A retractable pipe jacking system

Abstract

The utility model relates to a kind of backable pipe jacking system, including pipe jacking machine, horizontal jacking mechanism and the several pipe sections for being butted together in turn to constitute passageway, the pipe jacking machine includes hydraulic station, heading head and the base pipe sleeved on the rear end of heading head, the rear end of base pipe is equipped with the small diameter section of small diameter of inner diameter reduction and forms support step, the heading head is supported on the support step by the several connecting oil cylinders distributed along the circumference of base pipe, the connecting oil cylinder is connected together with the hydraulic station. The utility model aims at providing a kind of backable pipe jacking system, which can make the cutting head and the soil in a separated state for cooling, solves the problem of existing pipe jacking construction cutting head embedded in soil for cooling, resulting in secondary start damage to the cutting head.

Description

Technical Field

[0001] This utility model relates to the field of underground tunnel construction technology, and in particular to a retractable pipe jacking system. Background Technology

[0002] In engineering construction, underground tunnels (including pipelines) need to be built. Existing tunnel construction methods include: shield tunneling, blasting, open-cut excavation, and pipe jacking. Pipe jacking is a trenchless construction method, a technology for laying pipelines (tunnels) with little or no excavation. Pipe jacking involves using 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, and then removing the excavated soil. After one pipe section is pushed into the soil, the next section is installed and the process continues. The principle is to use the thrust from the main jacking cylinder and the pipeline itself, as well as intermediate sections, to advance the pipe section or tunneling machine (pipe jacking machine) from the starting shaft through the soil to the receiving shaft where it is lifted. The pipeline follows closely behind the pipe jacking machine, buried between the two pits. When there are construction obstacles on the surface, making open-cut excavation inconvenient and the tunnel is small, pipe jacking is the optimal construction method (pipe jacking is not considered rock geology). Pipe jacking construction has the following drawbacks: When the cutter head heats up and exceeds the set temperature, it stops working and is driven to continue tunneling only after the temperature drops to the required level. However, since the pipe jacking machine cannot reverse, the cutter head remains embedded in the soil when stopped, causing significant damage to the cutter head during restart. In frigid regions during winter construction, the resistance-reducing slurry (which can be mud) used to reduce resistance is prone to freezing, leading to loss of fluidity and potentially causing a sudden increase in jacking resistance, pipe jamming, or even failure to jack up. Utility Model Content

[0003] The present invention aims to provide a retractable pipe jacking system that allows the cutter head to be separated from the soil for cooling, thus solving the problem of damage to the cutter head caused by secondary startup when the cutter head is embedded in the soil for cooling in existing pipe jacking construction.

[0004] The above technical problems are solved by the following technical solution: a retractable pipe jacking system, including a pipe jacking machine, a horizontal jacking mechanism, and a number of pipe sections that are sequentially connected to form a channel. The pipe jacking machine includes a hydraulic station, a tunneling head, and a base pipe sleeved on the rear end of the tunneling head. The rear end of the base pipe has a small diameter section with a reduced inner diameter to form a support step. The tunneling head is supported on the support step by a number of connecting cylinders distributed along the circumference of the base pipe. The connecting cylinders are connected to the hydraulic station. The construction process using this invention is as follows: First, the pipe jacking machine enters the area where the pipeline needs to be formed, with one end entering a pipe section installation hole to accommodate the pipe sections. Second, during the formation of the installation hole, pipe sections are jacked one by one into the hole using a horizontal jacking mechanism until all pipe sections are installed. During the jacking process, a drag-reducing grout is injected between the pipe sections and the hole wall. During the pipe jacking process, when the temperature of the cutter head reaches the set temperature T1, the horizontal jacking mechanism maintains its current state while activating the hydraulic station. The hydraulic station drives the connecting cylinder to extend, driving the tunneling head forward. After the connecting cylinder extends to the set length, the hydraulic station drives the connecting cylinder to retract, causing the tunneling head to retract and reset, stopping further excavation. When the temperature of the cutter head reaches the set temperature T2, the tunneling head continues to excavate, jacking pipe sections using the horizontal jacking mechanism. This method, because the pipe jacking machine can retract, allows for cooling and separation of the cutter head from the soil, thus avoiding damage to the cutter head during secondary startup and the high power required for startup.

