Abrasive jet assisted TBM rock breaking test device coupled with confining pressure loading

Abstract

The utility model provides a coupling confining pressure loading abrasive jet assisted TBM (Tunnel Boring Machine) rock breaking test device, which comprises: an abrasive jet mechanism, the abrasive jet mechanism comprises a pressurizing part, the pressurizing part is connected with a slurry supply part, and the pressurizing part is connected with a jet nozzle; the confining pressure loading mechanism is internally provided with a loading seat, and a rock sample is placed on the loading seat; and the hobbing cutter penetration mechanism is mounted on the confining pressure loading mechanism. By additionally arranging the abrasive jet mechanism, the TBM rock breaking test under the assistance of abrasive jet can be realized; and by arranging the confining pressure loading mechanism, the confining pressure applied to the periphery of the rock sample can be adjusted, and then the influence on the abrasive jet assisted TBM rock breaking test under different confining pressure conditions is studied.

Description

Technical Field

[0001] This utility model relates to the field of rock breaking experiments, and in particular to an abrasive jet-assisted TBM rock breaking test device with coupled confining pressure loading. Background Technology

[0002] In recent years, with the development towards the west, factors such as high ground stress and extremely hard rock caused by deep burial have made TBM tunneling difficult. Therefore, high-pressure abrasive water jet assisted TBM rock breaking technology has received special attention and is regarded as the most promising assisted rock breaking technology for engineering applications.

[0003] TBM-assisted high-pressure water jet rock breaking is the result of the interaction between the TBM cutter head, high-pressure water jet, and rock. The mechanism model of this combined rock breaking is the theoretical basis for determining the rational design and arrangement of the TBM cutter head and high-pressure water jet, which is of great significance for improving the efficiency of combined rock breaking and reducing construction costs. However, existing TBM rock breaking test devices lack experimental research on combined rock breaking under abrasive jet assistance. Furthermore, existing tests cannot effectively simulate and control the initial in-situ stress, making it difficult to simulate abrasive jet-assisted TBM rock breaking tests under different confining pressure conditions. Utility Model Content

[0004] This invention addresses the technical problem of lacking research on combined rock-breaking tests using abrasive jet assistance. It provides an abrasive jet-assisted TBM rock-breaking test device with coupled confining pressure loading.

[0005] This utility model solves the above-mentioned technical problems through the following technical solutions:

[0006] This utility model provides an abrasive jet-assisted TBM rock-breaking test device with coupled confining pressure loading, comprising: an abrasive jet mechanism, the abrasive jet mechanism including a pressurizing part, the pressurizing part being connected to a slurry supply part, and the pressurizing part being connected to a jet nozzle; a confining pressure loading mechanism, the confining pressure loading mechanism having a carrier seat, on which a rock sample is placed; and a roller cutter penetration mechanism, the roller cutter penetration mechanism being installed on the confining pressure loading mechanism.

[0007] In this technical solution, by adding an abrasive jet mechanism, a TBM rock-breaking test assisted by abrasive jet can be realized; and by setting a confining pressure loading mechanism, the confining pressure applied around the rock sample can be adjusted, thereby studying the influence of different confining pressure conditions on the abrasive jet-assisted TBM rock-breaking test.

[0008] Preferably, the pressurizing part includes a high-pressure resistant cylinder and a first three-way pipe. A floating piston is connected to the high-pressure resistant cylinder. The high-pressure resistant cylinder is divided into a bottom cavity and a top cavity by the floating piston. The bottom cavity is connected to one end of the first three-way pipe. The other two ends of the first three-way pipe are respectively connected to a first pipe and a second pipe. The ends of the first pipe and the second pipe away from the first three-way pipe are both connected to a second container holding clean water. A high-pressure pump and a water supply check valve are installed sequentially on the first pipe in the direction away from the second container. A drain valve is installed on the second pipe.

[0009] In this technical solution, the pressurizing section injects high-pressure water into the bottom cavity and applies pressure to the top cavity through a floating piston, thereby pressurizing the abrasive slurry that enters the top cavity.

