A launching shaft structure for pipe jacking construction
By using retraction cylinders and anti-reverse mechanisms in pipe jacking construction, the resetting and limiting operations of the jacking iron are simplified, solving the problems of construction complexity and schedule delays in existing technologies, and achieving efficient pipe jacking construction.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHANGHAI CONSTRUCTION FIRST CONSTRUCTION (GROUP) CO LTD
- Filing Date
- 2023-09-25
- Publication Date
- 2026-05-12
AI Technical Summary
In existing pipe jacking construction, the repeated lifting and lowering of the jacking iron and the disassembly and assembly of connecting pins are complex procedures, which increases costs and prolongs the construction schedule.
The jacking device with a retraction cylinder and a backstop mechanism are adopted. The retraction of the jacking iron and the extension and retraction of the limit pin are controlled by the cylinder, which simplifies the construction process and improves efficiency.
It reduces construction steps, shortens the construction period, and improves the efficiency and safety of jacking construction.
Smart Images
Figure CN117329354B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of pipe jacking construction technology, and in particular to a starting shaft structure for pipe jacking construction. Background Technology
[0002] Pipe jacking, also known as trenchless construction, is a technology for laying pipelines with little or no excavation. In pipe jacking, the jacking force generated by jacking equipment within a working pit overcomes the friction between the pipe and the surrounding soil, pushing the pipe into the ground at a designed slope, and then removing the excavated soil. After one section of pipe is jacked into the soil, the second section is lowered and the jacking continues. The principle is that the thrust from the main jacking cylinder and the pipe sections, as well as intermediate sections, propels the tool pipe or tunneling machine from the working pit through the soil to the receiving pit where it is lifted. The pipeline follows closely behind the tool pipe or tunneling machine, buried between the two pits. Pipe jacking has advantages such as small excavation area, low overall cost, high construction efficiency, and high utilization rate of rectangular cross-sections, and has broad development prospects in the field of urban underground engineering construction.
[0003] In related technologies, the working pit includes a launching shaft and a receiving shaft. The launching shaft is equipped with a reaction frame, drive cylinders, a working platform, a jacking iron, a chute, and a backstop mechanism. During pipe jacking construction, the tunnel boring machine (TBM) and precast pipe sections are sequentially hoisted into the working platform and chute in the launching shaft. The drive cylinders then push the jacking iron, propelling the precast pipe sections and the TBM forward. After each forward stroke, the drive cylinders must retract. Before retraction, the backstop mechanism limits the precast pipe section. A crane then lifts and lowers the heavy jacking iron to its original position, providing space for the next precast pipe section. The next precast pipe section is then lowered for jacking, and the backstop mechanism is released before jacking begins. The anti-reverse mechanism includes an anti-reverse mechanism fixed to the working platform and a connecting pin inserted and fixed to both the anti-reverse mechanism and the precast pipe section. After a new precast pipe section is moved to the set position, the connecting pin is simultaneously inserted into both the anti-reverse mechanism and the new precast pipe section to secure it and prevent it from reversing. When removing the connecting pin, another jack needs to be tightened before the connecting pin can be easily removed, making the removal of the connecting pin inconvenient. In actual construction, the repeated hoisting and lowering of the jack and the repeated disassembly and assembly of the connecting pins complicate the construction process, increase construction costs, and delay the construction schedule.
[0004] In response to the aforementioned technologies, and in order to improve construction efficiency, the inventors designed a starting shaft structure for pipe jacking construction. Summary of the Invention
[0005] In order to reduce construction costs and shorten the construction period, this application provides a starting shaft structure for pipe jacking construction, which has the effect of reducing construction procedures and shortening the construction period.
[0006] This application provides a starting shaft structure for pipe jacking construction, which adopts the following technical solution:
[0007] A starting well structure for pipe jacking construction includes a well body, a working platform disposed within the well body, a jacking device mounted on the working platform, and a backstop mechanism disposed on the side of the jacking device. The jacking device includes a reaction frame, a hydraulic cylinder, and a jacking iron. The jacking iron is slidably mounted on the working platform. The reaction frame is used to fix the hydraulic cylinder and provide reaction force support. The hydraulic cylinder includes a pushing hydraulic cylinder for pushing the jacking iron forward and a retraction hydraulic cylinder for driving the jacking iron back to its original position. The retraction hydraulic cylinder includes a first retraction hydraulic cylinder, the telescopic head of which is ball-hinged to the jacking iron. The first retraction hydraulic cylinder is symmetrically disposed on both sides of the jacking iron.
