Model test system and method for simulating unstable starting and motion impact of dangerous rock

Abstract

The invention relates to a model test system and method for simulating unstable starting and motion impact of a dangerous rock. The model test system mainly comprises a sample release device, a slope model and a test system, the sample releasing device comprises a main frame, a dangerous rock releasing device is arranged on the main frame in a sliding manner, and the dangerous rock releasing device ascends or descends through a lifting mechanism; the side slope model is arranged on one side of the main frame and comprises a first side slope slide way and a second side slope slide way, and the first side slope slide way and the second side slope slide way are hinged and are adjusted in angle through respective lifting supports; the testing system is arranged on one side of the discharging end of the slope model, the testing system comprises a force measuring plate, the force measuring plate is connected with a bottom plate through a plurality of force sensors, and the bottom plate is supported through a bottom support; and the force sensor is electrically connected with the test data analysis system. According to the model test system and method for simulating unstable starting and motion impact of the dangerous rock, whole-process automation of motion, impact and data processing analysis of the slope dangerous rock in different unstable starting modes can be achieved.

Description

Technical Field

[0001] The invention relates to a dangerous rockfall model, in particular to a model test system and method for simulating the instability start-up and movement impact of dangerous rocks. Background Art

[0002] Dangerous rockfall is the second largest geological disaster in my country's mountainous areas after landslides. Its threat lies in the slope movement and impact behavior after the instability of dangerous rocks. Dangerous rock movement has the characteristics of fast speed, high energy, and strong randomness in the movement process. It often brings adverse effects to traffic routes and engineering construction in the area, and even causes personal safety accidents.

[0003] The collapse of dangerous rock mass is huge in scale, covers a wide range and has extremely strong destructive power. According to existing research, the instability start of dangerous rock is divided into three modes: dumping, sliding and falling. Different instability modes have an important influence on the subsequent movement and impact law of dangerous rock. Therefore, accurately describing the instability start state of dangerous rock mass on the slope, exploring the movement process of the collapsed dangerous rock, and mastering the movement law of dangerous rock are the key prerequisites for solving practical engineering problems.

[0004] At present, field tests, model tests, and numerical simulations are the main methods for studying the instability and movement impact process of falling rocks. Although numerical simulation methods can study the movement conditions under more working conditions at a lower cost to provide reference for prevention and control, it is difficult to verify the reliability of the conclusions using numerical simulation methods alone; field tests are time-consuming and labor-intensive, with prominent safety issues and high costs. Model tests can overcome the limitations of the on-site environment and examine the movement characteristics of falling rocks from many aspects, but the existing test devices generally need to be manually transported to the release device at the top of the dangerous rock slope model, and then the impact force test is carried out by free fall. This method is time-consuming and labor-intensive and cannot measure the movement and impact process of dangerous rocks under sliding and dumping modes. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a model test system and method for simulating the instability start-up and movement impact of dangerous rocks, which can safely transport and release dangerous rock samples and obtain dangerous rock movement and impact data, thereby realizing the full automation of slope dangerous rock movement, impact and data processing and analysis under different instability start-up modes.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: A model test system for simulating the instability start-up and movement impact of dangerous rocks, including a sample release device, a slope model and a test system; The sample release device comprises a main frame, on which a dangerous rock release device is slidably arranged, and the dangerous rock release device is lifted or lowered by a lifting mechanism; The slope model is arranged on one side of the main frame, and the slope model comprises a first slope slide and a second slope slide, the first slope slide and the second slope slide are hinged and the angles are adjusted through respective lifting brackets; The test system is arranged on one side of the discharge end of the slope model, and the test system includes a force plate, which is connected to a base plate through a plurality of force sensors, and the base plate is supported by a bottom bracket; the force sensor is electrically connected to a test data analysis system.

[0007] The dangerous rock release device comprises a box body, which has a side opening facing the slope model, one end of a bottom plate is hinged on the box body, and the other end drives the inclination angle through an electric push rod; an electromagnet is embedded in the bottom plate, and the electromagnet is magnetically attracted to or detached from a block; the block is located on one side of the dangerous rock sample and restricts the dangerous rock sample.

