferably, on one side close to the cylinder body of the annular top plate and the rotating seat, a plurality of connecting frames are fixedly connected and distributed in a circular array. The connecting frame is in a "C" shape and the opening is away from the center of the annular top plate. A waist hole is penetrated through the middle of the connecting frame and is movably connected with the cylinder body through a connecting pin. The end of the connecting pin is locked by a knob, and a gasket is fixed on the side of the knob.

[0018] Preferably, a load-bearing steel plate is provided on the side of the rear seat wall, and a plurality of positioning holes distributed in a circular array are opened at the edge of the load-bearing steel plate. The side of the rear seat wall is pre-embedded with embedded parts corresponding to the plurality of positioning holes one by one, and threaded columns are fixed on the surface of the embedded parts. Bosses corresponding to the plurality of threaded columns are fixed on the side walls of the mounting seat, and the embedded parts are fixedly connected to the mounting seat, the load-bearing steel plate and the rear seat wall by nuts.

[0019] Preferably, a fixed column is rotatably connected to the middle part of the rotating seat, and the fixed column is fixedly connected to the mounting seat, a worm gear ring is provided on the outer fixed sleeve of the fixed column, and a driving worm is meshed on the outer side of the worm gear ring, the driving worm is driven to rotate by a driving motor and worm racks are provided at both ends of the driving worm shaft, and the worm racks are fixed to the side of the rotating seat.

[0020] Preferably, the embedded part is arranged in an "L" shape and inserted into the rear seat wall, and a plurality of embedded steel bars distributed at equal intervals are fixed to the inner side of the embedded part.

[0021] Preferably, in step five, grouting holes are reserved when the casing pipe segment is prefabricated, and 4 grouting holes with a diameter of 5 cm and a hole spacing of 2 m are reserved in the pipe segment. The mass ratio of cement slurry to water glass during grouting is 1:1, and the grouting volume is 20% of the soil volume. The grouting volume is mainly controlled. When the injection rate is greater than 10L / min, a smaller grouting pressure is used, and the grouting pressure does not exceed 0.3MPa.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention installs the cylinder body between the annular top plate and the rotating seat. The annular top plate and the rotating seat are connected to the end of the cylinder body by connecting pins. The cylinder body can be easily disassembled. The rotating seat is rotatably installed on the side of the mounting seat and is driven to rotate by a driving worm. The cylinder body in a faulty state can be rotated to the highest position to facilitate lifting and replacement by an external crane, thereby reducing downtime and improving construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a three-dimensional schematic diagram of the overall structure of the present invention;

[0025] Figure 2 It is an exploded schematic diagram of the annular top plate and the rotating seat structure of the present invention;

[0026] Figure 3 It is a schematic diagram of the structural connection between the rotating seat and the mounting seat of the present invention;

[0027] Figure 4 It is a three-dimensional schematic diagram of the annular top plate structure of the present invention;

[0028] Figure 5It is a three-dimensional schematic diagram of the connecting frame structure of the present invention;

[0029] Figure 6 It is a schematic diagram of the explosion of the load-bearing steel plate and the rear wall structure of the present invention;

[0030] Figure 7 It is a three-dimensional schematic diagram of the embedded part structure of the present invention.

[0031] In the figure: 1. rear seat wall; 2. mounting seat; 21. boss; 22. fixing column; 3. rotating seat; 4. annular top plate; 5. cylinder body; 6. connecting frame; 61. waist hole; 62. connecting pin; 63. knob; 64. gasket; 7. worm gear ring; 8. driving worm; 9. worm frame; 10. driving motor; 11. load-bearing steel plate; 111. positioning hole; 12. embedded parts; 121. threaded column; 122. embedded steel bar; 13. pipe segment body; 14. guide rail; 15. bottom plate. DETAILED DESCRIPTION