[0008] By adopting the above technical solution, the jacking block is pushed forward by a jacking cylinder, which then pushes the precast pipe section forward. The jacking block is pulled back to its original position by a first retraction cylinder. The protruding head of the first retraction cylinder and the groove are connected by a spherical hinge, transmitting only axial force and not bending moment. The first retraction cylinders are symmetrically arranged on both sides of the jacking block, which can apply a stable pulling force to the jacking block, ensuring its stable retraction. By using retraction cylinders, the jacking block does not need to be hoisted, effectively improving the efficiency of the jacking construction and simplifying the construction process.
[0009] Optionally, the first retraction cylinder is installed at the middle position in the height direction of the top iron; the retraction cylinder also includes a second retraction cylinder, which is installed at the bottom of the top iron, and the telescopic head of the second retraction cylinder faces the direction of the prefabricated pipe section.
[0010] By adopting the above technical solution, the top iron is large in volume and weight, and has a large inertia when it changes from a static state to a moving state. By setting a second retraction cylinder, the top iron and the prefabricated pipe section are separated by pushing, which can ensure that the top iron is pulled smoothly and prevent the top iron from tilting, so as to complete the reset of the top iron smoothly.
[0011] Optionally, the working platform includes a jacking guide rail, which is arranged along the jacking direction of the precast pipe section, and the cross-section of the jacking guide rail is U-shaped or C-shaped with an upward opening; a steel structure slider is provided at the bottom of the jacking iron, and the steel structure slider is embedded in the jacking guide rail.
[0012] By adopting the above technical solution, the jacking guide rail is set to ensure the stability of the jacking iron's movement trajectory and guarantee the smooth progress of the jacking construction.
[0013] Optionally, the anti-reverse mechanism includes an anti-reverse frame and a limiting pin assembly mounted on the anti-reverse frame; the limiting pin assembly includes an electric cylinder, a first sliding cavity, a second sliding cavity, and a limiting pin; the first sliding cavity is fixed on the anti-reverse frame, and a stepped hole-shaped sliding hole is provided on the side of the first sliding cavity near the prefabricated pipe section; the second sliding cavity is slidably mounted in the first sliding cavity; a first spring is provided in the second sliding cavity, and the first spring applies a thrust away from the prefabricated pipe section to the second sliding cavity; a stepped hole-shaped sliding hole is provided on the side of the second sliding cavity near the prefabricated pipe section. The hole is shifted; a limiting pin is slidably installed in the second sliding cavity; a second spring is provided in the second sliding cavity, and the second spring applies a thrust to the limiting pin close to the prefabricated pipe section; an electric cylinder is fixed on the side of the first sliding cavity away from the prefabricated pipe section, and the telescopic rod of the electric cylinder passes through the first sliding cavity and the second sliding cavity and extends into the second sliding cavity; a limiting ring is provided at the end of the telescopic rod of the electric cylinder, and when the second sliding cavity is completely submerged in the first sliding cavity, the limiting ring abuts against the cavity wall of the second sliding cavity near the electric cylinder; a guide slope is provided at the end of the limiting pin near the prefabricated pipe section.
[0014] By adopting the above technical solution, the anti-reverse mechanism can automatically control the limit pin of the precast pipe section by controlling the extension and retraction of the limit pin through the electric cylinder, which is more efficient. The elastically set limit pin can continuously restrict the retraction of the precast pipe section. On the one hand, it plays a positioning role, which makes it convenient for the limit pin to be automatically inserted into the lifting hole. On the other hand, it improves safety and prevents accidents.
[0015] Optionally, a roller is rotatably mounted near the end of the prefabricated joint of the limiting pin, and the roller's axis of rotation is vertically arranged.
[0016] By adopting the above technical solution, the frictional resistance between the limit pins and prefabricated pipe sections is reduced, the damage to the limit pins is reduced, and the service life is extended.
