Automatic positioning device, method and arch dam geomechanics test model

Abstract

The application discloses an automatic positioning device, method and arch dam geomechanics test model, the positioning device comprises a fixed frame, a moving platform, a laser range finder and a control system; the moving platform is arranged on the top of the fixed frame, the laser range finder is arranged on the moving platform, the control system controls the moving platform to act according to the point coordinates in the different elevation horizontal cutting drawing of the arch dam geomechanics test model, so that the position of the laser range finder in the fixed frame is adjusted; the laser range finder emits a vertical laser beam downward at different positions of the fixed frame, so as to realize lofting positioning and measuring the distance between the vertical laser beam emission point and the masonry plane. The application utilizes laser to automatically position and measure the distance, shortens the time required for lofting positioning in the masonry process of the test model, improves the lofting positioning efficiency and accuracy, and further improves the masonry efficiency of the test model and the simulation accuracy of the test model.

Description

Technical Field

[0001] This invention belongs to the field of small block masonry positioning technology, and particularly relates to an automatic positioning device, method and geomechanical test model of arch dam applied to the geomechanical test model of arch dam. Background Technology

[0002] Geomechanical test models of arch dams are an effective means of evaluating the overall stability and reinforcement effects of arch dams. They can compensate for the shortcomings of numerical simulations and allow for comparison with numerical simulation results, thus ensuring the accuracy and authenticity of the evaluation results. Generally, a geometric similarity scale of 250:1 is used to scale down the prototype for three-dimensional geomechanical model testing. Model testing is essential for arch dams, especially high arch dams.

[0003] Current geomechanical test models for arch dams primarily employ the small-block construction method. This method involves compressing similar materials into small blocks, which are then used to construct the test model piece by piece. This method effectively simulates structural planes such as faults and joints within the rock mass. The small-block construction method for arch dam geomechanical test models uses the blocks themselves to simulate the deformation characteristics of the rock mass, while the low-strength bonding between the small blocks simulates the strength characteristics of fractured rock masses. This results in the model's stress-deformation characteristics closely resembling those of actual rock masses. The most crucial step in constructing the arch dam geomechanical test model is accurately determining the locations of faults and joints within the test model and characterizing the morphology of the arch dam.

[0004] The construction of a three-dimensional geomechanical test model using small-block masonry techniques involves manually building the model layer by layer according to elevation, based on drawings provided by the design unit (usually a plan view containing key geological information such as arch dam and rock mass type, faults, and joints). During the construction of each layer, the traditional method involves manual positioning using a plumb bob and measurement using a ruler. This positioning and measurement method is not only time-consuming and labor-intensive, but also inefficient, and has several shortcomings:

[0005] First, during the masonry process, the vertically suspended plumb bob may sway or shift due to airflow disturbances, affecting positioning accuracy. Second, the plumb bob inevitably wobbles within a small range after each movement, and the process of waiting for it to stabilize increases the model masonry time. Furthermore, since the measurements are taken manually using a ruler, the accuracy largely depends on the masonry worker's skill level, inevitably introducing some measurement and reading errors. Summary of the Invention

[0006] The purpose of this invention is to provide an automatic positioning device, method, and geomechanical test model for arch dams, in order to solve the problems of low positioning accuracy and low positioning efficiency caused by manual positioning using a plumb bob and measurement using a ruler in small block masonry technology.

[0007] This invention solves the above-mentioned technical problems through the following technical solution: an automatic positioning device, applied in the construction process of an arch dam geomechanical test model, the positioning device comprising:

[0008] A fixed frame, the defined range of which is adapted to the size of the arch dam geomechanical test model;

[0009] A motion platform is located on top of the fixed frame;

[0010] A laser rangefinder is mounted on the motion platform and is used to emit a vertical laser beam downwards at different positions of the fixed frame in order to achieve layout positioning and measure the distance between the vertical laser beam emission point and the masonry plane.

[0011] The control system is used to control the movement of the motion platform according to the point coordinates in the different elevation plane sections of the arch dam geomechanical test model, thereby adjusting the position of the laser rangefinder on the fixed frame.

[0012] Furthermore, the motion platform includes a first guide rail, a second guide rail, a third guide rail, a first slider, a second slider, a third slider, a first drive mechanism, and a second drive mechanism; the first guide rail and the second guide rail are respectively fixedly disposed on both sides of the top of the fixed frame, the first slider is disposed on the first guide rail and can slide along the first guide rail, the second slider is disposed on the second guide rail and can slide along the second guide rail; the two ends of the third guide rail are respectively fixedly disposed on the first slider and the second slider, the third slider is disposed on the third guide rail and can slide along the third guide rail; the laser rangefinder is disposed on the third slider;

[0013] The input end of the first driving mechanism is connected to the control system, and its output end is connected to the first slider and the second slider. The first driving mechanism is used to drive the first slider and the second slider to move synchronously under the control of the control system. The input end of the second driving mechanism is connected to the control system, and its output end is connected to the third slider. The second driving mechanism is used to drive the third slider to move under the control of the control system.