[0032] In order to make the purpose and technical solution of the present invention clearly and completely described, and the advantages more clearly understood, the embodiments of the present invention are further described in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are part of the embodiments of the present invention, rather than all of the embodiments, and are only used to explain the embodiments of the present invention, and are not used to limit the embodiments of the present invention. All other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] In the description of the present invention, it should be noted that the terms "center", "middle", "upper", "lower", "left", "right", "inner", "outer", "top", "bottom", "side", "vertical", "horizontal" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "one", "first", "second", "third", "fourth", "fifth", "sixth" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0034] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] For the purpose of simplicity and illustration, the principles of the embodiments are mainly described by reference to examples. In the following description, many specific details are proposed to provide a thorough understanding of the embodiments. However, it is obvious that for those of ordinary skill in the art, these embodiments may not be limited to these specific details in practice. In some instances, known methods and structures are not described in detail to avoid making these embodiments unnecessarily difficult to understand. In addition, all embodiments can be used in combination with each other.

[0036] See also Figures 1 to 7 , the present invention provides a technical solution:

[0037] Embodiment 1, a high-efficiency construction method for mud-water balanced pipe jacking crossing a railway roadbed, specifically comprises the following steps:

[0038] Step 1: Deep well construction, including deep well foundation pit excavation and well wall pouring and sinking. Deep wells include working wells and receiving wells, with a depth of 6.4-9.7m. Deep well foundation pits are excavated in layers, and soil is excavated evenly and symmetrically from the middle of the caisson to the blade foot. The caisson sinks using a long-arm excavator, and the thickness of each layer is controlled within 0.5m. After the earthwork in the middle part of the caisson is excavated, a 1.0-1.5m earth embankment is retained around the blade foot. The soil layer is thinned symmetrically and evenly in the direction of the blade foot at intervals of 2-3m to ensure stable sinking of the caisson. When the caisson sinks to about 1m above the design elevation, the sinking speed is appropriately slowed down. At this time, the excavation depth of each layer should be controlled at about 0.2m. When it is about 0.5m away from the design elevation, the excavation is stopped, and the caisson sinks to the design elevation according to its own weight to avoid over-sinking.

[0039] The side formwork of the caisson body is made of wooden formwork, and the tension screw is pulled by a pull rod with a diameter of Φ14. The small ridges are made of Φ48*3.5mm steel pipes with a spacing of 15cm, and the large ridges are made of Φ48*3.5mm double steel pipes with a spacing of 50cm. The inner side of the well body is set with steel pipes to form a connection every 2m along the vertical direction of the well body. Steel pipes are used to set the support inside and outside the well wall, and the horizontal steel pipes are used to connect the support into a whole. The bottom of the support is limited by steel bars to prevent the support from slipping. The top plate of the caisson is cast with a buckle bracket. The spacing between the bracket uprights is 0.9*0.9m, the step distance is 1.5m, the longitudinal and transverse beams on the upper part of the bracket are made of 10*10cm square wood, and the bottom formwork is made of 2cm wooden formwork;

[0040] The caisson wall pouring adopts the construction technology of two pouring and one sinking, including ground cushion construction, first section wall construction, second section wall construction, foundation pit excavation, caisson sinking, bottom plate sealing construction, top plate construction, brickwork capping and manhole cover installation. After the construction is completed, the caisson is backfilled with plain soil.

[0041] A protective railing is installed at the upper opening of the caisson, and a dense safety net is hung on the outside.

[0042] Step 2: Equipment installation and commissioning: The pipe jacking machine is hoisted into the working well by a crane for assembly and commissioning, and the pipe jacking machine is pushed forward by the pipe jacking cylinder in the working well;

[0043] Step 3: Open the hole and jack up. The jacking machine head will advance along the predetermined trajectory. The front cutter head will cut the soil and mix it with mud and water, which will be transported to the ground by the mud discharge system. The pipe section at the rear of the jacking machine will be pushed by the jacking cylinder in the working well. Analyze the jacking speed, jacking force, soil side pressure in the head soil bin, and cutter head torque. The jacking speed is determined according to the soil pressure in the head soil bin. The jacking is strictly carried out according to the predetermined soil bin soil pressure and cutter head torque. Overload operation of the machine head is prohibited. At the same time, the jacking process is measured and corrected on the ground. In addition, an axial flow fan is used for ventilation in the pipeline.

