Tunneling device of shield tunneling machine assisted by impact of rock particles on hard rock

Abstract

The invention discloses an auxiliary shield tunneling machine tunneling device for impact of rock particles on hard rock. The device mainly comprises a crushing and screening device, a storage tank, an air compressor, a booster pump, a gas storage bottle, a particle conveying screw rod, a rock particle acceleration launching tube and the like. The crushing and screening device screens out rock particles with the particle size ranging from 5 mm to 10 mm and the good acceleration effect through crushing blades and a screening net and conveys the rock particles to the storage tank to be stored. The air compressor and the booster pump compress air to 10MPa so as to drive the particles to be fully accelerated; the rock particles in the storage tank are uniformly conveyed into the rock particle acceleration launching tube by the particle conveying screw rod, and the rock particles are accelerated to 200m / s through the rock particle acceleration launching tube to impact the rock. According to the device, a rock particle impact system is additionally arranged in a traditional TBM, an air compression system arranged in the TBM is fully utilized, rock particles crushed during tunneling are used as impact particles, the rock strength of a tunneling face is reduced by impacting the rock, tool abrasion is reduced, and therefore the tunneling efficiency is improved, and the purpose of assisting rock breaking is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel excavation, and in particular to a shield machine excavation device assisted by rock particles impacting hard rock. Background Art

[0002] With the development of national infrastructure, more and more tunnel projects are being built. In the process of tunnel construction and excavation, TBM roller cutter excavation is often used for construction. The traditional TBM adopts the principle of mechanical rock breaking, which is to use roller cutters to press, roll, and grind the rocks, so that high stress areas and radial cracks are produced in the rocks. As the cracks expand, rock fragments are formed, and the rocks are broken to carry out tunnel excavation. However, in the process of rock breaking by the tunnel boring machine, the friction and heat generated by the cutting tool in the rock will increase the temperature of the roller cutter, which can reach hundreds of degrees, seriously shortening the life of the roller cutter. In addition, when the tunnel rock boring machine encounters high confining pressure hard rock, its mechanical rock breaking ability will be seriously insufficient. When the uniaxial compressive strength of the rock formation exceeds 100MPa, the excavation efficiency will be reduced and the roller cutter wear will be aggravated. When the wear of the roller cutter reaches 20mm, it needs to be replaced. For TBM, it is difficult to replace the roller cutter, and the replacement time is long. Frequent replacement of the cutter will increase the excavation cost, and it will greatly reduce the excavation speed and increase the tunnel construction cycle. In order to reduce the wear of the roller cutter and improve the rock breaking efficiency of TBM, various auxiliary rock breaking methods have been proposed, among which water jet assisted rock breaking methods have been studied more. For example, the patent number CN201910561800.3 discloses a shield machine and its water jet combined roller cutter rock breaking mechanism, which uses a high-pressure water jet to cut a circular cut on the rock to reduce the strength of the rock. However, the generation of high-pressure water jets requires a complete set of high-pressure water generation and transmission systems, which are large in size, complex in structure and require continuous water supply. Laser-assisted rock breaking is also a new rock breaking method. For example, the Chinese patent number CN201810503625.8 discloses a new laser-assisted rock breaking TBM structure. A laser transmitter is installed on the cutter head, and the rock on the excavation face is heated by a laser beam to weaken its structure and improve the rock crushing efficiency. However, laser-assisted rock breaking consumes a lot of energy, and the heating has a poor effect on rock damage. Moreover, more dust is generated when the rock is broken, which affects the conduction of the laser beam. Overheated rocks will accelerate the heating and loss of the cutter. Therefore, how to effectively reduce rock strength, improve excavation efficiency, and reduce tool wear is an urgent problem that needs to be solved in the current tunnel excavation process. Summary of the invention

[0003] The purpose of the present invention is to provide a rock particle impact hard rock auxiliary shield machine excavation device. This device adds a rock particle impact system on the basis of the traditional TBM excavation system. The rock particles broken during excavation are screened as impact particles, and the air is compressed by the TBM built-in air compressor. The high-pressure air is further accelerated in the Laval acceleration tube, driving the rock particles to fully accelerate to 200m / s in the rock particle acceleration launch tube and ejected from the pipeline to hit the rock on the tunnel excavation surface, causing tiny cracks inside the rock, thereby reducing the rock strength of the excavation surface, increasing the excavation efficiency, and achieving the purpose of auxiliary rock breaking.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A rock particle impact hard rock auxiliary shield machine excavation device, including a crushing screen, a screw conveyor, a rock particle conveyor belt, a belt conveyor, a solenoid valve, a storage tank, a particle conveying screw, a rock particle acceleration launch tube, a Laval acceleration tube, a booster pump, a gas storage bottle, an air compressor, etc. The screw conveyor, the belt conveyor and the air compressor are all built-in devices of the shield machine system;

[0006] Furthermore, the rock fragments generated by the shield machine are transported to the crushing and screening device through a screw conveyor. The crushing and screening device is equipped with a crushing blade, a screening net and a screening conveyor belt. The crushing blade is connected to a motor, and the motor drives the blade to rotate to further crush the large rocks.