[0010] Preferably, the abrasive jet mechanism further includes a second three-way pipe, one end of which is connected to the top cavity, and the other two ends of which are connected to the slurry supply section and the jet nozzle, respectively.

[0011] Preferably, the slurry supply unit includes a first container for holding abrasive slurry; the first container is connected to a third pipe at one end of the second three-way pipe, and a low-pressure pump and a feed check valve are sequentially installed on the third pipe in the direction away from the first container.

[0012] In this technical solution, the slurry supply unit is used to inject abrasive slurry into the top cavity, and after pressurization, it is ejected through the jet nozzle.

[0013] Preferably, the jet nozzle is connected to a fourth pipe at one end of the second three-way pipe, and a slurry discharge valve is installed on the fourth pipe.

[0014] In this technical solution, the slurry discharge valve is used to control whether the jet nozzle sprays out abrasive slurry.

[0015] Preferably, the confining pressure loading mechanism includes a metal frame; a first hydraulic jack is installed on the front inner wall and the right inner wall of the metal frame; a first wheel spoke sensor is installed on the rear inner wall and the left inner wall of the metal frame, and a first pressure head is provided on the first wheel spoke sensor.

[0016] Preferably, the carrier is placed on the bottom inner wall of the metal frame.

[0017] In this technical solution, the confining pressure loading mechanism applies pressure around the rock sample placed on the carrier.

[0018] Preferably, the cutter insertion mechanism includes a second hydraulic jack and a top plate; the top plate is located above the metal frame, and a second wheel spoke sensor is installed at the bottom of the top plate, a second pressure head is provided at the bottom of the second wheel spoke sensor, and a cutter is installed at the bottom of the second pressure head; the second hydraulic jack is located at the bottom of the metal frame.

[0019] Preferably, the cutter insertion mechanism further includes a base plate, with vertical guide posts fixedly installed at the four corners of the top surface of the base plate, and guide holes opened at the four corners of the bottom of the metal frame, with the guide posts slidably connected to the guide holes.

[0020] In this technical solution, a roller cutter penetration mechanism is used to penetrate into the rock sample to conduct a TBM rock breaking test.

[0021] Preferably, a stud is fixedly installed at the top of the guide post, and through holes are opened at the four corners of the top plate. The stud passes through the through holes and a nut is threaded onto the stud.

[0022] In this technical solution, the top plate can be disassembled through the above-mentioned nut installation design.

[0023] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of this utility model.

[0024] The positive and progressive effects of this utility model are as follows:

[0025] The aforementioned abrasive jet-assisted TBM rock-breaking test device with coupled confining pressure loading, by adding an abrasive jet mechanism, pre-damages the rock by cutting it with an abrasive jet before TBM rock breaking, thus enabling the TBM rock-breaking test to be conducted with the assistance of an abrasive jet for combined rock-breaking test research. Simultaneously, the abrasive jet mechanism pressurizes the rock through a pressurization section and releases it through a nozzle orifice, forming a high-energy water jet to meet the test requirements. Furthermore, a confining pressure loading mechanism is included to simulate initial geostress around the rock sample. By changing the applied pressure, the confining pressure can be controlled, thereby altering the initial geostress, allowing for the study of the influence of different confining pressures on the abrasive jet-assisted TBM rock-breaking test. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the abrasive jet mechanism and confining pressure loading mechanism of this utility model.

[0027] Figure 2 This is a schematic diagram of the confining pressure loading mechanism and the cutter penetration mechanism of this utility model.

[0028] Figure 3 This is a schematic diagram of the metal frame and guide hole of this utility model.

[0029] Explanation of reference numerals in the attached figures

[0030] 1. Abrasive jetting mechanism; 101. First container; 102. Second container; 103. High-pressure resistant cylinder; 104. Jet nozzle; 105. Low-pressure pump; 106. Feed check valve; 107. Slurry discharge valve; 108. High-pressure pump; 109. Water supply check valve; 110. Drain valve; 111. Floating piston; 112. First tee pipe; 113. Second tee pipe;

[0031] 2. Confining pressure loading mechanism; 201. Metal frame; 2011. Guide hole; 202. First spoke sensor; 203. First pressure head; 204. First hydraulic jack; 205. Carrier;

[0032] 3. Roller cutting mechanism; 301. Base plate; 302. Guide column; 303. Second hydraulic jack; 304. Top plate; 3041. Stud; 305. Nut; 306. Second spoke sensor; 307. Second pressure head; 308. Roller cutting tool;

[0033] 4. Rock samples. Detailed Implementation

[0034] The present invention will be further illustrated by way of embodiments below, but the present invention is not limited to the scope of the embodiments described herein.