[0044] During the jacking process, the coordinates and elevations of each point on the ground need to be brought into the well. The level and elevation errors of the jacking pipeline are measured by a laser theodolite. The instrument is fixed on the bottom plate of the caisson, and the computer-controlled laser receiving target is fixed on the front end of the machine head, with the coordinate center on the central axis of the tunnel boring machine. The laser theodolite is always turned on during jacking, and the machine head operator analyzes the deviation development trend and determines the correction method to be taken by observing the laser spot movement data and the jacking length on the computer display screen. The laser theodolite must be calibrated in elevation and horizontal direction according to the specified jacking length or measurement time. The elevation direction can also be corrected at any time during jacking using a connecting tube;

[0045] There are two types of deviation correction during the jacking process: one is the deviation correction during the initial jacking process. If the jacking direction is well mastered at the initial stage of jacking, it will not be easy to produce large deviations when jacking the pipe in the future, which can make the pipe jacking smooth. Therefore, the initial jacking axis, elevation and jacking speed should be strictly controlled, and the detection frequency should be increased; the second is the deviation correction during pipe jacking, which should emphasize the principles of frequent correction and slow correction. Frequent correction means that the direction of the tunnel boring machine should be observed and recorded frequently, and correction measures should be taken if a small deviation is found; slow correction means using a small correction angle to slowly return the jacking tunnel boring machine to the position of the designed axis within a long jacking distance;

[0046] Step 4: Equipment maintenance: When the pipe jacking cylinder in the working well fails, adjust the position of the pipe jacking cylinder, and then use the crane outside the well to lift the pipe jacking cylinder out and replace it in time to reduce the downtime;

[0047] Step 5: Grouting reinforcement: Use double slurry of cement slurry and water glass to grout the railway roadbed around the pipe segment. The grouting length is the full length of the top pipe. When the casing pipe segment is prefabricated, grouting holes are reserved. Four grouting holes with a diameter of 5 cm and a hole spacing of 2 m are reserved in the pre-section of the pipe segment. The mass ratio of cement slurry to water glass during grouting is 1:1. The grouting volume is 20% of the soil volume. The grouting volume is mainly controlled. When the injection rate is greater than 10L / min, a smaller grouting pressure is used, and the grouting pressure does not exceed 0.3MPa.

[0048] Step 6: Exit the hole. The pipe jacking machine and the first to third pipe sections are connected together with a tie rod to form a whole. After the three pipe sections are completely out of the hole together with the pipe jacking machine, the pipe jacking machine is disassembled and hoisted out. The sealing door of the exit hole adopts an inner sealing door. When the reserved hole of the caisson is prefabricated, the outer layer of steel bars is retained and the outer layer of 80mm thick concrete is poured in time. MU10 bricks are used to temporarily seal the reserved hole to the sealing door;

[0049] The exit procedure is:

[0050] ① Extend the jacking guide rail in the reserved hole and make a limit block;

[0051] ② Cut out the steel cross beams for sealing the door in the tunnel circle, and loosen the steel sheet piles in the tunnel door with a 50T hydraulic jack;

[0052] ③ Push the pipe jacking machine into the water stop belt and stop when the end of the pipe jacking machine is about 10 cm away from the outer sealing door;

[0053] ④Remove the inner sealed door;

[0054] ⑤ Remove the temporary brick-built blocking door and the 80mm thick reinforced concrete wall on the outside;

[0055] ⑥ Weld a limit block at the tail of the pipe jacking machine to prevent the pipe jacking machine from retreating under the action of the front soil when the main top jack is retracted;

[0056] ⑦ Retract the main top jack and hang the concrete pipe section;

[0057] ⑧Cut off the limit block and continue pushing forward;

[0058] ⑨ When exiting the hole, the measurement must track and observe the status of the pipe jacking machine, and timely feedback to guide the main jacking cylinder to correct the deviation to ensure the accuracy of the starting jacking axis;

[0059] ⑩ After exiting the hole, the pipe jacking machine and the first to third concrete pipe sections are connected together with tie rods to form a whole; after the pipe jacking machine and the concrete pipe sections are connected together, the stability is increased, which is very beneficial for the first stage of jacking construction after exiting the hole, and it is also convenient to control the pipe jacking machine in subsequent jacking construction.