[0014] Furthermore, the first drive mechanism includes a first servo motor, a first coupling, a first transmission bearing, a second coupling, a linkage rod, a third coupling, and a second transmission bearing connected in sequence; the first transmission bearing and the second coupling are respectively located on both sides of the first bearing seat, and the third coupling and the second transmission bearing are respectively located on both sides of the second bearing seat; the first guide rail has the first bearing seat at both ends, and the second guide rail has the second bearing seat at both ends; the first transmission bearing is connected to the track on the first guide rail, and the second transmission bearing is connected to the track on the second guide rail.

[0015] The second drive mechanism includes a second servo motor, a fourth coupling, and a third transmission bearing connected in sequence, wherein the third transmission bearing is connected to the track drive on the third guide rail.

[0016] Furthermore, both ends of the first guide rail are fixed to one side of the top of the fixed frame via a first support, both ends of the second guide rail are fixed to the other side of the top of the fixed frame via a second support, and both ends of the third guide rail are fixed to the first slider and the second slider via a third support.

[0017] Furthermore, the laser rangefinder is mounted on the third slider via an L-shaped connecting plate.

[0018] Furthermore, the laser rangefinder includes a rangefinder body and a laser transmitter and a laser receiver disposed on the rangefinder body, wherein the transmitting end of the laser transmitter and the receiving end of the laser receiver are both vertically downward.

[0019] Based on the same concept, the present invention also provides a method for constructing a geomechanical test model of an arch dam, comprising the following steps:

[0020] The dimensions of the geomechanical test model for the arch dam are determined based on the actual evaluation range of the arch dam and the geometric similarity scale.

[0021] Adjust the original design drawing of the arch dam according to the dimensions of the arch dam geomechanical test model, so that the range and coordinates of the horizontal cross-section of the arch dam at different elevations are consistent with the arch dam geomechanical test model, and obtain the horizontal cross-section of the arch dam geomechanical test model at different elevations;

[0022] Install the automatic positioning device as described above, and level the automatic positioning device so that it is in a horizontal position.

[0023] The different elevation planar cross-sections of the arch dam geomechanical test model are imported into the control system of the automatic positioning device, or the dimensions of the arch dam geomechanical test model and the different elevation planar cross-sections of the arch dam geomechanical test model are determined in the control system.

[0024] The position of the laser rangefinder of the automatic positioning device in the fixed frame is initialized based on the coordinate origin of the horizontal section of the arch dam geomechanical test model at different elevations.

[0025] During the layer-by-layer masonry construction according to the elevation of the arch dam geomechanical test model, the following operations are performed for each part that requires layout and positioning:

[0026] Obtain the coordinates of the different points that make up the part;

[0027] The movement platform of the automatic positioning device is controlled according to the coordinates of each point, thereby adjusting the position of the laser rangefinder in the fixed frame;

[0028] When the laser rangefinder reaches the position corresponding to the coordinates of the point, the laser rangefinder emits a vertical laser beam downwards. Based on the laser point of the vertical laser beam on the masonry plane, the accurate location of the point in the arch dam geomechanical test model is determined, thereby determining the accurate location of the part in the arch dam geomechanical test model.

[0029] Furthermore, the coordinates of different points that make up the aforementioned part are obtained, and the specific implementation process is as follows:

[0030] Use the point coordinate query function in the drawing software to obtain the coordinates of different points that make up the part.

[0031] Furthermore, the locations include faults, joints and fissures, rock mass category boundaries, and arch lines;

[0032] In a certain elevation sectional view, faults, joints, fissures, and rock mass category boundaries in the foundation are regarded as a straight line or a broken line. The two endpoints of the straight line determine the straight line or the multiple inflection points on the broken line determine the broken line.

[0033] For the arch line, the laser rangefinder is moved according to the coordinate trajectory corresponding to the arch line, and at the same time, the laser rangefinder emits a vertical laser beam downwards; the light trace formed by the laser points of different vertical laser beams on the masonry plane is used to cut off the excess part of the masonry block according to the light trace, and the accurate arch dam shape is carved out.

[0034] Furthermore, the masonry method also includes:

[0035] While using a laser rangefinder to emit a vertical laser beam downwards for positioning, the distance between the point of emission of the vertical laser beam and the masonry plane is also measured.

[0036] The theoretical value of the distance is obtained based on the current elevation of the masonry plane. The theoretical value of the distance is compared with the measured value, and the masonry is automatically checked based on the comparison result.

[0037] Based on the same concept, the present invention also provides a geomechanical test model for an arch dam, wherein the test model is constructed using the masonry method described above.

[0038] Beneficial effects

[0039] Compared with the prior art, the advantages of the present invention are as follows:

[0040] The automatic positioning device provided by this invention utilizes a control system to control the motion platform based on the coordinates of points on different elevation plane sections of the arch dam geomechanical test model, thereby adjusting the position of the laser rangefinder. By emitting a vertical laser beam from the laser rangefinder at the position corresponding to the point coordinates, accurate positioning of the point within the arch dam geomechanical test model can be achieved, thus ensuring accurate positioning of key components. During the construction of the arch dam geomechanical test model, this automatic positioning device enables automatic and accurate positioning of key components, avoiding the problems of poor positioning accuracy and low efficiency associated with traditional manual measurement and positioning methods. This invention utilizes laser for automatic positioning and ranging, shortening the time required for layout and positioning during the test model construction process, improving layout and positioning efficiency and accuracy, and consequently increasing the construction efficiency and simulation accuracy of the test model.