[0005] Preferably, a sealing ring is also included. The outer diameter of the base pipe is larger than the outer diameter of the pipe section, and the outer diameter of the base pipe is larger than the diameter of the hole excavated by the tunneling head. The outer diameter of the sealing ring is larger than the outer diameter of the base pipe, and its inner diameter is equal to the outer diameter of the pipe section. The base pipe has a drag-reducing slurry input channel connecting its inner circumferential surface and its rear end face. The outlet end of the drag-reducing slurry input channel is located on the rear end face of the base pipe, extending beyond the pipe section. The inlet end of the drag-reducing slurry input channel is connected to a slurry input pipe. The sealing ring is pressed against the inlet end of the pipe section installation hole by the horizontal jacking mechanism, thereby preventing the drag-reducing slurry from flowing out of the pipe section installation hole. This allows the jacking machine to compact the hole wall of the pipe section installation hole as it moves forward, thus better preventing the drag-reducing slurry from spreading. The independently installed sealing ring prevents the drag-reducing slurry from flowing out, ensuring that no leakage of the drag-reducing slurry occurs during the addition of pipe sections.

[0006] Preferably, the outlet end of the drag-reducing slurry inlet channel is located at the lower end of the rear end face of the base pipe. This can more reliably prevent excessive subsidence of the pipe section during the injection of the drag-reducing slurry.

[0007] Preferably, the front end of the base pipe is a conical surface that is larger at the rear end and smaller at the front end. This allows the pipe jacking machine to advance more effortlessly.

[0008] Preferably, the outer circumferential surface of the front end of the pipe section has a small-diameter section, and the inner circumferential surface of the rear end has a large-diameter section. The inner circumferential surface of the rear end of the base pipe has a large-diameter section. The horizontal jacking mechanism includes a mounting base, a pressing ring for pressing against the end face of the pipe section, and several hydraulic cylinders. One end of each hydraulic cylinder is connected to the mounting base, and the other end presses against the rear end of the pressing ring. The outer circumferential surface of the front end of the pressing ring has a small-diameter section. The small-diameter section of the pipe section at the foremost end passes through the large-diameter section of the base pipe, and the large-diameter section of the pipe section at the rearmost end is fitted onto the small-diameter section of the pressing ring. Between adjacent pipe sections, the small-diameter section of the rear pipe section passes through the large-diameter section of the front pipe section. This facilitates maintaining the pipe section suspended and aligned.

[0009] Preferably, the outer circumferential surface of the rear end of the base pipe is provided with a small-diameter section of the base pipe, the outer diameter of which is larger than the outer diameter of the pipe section. A grouting chamber is provided inside the base pipe, and several grout outlets distributed circumferentially along the outer circumference of the small-diameter section are provided on the outer circumferential surface of the base pipe. These grout outlets are connected to the grouting chamber via grouting pipes. During the pipe jacking process, waterproof grout is injected from the grouting chamber and sprayed out from the grout outlets. The sprayed waterproof grout solidifies on the hole wall of the pipe section installation hole to form a waterproof layer, and a drag-reducing grout storage cavity is formed between the waterproof layer and the pipe section. This more reliably prevents the drag-reducing grout from spreading. This invention has the following advantages: the pipe jacking machine can retract, the cutter head can be cooled while separated from the soil, the cutter head is less likely to be damaged during secondary startup, and the increased power is small. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the pipe jacking machine just entering the pipe jacking installation area in Example 1; Figure 2 This is a schematic diagram of the pipe jacking machine just entering the pipe jacking installation area in Example 2; Figure 3 for Figure 2 A magnified view of a portion of point A; Figure 4 This is a schematic diagram showing the two pipe sections installed in Example 2; Figure 5 for Figure 4A partially enlarged schematic diagram at point C. In the diagram: 1. Pipe jacking machine; 2. Horizontal jacking mechanism; 3. Pipe section; 11. Drag-reducing grout; 16. Sealing ring; 17. Base pipe; 18. Front end face of base pipe; 19. Small diameter section of base pipe; 20. Grouting chamber; 21. Grout outlet; 22. Grouting pipe; 23. Drag-reducing grout input channel; 25. Small diameter section of pipe section; 26. Large diameter section of base pipe; 27. Mounting seat; 28. Pressing ring; 29. ​​Hydraulic cylinder; 30. Small diameter section of pressing ring; 31. Waterproof layer; 32. Hydraulic station; 33. Tunneling head; 34. Support step; 35. Grout input pipe; 36. Connecting cylinder. Detailed Implementation

