Long-distance crossing river and lake pipe jacking construction method

Abstract

The application provides a long-distance crossing river and lake pipe jacking construction method, which comprises the following steps: when a long-distance crossing river and lake encounters a special stratum, injecting grouting material into the special stratum to reinforce the stratum; then driving a pipe jacking device to drive a pipe jacking tunnel and a pipe jacking machine to push into the special stratum, and simultaneously starting a grouting mechanism to pour resistance-reducing thixotropic mud outside the pipe jacking tunnel through a grouting hole; a hydraulic and grouting pressure sensor collects grouting pressure and hydraulic pressure in real time, and transmits the pressure values to a control system; the control system compares the collected pressure values with a pressure threshold value; when the pressure values are greater than the pressure threshold value, the grouting amount, grouting pressure, pushing force and tunneling parameters are increased, and the control system continues to compare the collected pressure values with the pressure threshold value until the collected pressure values are less than the pressure threshold value. The application can realize safe tunneling construction of the long-distance crossing river and lake pipe jacking tunnel without replacing cutters, reduce cutter wear and improve construction efficiency.

Description

Technical Field

[0001] This invention relates to a method for long-distance pipe jacking construction across rivers and lakes, applicable to underground engineering projects such as pipe jacking tunnel construction and shield tunneling, which can meet the quality and environmental protection requirements of municipal engineering construction and belongs to the field of underground engineering. Background Technology

[0002] In urban water conservancy pipeline construction, the pipe jacking method is commonly used for underground pipeline engineering. Especially when encountering projects crossing urban lakes and rivers, slurry balance pipe jacking machines are widely used. However, in projects crossing lakes and rivers, slurry balance pipe jacking machines often need to traverse long distances in a single operation, with no receiving shafts available to replace cutting tools. Simultaneously, complex geological features place high demands on the rock-breaking and jacking conditions of the pipe jacking machine, resulting in high jacking resistance and rapid cutting tool wear. The frictional resistance between the water pipeline and the surrounding rock is significant, making long-distance jacking posture control difficult. Sudden situations such as collapse of the surrounding rock above the pipe due to lake water seepage, pipeline damage, and other special geological disasters are difficult to detect and prone to occur. These engineering challenges seriously affect the safety and quality of long-distance pipe jacking tunnels crossing rivers and lakes. Summary of the Invention

[0003] To address the problems existing in the background technology, this invention proposes a method for long-distance pipe jacking construction across rivers and lakes, enabling safe excavation of pipe jacking tunnels across rivers and lakes over long distances without changing the cutting tools, reducing tool wear, and improving construction efficiency. The technical solution is as follows:

[0004] The system includes a vessel equipped with drilling and grouting equipment, a control system, and a pipe jacking machine. One end of the pipe jacking machine is equipped with a cutter head, and the other end is connected to a pipe jacking pipe and a pipe jacking device. The pipe jacking pipe is equipped with a grouting mechanism, and the side wall of the pipe jacking pipe is equipped with grouting holes that communicate with the grouting mechanism. The grouting mechanism is equipped with a grouting pressure sensor. The cutter head is equipped with a hydraulic wear detection head, which is connected to a hydraulic pipeline. A hydraulic pressure sensor is installed on the hydraulic pipeline. The control system is connected to the pipe jacking device, the grouting mechanism, the cutter head, the grouting pressure sensor, and the hydraulic pressure sensor. The control system has a preset pressure threshold, which is the jacking pressure value calculated according to the construction geological conditions and specifications.

[0005] The construction method includes the following steps:

[0006] S1. When encountering special geological formations while traversing rivers and lakes over long distances, the boat is driven to the waters with special geological formations. The drilling and grouting equipment is then activated to inject grouting material into the special geological formations to reinforce them.

[0007] S2. After the special stratum reinforcement is completed, the pipe jacking device drives the pipe jacking pipe and the pipe jacking machine to jack into the special stratum. At the same time, the grouting mechanism is started during the jacking process. The grouting mechanism injects drag-reducing thixotropic mud into the outside of the pipe jacking pipe through the grouting hole.