[0017] Optionally, a first pressure sensor is installed on the side of the limiting pin away from the guide slope, and a second pressure sensor is installed on the contact surface of the top iron with the precast pipe section.
[0018] By adopting the above technical solution, pressure sensors are used to monitor the construction status, and the pressure feedback from the pressure sensors can also be used for working condition analysis, which helps to gain a more comprehensive understanding of the project situation.
[0019] Optionally, the working platform also includes a support beam and a support plate. The support beam is arranged along the jacking direction of the precast pipe section, and multiple support beams are arranged in parallel and laid horizontally at the bottom of the well body. The support plate is fixed on the upper side of the support beam, and the jacking guide rail is fixed on the support plate.
[0020] Optionally, the reaction frame includes a back wall pad and a mounting frame. The back wall pad is fixed on the well body sidewall away from the jacking direction of the precast pipe section. The mounting frame is fixed on the support plate and is provided with an insertion hole for inserting the hydraulic cylinder.
[0021] In summary, this application includes at least one of the following beneficial technical effects:
[0022] 1. The starting shaft structure for pipe jacking construction disclosed in this application, by setting a retraction cylinder, eliminates the need for repeated hoisting by a crane to reset the top iron. The retraction of the top iron is controlled by the cylinder, which effectively improves the transfer efficiency of the top iron.
[0023] 2. By controlling the extension and retraction of the limit pins with an electric cylinder, the precast pipe sections can be automatically controlled and limited, which is more efficient. The flexible limit pins can continuously restrict the backward movement of the precast pipe sections. On the one hand, they play a positioning role, making it convenient for the limit pins to be automatically inserted into the lifting holes. On the other hand, they improve safety and prevent accidents. Attached Figure Description
[0024] Figure 1 This is a schematic diagram of the overall structure of the starting well construction according to an embodiment of this application;
[0025] Figure 2 This is a schematic diagram of the overall structure of the operating platform in the embodiments of this application;
[0026] Figure 3 This is a schematic diagram of the overall structure of the jacking device in the embodiments of this application;
[0027] Figure 4 This is a schematic diagram of the structure of the first retracting cylinder in the embodiments of this application;
[0028] Figure 5 This is a schematic diagram of the mounting structure of the top iron and the second retraction cylinder in the embodiments of this application;
[0029] Figure 6 This is a schematic diagram of the overall structure of the anti-reverse mechanism in the embodiments of this application;
[0030] Figure 7 This is a schematic diagram of the overall structure of the limit pin assembly in the embodiments of this application;
[0031] Figure 8 yes Figure 7 A magnified view of area A in the middle;
[0032] Figure 9 This is a schematic diagram of the retraction state of the limit pin assembly during the jacking construction of precast pipe sections;
[0033] Figure 10 This is a schematic diagram showing the extended state of the limit pin assembly when the prefabricated pipe section is fixed.
[0034] Reference numerals: 1. Well body; 11. Reinforced soil; 12. Diaphragm wall; 13. Lining wall; 14. Jacking hole; 2. Working platform; 21. Support beam; 22. Support plate; 23. Jacking guide rail; 3. Jacking device; 31. Reaction frame; 311. Back wall pad; 312. Mounting frame; 32. Hydraulic cylinder; 321. Pushing cylinder; 322. Retraction cylinder; 3221. First retraction cylinder; 3222. Second retraction cylinder; 3223. Flange; 3224. Spherical groove 33. Top iron; 331. Circular groove; 332. Mounting groove; 333. Steel structure slider; 4. Anti-reverse mechanism; 41. Anti-reverse frame; 42. Limit pin assembly; 421. Base plate; 422. Electric cylinder; 4221. Limit ring; 423. First sliding cavity; 424. Second sliding cavity; 425. Limit pin; 4251. Guide slope; 426. First spring; 427. Second spring; 428. Roller; 429. First pressure sensor; 5. Prefabricated pipe section; 51. Lifting hole. Detailed Implementation
[0035] The following is in conjunction with the appendix Figure 1-10 This application will be described in further detail.
[0036] This application discloses a starting shaft structure for pipe jacking construction, referring to... Figure 1 It includes a well body 1, a working platform 2, a jacking device 3, and a backstop mechanism 4. The working platform 2 is horizontally installed at the bottom of the well body 1, the backstop mechanism is set on the side of the working platform 2, and the jacking device 3 is installed on the working platform 2.