[0007] Furthermore, the mesh aperture of the screening net is 10mm, and the screening net is connected to a vibration motor, which causes rock particles with a particle size of less than 10mm to fall quickly through vibration to avoid blockage; the screening conveyor belt is located between the screening net and the belt conveyor inside the shield machine, and the mesh diameter of the screening conveyor belt is 5mm. It rotates counterclockwise, and the rock particles with a particle size between 5mm and 10mm on the screening conveyor belt are conveyed to the storage tank through the rock particle conveyor belt; the rock slag with a particle size of less than 5mm and weak acceleration effect and poor rock breaking ability will pass through the screening conveyor belt and fall to the belt conveyor, and the belt conveyor rotates clockwise to transport the rock slag to the slag truck supporting the shield machine;

[0008] Furthermore, the storage tank is divided into two parts, the upper and lower parts, and two solenoid valves are arranged inside to ensure that the device is always in a closed state, wherein solenoid valve 1 controls the upper and lower channels, the upper part of the storage tank is responsible for storing a large amount of rock particles, the lower part is connected to the outlet, and solenoid valve 2 is located at the rock particle outlet; a pressure sensor is arranged at the bottom of the abrasive tank to monitor the remaining rock particles in the lower part of the storage tank in real time, if the rock particles in the lower part of the storage tank are sufficient, solenoid valve 1 is closed, solenoid valve 2 is opened, and the rock particles enter the particle conveying screw; if the rock particles in the lower part of the storage tank are insufficient, solenoid valve 1 is opened, solenoid valve 2 is closed, and the rock particles stored in the upper part of the storage tank enter the lower part. A particle conveying screw is arranged at the outlet of the storage tank, and the rotation of the screw can evenly convey the rock particles entering from the storage tank to the rock particle acceleration launch tube;

[0009] Furthermore, the outlet of the air compressor is connected to a booster pump, which pressurizes the air to 5MP and then passes it into the booster pump, which further pressurizes the air to 10MP. The pressurized high-pressure gas is stored in a gas cylinder; a pressure gauge is provided between the booster pump and the gas cylinder, and the booster pump stops working when the pressure in the gas cylinder reaches 10MP;

[0010] Furthermore, a gas valve is provided at the outlet of the gas storage cylinder to control the high-pressure gas to enter the gas pipeline; the gas pipeline is provided with a Laval acceleration tube to further accelerate the high-pressure gas and enter the rock particle acceleration launch tube;

[0011] Furthermore, the diameter of the rock particle acceleration launch tube is 1.5 cm. According to the Bernoulli equation

[0012]

[0013] It can be seen that the speed of 10MPa high-pressure air entering the rock particle launch tube reaches 800m / s, and the high-speed gas drives the rock particles to accelerate. The rock particle acceleration launch tube is made of high-hardness manganese alloy material, which can reduce the wear of the rock particles on the acceleration launch tube; the length is 4m, ensuring that the rock particles with a particle size of 5mm-10mm are fully accelerated to 200m / s; the outlet of the rock particle acceleration launch tube is evenly arranged between the shield machine cutters to ensure that the rock particles can accurately impact the contact area between the rock and the cutter; the 200m / s high-speed rock particle impact causes tiny cracks inside the rock, reduces the compressive strength of the rock, and increases the excavation efficiency. And the rock particles are broken after impact, and will not cause damage to the cutterhead and the cutter.

[0014] Advantages of the present invention

[0015] 1. The rock particles used in this device come from the rock fragments produced by the shield machine excavation. They are sourced locally and do not require external supply, which reduces construction costs and saves time for stopping work and adding materials.

[0016] 2. This device uses high-speed rock particles to impact the rock on the excavation face, causing tiny cracks inside the rock, thereby destroying the internal structure of the rock and reducing the rock strength. It can reduce the wear of the shield machine's cutter and increase excavation efficiency.

[0017] 3. The device makes full use of the built-in equipment of the shield machine system, such as screw conveyors, belt conveyors and air compressors. The device is small in size and simple in structure, saving internal space of the shield machine.