[0008] The side of the box body is a transparent protective plate.

[0009] The bottom plate is provided with slots on the left and right sides, each slot is provided with a slider, the upper end of the slider extends out of the slot and is connected to the corresponding stopper, the stopper limits the dangerous rock sample; the lower end of the slider extends out of the slot and faces the electromagnets on the left and right sides of the outer end of the slot.

[0010] A lifting guide rail is vertically fixed on the main frame, and the corresponding dangerous rock release device is slidably matched with the lifting guide rail through a roller.

[0011] The lifting mechanism includes a lifting frame fixed on the top of the main frame, a pulley is installed on the lifting frame, an electric hoist is installed at the bottom of the main frame, one end of the wire rope is connected to the hanging ring of the dangerous rock release device through a hook, and the other end of the wire rope passes around the pulley and is released or reeled through the electric hoist.

[0012] The lower end of the first slope slide is hinged to the first lifting bracket and the second lifting bracket, and the lower end of the second slope slide is hinged to the third lifting bracket and the fourth lifting bracket; the lower parts of the first lifting bracket, the second lifting bracket, the third lifting bracket and the fourth lifting bracket are all equipped with rollers.

[0013] A binocular camera system is installed opposite to one side of the slope model. The binocular camera system includes two high-speed cameras. The two high-speed cameras are electrically connected to the test data analysis system 15 .

[0014] The two high-speed cameras are arranged at an angle of 60°.

[0015] A model test method for simulating the instability start-up and movement impact of dangerous rocks, comprising the following steps: Step 1: According to the test requirements, adjust the slope angles of the first slope slide and the second slope slide; place the dangerous rock specimen in the dangerous rock release device, and adjust the angle of the bottom plate of the dangerous rock release device according to the test requirements; check the coordination between the roller and the lifting rail of the dangerous rock release device, and ensure that the electric hoist, binocular camera system, and impact force test system are connected normally and all equipment is in the initial state; Step 2: Start the electric hoist and control its forward rotation through the remote controller to lift the dangerous rock release device to a predetermined height; start the binocular camera system to start capturing image data; trigger the electromagnet of the dangerous rock release device to release the dangerous rock sample; the dangerous rock sample moves on the first slope slide and the second slope slide and impacts the force plate, the force sensor measures the impact force, and the binocular camera system continuously captures the movement process of the dangerous rock; Step 3: After the test, stop the operation of each device; the test data analysis system collects the impact force data of the impact force test system and the image data of the binocular camera system; the image data is processed using the algorithm in the test data analysis system to calculate the three-dimensional motion speed, acceleration, displacement and other parameters of the dangerous rock; the impact force data, three-dimensional motion parameters and other data are comprehensively analyzed to study the movement law and impact characteristics of the dangerous rock, and provide a basis for the formulation of dangerous rock prevention and control measures; Step 4: According to the test purpose, adjust the dangerous rock instability start mode, slope type and slope, dangerous rock specimens and other test conditions, repeat the above test steps to obtain more data; after completing all tests, organize the test equipment and clean up the test site.

[0016] The present invention provides a model test system and method for simulating the instability start-up and movement impact of dangerous rocks, which has the following technical effects: 1) The device of the present invention realizes the integration of the dangerous rock lifting and releasing device, and does not need to manually carry the dangerous rock sample to the main frame slope slide, making the transportation of dangerous rocks more time-saving, labor-saving and safe, and making large model size testing more convenient.

[0017] 2) The present invention changes the initial sliding angle of the dangerous rock by adjusting the angle of the bottom plate in the dangerous rock release device, thereby realizing three different instability starting modes of the dangerous rock: sliding, tipping, and falling. It can be used to simulate the movement impact process of the dangerous rock under different instability modes, and explore the movement impact process of the dangerous rock from multiple aspects.