[0008] S3. When the tunnel boring machine is tunneling, the hydraulic pressure sensor and the grouting pressure sensor collect the grouting pressure and hydraulic pressure in real time, and transmit the collected pressure values ​​to the control system. The control system compares the collected pressure values ​​with the preset pressure threshold.

[0009] S4. When the collected pressure value is greater than the pressure threshold, the control system will control the grouting mechanism to increase the grouting volume and grouting pressure, and control the pipe jacking device to increase the jacking force and control the cutter head to increase the tunneling parameters. At the same time, the control system will continue to compare the collected pressure value with the pressure threshold until the collected pressure value is less than the pressure threshold.

[0010] When the collected pressure value is less than the pressure threshold, the control system controls the grouting mechanism to maintain the grouting volume and grouting pressure at a constant level, and controls the pipe jacking device to maintain the jacking force at a constant level, and controls the cutter head to maintain the tunneling parameters at a constant level.

[0011] Preferably, the grouting mechanism includes a mud pipe and a grouting pump installed on the mud pipe. One end of the mud pipe near the output end of the grouting pump is connected to the grouting hole. A grouting pressure sensor is installed on the grouting pump, and the grouting pump is connected to the control system.

[0012] Preferably, the cutter head includes a cutter disc and multiple cutters mounted on the cutter disc, and there are multiple hydraulic wear detection heads, which are respectively located at the center of the cutter disc and in the cutters.

[0013] Preferably, the grouting material used for reinforcement includes ordinary silicate cement, fine sand, fly ash, bentonite and water, and the mixing ratio of ordinary silicate cement, fine sand, fly ash, bentonite and water is 1:6.5:1.5:0.2:2.

[0014] Preferably, the fineness modulus of the fine sand is 2.28, and the slurry yield of the bentonite is greater than 9.5 m³. 3 / t, wherein the fly ash is Class I fly ash.

[0015] Preferably, the drag-reducing thixotropic mud comprises bentonite, carboxymethyl cellulose, alkaline inorganic treatment agent, flocculant, anti-collapse agent and water, wherein the proportions of bentonite, carboxymethyl cellulose, alkaline inorganic treatment agent, flocculant, anti-collapse agent and water are 8%, 0.1%, 3%, 0.04%, 0.3% and 88.56%, respectively.

[0016] Preferably, a camera is installed in the upper part of the front compartment of the tunnel boring machine.

[0017] Preferably, the outer diameter of the tunnel boring machine is larger than the outer diameter of the tunnel jacking pipe.

[0018] The beneficial effects of this invention are as follows:

[0019] 1. This invention reinforces special strata such as underwater soft clay and fractured faults with grouting materials, and injects drag-reducing thixotropic mud into the special strata for lubrication and drag reduction. This can effectively prevent the tunnel boring machine from getting stuck or unable to push in special strata, thereby reducing the wear of the cutting tools and meeting the requirements of long-distance tunnel boring machine construction without changing the cutting tools.

[0020] 2. This invention can collect pressure information in real time through sensors and conduct on-site testing and control of the construction parameters of the tunnel boring machine through the control system, which improves the convenience of construction and is simple and practical.

[0021] 3. The drag-reducing thixotropic mud involved in this invention has high drag reduction efficiency, strong applicability, environmental protection and safety, and convenient on-site processing.

[0022] 4. The underwater grouting material involved in this invention has a large slurry diffusion radius and strong compressive strength, which can effectively reinforce weak special strata. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the present invention during construction;

[0024] Figure 2 This is a schematic diagram of the grouting mechanism of the present invention;

[0025] Figure 3 This is a flowchart of the construction method of the present invention.

