An experimental simulation device for determining the location of karst caves excavated by slurry shield

Abstract

The present invention provides an experimental simulation device for determining the position of a karst cave excavated by a slurry shield. The model test box is provided with a box body, the upper end cover of the box body is provided with a box cover, a pressure plate and a simulated stratum are provided inside the box body, and the lower part of the pressure plate is in contact with the top of the simulated stratum; a model karst cave is provided inside the simulated stratum; a through hole is provided on the first side of the box body, and the position of the through hole matches the position of the model karst cave; a shield propulsion device is installed at the through hole, and the shield propulsion device extends into the box body from the through hole; an air pressurizing device is installed between the box cover and the pressure plate; the model karst cave is connected with a measuring device, and the measuring device is used to predict the position of the karst cave in front of the shield propulsion device according to the changes in the shield thrust, torque and propulsion distance. The present invention predicts the position of the karst cave in front of the shield propulsion device according to the changes in the shield thrust, torque and propulsion distance, thereby determining the position of the karst cave in the excavation area of ​​the slurry shield and ensuring the safe construction of the shield machine in the karst area.

Description

Background Art

[0002] During the construction of underground tunnels, karst problems are inevitable. When using slurry shield construction, when encountering karst, it will cause the mud in front to leak, causing instability of the face; at the same time, karst will cause the shield machine to sink and the shield posture control is difficult, and the risk is very high. Timely detection and treatment of karst caves can effectively avoid such situations.

[0003] A lot of research has been done on karst detection methods, most of which are geophysical methods, and basically all of them are ground detection methods; for areas where ground detection is not possible, most of the current excavation relies on experience, there are fewer in-tunnel detection methods, and fewer corresponding model tests. How to ensure the safe construction of shield machines in karst areas without ground geophysical exploration is an urgent problem that needs to be solved. Summary of the invention

[0004] The invention provides an experimental simulation device for determining the position of a karst cave excavated by a slurry shield. The device can simulate a karst detection method, detect and process the karst cave in a timely manner, and ensure the safe construction of the shield machine in a karst area.

[0005] The experimental simulation device for determining the location of the karst cave excavated by a slurry shield includes: a model test box;

[0006] The model test box is provided with a box body, the upper end cover of the box body is provided with a box cover, the inside of the box body is provided with a pressure plate and a simulated stratum, and the lower part of the pressure plate is in contact with the top of the simulated stratum;

[0007] A model cave is set inside the simulated stratum;

[0008] A through hole is opened on the first side of the box body, and the position of the through hole matches the position of the model cave;

[0009] A shield propulsion device is installed at the through hole, and the shield propulsion device extends from the through hole into the box body;

[0010] An air pressurizing device is installed between the box cover and the pressure plate;

[0011] The model cave is connected to a measuring device, which is used to predict the position of the cave in front of the shield propulsion device based on changes in shield thrust, torque and propulsion distance.

[0012] It should be further explained that the shield propulsion device includes: an outer cylinder, which passes through the through hole and is installed in the box body;

[0013] A propulsion rod is provided inside the outer cylinder, and a cutter disc is provided at one end of the propulsion rod, and the cutter disc extends to the end of the outer cylinder;

[0014] The other end of the propulsion rod extends out of the box body and is connected to a motor for driving the cutter disc to operate;

[0015] The outer cylinder is made of steel.

[0016] A speed sensor is installed on the propulsion rod, and the speed sensor is used to detect the speed of the propulsion rod;

[0017] A rotation speed sensor is provided at the rotating shaft position of the cutter disc, and the rotation speed sensor is used to detect the rotation speed of the cutter disc.

[0018] It should be further explained that a plurality of support frames are provided inside the outer cylinder;

[0019] The two ends of the support frame are supported on the inner wall of the outer cylinder, and the support frame and the inner wall of the outer cylinder are connected by welding;

[0020] The push rod is made of steel, and the length of the push rod is consistent with the length of the box.