[0037] The well body 1 consists of reinforced soil 11, underground continuous wall 12 and inner lining wall 13 from the outside to the inside. The bottom surface of the inner lining wall 13 is set as a horizontal plane. The inner lining wall 13 is provided with a jacking hole 14 corresponding to the opening direction of the underground pipeline and the outline of the underground pipeline.
[0038] refer to Figure 1 and Figure 2 The working platform 2 is a construction platform for placing the newly added precast pipe section 5. The working platform 2 includes a support beam 21 and a support plate 22. The support beam 21 is fixed on the bottom plate of the inner lining wall 13. Multiple support beams 21 are set along the opening direction of the underground pipeline and are set in parallel. All support beams 21 must be set horizontally. The support plate 22 is fixed on the support beam 21. The support plate 22 is also equipped with a jacking guide rail 23 to limit the movement trajectory of the jacking device 3.
[0039] refer to Figure 1 and Figure 3The jacking device 3 includes a reaction frame 31, a hydraulic cylinder 32, and a jacking iron 33. The reaction frame 31 includes a back wall pad 311 and a mounting bracket 312 for fixing the hydraulic cylinder 32. The back wall pad 311 is bolted to the inner lining wall 13 away from the jacking hole 14, and the back wall pad 311 provides reliable reaction support for the hydraulic cylinder. The mounting bracket 312 is a U-shaped truss with mounting holes for the hydraulic cylinder 32. The truss has insertion holes that are adapted to the size of the hydraulic cylinder 32. Multiple hydraulic cylinders 32 are symmetrically arranged at the bottom and sides of the truss. The mounting bracket 312 is bolted to the support plate 22.
[0040] The hydraulic cylinder 32 includes a pushing cylinder 321 and a retraction cylinder 322. The pushing cylinder 321 is used to push the jacking iron 33, thereby pushing the precast pipe section 5 forward. The protruding head of the pushing cylinder 321 is connected to the jacking iron 33 by a limiting connection, that is, a circular groove 331 is provided on the surface of the jacking iron 33 corresponding to the end of the pushing cylinder 321. The protruding head of the pushing cylinder 321 is embedded in the circular groove 331 during the pushing process. After the protruding head of the pushing cylinder 321 retracts, it directly disengages from the jacking iron 33. The pushing cylinder 321 is mounted on the mounting bracket 312. The retraction cylinder 322 is used to drive the jacking iron 33 back during the pushing construction. After each precast pipe section 5 is pushed into place, the jacking iron 33 is retracted by the retraction cylinder 322 to make room for the installation of the new standard section.
[0041] refer to Figure 3 and 4 The retraction cylinder 322 includes a first retraction cylinder 3221 and a second retraction cylinder 3222. The first retraction cylinder 3221 is mounted on the mounting bracket 312. The telescopic head of the first retraction cylinder 3221 is bolted to the top iron 33 via a flange 3223. The flange 3223 of the first retraction cylinder 3221 is provided with a spherical groove 3224. The protruding head of the first retraction cylinder 3221 is spherically hinged to the groove, which transmits only axial force and not bending moment. One first retraction cylinder 3221 is provided on each side of the mounting bracket 312. The height of the first retraction cylinder 3221 corresponds to the middle position of the height direction of the top iron 33, so as to apply a stable pull-back force.
[0042] refer to Figure 5 The second retraction cylinder 3222 is a cylinder 32 installed at the bottom of the top iron 33 for pushing. The top iron 33 is provided with a mounting groove 332 for installing the second retraction cylinder 3222 on the side near the precast pipe section 5. The protruding head of the second retraction cylinder 3222 faces the precast pipe section 5. When the protruding head of the second retraction cylinder 3222 is in the retracted state, it is located in the mounting groove 332 and is not flush with the end face of the top iron 33.
[0043] The top block 33 is made of steel. A steel structure slider 333 is installed at the bottom of the top block 33 within the jacking guide rail 23 to ensure the forward jacking, backward retraction, and lateral limiting of the top block 33. The jacking guide rail 23 is made of formed steel plate grooves, forming a U-shape or an upward-opening C-shape. The steel structure slider 333 of the top block 33 is embedded in the groove to ensure the lateral limiting of the top block 33.