[0018] 3) The present invention can simulate different straight slopes through the combination of slope slides, and can simulate the whole process of instability and movement impact of dangerous rocks under the combined slopes of concave slopes and convex slopes, which is efficient and practical.

[0019] 4) The present invention realizes the simulation of the whole process of instability, movement and impact of dangerous rocks under different instability modes. By connecting the binocular camera system and the impact force test system to the test data analysis system, the impact force, three-dimensional movement speed, acceleration, displacement and other parameters of dangerous rocks can be obtained. The movement and impact process of dangerous rocks can be recorded in an all-round and meticulous manner, which is of great significance for in-depth understanding of the movement laws and disaster mechanisms of dangerous rocks and scientific formulation of dangerous rock prevention and control measures. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below in conjunction with the accompanying drawings and embodiments: Figure 1 It is the installation schematic diagram of the present invention.

[0021] Figure 2 It is an external schematic diagram of the dangerous rock release device in the present invention.

[0022] Figure 3 This is the internal front view of the dangerous rock release device of the present invention (the first type of block).

[0023] Figure 4 This is an internal top view of the dangerous rock release device of the present invention (the first type of block).

[0024] Figure 5 It is a schematic diagram of the lifting frame in the present invention.

[0025] Figure 6 Schematic diagram of the impact force testing system of the present invention.

[0026] Figure 7 It is a schematic diagram of the distribution of force sensors in the present invention.

[0027] Figure 8 Schematic diagram of the structure of the second stopper in the present invention (open).

[0028] Fig. 9 This is a front view (open) of the second stopper of the present invention.

[0029] Fig.10 It is a schematic diagram of the structure of the second stopper in the present invention (close together).

[0030] Fig.11 This is a displacement trajectory curve diagram (45 degrees) of the dangerous rock after the test of the present invention.

[0031] Fig.12 This is the acceleration curve diagram of the dangerous rock after the test of the present invention (45 degrees).

[0032] Fig.13 This is a velocity curve diagram of the dangerous rock after the test of the present invention (45 degrees).

[0033] In the figure: main frame 1, dangerous rock release device 2, hanging ring 21, transparent guard plate 22, roller 23, electromagnet 24, block 25, bottom plate 26, dangerous rock sample 27, electric push rod 28, electric hoist 3, lifting rail 4, lifting frame 5, pulley 51, wire rope 52, hook 53, first slope slide 6, connecting mechanism 7, second slope slide 8, first lifting bracket 9, second lifting bracket 10, third lifting bracket 11, fourth lifting bracket 12, impact force testing system 13, force plate 131, bottom plate 132, bottom bracket 133, force sensor 134, binocular camera system 14, test data analysis system 15, connecting line 16. DETAILED DESCRIPTION

[0034] A model test system for simulating the instability start-up and movement impact of dangerous rocks mainly includes a main frame 1, a dangerous rock release device 2, an electric hoist 3, a lifting guide rail 4, a lifting frame 5, a first slope slide 6, a connecting mechanism 7, a second slope slide 8, a first lifting bracket 9, a second lifting bracket 10, a third lifting bracket 11, a fourth lifting bracket 12, an impact force testing system 13, a binocular camera system 14, a test data analysis system 15 and a number of connecting lines 16 and other components.

[0035] like Figure 1 As shown, the main frame 1 is formed by welding a number of square tubes, four of which are used as vertical columns, and four horizontal square tube beams are used to weld and connect the vertical columns at regular intervals. The welding quality is ensured during welding, and each welding point is firm and reliable without welding defects such as pores and slag inclusions.

[0036] like Figure 2-4 As shown, the dangerous rock release device 2 is composed of a bottom plate angle adjustment mechanism and an electromagnet starting mechanism. The dangerous rock release device 2 is a rectangular parallelepiped structure, including a box body, and a transparent protective plate 22 is installed on the side of the box body. The transparent protective plate 22 is organic glass. The advantages of using transparent organic glass are: 1. Easy to observe: The transparent property of organic glass allows the operator to better observe the placement of the dangerous rock sample in the box and check whether it is placed in place. At the same time, during the simulation of the dangerous rock instability start-up process, the movement trajectory, posture changes, and interaction with the surrounding environment of the dangerous rock sample can be clearly seen, which is convenient for researchers to record data and analyze the dangerous rock instability mechanism.