[0021] It should be further explained that the air pressurizing device comprises: a torsion plate, a threaded torsion rod and a tray;

[0022] The tray is fixed to the pressure plate; the tray and the box cover are respectively provided with threaded holes matching the threaded torsion rods of the torsion plate;

[0023] The torsion plate threaded torsion rod is connected to the box cover through a threaded hole, and the torsion plate threaded torsion rod is connected to the tray through a threaded hole. The torsion plate threaded torsion rod is rotated to pressurize the pressure plate so that the pressure plate compacts the simulated stratum.

[0024] It should be further explained that the air pressurizing device includes: an air compressor;

[0025] The output end of the air compressor is connected to an air pipeline, one end of which extends between the box cover and the pressure plate; a valve, a pressure stabilizer and a pressure sensor for sensing the air pressure value are installed on the air pipeline.

[0026] It should be further explained that the measuring device includes: a computer, a stress-strain pore pressure gauge, a measuring line and a measuring rod;

[0027] The measuring rod is set in the model cave; the measuring rod is connected to the stress-strain pore pressure gauge through the measuring line;

[0028] The stress-strain piezometer obtains the water and soil pressure values ​​of the model cave and transmits the pressure values ​​to the computer, which realizes simulation data monitoring.

[0029] The computer is connected to the speed sensor and the rotation speed sensor respectively to obtain the rotation speed of the propulsion rod and the rotation speed of the cutter disc; the computer also obtains the propulsion distance of the shield propulsion device.

[0030] It should be further explained that the computer obtains the relationship between force, torque and power through the following formula:

[0031] P(t)=F(t)×V(t)

[0032]

[0033] By measuring the speed and rotation speed, the change values ​​of thrust F and torque T during shield advancement are derived, and the change relationship between thrust F and time t, and torque T and time t is established;

[0034] By integrating the velocity V and time t, the relationship between the displacement X and time t is obtained, and the correlation between the thrust F and the displacement X, and the torque T and the displacement X is obtained;

[0035] By changing the distance between the cave and the initial position of the cutterhead, multiple sets of correlations between thrust F and displacement X, torque T and displacement X were obtained;

[0036] The location of the cave in front of the shield propulsion device is predicted based on the changes in shield thrust, torque and propulsion distance.

[0037] It should be further explained that a sealing cover is attached to the box cover;

[0038] The sealing cover and the box cover are respectively provided with threaded holes;

[0039] The second side portion and the bottom portion of the box body are both closed structures;

[0040] The box body is made of transparent material, and the sealing cover is made of rubber sheet;

[0041] There are multiple holes evenly distributed on the pressure plate;

[0042] The model cave is cast by a mold, and the materials of the model cave include: gypsum or limestone.

[0043] It can be seen from the above technical solutions that the present invention has the following advantages:

[0044] In the experimental simulation device for determining the position of the karst cave excavated by the slurry shield provided by the present invention, the excavation of the shield tunnel can be simulated, and the model karst cave and the influence of the groundwater pressure can be simulated. By changing the parameters of the karst cave properties, the change law of the shield parameters can be studied. The present invention establishes the corresponding change relationship between the thrust F and time t, and the torque T and time t; by integrating the speed V-time t, the displacement X-time t relationship can be obtained, so that the correlation between the thrust F and the displacement X, and the torque T and the displacement X can be deduced. By changing the distance between the karst cave and the initial position of the cutterhead, multiple groups of correlations between the thrust F and the displacement X, and the torque T and the displacement X can be obtained. According to the changes in the thrust, torque and propulsion distance of the shield, the position of the karst cave in front of the shield propulsion device is predicted, so as to determine the position of the karst cave in the excavation area of ​​the slurry shield and ensure the safe construction of the shield machine in the karst area. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the description will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0046] Figure 1 Schematic diagram of a device for determining the location of a karst cave excavated by a slurry shield.

[0047] Figure 2 It is a schematic diagram of the structure of the torsion pressurizing device of the present invention.