[0044] During the jacking operation, the jacking cylinder 321 and the first retraction cylinder 3221 extend synchronously, pushing the jacking iron 33 to move and jack the precast pipe section 5. After the jacking is completed, the jacking pipe section is temporarily fixed in place by the anti-retraction mechanism 4. Then, the jacking cylinder 321 and the first retraction cylinder 3221 retract synchronously, and the second retraction cylinder 3222 pushes out. The first retraction cylinder 3221 and the second retraction cylinder 3222 act on the middle and bottom positions of the two sides of the jacking iron 33, respectively, driving the jacking iron 33 back to its original position. After the jacking iron 33 returns to its original position, the second retraction cylinder 3222 retracts and resets.
[0045] Specifically, the second retraction cylinder 3222 has two configurations: 1. The stroke of the second retraction cylinder 3222 is shorter than the return stroke of the top iron 33. The second retraction cylinder 3222 is mainly used to provide sufficient thrust to the bottom of the top iron 33 when the top iron 33 moves from a stationary position. The subsequent continuous movement of the top iron 33 is maintained by the first retraction cylinder 3221; 2. The stroke of the second retraction cylinder 3222 is greater than or equal to the return stroke of the top iron 33. The second retraction cylinder 3222 participates in the return of the top iron 33 throughout the entire process, making the reset process of the top iron 33 more stable and safer.
[0046] refer to Figure 6 The anti-reverse mechanism 4 includes an anti-reverse frame 41 and a limit pin assembly 42. The anti-reverse frame 41 is a steel frame fixed to the bottom of the well body 1. Two anti-reverse frames 41 are provided and symmetrically arranged on both sides of the working platform, that is, on both sides of the top iron 33 and the prefabricated pipe section 5.
[0047] refer to Figure 7 The limiting pin assembly 42 is temporarily fixed in conjunction with the lifting hole 51 on the prefabricated pipe section 5. The limiting pin assembly 42 includes a base plate 421, an electric cylinder 422, a first sliding cavity 423, a second sliding cavity, and a limiting pin 425. The base plate 421 is a frame that is fixed to the anti-reverse bracket 41 by bolts. The anti-reverse bracket 41 is provided with multiple bolt mounting holes along the height direction to adjust the height of the base plate 421.
[0048] The first sliding cavity 423 is welded and fixed on the substrate 421. The side of the first sliding cavity 423 near the prefabricated tube section 5 is provided with a stepped hole. The opening of the first sliding cavity 423 is a small hole. The second sliding cavity 424 is slidably installed in the first sliding cavity 423. The main body of the second sliding cavity 424 slides and engages with the small hole of the first sliding cavity 423. The end of the second sliding cavity 424 away from the prefabricated tube section 5 is provided with an annular protrusion structure that slides and engages with the large hole of the first sliding cavity 423. A first spring 426 is provided between the annular protrusion structure on the second sliding cavity 424 and the inner wall of the first sliding cavity 423. The first spring 426 applies a thrust to the second sliding cavity 424 away from the prefabricated tube section 5.
[0049] The second sliding cavity 424 is provided with a stepped orifice-shaped sliding hole on the side near the precast pipe section 5, and the opening of the second sliding cavity 424 is a small hole; the limiting pin 425 is slidably installed in the second sliding cavity 424, and the limiting pin 425 slides and engages with the small hole of the second sliding cavity 424; the end of the limiting pin 425 away from the precast pipe section 5 is provided with an annular protrusion structure that slides and engages with the large hole of the second sliding cavity 424; a second spring 427 is provided between the annular protrusion structure on the limiting pin 425 and the inner wall of the second sliding cavity 424, and the second spring 427 applies a thrust to the limiting pin 425 near the precast pipe section 5.
[0050] The electric cylinder 422 is fixed on the side of the first sliding cavity 423 away from the prefabricated pipe section 5. The telescopic rod of the electric cylinder 422 passes through the first sliding cavity 423 and the second sliding cavity 424 and extends into the second sliding cavity 424. A limit ring 4221 is provided at the end of the telescopic rod of the electric cylinder 422. When the second sliding cavity 424 is completely submerged in the first sliding cavity 423, the limit ring 4221 abuts against the cavity wall of the second sliding cavity 424 near the side of the electric cylinder 422.