[0037] 2. Organic glass has high strength, light weight and is not easy to break. It can prevent dangerous rocks from being thrown from the side due to instability and causing harm to operators and surrounding equipment, thus providing protection for experimental safety.

[0038] 3. Reduce the weight of the device: Organic glass is light in weight. Using it as a guard plate can reduce the weight of the entire dangerous rock release device without affecting the function of the device. It is convenient to connect it with the lifting device through a hanging ring for lifting operations, reduce the load of the lifting device, and improve the convenience of device operation.

[0039] The transparent guard plate 22 is open to the side of the slope, and the opening is used to place the dangerous rock sample 27 or pour out the dangerous rock sample 27. One end of the bottom plate 26 is hinged to the box, and the other end is hinged to the electric push rod 28. The lower end of the electric push rod 28 is hinged to the bottom of the release device box to adjust the inclination angle of the bottom plate 26. The hanging ring 21 is welded on the top of the box to connect with the lifting device to achieve lifting. By adjusting the stroke of the electric push rod 28, the inclination angle of the bottom plate is changed, so as to realize the simulation of different instability start-up modes of dangerous rocks (such as sliding, dumping, and falling).

[0040] Furthermore, the first type of electromagnet starting mechanism is located at the lower front end of the bottom plate, and a 12V square electromagnet 24 is embedded in the lower front end of the bottom plate 26. When the power is turned on by remote control, the electromagnet 24 and the block 25 are attracted to prevent the dangerous rock from sliding down. The block 25 is L-shaped, and one side of the block 25 is connected to the box body by a connecting rope. When the power is disconnected, the block 25 instantly detaches from the electromagnet 24, realizing the accurate release of the dangerous rock.

[0041] Since one side of the stopper 25 is connected to the connecting rope, and the other end of the connecting rope is connected to the box, the stopper 25 is prevented from falling. However, in the next test, it needs to be manually placed in place and magnetically fixed again after power is turned on.

[0042] In order to reduce labor intensity, Figure 8-10 As shown, the corresponding bottom plate 26 is provided with slots 25.2 on the left and right sides, each slot 25.2 is provided with a slider 25.1, the upper end of the slider 25.1 extends out of the slot 25.2 and is connected to the corresponding stopper 25, the stopper 25 is an arc structure, and the arc structure matches the corresponding dangerous rock sample 27. The lower end of the slider 25.1 extends out of the slot 25.2 and faces the electromagnet 24 on the left and right sides of the outer end of the slot 25.2.

[0043] like Fig. 9 As shown, for the block 25 on one side, when it is necessary to limit the dangerous rock sample 27, the inner electromagnet 24 is energized, and the outer electromagnet 24 is de-energized, and the inner electromagnet 24 adsorbs and fixes the slider 25.1, so that the two block 25 are close to fit the dangerous rock sample 27, support and limit the dangerous rock sample 27, and keep it stable during the lifting process of the dangerous rock sample 27; when it is necessary to release the dangerous rock sample 27, the inner electromagnet 24 is de-energized, and the outer electromagnet 24 is energized, and the outer electromagnet 24 adsorbs and fixes the slider 25.1, and the two block 25 are separated, as shown in FIG. Fig.10 As shown, the dangerous rock sample 27 is released freely, so there is no need to manually restore the electromagnet 24.

[0044] The lifting guide rail 4 is composed of four square steels, which are firmly connected to the main frame 1 by welding. The roller 23 of the dangerous rock release device 2 is closely matched with the guide rail. The roller 23 is made of high-strength nylon material. The roller bracket is firmly connected to the release device 2 by bolts to ensure low-friction sliding between the roller 23 and the lifting guide rail 4, withstand large loads, and provide stable guidance for the lifting of the dangerous rock release device 2.