[0048] Figure 3 It is a schematic diagram of the structure of the air pressurizing device of the present invention.

[0049] Figure 4 It is a schematic diagram of the structure of the shield propulsion device of the present invention.

[0050] Figure 5 It is a schematic diagram of the structure of the model test box of the present invention.

[0051] In the figure: 1-stress-strain pore pressure gauge, 2-measuring line, 3-torsion disk threaded torsion rod, 4-tray, 5-measuring rod, 6-pressure sensor, 7-pressure regulator, 8-valve, 9-air compressor, 10-sealing plate, 11-box cover, 12-pressure plate, 13-box body, 14-model cave, 15-speed sensor, 16-cutter head, 17-support frame, 18-outer cylinder, 19-thrust rod, 20-speed sensor, 21-motor, 22-simulated formation. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0053] When a certain element or layer is said to be "on" another element or layer, "connected" or "coupled" to another element or layer, the experimental simulation device for determining the position of a karst cave excavated by a slurry shield provided by the present invention may be directly on another element or layer, directly connected or coupled to the other element or layer, or there may be an intermediate element or layer. On the contrary, when a certain element is said to be "directly on" another element or layer, "directly connected" or "directly coupled" to another element or layer, there is no intermediate element or layer. Similar numbers in all drawings indicate similar elements. As used herein, the term "and / or" includes any and all combinations of one or more of the relevant listed items.

[0054] The experimental simulation device for determining the position of a karst cave excavated by a slurry shield provided by the present invention may use spatial relative terms for ease of description, such as "under," "below," "lower," "above," "above," etc. to describe the relationship between one element or feature and another element or feature as shown in the figure. It should be understood that the spatial relative terms are intended to include different orientations of the device in use or work other than the orientation shown in the figure. For example, if the device in the figure is turned over, the elements described as being "under" or "below" other elements or features will be facing "above" the other elements or features. Thus, the exemplary term "below" can include both above and below orientations. The device can be made to take other orientations (rotated 90 degrees or other orientations), and the spatial relative terms used here are interpreted accordingly.

[0055] The terms used in the experimental simulation device for determining the location of a karst cave excavated by a slurry shield provided by the present invention are only used to describe specific embodiments and are not intended to limit the expressions in this document. As used herein, the singular forms "one", "an" and "the" are intended to include the plural forms unless the context clearly indicates otherwise. It is also to be understood that when used in this specification, the term "comprising" refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0056] like Figures 1 to 5 As shown, the experimental simulation device for determining the position of a karst cave excavated by a slurry shield provided by the present invention specifically comprises: a model test box;

[0057] The model test box is provided with a box body 13, the upper end cover of the box body 13 is provided with a box cover 11, a pressure plate 12 and a simulated stratum 22 are provided inside the box body 13, and the lower part of the pressure plate 12 is in contact with the top of the simulated stratum 22; a sealing cover 10 is attached to the box cover 11; the sealing cover 10 and the box cover 11 are respectively provided with threaded holes; the side and bottom of the box body 13 are both closed structures, and the simulated stratum 22 is installed inside the box body. A model cave 14 is provided inside the simulated stratum 22; the model cave 14 can be set at any position of the simulated stratum 22, and the specific position can be set according to the test needs. The model cave 14 is cast by a mold, and the material of the model cave includes: gypsum or limestone.

[0058] The box body 13 is made of transparent material, which is convenient for observing the internal situation of the box body. The sealing cover 10 is made of rubber plate; and the pressure plate 12 is evenly distributed with multiple holes to increase the bearing pressure.

[0059] A through hole is opened on the first side of the box body 13, and the position of the through hole matches the position of the model cave 14; a shield propulsion device is installed at the through hole, and the shield propulsion device extends into the box body 13 from the through hole; an air pressurizing device is installed between the box cover 11 and the pressure plate 12; a measuring device is connected to the model cave 14, and the measuring device is used to predict the position of the cave in front of the shield propulsion device according to changes in shield thrust, torque and propulsion distance.