[0018] 4. This device uses rock fragments generated by excavation as impact particles, and the rock particles are broken after impact, reducing the generation of waste materials such as rock slag, reducing the impact on the environment, and being more green and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a system diagram of a rock particle impact hard rock auxiliary shield machine excavation device of the present invention.

[0020] Figure 2 It is a cross-sectional view of the crushing screen of the present invention.

[0021] 1-air compressor; 2-boosting pump; 3-pressure gauge; 4-gas cylinder; 5-high-pressure gas pipeline; 6-gas valve; 7-Laval acceleration tube; 8-motor 1; 9-particle conveying screw; 10-storage tank; 11-screw conveyor; 12-crushing screen; 13-rock particle conveyor belt; 14-rock particle acceleration launch tube; 15-diversion interface; 16-belt conveyor; 17-solenoid valve 1; 18-pressure sensor; 19-solenoid valve 2; 121-crushing blade; 122-motor 2; 123-screening net; 124-vibration motor; 125-screening conveyor belt; DETAILED DESCRIPTION

[0022] The terms front and rear in the embodiments are based on the advancing direction of the shield machine, and up and down are based on the orientation in the figure.

[0023] As shown in the figure, a rock particle impact hard rock auxiliary shield machine excavation device includes a crushing screen 12, a screw conveyor 11, a rock particle conveyor belt 13, a rock particle conveyor belt 16, a solenoid valve 17, a pressure sensor 18, a storage tank 10, a particle conveying screw 9, a rock particle acceleration launch tube 14, a Laval acceleration tube 7, a booster pump 2, a pressure gauge 3, a gas cylinder 4, an air compressor 1, etc.; the screw conveyor 11, the belt conveyor 16 and the air compressor 1 are all built-in devices of the shield machine system. The crushing screen 12 includes a crushing blade 121, and the crushing blade 121 is connected to a motor 122, and the motor 122 provides a rotational crushing power; the screening net 123 is connected to a vibration motor 124, and a screening conveyor belt 125 is provided below the screening net;

[0024] A rock particle impact hard rock auxiliary shield machine excavation device comprises the following steps:

[0025] (1) The rock fragments generated by the shield machine are collected by the screw conveyor 11 and conveyed to the crushing screen 12. The crushing screen is provided with a crushing blade 121, which is connected to the motor 122. The motor drives the crushing blade to rotate and further crush the large rock into rock particles.

[0026] (2) The mesh aperture of the screening net 123 is 10 mm, and the vibration motor 124 drives the screening net to vibrate back and forth, so that the rock particles with a particle size less than 10 mm can pass through the screening net smoothly and fall into the screening conveyor belt 125 below; the mesh diameter of the screening conveyor belt is 5 mm, so that the rock slag with a particle size less than 5 mm falls to the belt conveyor 16, and the belt conveyor rotates clockwise to transport the rock slag to the slag truck behind the shield machine. The screening conveyor belt is connected to the rock particle conveyor belt 13, and the two rotate clockwise to transport the rock particles with a particle size between 5 mm and 10 mm to the storage tank 10;

[0027] (3) The air compressor 1 is running to pressurize the air to 5MPa, and then the air is passed into the booster pump 2. The booster pump further compresses the air to 10MPa. The pressurized 10MPa high-pressure gas is stored in the gas cylinder 4. The pressure gauge 3 is arranged between the booster pump 2 and the gas cylinder 4. When the pressure in the gas cylinder reaches 10MPa, the booster pump 2 stops working;

[0028] (4) The solenoid valve 6 is opened, and the high-pressure air enters the Laval acceleration tube 7 through the high-pressure gas pipeline 5. The high-pressure air is further accelerated by the Laval acceleration tube to improve the acceleration capability of the rock particles;

[0029] (5) The electromagnetic valve 17 in the storage tank is opened, the electromagnetic valve 2 19 is closed, and the rock particles enter the lower part of the storage tank. When the lower part has sufficient particles, the electromagnetic valve 17 is closed, the electromagnetic valve 2 19 is opened, and the rock particles fall to the particle conveying screw 9. The motor 18 drives the particle conveying screw to rotate, and the rock particles are uniformly conveyed to the rock particle acceleration launch tube 14;

[0030] (6) High-pressure gas pushes rock particles to accelerate continuously to 200 m / s in the rock particle acceleration launch tube. The fully accelerated rock particles enter different launch outlets through the diversion interface 15. The ejected rock particles impact the contact area between the rock and the roller cutter, causing tiny cracks inside the rock, reducing the compressive strength of the rock, thereby reducing tool wear and increasing excavation efficiency.