[0045] The lifting frame 5 is welded to the top of the main frame 1 with high-strength steel, and a pulley 51 is welded in the middle of the top of the lifting frame 5. The electric hoist 3 is fixed to the bottom of the main frame 1 with bolts, and is connected to the hanging ring 21 of the dangerous rock release device 2 through a wire rope 52 and a hook 53. The electric hoist 3 is controlled by a remote controller, and can realize forward and reverse rotation and speed adjustment, and is used to lift and lower the rolling stone release device 2.

[0046] The simulated test slope is composed of a first slope slide 6, a second slope slide 8, a first lifting bracket 9, a second lifting bracket 10, a third lifting bracket 11, and a fourth lifting bracket 12. The two sections of the slide are connected by a hinge 71 and a connecting shaft 72, the first lifting bracket 9 and the second lifting bracket 10 are hinged to the first slope slide 6, the third lifting bracket 11 and the fourth lifting bracket 12 are hinged to the second slope slide 8, and rollers are installed at the bottom of each lifting bracket.

[0047] Furthermore, the heights and roller positions of the first lifting bracket 9 and the second lifting bracket 10 are adjusted to tilt the first slope slide 6 to the desired slope angle, and then the heights and roller positions of the third lifting bracket 11 and the fourth lifting bracket 12 are adjusted to tilt the second slope slide 8 to the desired slope angle, so as to simulate the whole process of instability and movement impact of dangerous rocks under different linear slopes and combined slopes of concave and convex slopes.

[0048] The impact force testing system 13 includes a force plate 131, a bottom plate 132, a bottom bracket 133, and a force sensor 134, which are placed at the location where the dangerous rock falls and impacts. The force sensor 134 is connected to the test data analysis system 15 through a connecting line 16 to measure the impact force generated when the dangerous rock hits.

[0049] The binocular camera system includes two high-speed cameras 14, which are arranged at an angle of 60° at the front end of the simulation device facing the two sections of the slope slide, and are connected to the test data analysis system 15 through a connecting line 16. After the dangerous rock is released, the camera starts to capture the three-dimensional motion image data of the dangerous rock.

[0050] Observation and analysis using the Qianyanlang high-speed image analysis system: mainly based on video or picture sequences to solve motion problem analysis in various scenarios, as well as the entire analysis process and visual presentation of results and report output. The software is based on sub-pixel detection and tracking algorithms, and in the best case, the accuracy can reach 0.01 pixels.

[0051] Furthermore, the binocular camera 14 and the impact force testing system 13 are connected to the test data analysis system 15. The test data processing system 15 receives the impact force data and image data through the connecting line 16, and uses relevant algorithms to obtain the three-dimensional movement speed, acceleration, and displacement data of the dangerous rock, so as to comprehensively and meticulously record the movement and impact process of the dangerous rock, and provide data support for studying the movement laws of the dangerous rock.

[0052] After the displacement, acceleration and velocity data are obtained from the test, the displacement trajectory curve, acceleration curve and velocity curve of the dangerous rock can be drawn. The curves can show the displacement, acceleration and velocity values ​​of the dangerous rock at each moment of movement, as well as their changing trends over time.

[0053] A model test method for simulating the instability start-up and movement impact of dangerous rocks, including the following process: Step 1: According to the test requirements, set the corresponding slope type (straight slope, concave slope, convex slope or a combination thereof) at the slope slide, and adjust the slope angles of the first slope slide 6 and the second slope slide 8. Place the dangerous rock specimen 27 in the dangerous rock release device 2, adjust the angle of the bottom plate 26 of the dangerous rock release device 2 according to the test requirements, and determine the dangerous rock instability start mode (slip, dumping or falling).

[0054] There is no absolute standard numerical range for the sliding, tipping and falling angles of dangerous rockfall. In actual research scenarios, factors such as the shape, mass distribution and center of gravity of the dangerous rock itself will affect the instability start mode.

[0055] Sliding type: The bottom plate 26 angle is generally below 45°, and the dangerous rock will slide along the bottom plate under certain conditions and start to become unstable.