[0060] For the shield propulsion device provided by the present invention, the shield propulsion device includes: an outer cylinder 18, the outer cylinder 18 passes through the through hole and is installed in the box body 13; a propulsion rod 19 is arranged inside the outer cylinder 18, and a cutter head 15 is arranged at one end of the propulsion rod 19, and the cutter head 15 extends to the end of the outer cylinder 18; the other end of the propulsion rod 19 extends to the outside of the box body 13, and is connected to a motor 21 for driving the cutter head 15 to operate; the motor 21 can drive the propulsion rod 19 to rotate and then drive the cutter head 15 to rotate, and excavate the simulated stratum 22 forward. The outer cylinder 18 in the present invention is made of steel material and plays a supporting role.

[0061] In order to obtain the rotation speed of the propulsion rod 19 and the torque of the cutter disc 15, a speed sensor 20 is installed on the propulsion rod 19, and the speed sensor 20 is used to detect the speed of the propulsion rod 19; a speed sensor 16 is provided at the rotating shaft position of the cutter disc 15, and the speed sensor 16 is used to detect the rotation speed of the cutter disc 15.

[0062] In order to ensure the sturdiness of the outer cylinder, multiple support frames 17 are provided inside the outer cylinder 18; both ends of the support frames 17 are supported on the inner wall of the outer cylinder 18, and the support frames 17 are connected to the inner wall of the outer cylinder 18 by welding; the push rod 19 is made of steel material, and the length of the push rod 19 is consistent with the length of the box body 13.

[0063] In order to increase the pressure of the simulated stratum 22 in the present invention and simulate the pressure of the real deep stratum, the air pressurizing device includes: a torsion disc threaded torsion rod 3 and a tray 4; the tray 4 is fixed to the pressure plate 12; the tray 4 and the box cover 11 are respectively provided with threaded holes adapted to the torsion disc threaded torsion rod 3; the torsion disc threaded torsion rod 3 is connected to the box cover 11 through the threaded hole, and the torsion disc threaded torsion rod 3 is connected to the tray 4 through the threaded hole, and the torsion disc threaded torsion rod 3 is rotated to pressurize the pressure plate 12 so that the pressure plate 12 compacts the simulated stratum 22 to ensure that the stratum has a certain pressure during excavation.

[0064] Furthermore, the air pressurizing device described in the present invention includes: an air compressor 9; the output end of the air compressor 9 is connected to an air pipeline, one end of the air pipeline extends between the box cover 11 and the pressure plate 12; the air pipeline is installed with a valve 8, a voltage stabilizer 7 and a pressure sensor 6 for sensing the air pressure value.

[0065] The regulator 7 can maintain the pressure at a constant value, the valve 8 can control the inflow and outflow of gas, and the pressure sensor 6 can obtain the air pressure value between the box cover 11 and the pressure plate 12. If the air pressure value is lower than the preset value, the air compressor 9 can be turned on to pressurize the space between the box cover 11 and the pressure plate 12. Since there are multiple holes evenly distributed on the pressure plate 12, it simulates the groundwater pressure. The groundwater pressure effect of different depths of strata can be simulated by adjusting the air pressure.

[0066] The measuring device in the present invention comprises: a computer, a stress-strain piezometer 1, a measuring line 2 and a measuring rod 5; the measuring rod 5 is set in a model cave 14; the measuring rod 5 is connected to the stress-strain piezometer 1 through the measuring line 2; the stress-strain piezometer 1 obtains the water and soil pressure value of the model cave 14, and transmits the pressure value to the computer, and the computer realizes simulation data monitoring.

[0067] Furthermore, the computer is connected to the speed sensor 20 and the rotation speed sensor 16 respectively to obtain the rotation speed of the propulsion rod 19 and the rotation speed of the cutter head 15; the computer also obtains the propulsion distance of the shield propulsion device.