[0041] The laser rangefinder can move freely within the defined range of a fixed frame. For corner areas that are difficult to measure using traditional manual layout and positioning methods, the automatic positioning device of this invention can also achieve rapid and accurate positioning and measurement. Attached Figure Description

[0042] To more clearly illustrate the technical solution of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only one embodiment of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a perspective view of the automatic positioning device in an embodiment of the present invention;

[0044] Figure 2 This is a front view of the automatic positioning device in an embodiment of the present invention;

[0045] Figure 3 This is a top view of the automatic positioning device in an embodiment of the present invention;

[0046] Figure 4 This is a right view of the automatic positioning device in an embodiment of the present invention;

[0047] Figure 5 This is an embodiment of the present invention. Figure 1 A magnified view of part A in the middle;

[0048] Figure 6 This is an embodiment of the present invention. Figure 1 A magnified view of part B in the middle;

[0049] Figure 7 This is an embodiment of the present invention. Figure 1 A magnified view of part C in the middle;

[0050] Figure 8 This is an embodiment of the present invention. Figure 1 A magnified view of part D in the middle;

[0051] Figure 9 This is an embodiment of the present invention. Figure 1 A magnified view of the central part E;

[0052] Figure 10 This is an embodiment of the present invention. Figure 1 A magnified view of the central part F;

[0053] Figure 11 This is a flowchart of the masonry method for the geomechanical test model of the arch dam in this embodiment of the invention;

[0054] Figure 12 This is a schematic diagram of the actual evaluation range of the 2325m elevation horizontal section in an embodiment of the present invention;

[0055] Figure 13 This is a schematic diagram showing the delineation and adjustment of the 2325m elevation plane in an embodiment of the present invention.

[0056] Among them, 1-fixed frame, 2-motion platform, 21-first guide rail, 211-first support, 212-first bearing seat, 22-second guide rail, 221-second support, 222-second bearing seat, 23-third guide rail, 231-third support, 232-third bearing seat, 24-first drive mechanism, 241-first servo motor, 242-first transmission bearing, 243-linkage light rod, 244-first bearing housing, 25-first slider, 26-second slider, 27-third slider, 28-second drive mechanism, 281-second servo motor, 282-third transmission bearing, 283-second bearing housing, 3-L-shaped connecting plate, 4-laser rangefinder, 41-laser emitter. Detailed Implementation

[0057] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0058] The technical solutions of this application will be described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0059] like Figures 1-4 As shown in the figure, the automatic positioning device provided in this embodiment is applied in the construction process of the geomechanical test model of the arch dam. The positioning device includes a fixed frame 1, a motion platform 2, a laser rangefinder 4 and a control system. The motion platform 2 is located on the top of the fixed frame 1, and the laser rangefinder 4 is located on the motion platform 2. The motion platform 2 and the laser rangefinder 4 are electrically connected to the control system.

[0060] The fixed frame 1 is used to define the scope of the arch dam geomechanical test model. Therefore, the defined scope of the fixed frame 1 is adapted to the size of the arch dam geomechanical test model. At the same time, the fixed frame 1 is fixed to the ground and serves as a support. In this embodiment, the fixed frame 1 is a steel frame with dimensions of 4.4m × 3.7m × 3m.

[0061] The motion platform 2 moves under the control of the control system, and the movement of the motion platform 2 can change the position of the laser rangefinder 4 on the top of the fixed frame 1. In this embodiment, the motion platform 2 is a two-axis motion platform, namely an XY-axis motion platform. In a specific embodiment of the present invention, as follows... Figures 5-10 As shown, the motion platform 2 includes a first guide rail 21, a second guide rail 22, a third guide rail 23, a first slider 25, a second slider 26, a third slider 27, a first drive mechanism 24, and a second drive mechanism 28. The first guide rail 21 and the second guide rail 22 are respectively fixed on both sides of the top of the fixed frame 1. The first slider 25 is disposed on the first guide rail 21 and can slide along the first guide rail 21. The second slider 26 is disposed on the second guide rail 22 and can slide along the second guide rail 22. The two ends of the third guide rail 23 are respectively fixed on the first slider 25 and the second slider 26. The third slider 27 is disposed on the third guide rail 23 and can slide along the third guide rail 23. The laser rangefinder 4 is disposed on the third slider 27. The input end of the first drive mechanism 24 is connected to the control system, and its output end is connected to the first slider 25 and the second slider 26. The first drive mechanism 24 is used to drive the first slider 25 and the second slider 26 to move synchronously under the control of the control system. The input end of the second drive mechanism 28 is connected to the control system, and its output end is connected to the third slider 27. The second drive mechanism 28 is used to drive the third slider 27 to move under the control of the control system.