[0056] Tipping type: The angle of the bottom plate is generally greater than 45°, and the dangerous rock tips over and becomes unstable due to the shift of the center of gravity.

[0057] Falling type: The angle of the bottom plate 26 is greater than 80°, and the dangerous rock falls almost vertically, causing instability.

[0058] If the stopper 25 is not provided, the bottom plate 26 is kept horizontal first, and after the dangerous rock release device 2 is lifted to a suitable height, the bottom plate 26 is flipped at a certain angle, and the dangerous rock test piece 27 is poured out to simulate the situation of sliding, tipping or falling. Compared with the method of the present invention, this situation cannot achieve the same effect.

[0059] In the case where the stopper 25 is not provided, if the dangerous rock specimen 27 is released only by flipping the bottom plate 26, the specimen may enter the sliding state prematurely due to the gradual increase in the bottom plate angle, resulting in a deviation between the actual instability mode and the preset test conditions (the actual instability mode is sudden instability in the tilted static state).

[0060] In contrast, the block 25 of the present invention can achieve precise release control of the dangerous rock sample through the adsorption and detachment mechanism of the electromagnet 24, which is consistent with the actual instability mode and has authenticity. Specifically, the arc-shaped fitting structure of the block 25 can effectively limit the dangerous rock during the bottom plate angle adjustment process, preventing it from sliding due to vibration or gravity during the lifting or angle adjustment stage. The instantaneous power-off design of the electromagnet 24 ensures that the block 25 is detached synchronously, allowing the dangerous rock to start moving at a predetermined position with a specific initial state, thereby ensuring the consistency of the initial conditions of the test.

[0061] If the block 25 is removed, the dangerous rock may be offset due to vibration during the lifting process, and the release depends only on the flipping of the bottom plate. The dangerous rock may start to slide directly when the bottom plate angle is low, resulting in the release position offset or the initial motion mode mixing, which directly affects the accuracy and repeatability of the test data. Therefore, the synergy between the block 25 and the electromagnetic control system is the core technical support for achieving accurate simulation of different instability start-up modes.

[0062] Check the coordination between the roller 23 of the dangerous rock release device 2 and the lifting guide rail 4, and ensure that the electric hoist 3, binocular camera system 14, impact force test system 13 and other equipment are connected normally and all equipment are in the initial state.

[0063] Step 2: Start the electric hoist 3, control it to rotate forward through the remote controller, and lift the dangerous rock release device 2 to a predetermined height (the height can be determined according to the test design). Start the binocular camera system 14 to start capturing image data. Trigger the electromagnet 24 of the dangerous rock release device 2 to release the dangerous rock sample 27. The dangerous rock moves on the first slope slide 6 and the second slope slide 8 and impacts the force plate 131. The force sensor 134 measures the impact force, and the binocular camera system 14 continuously captures the movement process of the dangerous rock.

[0064] Step 3: After the test is completed, stop the operation of each device. The test data analysis system 15 collects the impact force data of the impact force test system 13 and the image data of the binocular camera system 14. The image data is processed using the algorithm in the test data analysis system 15 to calculate the three-dimensional motion speed, acceleration, displacement and other parameters of the dangerous rock. Comprehensively analyze the impact force data, three-dimensional motion parameters and other data, study the movement law and impact characteristics of the dangerous rock, and provide a basis for the formulation of dangerous rock prevention and control measures.

[0065] Step 4: According to the test purpose, the test conditions such as the dangerous rock instability start mode, the slope type and slope of the slope slide, and the dangerous rock specimen can be adjusted, and the above test steps can be repeated to obtain more data. After completing all tests, organize the test equipment and clean up the test site.

[0066] In step 3, the relevant algorithm is used to obtain the three-dimensional motion velocity, acceleration, and displacement data of the dangerous rock. The calculation process is as follows: 1. Three-dimensional displacement calculation Triangulation principle based on binocular vision: The two high-speed cameras in the binocular camera system are arranged at an angle of 60°, and the three-dimensional coordinates of the dangerous rock are calculated using the triangulation principle.