[0011] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0012] Example 1, see Figure 1 A retractable pipe jacking system includes a pipe jacking machine 1, a horizontal jacking mechanism 2, and several pipe sections 3 for sequentially connecting to form a channel. The pipe jacking machine includes a hydraulic station 32, a tunneling head 33, and a base pipe 17 mounted on the rear end of the tunneling head. The rear end of the base pipe has a small-diameter section with a reduced inner diameter, forming a support step 34. The tunneling head is supported on the support step by several connecting cylinders 36 distributed circumferentially along the base pipe. The connecting cylinders are connected to the hydraulic station. The inner circumferential surface of the rear end of the base pipe has a large-diameter section 26. The horizontal jacking mechanism includes a mounting base 27, a pressing ring 28 for pressing against the end face of the pipe section, and several hydraulic cylinders 29. One end of each hydraulic cylinder is connected to the mounting base, and the other end presses against the rear end of the pressing ring. The outer circumferential surface of the front end of the pressing ring has a small-diameter section 30. When the pipe jacking machine is tunneling, the horizontal jacking mechanism pushes against the rear end of the base pipe. The outer diameter of the base pipe is larger than the outer diameter of the pipe section. The front end face 18 of the base tube is a conical surface with a larger rear end and a smaller front end.

[0013] The construction process is as follows: First, the pipe jacking machine enters the area where the pipeline needs to be formed, and one end of the machine enters the pipe section installation hole to accommodate the pipe sections. Second, during the formation of the pipe section installation hole, the pipe sections are pushed one by one into the installation hole using a horizontal jacking mechanism until all pipe sections are installed. During the pipe section jacking process, a drag-reducing grout is injected between the pipe section and the hole wall (see [link to grouting process]). Figure 3During the tunneling process of the pipe jacking machine, when the temperature of the cutter head reaches the set temperature T1, the horizontal jacking mechanism maintains the current state and starts the hydraulic station. The hydraulic station drives the connecting cylinder to extend and drives the tunneling head forward. After the connecting cylinder extends to the set length, the hydraulic station drives the connecting cylinder to retract, causing the tunneling head to retract and reset, and stopping the tunneling. When the temperature of the cutter head reaches the set temperature T2, T1>T2, the tunneling head continues to tunnel and jacks pipe sections through the horizontal jacking mechanism.

[0014] Example 2 differs from Example 1 in that: See Figures 2 to 5 It also includes a sealing ring 16. The outer diameter of the sealing ring is larger than the outer diameter of the base pipe, and the inner diameter is equal to the outer diameter of the pipe section. A small-diameter section 19 is provided on the outer circumferential surface of the rear end of the base pipe. The outer diameter of the small-diameter section is larger than the outer diameter of the pipe section. A grouting chamber 20 is provided inside the base pipe. Several grout outlets 21 distributed circumferentially along the base pipe are provided on the outer circumferential surface of the small-diameter section. The grout outlets are connected to the grouting chamber through grouting pipes 22. During the jacking process, waterproof grout is injected from the grouting chamber and sprayed out from the grout outlets. The sprayed waterproof grout solidifies on the hole wall of the pipe section installation hole to form a waterproof layer 31. A drag-reducing grout storage cavity is formed between the waterproof layer and the pipe section. A drag-reducing grout input channel 23 is provided inside the base pipe, connecting the inner circumferential surface of the base pipe and the rear end surface of the base pipe. The outlet end of the drag-reducing grout input channel is located on the rear end surface of the base pipe beyond the pipe section. A grout input pipe 35 is connected to the inlet end of the drag-reducing grout input channel. The sealing ring is pressed against the inlet end of the pipe section mounting hole by the horizontal jacking mechanism, thereby preventing the drag-reducing grout from flowing out of the pipe section mounting hole. The outlet end of the drag-reducing grout input channel is located at the lower end of the base pipe. The outer circumferential surface of the front end of the pipe section is provided with a small-diameter section 24, and the inner circumferential surface of the rear end is provided with a large-diameter section 25. During construction, the small-diameter section of the pipe section at the foremost end passes through the large-diameter section of the base pipe, and the large-diameter section of the pipe section at the rear end is fitted onto the small-diameter section of the pressing ring; between adjacent pipe sections, the small-diameter section of the pipe section at the rear passes through the large-diameter section of the pipe section at the front. Finally, it should be noted that the above description is only a preferred embodiment of this utility model and is not intended to limit this utility model. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model shall be included within the protection scope of this utility model.