[0068] For the present invention, the air pressurizing device can apply pressure to simulate the influence of ground stress; install the air pressurizing device to apply pressure to simulate the influence of groundwater pressure, and maintain the pressure through the stabilizer. The computer can also be connected to the motor 21 to control the operation of the motor 21 so that the shield propulsion device maintains constant power and propels forward to simulate shield tunnel excavation. The present invention can measure the shield propulsion distance by a tape measure, and according to the real-time monitoring of the speed sensor and the speed sensor during the propulsion process, the instantaneous change value of the speed V and the speed n can be obtained. Then, the change law of the shield parameters is statistically calculated through the change of the cave parameters, and the relationship between the two is established. There are two crucial parameters in the propulsion process of the shield machine, one is the jack thrust, and the other is the torque of the cutterhead. The changes in these two parameters are related to the properties of the stratum, and the difference in geological characteristics is reflected in the changes in the parameters to a certain extent. In physics, force, torque and power have the following relationship:

[0069] P(t)=F(t)×V(t)

[0070]

[0071] Through the speed and rotation speed values ​​measured above, the change values ​​of thrust F and torque T during shield advancement can be derived, and then the corresponding change relationships between thrust F and time t, and torque T and time t can be established; by integrating speed V-time t, the displacement X-time t relationship can be obtained, and thus the correlation between thrust F and displacement X, and torque T and displacement X can be deduced. By changing the distance between the cave and the initial position of the cutterhead, multiple sets of correlations between thrust F and displacement X, and torque T and displacement X can be obtained. According to the changes in shield thrust, torque and advancement distance, the position of the cave in front of the shield advancement device can be predicted.

[0072] The present invention changes the parameters of the karst cave properties, studies the changing rules of the shield parameters, and establishes the relationship between the two, thereby determining the location of the karst cave in the slurry shield excavation area. The device of the present invention is designed based on the similarity criterion, so it has a certain reference value for actual engineering.

[0073] The computer to which the present invention relates may include mobile terminals such as smart phones, notebook computers, personal digital assistants (PDAs), tablet computers (PADs), etc., and fixed terminals such as digital TVs, desktop computers, etc. The computer may include a wireless communication unit, an audio / video (A / V) input unit, a user input unit, a sensing unit, an output unit, a memory, an interface unit, a controller, and a power supply unit, etc. However, it should be understood that it is not required to implement all the components shown. More or fewer components may be implemented alternatively.

[0074] The experimental simulation device for determining the location of a karst cave excavated by a slurry shield according to the present invention is a unit and algorithm step of each example described in combination with the embodiments disclosed herein, and can be implemented by electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0075] Those skilled in the art will appreciate that the various aspects of the experimental simulation device for determining the location of a karst cave excavated by a slurry shield according to the present invention can be implemented as a system, method or program product. Therefore, the various aspects of the present disclosure can be specifically implemented in the following forms, namely: a complete hardware implementation, a complete software implementation (including firmware, microcode, etc.), or an implementation combining hardware and software, which can be collectively referred to as a "circuit", "module" or "system" herein.

[0076] The computer may write program code for performing the operations of the present disclosure in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, C++, etc., and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as a separate software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device may be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (e.g., through the Internet using an Internet service provider).