[0062] Under the control of the control system, the first drive mechanism 24 and the second drive mechanism 28 operate. The first drive mechanism 24 drives the first slider 25 and the second slider 26 to move synchronously along the first guide rail 21 and the second guide rail 22, respectively. This causes the third guide rail 23 and the laser rangefinder 4, which are mounted on the first slider 25 and the second slider 26, to move, thus changing the longitudinal position of the laser rangefinder 4 in the fixed frame 1. The second drive mechanism 28 drives the third slider 27 to move along the third guide rail 23, thus causing the laser rangefinder 4, which is mounted on the third slider 27, to move, thus changing the lateral position of the laser rangefinder 4 in the fixed frame 1. Assuming that the lateral direction of the fixed frame 1 (i.e., along the direction of the third guide rail 23) is the X-axis direction, the longitudinal direction of the fixed frame 1 (i.e., along the direction of the second guide rail 22 or the first guide rail 21) is the Y-axis direction, and the top surface of the fixed frame 1 is the XY plane, then under the control of the control system, the coordinate position of the laser rangefinder 4 in the XY plane can be changed by the motion platform 2.

[0063] like Figure 5 and Figure 8 As shown, the first drive mechanism 24 includes a first servo motor 241, a first coupling, a first transmission bearing 242, a second coupling, a linkage rod 243, a third coupling, and a second transmission bearing connected in sequence. The first transmission bearing 242 and the second coupling are located on both sides of the first bearing seat 212, and the third coupling and the second transmission bearing are located on both sides of the second bearing seat 222. The first guide rail 21 has a first bearing seat 212 at both ends, and the second guide rail 22 has a second bearing seat 222 at both ends. The first transmission bearing 242 is connected to the track on the first guide rail 21, and the second transmission bearing is connected to the track on the second guide rail 22. When the first servo motor 241 rotates under the control of the control system, it drives the first transmission bearing 242 and the second transmission bearing to rotate, which in turn drives the track drive on the first guide rail 21 and the second guide rail 22. The track drive drives the first slider 25 and the second slider 26 to move on the first guide rail 21 and the second guide rail 22 respectively, which in turn drives the third guide rail 23 to move, changing the longitudinal position of the laser rangefinder 4 on the fixed frame 1. The first guide rail 21 and the second guide rail 22 are equivalent to the Y-axis, and the third guide rail 23 is equivalent to the X-axis.

[0064] In this embodiment, a first bearing housing 244 is also provided outside the first coupling and the first transmission bearing 242 to protect the first coupling and the first transmission bearing 242; for example Figure 7 As shown, the two ends of the first guide rail 21 are fixed to one side of the top of the fixed frame 1 by the first support 211, and the two ends of the second guide rail 22 are fixed to the other side of the top of the fixed frame 1 by the second support 221.

[0065] like Figure 9As shown, the second drive mechanism 28 includes a second servo motor 281, a fourth coupling, and a third transmission bearing 282 connected in sequence. The third transmission bearing 282 is connected to the track drive on the third guide rail 23. When the second servo motor 281 rotates under the control of the control system, it drives the third transmission bearing 282 to rotate, which in turn drives the track drive on the third guide rail 23. The track drive drives the third slider 27 to move on the third guide rail 23, thereby moving the laser rangefinder 4 mounted on the third slider 27 and changing the lateral position of the laser rangefinder 4 on the fixed frame 1.

[0066] In this embodiment, third bearing seats 232 are provided at both ends of the third guide rail 23, and the third transmission bearing 282 and the second servo motor 281 are located on one side of the third bearing seat 232; a second bearing housing 283 is also provided outside the fourth coupling and the third transmission bearing 282 to protect the fourth coupling and the third transmission bearing 282; Figure 9 As shown, the two ends of the third guide rail 23 are fixed to the first slider 25 and the second slider 26 respectively by the third support 231.

[0067] In one specific embodiment of the present invention, the laser rangefinder 4 is mounted on the third slider 27 via an L-shaped connecting plate 3.

[0068] In another specific embodiment of the present invention, the motion platform 2 adopts a robotic arm set on the top of the fixed frame 1. Under the control of the control system, the robotic arm grabs the laser rangefinder 4 and moves it to a designated position, stops at the designated position, so that the laser rangefinder 4 can perform laser positioning and distance measurement. After the positioning and distance measurement are completed, the laser rangefinder 4 is sent back to the initial position.

[0069] The laser rangefinder 4 is used to emit a vertical laser beam downwards at different positions of the fixed frame 1 to achieve layout positioning (i.e., positioning of small blocks) and to measure the distance between the vertical laser beam emission point and the masonry plane. In a specific embodiment of the present invention, the laser rangefinder 4 includes a rangefinder body and a laser emitter 41 and a laser receiver disposed on the rangefinder body. In order to emit a vertical laser beam and receive the reflected light of the vertical laser beam during positioning, the emitting end of the laser emitter 41 and the receiving end of the laser receiver are both arranged vertically downwards, ensuring that the laser beam emitted by the laser emitter 41 is perpendicular to the top or bottom surface of the fixed frame 1, that is, to emit a vertical laser beam.