[0035] like Figure 1-3 As shown, an abrasive jet-assisted TBM rock-breaking test device with coupled confining pressure loading includes: an abrasive jet mechanism 1, which includes a pressurizing part connected to a slurry supply part and a jet nozzle 104; a confining pressure loading mechanism 2, which has a carrier 205 inside and a rock sample 4 placed on the carrier 205; and a cutter penetration mechanism 3, which is installed on the confining pressure loading mechanism 2.

[0036] like Figure 2 As shown, the confining pressure loading mechanism 2 includes a metal frame 201; a first hydraulic jack 204 is installed on the front inner wall and the right inner wall of the metal frame 201; a first wheel spoke sensor 202 is installed on the rear inner wall and the left inner wall of the metal frame 201, and a first pressure head 203 is provided on the first wheel spoke sensor 202. The carrier 205 is placed on the bottom inner wall of the metal frame 201.

[0037] At the start of the test, the top plate 304 is removed, the top of the metal frame 201 of the confining pressure loading mechanism 2 is no longer obstructed, and the rock sample 4 to be tested is placed on the carrier 205.

[0038] Subsequently, two first hydraulic jacks 204 were used to apply lateral confining pressure, and two first wheel spoke sensors 202 were used to monitor the confining pressure in real time. Finally, the constant pressure was maintained for 5 minutes to ensure the loading conditions, and then the abrasive jet mechanism 1 was used to cut the rock.

[0039] By controlling the applied confining pressure as described above, TBM rock-breaking tests with different confining pressures were achieved.

[0040] like Figure 1 As shown, the pressurizing unit includes a high-pressure resistant cylinder 103 and a first three-way pipe 112. A floating piston 111 is connected inside the high-pressure resistant cylinder 103. The high-pressure resistant cylinder 103 is divided into a bottom cavity and a top cavity by the floating piston 111. The bottom cavity is connected to one end of the first three-way pipe 112. The other two ends of the first three-way pipe 112 are respectively connected to a first pipe and a second pipe. The ends of the first pipe and the second pipe away from the first three-way pipe 112 are both connected to a second container 102 containing clean water. A high-pressure pump 108 and a water supply check valve 109 are installed sequentially on the first pipe in the direction away from the second container 102. A drain valve 110 is installed on the second pipe.

[0041] The abrasive jetting mechanism 1 also includes a second three-way pipe 113, one end of which is connected to the top cavity, and the other two ends of which are connected to the slurry supply section and the jetting nozzle 104, respectively.

[0042] The slurry supply unit includes a first container 101 for holding abrasive slurry; one end of the first container 101 is connected to a third pipe, and a low-pressure pump 105 and a feed check valve 106 are sequentially installed on the third pipe in a direction away from the first container 101.

[0043] The jet nozzle 104 is connected to a fourth pipe at one end of the second three-way pipe 113, and a slurry discharge valve 107 is installed on the fourth pipe.

[0044] When the abrasive jet mechanism 1 cuts the rock, the jet nozzle 104 is placed on top of the rock sample 4, and the slurry discharge valve 107 and the drain valve 110 are closed. The low-pressure pump 105 is started to draw abrasive slurry from the first container 101 and input it into the top cavity. Then the high-pressure pump 108 is turned on to draw clean water from the second container 102 and input it into the bottom cavity. The pressure of the high-pressure water flow formed in the bottom cavity acts on the abrasive slurry in the top cavity through the floating piston 111. By opening the slurry discharge valve 107, the pressurized abrasive slurry is ejected through the jet nozzle 104, and the abrasive jet cutting of the rock sample 4 under confining pressure begins.