[0067] 1.1. For a point on the dangerous rock, there is a difference in the image point position in the two camera images (parallax). Knowing the baseline distance of the two cameras (the horizontal distance between the two cameras) and their respective focal lengths, according to the principle of similar triangles, the distance (depth) from the point to the camera plane can be calculated. The formula is ,in B is the baseline distance, f is the focal length, x l , x r are the horizontal coordinates of the point in the left and right images respectively.

[0068] 1.2. Calculate the coordinates in three-dimensional space through further geometric relationships ( X , Y , Z ),like , , ( c x ,c y ) is the image center coordinate, Represents the vertical coordinate of the point on the dangerous rock in the left image.

[0069] 1.3. By calculating the same point on the dangerous rock at different times, the three-dimensional coordinates at different times are obtained P 1( X 1, Y 1, Z 1) P 2( X 2, Y 2, Z 2), and thus calculate the displacement , , .

[0070] 2. Three-dimensional velocity calculation Difference method: After obtaining the displacement data, the velocity can be calculated by the difference between the displacement and time. t n and t n+1 ,speed v exist X Direction Component v x It can be approximately expressed as , similarly, speed v exist Y Direction Component v y It can be approximately expressed as ,speed v exist Z Direction Component v z It can be approximately expressed as .

[0071] 3. Three-dimensional acceleration calculation Difference method: Acceleration is the rate of change of velocity over time. After obtaining the velocity data, the difference method is also used to calculate the acceleration. t n , t n+1 and t n+2 , acceleration a exist X Direction Component a x It can be approximately expressed as , similarly, a y and a z The calculation formula for .

[0072] 4. Impact force calculation The four channels correspond to four force sensors. When the rock impacts the force plate, each force sensor converts the impact force into an electrical signal. The force sensor is electrically connected to the test data analysis system. The system collects the electrical signal data of the four channels in real time and converts the electrical signal into actual force value data according to the calibration parameters of the force sensor to obtain the impact force data of the four channels at different times. F 1( t ), F 2( t ), F 3( t ), F 4( t ).

[0073] Add the impact force data of the four channels to obtain the total impact force calculation formula generated by the dangerous rock impacting the force plate: F ( t )= F 1( t )+ F 2( t )+ F 3( t )+ F 4( t ).

Claims

1. A model test system for simulating the instability start-up and movement impact of dangerous rocks, characterized by: It includes a sample release device, a slope model and a test system; The sample release device comprises a main frame (1), on which a dangerous rock release device (2) is slidably arranged, and the dangerous rock release device (2) is lifted or lowered by a lifting mechanism; The side slope model is arranged on one side of the main frame (1), and comprises a first side slope slideway (6) and a second side slope slideway (8), wherein the first side slope slideway (6) and the second side slope slideway (8) are hingedly connected and their angles are adjusted through respective lifting brackets; The test system is arranged on one side of the discharge end of the slope model, and comprises a force plate (131), the force plate (131) is connected to a bottom plate (132) via a plurality of force sensors (134), and the bottom plate (132) is supported by a bottom bracket (133); the force sensor (134) is electrically connected to a test data analysis system (15).

2. A model test system for simulating unstable start-up and motion impact of dangerous rocks according to claim 1, characterized in that: The dangerous rock release device (2) comprises a box body, the side opening of the box body facing the side of the slope model, one end of a bottom plate (26) is hinged to the box body, and the other end drives the inclination angle through an electric push rod (28); an electromagnet (24) is embedded in the bottom plate (26), and the electromagnet (24) and a stopper (25) are magnetically attracted or separated; the stopper (25) is located on one side of the dangerous rock sample (27) and restricts the dangerous rock sample (27).

3. A model test system for simulating unstable start-up and motion impact of dangerous rocks according to claim 2, characterized in that: The side of the box body is a transparent protective plate (22).