[0051] refer to Figure 8 The limiting pin 425 is provided with a guide slope 4251 at one end near the precast pipe section 5, and the guide slope 4251 faces the jacking device 3; a roller 428 is rotatably installed on the limiting pin 425 near the end of the precast joint, and the shaft of the roller 428 is vertically arranged; a first pressure sensor 429 is provided on the side of the limiting pin 425 away from the guide slope 4251.
[0052] refer to Figure 9 During the jacking construction of precast pipe section 5, the electric cylinder 422 remains in the retracted state. When the jacking device 3 pushes the precast pipe section 5 to move, the precast pipe section 5, in conjunction with the guide inclined surface 4251 and roller 428, presses the limiting pin 425 into the second sliding cavity 424. When the limiting pin 425 moves to the lifting hole 51 position of the next precast pipe section 5, it will quickly extend due to the action of the second spring 427 and insert into the lifting hole 51, thus playing a role in preventing backward movement.
[0053] refer to Figure 10When the precast pipe section 5 moves to the set position, and the top iron 33 needs to be returned to the lower position to put down the next precast pipe section 5, the telescopic rod of the control cylinder 422 extends. The telescopic rod of the control cylinder 422 pushes the limit pin 425 and the second sliding cavity 424 together to move towards the precast pipe section 5. The limit pin 425 is further inserted into the lifting hole 51 to more reliably limit and stop the precast pipe section 5.
[0054] Electric pianos can be controlled using either automatic control or linkage control.
[0055] Automatic control is employed. A second pressure sensor is installed at one end of the jacking iron 33 near the precast pipe section 5. With the pressure feedback control of the first pressure sensor 429 and the second pressure sensor, when the jacking iron 33 pushes a new precast pipe section 5 to abut the other end of the precast pipe section 5, the pressure exceeds the pressure of pushing the precast pipe section 5, triggering the retraction action of the electric cylinder 422. The retraction of the electric cylinder 422 drives the second sliding cavity 424 and the limit pin 425 to retract through the limit ring 4221, so that the precast pipe section 5 can be smoothly pushed in. After the precast pipe section 5 is pushed into the preset position, the jacking iron 33 retracts. The precast pipe section 5 is subjected to soil pressure and will have a backward tendency. The first pressure sensor 429 of the limit pin 425 receives increased pressure, triggering the extension action of the electric cylinder 422. The telescopic rod of the electric cylinder 422 extends and pushes the limit pin 425 completely into the lifting hole 51.
[0056] In the linkage control, before the jacking device 3 performs the retraction action, the telescopic rod of the control cylinder 422 extends, so that the limit pin 425 is fully inserted into the lifting hole 51; when the jacking device 3 pushes the next precast pipe section 5 to abut the previous precast pipe section 5, the telescopic rod of the control cylinder 422 retracts, so that the precast pipe section 5 can be jacked in smoothly.
[0057] The implementation principle of the starting shaft structure for pipe jacking construction disclosed in this application embodiment is as follows: By setting a retraction cylinder 322, the resetting of the top iron 33 does not require repeated hoisting by a crane. The retraction of the top iron 33 is controlled by the cylinder 32, which effectively improves the transfer efficiency of the top iron 33. In the anti-retraction mechanism 4, the extension and retraction of the limit pin 425 is controlled by the electric cylinder 422, which can automatically control the limit of the prefabricated pipe section 5, which is more efficient. The elastically set limit pin 425 can continuously limit the retraction of the prefabricated pipe section 5. On the one hand, it plays a positioning role, which makes it convenient for the limit pin 425 to automatically insert into the lifting hole 51. On the other hand, it improves safety and prevents accidents.
[0058] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.