[0070] The control system controls the movement of the motion platform 2 based on the point coordinates in the horizontal cross-sections of the arch dam geomechanical test model at different elevations, thereby adjusting the position of the laser rangefinder 4 on the fixed frame 1. This allows the laser rangefinder 4 to perform layout positioning by emitting laser beams at different positions on the fixed frame 1. In this embodiment, the control system can be an integrated industrial computer, a PC, or similar device.

[0071] To simplify the control of the laser rangefinder 4's position without requiring position calculations, before the control system controls the movement platform 2 based on the coordinates of points on different elevation plane sections of the arch dam geomechanical test model, the position of the laser rangefinder 4 within the fixed frame 1 needs to be initialized using the coordinate origin of these plane sections. Specifically, after initialization, the laser rangefinder 4's position within the fixed frame 1 becomes the coordinate origin. With the horizontal axis of the fixed frame 1 as the X-axis and the vertical axis as the Y-axis, the origin of the XY coordinate system on the top surface of the fixed frame 1 coincides with the origin of the coordinates on the different elevation plane sections of the arch dam geomechanical test model. Therefore, the movement platform 2 can be directly controlled based on the coordinates of any point on the different elevation plane sections of the arch dam geomechanical test model, moving the laser rangefinder 4 to the position corresponding to that point's coordinates (i.e., its position in the XY coordinate system on the top surface of the fixed frame 1). This eliminates the need for coordinate transformation before control, simplifying the position control of the laser rangefinder 4.

[0072] The laser rangefinder 4, while emitting a vertical laser beam for layout and positioning, also measures the distance between the laser beam emission point and the masonry plane, feeding this distance (i.e., the measured value) back to the control system. The control system can obtain the theoretical value of this distance from the current elevation of the masonry plane, compare the theoretical value with the measured value, and automatically verify the masonry work based on the comparison result. When the difference between the theoretical and measured values ​​is within the set error tolerance range, it indicates that the masonry work is normal and can continue. When the difference is outside the set error tolerance range, it indicates that there is a deviation in the masonry work, and the control system issues an alarm. The masonry workers then adjust or re-lay the masonry work until the difference between the theoretical and measured values ​​is within the set error tolerance range before proceeding to the next step, ensuring the accuracy of the masonry work for the arch dam geomechanical test model.

[0073] The automatic positioning device of the present invention has a reasonable structural design, with no conflict between the components, and a large range of free adjustment and high flexibility; the movement of each slider is smooth and noiseless, ensuring a good user experience, and the whole device is green, environmentally friendly and harmless.

[0074] As shown in Figure 11, this embodiment of the invention also provides a method for constructing a geomechanical test model of an arch dam, comprising the following steps:

[0075] Step 1: Determine the dimensions of the geomechanical test model of the arch dam based on the actual evaluation range and geometric similarity scale.

[0076] The original design drawings of the arch dam are provided by the design unit and usually include elevation cross-sections of the arch dam and its left and right bank foundations. When evaluating the overall stability of the arch dam and the effectiveness of reinforcement measures, the entire arch dam and its left and right bank foundations are not evaluated. Instead, the actual evaluation scope is selected based on the evaluation requirements. To evaluate the overall stability of the arch dam and its foundations, this embodiment uses the arch dam as the center and selects the area upstream of the dam (greater than 1 times the dam height), downstream (greater than 2 times the dam height), both banks (greater than 2 times the dam height), the foundation depth (greater than 1 times the dam height), and the mountainside 100m above the dam crest as the actual evaluation scope.

[0077] The dimensions of the arch dam geomechanical test model can be obtained by converting the selected actual evaluation range according to the geometric similarity scale. Specifically, this includes the length, width, and height of the arch dam geomechanical test model. The dimensions of the arch dam and various geological structural surfaces in the arch dam geomechanical test model can also be obtained by converting them according to the geometric similarity scale.

[0078] Step 2: Adjust the original design drawing of the arch dam according to the dimensions of the arch dam geomechanical test model, so that the range and coordinates of the horizontal cross-section of the arch dam at different elevations are consistent with the arch dam geomechanical test model, and obtain the horizontal cross-section of the arch dam geomechanical test model at different elevations.

[0079] The original design drawings of the arch dam are not consistent with the actual evaluation range. Therefore, the original design drawings of the arch dam are adjusted according to the size of the arch dam geomechanical test model or the actual evaluation range, so that the range and coordinates of the horizontal cross-sections of the arch dam at different elevations are consistent with the geomechanical test model of the arch dam. This results in horizontal cross-sections of the arch dam at different elevations, which are the geomechanical test model drawings of the arch dam used for construction.

[0080] For example, taking the 2325m elevation plan view as an example, information such as hydraulic structures and geological structures to be evaluated is selected from the original plan view provided by the design unit. The apex of the arch crown beam on the upstream side of the arch dam is taken as the origin of the coordinate system, with the positive X-axis direction to the left bank and the positive Y-axis direction to the downstream side, and the actual evaluation range is delineated. Figure 12 (The green rectangle in the middle) is then used to adjust the original design drawing according to the actual evaluation range, resulting in a 2325m elevation plan view for masonry construction. Figure 13 (Green rectangle in the middle). Similarly, the horizontal sections at other elevations were delineated and adjusted, and the geomechanical test model of the arch dam was constructed according to the adjusted horizontal sections at each elevation.