[0026] The following are the labels in the diagram: 1. Pipe jacking machine; 2. Pipe jacking pipe; 3. Pipe jacking device; 4. Ship; 5. Drill pipe; 6. Special strata; 7. Mud pipe; 8. Grouting pump; 9. Grouting pressure sensor; 10. Grouting hole; 11. Control system. Detailed Implementation

[0027] To make the present invention clearer and more understandable, the technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the given embodiments are only one implementation method and do not represent all embodiments.

[0028] Combined with appendix Figure 1-3A method for long-distance pipe jacking construction across rivers and lakes includes a vessel 4 equipped with drilling and grouting equipment, a control system 11, and a pipe jacking machine 1. One end of the pipe jacking machine 1 is equipped with a cutterhead, and the other end is sequentially connected to a pipe jacking pipe 2 and a pipe jacking device 3. A grouting mechanism is installed inside the pipe jacking pipe 2, comprising a mud pipe 7 and a grouting pump 8 mounted on the mud pipe 7. A grouting hole 10 communicating with the grouting mechanism is provided on the side wall of the pipe jacking pipe 2. One end of the mud pipe 7 near the output end of the grouting pump 8 is connected to the grouting hole 10. A grouting pressure sensor 9 is installed on the grouting pump 8. The cutterhead includes a cutter disc and a cutter head mounted on the cutter head. The disc has multiple cutting tools, each with a hydraulic wear detection head for detecting the wear of the cutting tool head. The hydraulic wear detection heads are located at the center of the disc and within the cutting tools. Specifically, the cutting tools are circular, and the hydraulic detection heads are installed on the axial position inside the circular cutting tools. The hydraulic wear detection heads are connected to hydraulic pipelines, and hydraulic pressure sensors are installed on the hydraulic pipelines. The control system 11 is connected to the pipe jacking device 3, the grouting pump 8, the cutting tool head, the grouting pressure sensor 9, and the hydraulic pressure sensor. The control system 11 has a preset pressure threshold, which is the jacking pressure value calculated according to the construction geological conditions and specifications.

[0029] The construction method includes the following steps:

[0030] S1. When encountering special geological formations 6 during long-distance crossings of rivers and lakes, the boat 4 is driven to the waters containing the special geological formations 6. The drilling and grouting equipment is activated to inject reinforcement grouting material into the special geological formations 6. This reinforces the weak special geological formations 6, such as soft clay and fractured faults, thereby increasing the strength and stability of the special geological formations 6. The grouting material is a cement-based mixture, including ordinary Portland cement, fine sand, fly ash, bentonite, and water. The mixing ratio of ordinary Portland cement, fine sand, fly ash, bentonite, and water is 1:6.5:1.5:0.2:2. The grout diffusion radius of the grouting material is greater than 5m, and the compressive strength is greater than 2.0MPa. Specifically, the fineness modulus of the fine sand is 2.28, the slurry production rate of the bentonite is greater than 9.5m3 / t, and the fly ash is Class I fly ash.

[0031] S2. After the reinforcement of the special stratum 6 is completed, the pipe jacking device 3 drives the pipe jacking pipe 2 and the pipe jacking machine 1 to advance into the special stratum 6. At the same time, the grouting mechanism is activated during the jacking process. The grouting mechanism injects drag-reducing thixotropic mud into the outside of the pipe jacking pipe 2 through the grouting hole 10. The drag-reducing thixotropic mud is a slurry composed of bentonite, carboxymethyl cellulose, alkaline inorganic treatment agent, flocculant, anti-collapse agent and water. The proportions of bentonite, carboxymethyl cellulose, alkaline inorganic treatment agent, flocculant, anti-collapse agent and water are 8%, 0.1%, 3%, 0.04%, 0.3% and 88.56%, respectively. The outer diameter of the pipe jacking machine 1 is larger than the outer diameter of the pipe jacking pipe 2, which can ensure that the drag-reducing thixotropic mud flows out better from the grouting hole 10. When the pipe jacking machine 1 advances forward, the drag-reducing thixotropic mud will be in a flowing state. At this time, the drag-reducing thixotropic mud will cause the initial soil of the special stratum 6 to be separated from the pipe jacking pipe. The friction between the two tunnels changes from dry friction to wet friction, providing good lubrication. Generally, the lubrication and drag reduction effect can reach 70%. Under the grouting pressure provided by the grouting mechanism, the drag-reducing thixotropic mud flows continuously from the grouting hole 10, forming a mud sleeve. The thickness of the mud sleeve is generally between 10mm and 25mm. When the pipe jacking construction is completed and there is no external disturbance to the mud sleeve, the drag-reducing thixotropic mud will return to its solidified state, providing support and filling to prevent grout leakage. The injection of drag-reducing thixotropic mud has two functions: first, to balance the soil pressure and groundwater pressure in the soil layer where the pipe jacking machine 1 is located; and second, to reduce the frictional resistance between the cutterhead and the surrounding rock of the tunnel face, as well as the frictional resistance between the pipe and the surrounding rock. The drag-reducing thixotropic mud can give the excavation part of the special strata 6 good fluidity and stability, and can adapt to the drag reduction effect of the pipe jacking machine 1 in complex strata.