[0060] For the installation of the pipe jacking cylinder, the present application also has the following in step four. The pipe jacking cylinder includes a plurality of cylinder bodies 5 distributed in an annular array. The cylinder bodies 5 are controlled to expand and contract by hydraulic oil. Both ends of the cylinder bodies 5 are respectively connected with a rotating seat 3 and an annular top plate 4. The rotating seat 3 is rotatably installed on the side of the mounting seat 2, and the mounting seat 2 is fixed to the side of the rear seat wall 1. The side of the annular top plate 4 is attached to the pipe joint body 13. The pipe joint body 13 is located above the bottom plate 15 and is supported by the guide rail 14, as Figure 1 shown. When the cylinder body 5 works and extends, it drives the annular top plate 4 to move, and the annular top plate 4 jacks the pipe joint body 13. When the pipe joint body 13 is located in the working well, the pipe joint body 13 moves along the length direction of the guide rail 14 to avoid side deviation. Then the cylinder body 5 contracts, and a space is generated between the annular top plate 4 and the pipe joint body 13 for the next pipe joint body 13 to be placed. By repeating the above process, the pipe joint body 13 is continuously pushed forward. During this process, the rear seat wall 1 provides support for the cylinder body 5.

[0061] To facilitate the disassembly and replacement of the cylinder body 5, the present application also has a plurality of connecting frames 6 distributed in an annular array and fixedly connected to the sides of the annular top plate 4 and the rotating seat 3 close to the cylinder body 5. The connecting frames 6 are in a "C" shape and the openings are away from the center of the annular top plate 4. A waist hole 61 is formed through the middle of the connecting frame 6 and is movably connected to the cylinder body 5 through a connecting pin 62. The end of the connecting pin 62 is locked by a knob 63, and a gasket ring 64 is fixed to the side of the knob 63, as Figure 4 and Figure 5 shown. Both ends of the cylinder body 5 are connected and positioned by the connecting pins 62. When a certain cylinder body 5 fails or is damaged, by pulling out the connecting pin 62, the cylinder body 5 can be quickly disassembled and replaced. The setting of the waist hole 61 can prevent the cylinder body 5 from applying thrust to the connecting pin 62 during the extension process. That is to say, when the cylinder body 5 extends, its thrust acts on the rotating seat 3 and the annular top plate 4, without affecting the connecting pin 62. Therefore, the connecting pin 62 is more convenient for the staff to disassemble.

[0062] To reduce the local stress on the rear seat wall 1, the present application also has a bearing steel plate 11 arranged on the side of the rear seat wall 1. A plurality of positioning holes 111 are formed at the edge of the bearing steel plate 11 and are distributed in an annular array. Embedded parts 12 corresponding to the plurality of positioning holes 111 one by one are pre-buried and fixed on the side of the rear seat wall 1. A threaded column 121 is fixed on the surface of the embedded part 12, and a boss 21 corresponding to the plurality of threaded columns 121 one by one is fixed on the side wall of the mounting seat 2. The embedded part 12 fixedly connects the mounting seat 2, the bearing steel plate 11 and the rear seat wall 1 through nuts, as Figure 6 and Figure 3As shown, the mounting seat 2, the load-bearing steel plate 11 and the rear seat wall 1 are kept in fixed connection, and the rear seat wall 1 bears the thrust applied by the cylinder body 5 to the rotating seat 3, and the load-bearing steel plate 11 and the mounting seat 2 evenly disperse the thrust received by the rotating seat 3, thereby reducing the local force on the rear seat wall 1.