[0081] Step 3: Install the automatic positioning device as described above, and level the automatic positioning device so that it is in a horizontal position.

[0082] In this embodiment, a level and a leveling nut are provided at the supports of the first guide rail 21, the second guide rail 22 and the third guide rail 23. When the motion platform 2 and the laser rangefinder 4 are installed on the top of the fixed frame 1, the leveling nut is adjusted to ensure that the motion platform 2 and the laser rangefinder 4 are in a horizontal position, thus avoiding positioning errors caused by installation errors.

[0083] Step 4: Import the horizontal cross-sections of the arch dam geomechanical test model at different elevations into the control system of the automatic positioning device, or determine the size of the arch dam geomechanical test model and obtain the horizontal cross-sections of the arch dam geomechanical test model at different elevations in the control system.

[0084] Steps 1 and 2 can be performed on other equipment, and then the different elevation planar cross-sections of the arch dam geomechanical test model obtained in step 2 can be imported into the control system of the automatic positioning device; alternatively, steps 1 and 2 can be performed directly in the control system of the automatic positioning device.

[0085] Step 5: Initialize the position of the laser rangefinder 4 of the automatic positioning device in the fixed frame 1 according to the coordinate origin of the horizontal section of the arch dam geomechanical test model at different elevations.

[0086] Since the frame 1 is adapted to the size of the arch dam geomechanical test model, the laser rangefinder 4 can move within the XY coordinate system on the top surface of the fixed frame 1 to meet the positioning requirements during the construction of the arch dam geomechanical test model.

[0087] To simplify the control of the laser rangefinder 4's position within the XY coordinate system on the top surface of the fixed frame 1, eliminating the need for position calculations, the position of the laser rangefinder 4 within the fixed frame 1 needs to be initialized based on the origin of the coordinates of the different elevation plane sections of the arch dam geomechanical test model before the control system controls the movement of the motion platform 2. This initialization uses the position of the laser rangefinder 4 within the XY coordinate system on the top surface of the fixed frame 1 as the origin, with the horizontal axis of the fixed frame 1 as the X-axis and the vertical axis as the Y-axis. Therefore, the origin of the XY coordinate system on the top surface of the fixed frame 1 coincides with the origin of the coordinates of the different elevation plane sections of the arch dam geomechanical test model. Consequently, the movement of the motion platform 2 can be directly controlled based on the coordinates of any point in the different elevation plane sections of the arch dam geomechanical test model, moving the laser rangefinder 4 to the position corresponding to that point's coordinates without requiring coordinate transformation, thus simplifying the position control of the laser rangefinder 4.

[0088] Step 6: During the process of constructing the arch dam geomechanical test model layer by layer using the small block masonry method according to the elevation of the arch dam geomechanical test model, the following operations are performed for each part that requires layout and positioning (i.e., small block positioning):

[0089] Step 61: Obtain the coordinates of different points in the constituent parts;

[0090] Step 62: Control the movement platform 2 of the automatic positioning device according to the coordinates of each point, thereby adjusting the position of the laser rangefinder 4 in the XY coordinate system on the top surface of the fixed frame 1;

[0091] Step 63: When the laser rangefinder 4 reaches the position corresponding to the coordinates of the point, the laser rangefinder 4 emits a vertical laser beam downwards. Based on the laser point (the diameter of the laser point is 1-2 mm) on the masonry plane, the accurate location of the point in the arch dam geomechanical test model is determined, thereby determining the accurate location of the part in the arch dam geomechanical test model.

[0092] In step 61, AutoCAD software is installed in the control system. The AutoCAD software is used to open different elevation plane sections of the arch dam geomechanical test model. When the mouse clicks on a point in a certain elevation plane section, the point coordinate query function built into the AutoCAD software is called to obtain the XYZ coordinates of the point and read the XY coordinates of the point. Based on the XY coordinates of the point, the motion platform 2 is controlled to move, thereby adjusting the position of the laser rangefinder 4 in the XY coordinate system on the top surface of the fixed frame 1, so that the laser rangefinder 4 moves to the position corresponding to the coordinates of the point.

[0093] In step 61, the locations include faults, joints and fissures, rock mass category boundaries, and arch lines.

[0094] In a certain elevation sectional view, faults, joints, and rock mass category boundaries in the foundation are considered as a straight line or a broken line. The two endpoints of a straight line determine the line, and the multiple inflection points of a broken line determine the broken line. Since the range and coordinates of each elevation sectional view in step 2 are consistent with the geomechanical test model of the arch dam, during the construction of the test model, when it is necessary to determine the location of a fault, joint, or rock mass category boundary in the test model, it is only necessary to click on the constituent point (i.e., endpoint or inflection point) of the fault, joint, or rock mass category boundary in the corresponding elevation sectional view in the control system. The laser rangefinder 4 at the top of the fixed frame 1 can then move to the specified XY coordinates and emit a vertical laser beam downwards. The test model construction personnel can then determine the accurate location of the fault, joint, or rock mass category boundary in the test model based on the laser point irradiated on the current working surface (i.e., the current construction plane), thereby determining the location of structural surfaces such as faults, joints, and rock mass category boundaries.