[0032] S3. When the tunnel boring machine 1 is tunneling, the hydraulic pressure sensor and the grouting pressure sensor 9 collect the grouting pressure and hydraulic pressure in real time, and transmit the collected pressure values ​​to the control system 11. The control system 11 compares the collected pressure values ​​with the preset pressure threshold.

[0033] S4. When the collected pressure value is greater than the pressure threshold, the control system 11 will control the grouting mechanism to increase the grouting volume and grouting pressure, and control the pipe jacking device 3 to increase the jacking force and control the cutter head to increase the tunneling parameters. The cutter head tunneling parameters mainly include the cutter head motor power, rated torque and speed. At the same time, the control system 11 will continue to compare the collected pressure value with the pressure threshold until the collected pressure value is less than the pressure threshold.

[0034] When the collected pressure value is less than the pressure threshold, the control system 11 controls the grouting mechanism to maintain the grouting volume and grouting pressure unchanged, and controls the pipe jacking device 3 to maintain the jacking force unchanged and controls the cutter head to maintain the tunneling parameters unchanged.

[0035] Specifically, a camera is installed in the upper part of the front compartment of the tunnel boring machine 1 to view the situation inside the front compartment of the tunnel boring machine 1.

[0036] Specifically, the vessel 4 equipped with drilling and grouting equipment includes a surface drilling vessel 4, a drilling rig, a grouting machine, and grouting materials. The surface drilling vessel 4 can consist of two ordinary vessels connected by wooden planks, with a pre-reserved drilling and grouting channel between them. The drilling rig, grouting machine, and grouting materials are placed on the surface drilling vessel 4. The drilling rig drills a hole in the special formation 6 through the drilling channel, and then the grouting machine injects the grouting materials into the hole through the grouting channel, thereby injecting the grouting materials into the special formation 6. The drilling rig is a lightweight drilling rig, and the grouting machine is a conventional grouting device. The grouting machine injects grout into the special formation 6 through the drill pipe 5.