4. A model test system for simulating unstable start-up and motion impact of dangerous rocks according to claim 2, characterized in that: The bottom plate (26) is provided with slots (25.2) on the left and right sides. A slider (25.1) is provided in each slot (25.2). The upper end of the slider (25.1) extends out of the slot (25.2) and is connected to a corresponding stopper (25). The stopper (25) limits the position of the dangerous rock sample (27). The lower end of the slider (25.1) extends out of the slot (25.2) and faces the electromagnets (24) on the left and right sides of the outer ends of the slot (25.2).

5. A model test system for simulating unstable start-up and motion impact of dangerous rocks according to claim 2, characterized in that: A lifting guide rail (4) is vertically fixed on the main frame (1), and the corresponding dangerous rock release device (2) is slidably matched with the lifting guide rail (4) via a roller (23).

6. A model test system for simulating unstable start-up and motion impact of dangerous rocks according to claim 1, characterized in that: The lifting mechanism comprises a lifting frame (5) fixed to the top of the main frame (1), a pulley (51) being installed on the lifting frame (5), an electric hoist (3) being installed at the bottom of the main frame (1), one end of a steel wire rope (52) being connected to a hanging ring (21) of a dangerous rock release device (2) via a hook (53), and the other end of the steel wire rope (52) passing around the pulley (51) and being released or reeled in via the electric hoist (3).

7. A model test system for simulating unstable start-up and motion impact of dangerous rocks according to claim 6, characterized in that: The lower end of the first side slope slideway (6) is hinged to the first lifting bracket (9) and the second lifting bracket (10), and the lower end of the second side slope slideway (8) is hinged to the third lifting bracket (11) and the fourth lifting bracket (12); the lower parts of the first lifting bracket (9), the second lifting bracket (10), the third lifting bracket (11) and the fourth lifting bracket (12) are all equipped with rollers.

8. A model test system for simulating unstable start-up and motion impact of dangerous rocks according to claim 1, characterized in that: A binocular camera system is installed opposite one side of the slope model. The binocular camera system comprises two high-speed cameras (14). The two high-speed cameras (14) are electrically connected to a test data analysis system (15).

9. A model test system for simulating unstable start-up and motion impact of dangerous rocks according to claim 8, characterized in that: The two high-speed cameras (14) are arranged at an angle of 60°.

10. A method for conducting a test on a model test system simulating unstable start-up and motion impact of dangerous rocks according to any one of claims 1 to 9, comprising the following steps: Step 1: According to the test requirements, adjust the slope angles of the first slope slide (6) and the second slope slide (8); place the dangerous rock specimen (27) in the dangerous rock release device (2), and adjust the angle of the bottom plate (26) of the dangerous rock release device (2) according to the test requirements; check the matching of the roller (23) of the dangerous rock release device (2) and the lifting guide rail (4), and ensure that the electric hoist (3), the binocular camera system (14), and the impact force test system (13) are connected normally and are in the initial state; Step 2: Start the electric hoist (3), control it to rotate forward through a remote controller, and lift the dangerous rock release device (2) to a predetermined height; start the binocular camera system (14) to start capturing image data; trigger the electromagnet (24) of the dangerous rock release device (2) to release the dangerous rock sample (27); the dangerous rock sample (27) moves on the first side slope slide (6) and the second side slope slide (8) and impacts the force plate (131), the force sensor (134) measures the impact force, and the binocular camera system (14) continuously captures the movement process of the dangerous rock; Step 3: After the test is completed, the operation of each device is stopped; the test data analysis system (15) collects the impact force data of the impact force test system (13) and the image data of the binocular camera system (14); the image data is processed using the algorithm in the test data analysis system (15) to calculate the three-dimensional motion speed, acceleration, displacement and other parameters of the dangerous rock; Comprehensively analyze impact force data, three-dimensional motion parameters and other data to study the movement laws and impact characteristics of dangerous rocks, and provide a basis for the formulation of dangerous rock prevention and control measures; Step 4: According to the test purpose, adjust the dangerous rock instability start mode, slope type and slope, dangerous rock specimens and other test conditions, repeat the above test steps to obtain more data; after completing all tests, organize the test equipment and clean up the test site.

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