[0095] The shape of the arch dam is determined by the arch line. For the arch line, the laser rangefinder 4 is moved according to the coordinate trajectory corresponding to the arch line, and at the same time, the laser rangefinder 4 emits a vertical laser beam downwards; the light trace formed by the laser points of different vertical laser beams on the masonry plane is used to cut off the excess part of the masonry block according to the light trace, thus carving out the accurate shape of the arch dam.

[0096] During the construction of the arch dam, due to the curvature of the dam body (i.e., the arch line of the arch dam is curved), it is difficult to directly press the small blocks used for construction into shape. Initially, it is difficult to ensure that the arch line is a strict curve when using small blocks for construction. Therefore, the construction of the arch dam model requires a process of building first and then carving. When building with small blocks, sufficient leeway is usually left on the upstream and downstream sides of the arch dam model. Then, the arch line of the planar section corresponding to the current elevation is clicked in the control system. The laser rangefinder 4 at the top of the frame is fixed and moves along the coordinate trajectory corresponding to the arch line, while simultaneously emitting a vertical laser beam downwards. The test model builders can then use a carving knife to remove the excess parts of the blocks according to the light trail, thereby carving an accurate arch dam shape. At the same time, the test model builders can adjust the movement speed of the laser rangefinder 4 in the control system according to the carving speed at the time.

[0097] Step 64: During the process of constructing the arch dam geomechanical test model layer by layer using the small block masonry method according to the elevation of the arch dam geomechanical test model, the following operations are performed for each part that requires layout and positioning (i.e., small block positioning):

[0098] In step 63, while using the laser rangefinder 4 to emit a vertical laser beam downwards for positioning, the distance between the vertical laser beam emission point and the masonry plane is also measured. The theoretical value of this distance is obtained based on the current elevation of the masonry plane. The theoretical value of this distance is compared with the measured value, and the masonry is automatically checked based on the comparison result.

[0099] The laser rangefinder 4, while emitting a vertical laser beam for layout and positioning, also measures the distance between the laser beam emission point and the masonry plane, feeding this distance (i.e., the measured value) back to the control system. The control system can obtain the theoretical value of this distance from the current elevation of the masonry plane, compare the theoretical value with the measured value, and automatically verify the masonry work based on the comparison result. When the difference between the theoretical and measured values ​​is within the set error tolerance range, it indicates that the masonry work is normal and can continue. When the difference is outside the set error tolerance range, it indicates that there is a deviation in the masonry work, and the control system issues an alarm. The masonry workers then adjust or re-lay the masonry work until the difference between the theoretical and measured values ​​is within the set error tolerance range before proceeding to the next step, ensuring the accuracy and precision of the masonry work for the arch dam geomechanical test model.

[0100] This invention, during the construction of an arch dam geomechanical test model, directly controls the movement of a motion platform and a laser rangefinder based on the coordinates of points on the elevation cross-sections of the test model through a control system. It utilizes a downward-emitting vertical laser beam from the laser rangefinder for precise positioning, achieving accurate positioning of the test model during layered construction. The positioning accuracy reaches 0.1 mm, significantly improving and ensuring the construction precision of the arch dam geomechanical test model. Simultaneously, it measures the distance between the vertical laser beam emission point and the construction plane, comparing it with theoretical values ​​to verify the elevation during the layered construction process. This invention offers high positioning accuracy, fast positioning speed, and elevation verification capabilities, greatly improving the construction speed and quality of the arch dam geomechanical test model, which is beneficial for the smooth and high-quality completion of large-scale engineering model tests such as arch dams.