[0063] In order to facilitate the disassembly and lifting of the cylinder body 5, the present application also has a fixed column 22 rotatably connected to the middle of the rotating seat 3, and the fixed column 22 is fixedly connected to the mounting seat 2, the outer fixed sleeve of the fixed column 22 is provided with a worm ring 7, and the outer side of the worm ring 7 is meshed with a driving worm 8, the driving worm 8 is driven to rotate by a driving motor 10, and both ends of the driving worm 8 shaft are provided with a worm rack 9, and the worm rack 9 is fixed to the side of the rotating seat 3, such as Figure 3 As shown, when the driving motor 10 is working, it drives the driving worm 8 to rotate. Since the driving worm 8 is meshed with the worm wheel ring 7, and the worm wheel ring 7, the fixed column 22 and the mounting seat 2 are kept in fixed connection, the rotating seat 3 can be driven by the driving motor 10 to rotate around the fixed column 22. When a cylinder body 5 is damaged, it can be rotated to the highest position, so as to facilitate the external crane to lift it. At the same time, the opening of the connecting frame 6 connected to the cylinder body 5 is just facing upwards, which will not hinder the disassembly of the cylinder body 5.

[0064] In order to improve the embedded strength of the embedded part 12, the embedded part 12 of the present application is set in an "L" shape and inserted into the rear seat wall 1. A plurality of embedded steel bars 122 distributed at equal intervals are fixed to the inner side of the embedded part 12, such as Figure 7 As shown, the provision of the embedded steel bars 122 can increase the embedded strength of the embedded part 12 on the side of the rear seat wall 1, thereby preventing the embedded part 12 from falling off easily.

[0065] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An efficient construction device for mud-water balanced pipe jacking across railway roadbed, characterized in that: It includes a pipe jacking oil cylinder. The pipe jacking oil cylinder includes a plurality of oil cylinder bodies (5) distributed in an annular array. Both ends of the oil cylinder body (5) are respectively connected with a rotating seat (3) and an annular top plate (4). The rotating seat (3) is rotatably installed on the side of the mounting seat (2), and the mounting seat (2) is fixed on the side of the rear seat wall (1). The side of the annular top plate (4) is attached to the pipe section body (13), and the pipe section body (13) is located above the bottom plate (15) and supported by the guide rail (14). On one side close to the oil cylinder body (5) of the annular top plate (4) and the rotating seat (3), a plurality of connecting frames (6) distributed in an annular array are fixedly connected. The connecting frame (6) is in a "C" shape and the opening is away from the center of the annular top plate (4). A waist hole (61) is formed through the middle of the connecting frame (6) and is movably connected with the oil cylinder body (5) through a connecting pin (62). The end of the connecting pin (62) is locked by a knob (63), and a gasket ring (64) is fixed on the side of the knob (63).

2. The high-efficiency construction device for mud-water balanced pipe jacking across railway roadbed according to claim 1 is characterized by: A bearing steel plate (11) is arranged on the side of the rear seat wall (1). A plurality of positioning holes (111) distributed in an annular array are formed at the edge of the bearing steel plate (11). Embedded parts (12) corresponding to the plurality of positioning holes (111) one by one are pre-buried and fixed on the side of the rear seat wall (1). A threaded column (121) is fixed on the surface of the embedded part (12). A boss (21) corresponding to the plurality of threaded columns (121) one by one is fixed on the side wall of the mounting seat (2). The embedded part (12) fixedly connects the mounting seat (2), the bearing steel plate (11) and the rear seat wall (1) through nuts.

3. The high-efficiency construction device for mud-water balanced pipe jacking across railway roadbed according to claim 2 is characterized by: A fixed column (22) is rotatably connected to the middle of the rotating seat (3), and the fixed column (22) is fixed to the mounting seat (2). A worm gear ring (7) is fixedly sleeved on the outside of the fixed column (22), and a driving worm (8) is meshed with the outside of the worm gear ring (7). The driving worm (8) is driven to rotate by a driving motor (10), and both ends of the rotating shaft of the driving worm (8) are provided with worm racks (9), and the worm racks (9) are fixed on the side of the rotating seat (3).