[0045] like Figure 2As shown, the roller cutting mechanism 3 includes a second hydraulic jack 303 and a top plate 304; the top plate 304 is located above the metal frame 201, and a second wheel spoke sensor 306 is installed at the bottom of the top plate 304. A second pressure head 307 is provided at the bottom of the second wheel spoke sensor 306, and a roller cutter 308 is installed at the bottom of the second pressure head 307; the second hydraulic jack 303 is located at the bottom of the metal frame 201.

[0046] The cutter insertion mechanism 3 also includes a base plate 301. Vertical guide posts 302 are fixedly installed at the four corners of the top surface of the base plate 301. Guide holes 2011 are opened at the four corners of the bottom of the metal frame 201. The guide posts 302 are slidably connected to the guide holes 2011.

[0047] A stud 3041 is fixedly installed at the top of the guide post 302. Through holes are opened at the four corners of the top plate 304. The stud 3041 passes through the through holes and a nut 305 is threaded on the stud 3041.

[0048] After the abrasive jet cutting of the rock is completed, the top plate 304 is installed, and the TBM cutter 308 is prepared to break the rock. Pressure is applied using the second hydraulic jack 303, causing the metal frame 201 and the rock sample 4 to move upwards together. During upward movement, vertical guidance is provided through the guide hole 2011 and guide post 302 to simulate the penetration of the TBM cutter 308. The penetration data is recorded in real time using the second spoke sensor 306. Finally, after the test, the second hydraulic jack 303 is unloaded, followed by confined pressure unloading, and finally the top plate 304 is removed to take out the rock sample 4.

[0049] In the above, the second hydraulic jack 303 lifts the metal frame 201, causing the rock sample 4 to interact with the cutter 308. According to Newton's third law, forces act in pairs, which is equivalent to the cutter 308 acting on the rock. The normal force data of the cutter 308 can be monitored in real time through the second spoke sensor 306.

[0050] In practical implementation, the measuring equipment used in the experiment mainly includes a displacement measuring device, a force measuring device, and an acoustic emission detection device. The displacement measuring device is used to record the normal displacement change of the TBM cutter 308 during the penetration process, i.e., the penetration depth of the cutter 308. The force measuring device is used to record the normal force and confining pressure of the TBM cutter 308. The acoustic emission detection device is used to record the damage and failure of the rock during the penetration of the cutter 308.

[0051] The displacement measuring device is a high-precision laser rangefinder, installed on the side of the bottom of the hobbing cutter 308. During the penetration process, the high-precision laser rangefinder accurately measures the penetration displacement as the hobbing cutter 308 moves. After the measuring device is installed, it is connected to a data acquisition device via a USB data acquisition card, enabling real-time acquisition of the normal displacement of the hobbing cutter 308 during the penetration process. After connecting the acquisition card to a computer, the penetration displacement data of the hobbing cutter 308 can be read and saved in real time.

[0052] The force measuring device consists of a first spoke sensor 202 and a second spoke sensor 306. By connecting to a data acquisition device, the changes in normal force and confining pressure in both directions during the penetration process can be collected and recorded in real time. The supporting software can be used to read and store the normal force data in real time.

[0053] The acoustic emission detection device is an acoustic emission instrument. Since the acoustic emission record number is used during the high-pressure water jet cutting process, the signal will be blurred and submerged. Therefore, the acoustic emission instrument is added to record the signal during the penetration of the TBM cutter 308. The main purpose is to study the effect of the TBM cutter 308 on the micro-fracture of the rock.

[0054] An SR150M acoustic emission sensor was placed on each side of rock sample 4. The response frequency range of this type of sensor is 60~400KHz. The acoustic emission sensor was fixed to the rock surface with quick-drying glue. After the lead breaking test was conducted to confirm that the detection signal was qualified, the penetration test was carried out. The acoustic emission signal was monitored and analyzed by acoustic emission signal processing software.

[0055] This utility model is not limited to the above-described embodiments. Any changes in its shape or structure fall within the protection scope of this utility model. The protection scope of this utility model is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of this utility model, but all such changes and modifications fall within the protection scope of this utility model.