Claims

1. A retractable pipe jacking system, characterized in that, The system includes a pipe jacking machine, a horizontal jacking mechanism, and several pipe sections that are sequentially connected to form a channel. The pipe jacking machine includes a hydraulic station, a tunneling head, and a base pipe mounted on the rear end of the tunneling head. The rear end of the base pipe has a small-diameter section with a reduced inner diameter to form a support step. The tunneling head is supported on the support step by several connecting cylinders distributed circumferentially along the base pipe. The connecting cylinders are connected to the hydraulic station.

2. The retractable pipe jacking system according to claim 1, characterized in that, It also includes a sealing ring. The outer diameter of the base pipe is larger than the outer diameter of the pipe section. The outer diameter of the base pipe is larger than the diameter of the hole excavated by the tunneling head. The outer diameter of the sealing ring is larger than the outer diameter of the base pipe and the inner diameter is equal to the outer diameter of the pipe section. The base pipe is provided with a drag-reducing slurry input channel that connects the inner circumferential surface of the base pipe and the rear end face of the base pipe. The outlet end of the drag-reducing slurry input channel is located on the rear end face of the base pipe beyond the pipe section. The inlet end of the drag-reducing slurry input channel is connected to a slurry input pipe. The sealing ring is pressed against the inlet end of the pipe section installation hole by a horizontal jacking mechanism to prevent the drag-reducing slurry from flowing out of the pipe section installation hole.

3. The retractable pipe jacking system according to claim 2, characterized in that, The outlet end of the drag-reducing slurry input channel is located at the lower end of the rear end face of the base pipe.

4. A retractable pipe jacking system according to claim 2 or 3, characterized in that, The front end face of the base tube is a conical surface that is larger at the rear end and smaller at the front end.

5. A retractable pipe jacking system according to claim 1, 2, or 3, characterized in that, The pipe section has a small-diameter section on the outer circumferential surface of its front end and a large-diameter section on the inner circumferential surface of its rear end. The base pipe has a large-diameter section on the inner circumferential surface of its rear end. The horizontal jacking mechanism includes a mounting base, a pressing ring for pressing against the end face of the pipe section, and several hydraulic cylinders. One end of each hydraulic cylinder is connected to the mounting base, and the other end presses against the rear end of the pressing ring. The pressing ring has a small-diameter section on the outer circumferential surface of its front end. The small-diameter section of the pipe section at the foremost end passes through the large-diameter section of the base pipe, and the large-diameter section of the pipe section at the rearmost end is fitted onto the small-diameter section of the pressing ring. Between adjacent pipe sections, the small-diameter section of the pipe section at the rear passes through the large-diameter section of the pipe section at the front.

6. A retractable pipe jacking system according to claim 1, 2, or 3, characterized in that, The outer circumferential surface of the rear end of the base pipe is provided with a small diameter section of the base pipe, the outer diameter of the small diameter section of the base pipe is larger than the outer diameter of the pipe section, the base pipe is provided with a grouting chamber, and the outer circumferential surface of the small diameter section of the base pipe is provided with a number of grout outlets distributed along the circumference of the base pipe, and the grout outlets are connected to the grouting chamber through grouting pipes.

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