4. The high-efficiency construction device for slurry-balanced pipe jacking across railway roadbed according to claim 3 is characterized by: The embedded part (12) is arranged in an "L" shape and inserted into the rear seat wall (1). A plurality of pre-buried steel bars (122) distributed at equal intervals are fixed on the inner side of the embedded part (12).

5. An efficient construction method for mud-water balanced pipe jacking crossing a railway roadbed according to any one of claims 1 to 4, characterized in that: Specifically, it includes the following steps: Step 1: Deep well construction, including deep well foundation pit excavation and well wall pouring and sinking. Step 2: Equipment installation and debugging. The pipe jacking machine is hoisted into the working well by a crane for assembly and debugging. The pipe jacking machine is pushed forward by the pipe jacking oil cylinder in the working well. Step 3: Hole opening and jacking. The pipe jacking machine head tunnels along a predetermined track. The cutter head at its front end cuts the soil and stirs it with the muddy water, which is transported to the ground by the mud discharge system. The pipe sections at the rear of the pipe jacking machine are pushed by the pipe jacking oil cylinder in the working well. Step 4: Equipment maintenance. When a failure occurs to the pipe jacking oil cylinder in the working well, the position of the pipe jacking oil cylinder is adjusted, and then the pipe jacking oil cylinder is promptly hoisted out and replaced by a crane outside the well to reduce the failure shutdown time. Step 5: Grouting reinforcement: Use cement slurry and water glass double slurry to grout the railway roadbed around the pipe segment, and the grouting length is the full length along the top pipe direction; Step six, exit the hole. The pipe jacking machine and the first to third pipe sections thereafter are connected together with tie rods to form a whole. After the three pipe sections are completely exit the hole together with the pipe jacking machine, the pipe jacking machine is disassembled and hoisted out.

6. The efficient construction method for mud-water balanced pipe jacking crossing railway roadbed according to claim 5 is characterized by: In the step 1, the deep well foundation pit is excavated in layers, and the soil is excavated evenly and symmetrically from the middle of the caisson to the blade foot, and the thickness of each layer is controlled within 0.5m. After the earthwork in the middle part of the caisson is excavated, a 1.0-1.5m earth embankment is retained around the blade foot, and the soil layer is thinned symmetrically and evenly in the direction of the blade foot at intervals of 2-3m to ensure stable sinking of the caisson. When the caisson sinks to 1m above the design elevation, the sinking speed is appropriately slowed down. At this time, the excavation depth of each layer should be controlled at about 0.2m. When it is about 0.5m away from the design elevation, the excavation is stopped, and the caisson sinks to the design elevation according to its own weight to avoid over-sinking.

7. The efficient construction method for mud-water balanced pipe jacking crossing railway roadbed according to claim 6 is characterized by: In the step one, the well wall casting adopts a construction process of two castings and one sinking, including ground cushion construction, first section well wall construction, second section well wall construction, foundation pit excavation and caisson sinking, bottom plate sealing construction, top plate construction, brick-laying capping and setting of well cover.

8. The efficient construction method for mud-water balanced pipe jacking crossing railway roadbed according to claim 7 is characterized in that: In the step three, the jacking speed, jacking force, soil side pressure in the machine head soil bin, and cutter disc torque are analyzed. The jacking speed is determined according to the soil pressure in the machine head soil bin. The jacking is strictly carried out according to the predetermined soil bin soil pressure and cutter disc torque. Overload operation of the machine head is prohibited. At the same time, the jacking process is measured and corrected on the ground. In addition, an axial flow fan is used for ventilation in the pipeline.

9. The efficient construction method for mud-water balanced pipe jacking crossing railway roadbed according to claim 8, characterized in that: In the step five, grouting holes are reserved when the casing pipe segment is prefabricated, and 4 grouting holes with a diameter of 5 cm and a hole spacing of 2 m are reserved in the pipe segment. The mass ratio of cement slurry to water glass during grouting is 1:1, and the grouting volume is 20% of the soil volume. The grouting volume is mainly controlled. When the injection rate is greater than 10L / min, a smaller grouting pressure is used, and the grouting pressure does not exceed 0.3MPa.

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