[0101] The above description only discloses specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or modifications that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for constructing a geomechanical test model of an arch dam, characterized in that, The masonry method includes the following steps: The dimensions of the geomechanical test model for the arch dam are determined based on the actual evaluation range of the arch dam and the geometric similarity scale. Adjust the original design drawing of the arch dam according to the dimensions of the arch dam geomechanical test model, so that the range and coordinates of the horizontal cross-section of the arch dam at different elevations are consistent with the arch dam geomechanical test model, and obtain the horizontal cross-section of the arch dam geomechanical test model at different elevations; An automatic positioning device is installed and leveled to ensure it is in a horizontal position. The automatic positioning device includes a fixed frame, a moving platform, a laser rangefinder, and a control system. The fixed frame's defined area is adapted to the dimensions of the arch dam geomechanical test model. The moving platform is positioned on top of the fixed frame. The laser rangefinder is mounted on the moving platform and is used to emit a vertical laser beam downwards at different positions on the fixed frame to achieve layout positioning and measure the distance between the laser beam emission point and the masonry plane. The control system controls the movement of the moving platform based on the coordinates of points on different elevation plane sections of the arch dam geomechanical test model, thereby adjusting the position of the laser rangefinder on the fixed frame. Import the horizontal cross-sections of the arch dam geomechanical test model at different elevations into the control system, or determine the size of the arch dam geomechanical test model and obtain the horizontal cross-sections of the arch dam geomechanical test model at different elevations in the control system; The position of the laser rangefinder in the fixed frame is initialized based on the coordinate origin of the horizontal section of the arch dam geomechanical test model at different elevations. During the layer-by-layer masonry construction according to the elevation of the arch dam geomechanical test model, the following operations are performed for each part that requires layout and positioning: Obtain the coordinates of the different points that make up the part; The motion platform is controlled according to the coordinates of each point, thereby adjusting the position of the laser rangefinder in the fixed frame; When the laser rangefinder reaches the position corresponding to the coordinates of the point, the laser rangefinder emits a vertical laser beam downwards. Based on the laser point of the vertical laser beam on the masonry plane, the accurate location of the point in the arch dam geomechanical test model is determined, thereby determining the accurate location of the part in the arch dam geomechanical test model.

2. The method for constructing the geomechanical test model of the arch dam according to claim 1, characterized in that: The motion platform includes a first guide rail, a second guide rail, a third guide rail, a first slider, a second slider, a third slider, a first drive mechanism, and a second drive mechanism. The first and second guide rails are respectively fixed on both sides of the top of the fixed frame. The first slider is disposed on the first guide rail and can slide along the first guide rail. The second slider is disposed on the second guide rail and can slide along the second guide rail. The two ends of the third guide rail are respectively fixed on the first slider and the second slider. The third slider is disposed on the third guide rail and can slide along the third guide rail. The laser rangefinder is disposed on the third slider. The input end of the first driving mechanism is connected to the control system, and its output end is connected to the first slider and the second slider. The first driving mechanism is used to drive the first slider and the second slider to move synchronously under the control of the control system. The input end of the second driving mechanism is connected to the control system, and its output end is connected to the third slider. The second driving mechanism is used to drive the third slider to move under the control of the control system.

3. The method for constructing the arch dam geomechanical test model according to claim 2, characterized in that: The first drive mechanism includes a first servo motor, a first coupling, a first transmission bearing, a second coupling, a linkage rod, a third coupling, and a second transmission bearing connected in sequence. The first transmission bearing and the second coupling are located on both sides of the first bearing seat, and the third coupling and the second transmission bearing are located on both sides of the second bearing seat. The first guide rail has the first bearing seat at both ends, and the second guide rail has the second bearing seat at both ends. The first transmission bearing is connected to the track on the first guide rail, and the second transmission bearing is connected to the track on the second guide rail. The second drive mechanism includes a second servo motor, a fourth coupling, and a third transmission bearing connected in sequence, wherein the third transmission bearing is connected to the track drive on the third guide rail.

4. The method for constructing the geomechanical test model of the arch dam according to claim 2, characterized in that: Both ends of the first guide rail are fixed to one side of the top of the fixed frame via a first support, both ends of the second guide rail are fixed to the other side of the top of the fixed frame via a second support, and both ends of the third guide rail are fixed to the first slider and the second slider via a third support.

5. The method for constructing the geomechanical test model of the arch dam according to claim 1, characterized in that: The laser rangefinder includes a rangefinder body and a laser transmitter and a laser receiver mounted on the rangefinder body. The transmitting end of the laser transmitter and the receiving end of the laser receiver are both vertically downward.

6. The method for constructing the arch dam geomechanical test model according to claim 1, characterized in that, The specific process for obtaining the coordinates of different points that make up the aforementioned part is as follows: Use the point coordinate query function in the drawing software to obtain the coordinates of different points that make up the part.

7. The method for constructing the arch dam geomechanical test model according to claim 1, characterized in that, The locations mentioned include faults, joints and fissures, rock mass category boundaries, and arch lines; In a certain elevation sectional view, faults, joints, fissures, and rock mass category boundaries in the foundation are regarded as a straight line or a broken line. The two endpoints of the straight line determine the straight line or the multiple inflection points on the broken line determine the broken line. For the arch line, the laser rangefinder is moved according to the coordinate trajectory corresponding to the arch line, and at the same time, the laser rangefinder emits a vertical laser beam downwards; the light trace formed by the laser points of different vertical laser beams on the masonry plane is used to cut off the excess part of the masonry block according to the light trace, and the accurate arch dam shape is carved out.

8. The method for constructing the geomechanical test model of the arch dam according to any one of claims 1 to 7, characterized in that, The masonry method also includes: While using a laser rangefinder to emit a vertical laser beam downwards for positioning, the distance between the point of emission of the vertical laser beam and the masonry plane is also measured. The theoretical value of the distance is obtained based on the current elevation of the masonry plane. The theoretical value of the distance is compared with the measured value, and the masonry is automatically checked based on the comparison result.

9. A geomechanical test model for arch dams, characterized in that, The experimental model was constructed using the masonry method described in any one of claims 1 to 8.

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