Claims

1. A rock particle impact hard rock auxiliary shield machine excavation device, characterized in that: It includes a crushing screen, a screw conveyor, a rock particle conveyor belt, a belt conveyor, an electromagnetic valve, a storage tank, a particle conveying screw, a rock particle acceleration launch tube, a Laval acceleration tube, a booster pump, a gas storage cylinder and an air compressor. The crushing screen includes a crushing blade, a screening net and a screening conveyor belt. The crushing blade is connected to the motor. The screening net has an aperture of 10 mm and is connected to the vibration motor. The screening conveyor belt with a mesh diameter of 5 mm is located between the screening net and the belt conveyor inside the shield machine. The tail of the screening conveyor belt is connected to the front end of the rock particle conveyor belt, and the rear end of the rock particle conveyor belt is connected to the storage tank; the front end of the belt conveyor is located below the screening conveyor belt, and the rear end is connected to the slag truck supporting the shield machine. The screw conveyor, belt conveyor and air compressor are all built-in devices of the shield machine system.

2. A rock particle impact hard rock auxiliary shield machine excavation device as claimed in claim 1, characterized in that: The storage tank is divided into two parts, the upper and lower parts. The storage tank includes an electromagnetic valve 1 located at the upper and lower channels, an electromagnetic valve 2 located at the rock particle outlet, and a pressure sensor located at the bottom of the storage tank. The pressure sensor is associated with the two electromagnetic valves. The electromagnetic valve 1 and the electromagnetic valve 2 always maintain an open and a closed state.

3. A rock particle impact hard rock auxiliary shield machine excavation device as claimed in claim 2, characterized in that: The high-pressure gas pipeline is provided with a Laval accelerating tube, and the Laval accelerating tube is communicated with the rock particle accelerating launching tube.

4. A rock particle impact hard rock auxiliary shield machine excavation device as claimed in claim 3, characterized in that: The particle acceleration launch tube has a diameter of 15 mm and a length of 4 m, and is made of a high-hardness manganese alloy.

5. A tunneling method for a shield machine tunneling device assisted by rock particle impact on hard rock as described in claims 1-4, characterized in that: The following steps are involved: (1) The rock fragments generated by the shield machine are collected by the screw conveyor 11 and conveyed to the crushing screen 12. The crushing screen is provided with a crushing blade 121, which is connected to the second motor 122. The second motor drives the crushing blade to rotate and further crush the large rock into rock particles. (2) The aperture of the screening net 123 is 10 mm, and the vibration motor 124 drives the screening net to vibrate back and forth, so that the rock particles with a particle size less than 10 mm can pass through the screening net smoothly and fall into the screening conveyor belt 125 below; the mesh diameter of the screening conveyor belt is 5 mm, so that the rock slag with a particle size less than 5 mm falls to the belt conveyor 16, and the belt conveyor rotates clockwise to transport the rock slag to the slag truck behind the shield machine. The screening conveyor belt is connected to the rock particle conveyor belt 13, and the two rotate clockwise to transport the rock particles with a particle size between 5 mm and 10 mm to the storage tank 10; (3) The air compressor 1 is running to pressurize the air to 5MPa, and then the air is passed into the booster pump 2. The booster pump further compresses the air to 10MPa. The pressurized 10MPa high-pressure gas is stored in the gas cylinder 4. The pressure gauge 3 is arranged between the booster pump 2 and the gas cylinder 4. When the pressure in the gas cylinder reaches 10MPa, the booster pump 2 stops working; (4) The solenoid valve 6 is opened, and the high-pressure air enters the Laval acceleration tube 7 through the high-pressure gas pipeline 5. The high-pressure air is further accelerated by the Laval acceleration tube to improve the acceleration capability of the rock particles; (5) The electromagnetic valve 17 in the storage tank is opened, the electromagnetic valve 2 19 is closed, and the rock particles enter the lower part of the storage tank. When the lower part has sufficient particles, the electromagnetic valve 17 is closed, the electromagnetic valve 2 19 is opened, and the rock particles fall to the particle conveying screw 9. The motor 18 drives the particle conveying screw to rotate, and the rock particles are uniformly conveyed to the rock particle acceleration launch tube 14; (6) High-pressure gas pushes rock particles to accelerate continuously to 200 m / s in the rock particle acceleration launch tube. The fully accelerated rock particles enter different launch outlets through the diversion interface 15. The ejected rock particles impact the contact area between the rock and the roller cutter, causing tiny cracks inside the rock, reducing the compressive strength of the rock, thereby reducing tool wear and increasing excavation efficiency.

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