Claims

1. A test device for rock breaking using abrasive jet-assisted TBM with coupled confining pressure loading, characterized in that, include: Abrasive jetting mechanism (1) includes a pressurizing part, which is connected to a slurry supply part and a jetting nozzle (104). A confining pressure loading mechanism (2) is provided inside the confining pressure loading mechanism (2), and a rock sample (4) is placed on the carrier (205). The cutter insertion mechanism (3) is installed on the confining pressure loading mechanism (2).

2. The abrasive jet-assisted TBM rock-breaking test device with coupled confining pressure loading as described in claim 1, characterized in that: The pressurizing unit includes a high-pressure resistant cylinder (103) and a first three-way pipe (112). A floating piston (111) is connected inside the high-pressure resistant cylinder (103). The high-pressure resistant cylinder (103) is divided into a bottom cavity and a top cavity by the floating piston (111). The bottom cavity is connected to one end of the first three-way pipe (112). The other two ends of the first three-way pipe (112) are respectively connected to a first pipe and a second pipe. The ends of the first pipe and the second pipe away from the first three-way pipe (112) are both connected to a second container (102) containing clean water. A high-pressure pump (108) and a water supply check valve (109) are installed sequentially on the first pipe in the direction away from the second container (102). A drain valve (110) is installed on the second pipe.

3. The abrasive jet-assisted TBM rock-breaking test device with coupled confining pressure loading as described in claim 1, characterized in that: The abrasive jet mechanism (1) further includes a second three-way pipe (113), one end of which is connected to the top cavity, and the other two ends of which are connected to the slurry supply section and the jet nozzle (104) respectively.

4. The abrasive jet-assisted TBM rock-breaking test device with coupled confining pressure loading as described in claim 1, characterized in that: The slurry supply unit includes a first container (101) for holding abrasive slurry; the first container (101) is connected to a third pipe at one end of a second three-way pipe (113), and a low-pressure pump (105) and a feed check valve (106) are installed sequentially on the third pipe in a direction away from the first container (101).

5. The abrasive jet-assisted TBM rock-breaking test device with coupled confining pressure loading as described in claim 1, characterized in that: The jet nozzle (104) is connected to a fourth pipe at one end of the second three-way pipe (113), and a slurry discharge valve (107) is installed on the fourth pipe.

6. The abrasive jet-assisted TBM rock-breaking test device with coupled confining pressure loading as described in claim 1, characterized in that: The confining pressure loading mechanism (2) includes a metal frame (201); a first hydraulic jack (204) is installed on the front inner wall and the right inner wall of the metal frame (201); a first wheel spoke sensor (202) is installed on the rear inner wall and the left inner wall of the metal frame (201), and a first pressure head (203) is provided on the first wheel spoke sensor (202).

7. The abrasive jet-assisted TBM rock-breaking test device with coupled confining pressure loading as described in claim 1, characterized in that: The carrier (205) is placed on the bottom inner wall of the metal frame (201).

8. The abrasive jet-assisted TBM rock-breaking test device with coupled confining pressure loading as described in claim 6, characterized in that: The roller cutting mechanism (3) includes a second hydraulic jack (303) and a top plate (304); the top plate (304) is located above the metal frame (201), and a second wheel spoke sensor (306) is installed at the bottom of the top plate (304). A second pressure head (307) is provided at the bottom of the second wheel spoke sensor (306), and a roller cutter (308) is installed at the bottom of the second pressure head (307); the second hydraulic jack (303) is located at the bottom of the metal frame (201).

9. The abrasive jet-assisted TBM rock-breaking test device with coupled confining pressure loading as described in claim 8, characterized in that: The cutter insertion mechanism (3) also includes a base plate (301), and vertical guide columns (302) are fixedly installed at the four corners of the top surface of the base plate (301). Guide holes (2011) are opened at the four corners of the bottom of the metal frame (201), and the guide columns (302) are slidably connected to the guide holes (2011).

10. The abrasive jet-assisted TBM rock-breaking test device with coupled confining pressure loading as described in claim 9, characterized in that: A stud (3041) is fixedly installed at the top of the guide post (302). Through holes are opened at the four corners of the top plate (304). The stud (3041) passes through the through holes and a nut (305) is threaded on the stud (3041).

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