[0037] The above embodiments merely illustrate the basic principles and characteristics of the present invention, but are not limited to these embodiments. It should be understood that those skilled in the art can make various changes and modifications to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for long-distance pipe jacking construction across rivers and lakes, characterized in that: The system includes a ship (4) equipped with drilling and grouting equipment, a control system (11), and a pipe jacking machine (1). One end of the pipe jacking machine (1) is equipped with a cutter head, and the other end of the pipe jacking machine (1) is connected to a pipe jacking pipe (2) and a pipe jacking device (3) in sequence. The pipe jacking pipe (2) is equipped with a grouting mechanism. The side wall of the pipe jacking pipe (2) is equipped with a grouting hole (10) that communicates with the grouting mechanism. The grouting mechanism is equipped with a grouting pressure sensor (9). The cutter head is equipped with a hydraulic wear detection head. The hydraulic wear detection head is connected to a hydraulic pipeline. The hydraulic pipeline is equipped with a hydraulic pressure sensor. The control system (11) is connected to the pipe jacking device (3), the grouting mechanism, the cutter head, the grouting pressure sensor (9), and the hydraulic pressure sensor respectively. The control system (11) is preset with a pressure threshold. The pressure threshold is the jacking pressure value calculated according to the construction geological conditions and specifications. The construction method includes the following steps: S1. When encountering special strata (6) while traversing rivers and lakes over long distances, the boat (4) is driven to the waters with special strata (6), and the drilling and grouting equipment is started to inject grouting material for reinforcement into the special strata (6) to reinforce the special strata (6). S2. After the reinforcement of the special stratum (6) is completed, the jacking device (3) drives the jacking pipe (2) and the jacking machine (1) to jack into the special stratum (6). At the same time, the grouting mechanism is started during the jacking process. The grouting mechanism injects drag-reducing thixotropic mud into the outside of the jacking pipe (2) through the grouting hole (10). S3. When the tunnel boring machine (1) is tunneling, the hydraulic pressure sensor and the grouting pressure sensor (9) collect the grouting pressure and hydraulic pressure in real time, and transmit the collected pressure values ​​to the control system (11). The control system (11) compares the collected pressure values ​​with the preset pressure threshold. S4. When the collected pressure value is greater than the pressure threshold, the control system (11) will control the grouting mechanism to increase the grouting volume and grouting pressure, and control the jacking device (3) to increase the jacking force and control the cutter head to increase the tunneling parameters. At the same time, the control system (11) will continue to compare the collected pressure value with the pressure threshold until the collected pressure value is less than the pressure threshold. When the collected pressure value is less than the pressure threshold, the control system (11) controls the grouting mechanism to maintain the grouting volume and grouting pressure unchanged, and controls the pipe jacking device (3) to maintain the jacking force unchanged and controls the cutter head to maintain the tunneling parameters unchanged.

2. The method for long-distance pipe jacking across rivers and lakes according to claim 1, characterized in that: The grouting mechanism includes a mud pipe (7) and a grouting pump (8) installed on the mud pipe (7). One end of the mud pipe (7) near the output end of the grouting pump (8) is connected to the grouting hole (10). A grouting pressure sensor (9) is installed on the grouting pump (8). The grouting pump (8) is connected to the control system (11).

3. The method for long-distance pipe jacking across rivers and lakes according to claim 1, characterized in that: The cutter head includes a cutter disc and multiple cutters mounted on the cutter disc. There are multiple hydraulic wear detection heads, which are located at the center of the cutter disc and in the cutters.

4. The method for long-distance pipe jacking across rivers and lakes according to claim 1, characterized in that: The grouting material used for reinforcement includes ordinary silicate cement, fine sand, fly ash, bentonite, and water, with a mixing ratio of 1:6.5:1.5:0.2:

2.

5. The method for long-distance pipe jacking across rivers and lakes according to claim 4, characterized in that: The fineness modulus of the fine sand is 2.28, the slurry yield of the bentonite is greater than 9.5 m3 / t, and the fly ash is Grade I fly ash.

6. The method for long-distance pipe jacking across rivers and lakes according to claim 1, characterized in that: The drag-reducing thixotropic mud comprises bentonite, carboxymethyl cellulose, alkaline inorganic treatment agent, flocculant, anti-collapse agent, and water, with the proportions of bentonite, carboxymethyl cellulose, alkaline inorganic treatment agent, flocculant, anti-collapse agent, and water being 8%, 0.1%, 3%, 0.04%, 0.3%, and 88.56%, respectively.

7. The method for long-distance pipe jacking across rivers and lakes according to claim 1, characterized in that: The upper part of the front compartment of the tunnel boring machine (1) is equipped with a camera.

8. The method for long-distance pipe jacking across rivers and lakes according to claim 1, characterized in that: The outer diameter of the tunnel boring machine (1) is larger than the outer diameter of the tunnel jacking pipe (2).

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