[0077] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An experimental simulation device for determining the location of a karst cave excavated by a slurry shield, characterized in that: include: Model test chamber; The model test box is provided with a box body (13), the upper end cover of the box body (13) is provided with a box cover (11), a pressure plate (12) and a simulated stratum (22) are provided inside the box body (13), and the lower part of the pressure plate (12) is in contact with the top of the simulated stratum (22); A model cave (14) is provided inside the simulated stratum (22); A through hole is formed on the first side of the box body (13), and the position of the through hole matches the position of the model cave (14); A shield propulsion device is installed at the through hole, and the shield propulsion device extends from the through hole into the box body (13); An air pressurizing device is installed between the box cover (11) and the pressure plate (12); The model cave (14) is connected to a measuring device, which is used to predict the position of the cave in front of the shield propulsion device according to changes in the shield thrust, torque and propulsion distance; The shield propulsion device comprises: an outer cylinder (18), the outer cylinder (18) passes through the through hole and is installed in the box body (13); A propulsion rod (19) is provided inside the outer cylinder (18), a cutter disc (15) is provided at one end of the propulsion rod (19), and the cutter disc (15) extends to the end of the outer cylinder (18); The other end of the propulsion rod (19) extends out of the box body (13) and is connected to a motor (21) for driving the cutter disc (15) to operate; The outer cylinder (18) is made of steel; A speed sensor (20) is installed on the propulsion rod (19), and the speed sensor (20) is used to detect the speed of the propulsion rod (19); A rotation speed sensor (16) is provided at the rotation axis position of the cutter disc (15), and the rotation speed sensor (16) is used to detect the rotation speed of the cutter disc (15); A plurality of support frames (17) are arranged inside the outer cylinder (18); The two ends of the support frame (17) are supported on the inner wall of the outer cylinder (18), and the support frame (17) and the inner wall of the outer cylinder (18) are connected by welding; The propulsion rod (19) is made of steel material, and the length of the propulsion rod (19) is consistent with the length of the box body (13); The air pressurizing device comprises: a torsion disc threaded torsion rod (3) and a tray (4); The tray (4) is fixed to the pressure plate (12); the tray (4) and the box cover (11) are respectively provided with threaded holes that are compatible with the torsion plate threaded torsion rod (3); The torsion plate threaded torsion rod (3) is connected to the box cover (11) through a threaded hole, and the torsion plate threaded torsion rod (3) is connected to the tray (4) through a threaded hole. The torsion plate threaded torsion rod (3) is rotated to apply pressure to the pressure plate (12), so that the pressure plate (12) compacts the simulated stratum (22); The air pressurizing device comprises: an air compressor (9); The output end of the air compressor (9) is connected to an air pipeline, one end of which extends between the box cover (11) and the pressure plate (12); a valve (8), a pressure stabilizer (7) and a pressure sensor (6) for sensing the air pressure value are installed on the air pipeline; The measuring device comprises: a computer, a stress-strain pore pressure gauge (1), a measuring line (2) and a measuring rod (5); The measuring rod (5) is arranged in the model cave (14); the measuring rod (5) is connected to the stress-strain pore pressure gauge (1) through the measuring line (2); The stress-strain piezometer (1) obtains the water and soil pressure value of the model cave (14), and transmits the pressure value to the computer, and the computer realizes simulation data monitoring; The computer is connected to the speed sensor (20) and the rotation speed sensor (16) respectively to obtain the rotation speed of the propulsion rod (19) and the rotation speed of the cutter head (15); the computer also obtains the propulsion distance of the shield propulsion device; The computer obtains the relationship between force, torque and power through the following formula: P(t)=F(t)×V(t) By measuring the speed and rotation speed, the change values ​​of thrust F and torque T during shield advancement are derived, and the change relationship between thrust F and time t, and torque T and time t is established; By integrating the velocity V and time t, the relationship between the displacement X and time t is obtained, and the correlation between the thrust F and the displacement X, and the torque T and the displacement X is obtained; By changing the distance between the cave and the initial position of the cutterhead, multiple sets of correlations between thrust F and displacement X, torque T and displacement X were obtained; According to the changes of shield thrust, torque and propulsion distance, the location of the cave in front of the shield propulsion device is predicted; A sealing cover (10) is attached to the box cover (11); The sealing cover (10) and the box cover (11) are respectively provided with threaded holes; The second side portion and the bottom portion of the box body (13) are both closed structures; The box body (13) is made of transparent material, and the sealing cover (10) is made of rubber sheet; A plurality of holes are evenly distributed on the pressure plate (12); The model cave (14) is cast by a mold, and the material of the model cave includes: gypsum or limestone.

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