Claims
1. A starting shaft structure for pipe jacking construction, comprising a shaft body (1), a working platform (2) disposed within the shaft body (1), a jacking device (3) installed on the working platform (2), and a backstop mechanism (4) disposed on the side of the jacking device (3), characterized in that: The jacking device (3) includes a reaction frame (31), a hydraulic cylinder (32), and a jacking iron (33). The jacking iron (33) is slidably mounted on the working platform (2). The reaction frame (31) is used to fix the hydraulic cylinder (32) and provide reaction force support. The hydraulic cylinder (32) includes a jacking hydraulic cylinder (321) for pushing the jacking iron (33) forward and a retraction hydraulic cylinder (322) for driving the jacking iron (33) back to its original position. The retraction hydraulic cylinder (322) includes a first retraction hydraulic cylinder (3221). The telescopic head of the first retraction hydraulic cylinder (3221) is ball-hinged to the jacking iron (33). The first retraction hydraulic cylinder (3221) is symmetrically arranged on both sides of the jacking iron (33). The first retraction cylinder (3221) is installed at the middle position in the height direction of the top iron (33); the retraction cylinder (322) also includes a second retraction cylinder (3222), the second retraction cylinder (3222) is installed at the bottom of the top iron (33), and the telescopic head of the second retraction cylinder (3222) faces the prefabricated pipe section (5); The anti-reverse mechanism (4) includes an anti-reverse frame (41) and a limiting pin assembly (42) mounted on the anti-reverse frame (41); the limiting pin assembly (42) includes an electric cylinder (422), a first sliding cavity (423), a second sliding cavity, and a limiting pin (425); the first sliding cavity (423) is fixed on the anti-reverse frame (41), and a stepped hole is provided on the side of the first sliding cavity (423) near the prefabricated pipe section (5); the second sliding cavity (424) is slidably mounted in the first sliding cavity (423); A first spring (426) is provided inside the second sliding cavity (424), and the first spring (426) applies a thrust to the second sliding cavity (424) away from the prefabricated pipe section (5); The second sliding cavity (424) is provided with a stepped hole on the side near the precast pipe section (5); the limiting pin (425) is slidably installed in the second sliding cavity (424); A second spring (427) is provided inside the second sliding cavity (424), and the second spring (427) applies a thrust to the limiting pin (425) close to the prefabricated pipe section (5); The electric cylinder (422) is fixed on the side of the first sliding cavity (423) away from the prefabricated pipe section (5). The telescopic rod of the electric cylinder (422) passes through the first sliding cavity (423) and the second sliding cavity (424) and extends into the second sliding cavity (424). A limit ring (4221) is provided at the end of the telescopic rod of the electric cylinder (422). When the second sliding cavity (424) is completely submerged in the first sliding cavity (423), the limit ring (4221) abuts against the cavity wall of the second sliding cavity (424) near the electric cylinder (422). The end of the limiting pin (425) near the precast pipe section (5) is provided with a guide slope (4251).
2. The launching shaft structure for pipe jacking construction according to claim 1, characterized in that: The working platform (2) includes a jacking guide rail (23), which is set along the jacking direction of the precast pipe section (5). The cross section of the jacking guide rail (23) is U-shaped or C-shaped groove with the opening facing upward. A steel structure slider (333) is set at the bottom of the jacking iron (33), and the steel structure slider (333) is embedded in the jacking guide rail (23).
3. The launching shaft structure for pipe jacking construction according to claim 1, characterized in that: The limiting pin (425) is rotatably mounted with a roller (428) near the end of the precast joint, and the axis of rotation of the roller (428) is vertically arranged.
4. The launching shaft structure for pipe jacking construction according to claim 1, characterized in that: A first pressure sensor (429) is installed on the side of the limiting pin (425) away from the guide slope (4251), and a second pressure sensor is installed on the contact surface of the top iron (33) on the prefabricated pipe section (5).
5. The launching shaft structure for pipe jacking construction according to claim 2, characterized in that: The working platform (2) also includes a support beam (21) and a support plate (22). The support beam is set along the jacking direction of the precast pipe section (5). Multiple support beams are set in parallel and laid horizontally at the bottom of the well body (1). The support plate (22) is fixed on the upper side of the support beam (21), and the jacking guide rail (23) is fixed on the support plate (22).
6. The launching shaft structure for pipe jacking construction according to claim 5, characterized in that: The reaction frame (31) includes a back wall pad (311) and a mounting frame (312). The back wall pad (311) is fixed on the side wall of the well body (1) away from the jacking direction of the precast pipe section (5). The mounting frame (312) is fixed on the support plate (22). The mounting frame (312) is provided with an insertion hole for inserting the mounting cylinder (32).