Method for grading a roadbed

Abstract

This invention discloses a method for leveling a subgrade bed, comprising: S1: After ramming and compacting the subgrade bed, underwater analysis is performed to obtain information on the pits and depressions in the area to be leveled. The area to be leveled is then divided into overlapping target areas according to the size of the leveling machine; S2: The leveling machine is lowered to the first target area and adjusted to the design elevation; S3: Stones are added to the placing boom, driving it to move. The discharge port is controlled according to the pit and depression conditions. After even distribution, the material is leveled by a scraper. This process is repeated until the target area to be leveled is completed; S4: The elevation of the area is measured. If it is qualified, the leveling machine moves to the next target area to be leveled; S5: S2 to S4 are repeated until all target areas to be leveled are completed. No more material is added to the overlapping areas. This invention has the advantages of achieving uniform distribution of stone, high construction efficiency, and good quality.

Description

Technical Field

[0001] This invention relates to the field of underwater engineering. More specifically, this invention relates to a method for leveling a substrate bed. Background Technology

[0002] In the field of underwater subgrade leveling construction, existing technologies have many shortcomings. Traditional subgrade leveling methods often rely on manual underwater leveling, which is labor-intensive, has low construction accuracy, and fails to meet high-standard engineering requirements. Existing small leveling machines, when used for large-area leveling operations, lack effective area division and overlap handling, resulting in low construction efficiency and a tendency for omissions or poor connections. Furthermore, in the stone placement stage, the placement parameters cannot be dynamically adjusted according to the specific conditions of potholes, leading to uneven stone distribution, which affects the leveling effect and wastes resources. Therefore, there is an urgent need for a subgrade leveling method that can solve the above problems, improve the accuracy, efficiency, and quality of underwater subgrade leveling construction, reduce construction costs, and meet the high-standard requirements of modern underwater engineering. Summary of the Invention

[0003] One object of the present invention is to provide a method for leveling a subgrade bed to at least solve the above-mentioned problems.

[0004] To achieve the objectives and other advantages of this invention, a method for leveling a subgrade bed is provided, comprising: S1, after ramming and compacting the subgrade bed, a sweeping analysis is performed on the predetermined underwater area to be leveled to obtain the location, depth, projected area, and volume of pits and depressions in the predetermined area to be leveled, and the predetermined area to be leveled is divided into multiple target areas to be leveled according to the size of the leveling machine, with adjacent target areas to be leveled overlapping each other; S2, the leveling machine is lowered to the first target area to be leveled and adjusted to the design elevation; S3, the leveling machine is used to lay and level the material in the first target area to be leveled; S4, the elevation of the first target area to be leveled is measured, and after acceptance, the leveling machine is moved to the next target area to be leveled; S5, S2 is repeated. S4, no repeated material is applied to the overlapping area until the material application and leveling of the predetermined area to be leveled are completed; wherein, the width of the overlapping area is 0.1 to 0.3 times the short side length of the leveling machine; and the overlapping width is dynamically adjusted according to the position of potholes in the three-dimensional digital terrain model, so that the boundaries of all potholes fall completely within the single target area to be leveled: when the pothole is close to the boundary of the adjacent area, the overlapping width is increased to 0.3 times the short side length to ensure that the pothole is completely covered; when the pothole is far from the boundary, the overlapping width is reduced to 0.1 times the short side length to optimize construction efficiency.

[0005] Preferably, in S1, the sea-scanning analysis specifically includes: S11, using a multibeam echo sounder to perform a full-coverage scan of the predetermined area to be leveled, obtaining high-density water depth point cloud data; S12, eliminating wave and suspended object interference through median filtering, and constructing a three-dimensional digital terrain model using Kriging interpolation; S13, performing gridding processing on the three-dimensional digital terrain model, removing outliers, automatically identifying the boundaries of depression areas and calculating the maximum depth, projected area, and volume parameters, thereby obtaining the location, depth, projected area, and volume of the depressions in the predetermined area to be leveled; wherein, the area of ​​the predetermined area to be leveled is adjusted according to the water flow conditions, the construction area of ​​the leveling machine, and the construction efficiency, and two adjacent predetermined areas to be leveled overlap each other.

[0006] Preferably, in S1, the dynamic adjustment of the overlap width specifically includes: based on the three-dimensional digital terrain model, extracting the minimum distance d between the boundary of the pothole and the boundary of the adjacent target area to be leveled; if d ≤ 0.1 times the short side length of the leveling machine, the overlap width is adjusted to 0.3 times the short side length; if d > 0.1 times the short side length, the overlap width is adjusted to 0.1 times the short side length; the adjusted overlap area completely covers the boundary of the pothole, and the distance between the center of the pothole projection and the boundary line of the adjacent area is not less than 0.05 times the short side length.

[0007] Preferably, in step S2, after the leveling machine is in place, measuring marks are made on the material placing rod, the material placing rod is moved to the four corner points of the leveling machine, and the leveling machine is adjusted to the design elevation by remotely controlling the hydraulic outriggers and cooperating with the level.

[0008] Preferably, in S3, based on the location, depth, projected area, and volume of the pits in the first target area to be leveled, the opening, rotation speed, and extension distance of the discharge port located at the lower end of the placing boom are controlled. Specifically, this includes: S31, dividing the first target area to be leveled into a 1m×1m grid, and extracting the real-time elevation deviation value Δh of each grid based on the three-dimensional digital terrain model. Δh is the difference between the pit depth h and the design elevation, in meters; S32, when the placing boom moves to the target grid: 1) The opening D of the discharge port is controlled according to Δh using a piecewise function: if Δh ≥ 0.3m, D = 0.8D max If 0.1m ≤ Δh < 0.3m, then D = 0.5D max If 0 < Δh < 0.1m, then D = 0.3D max If Δh≤0m, then D=0, where D max 1) The maximum opening of the discharge port; 2) The rotational speed ω is related to the projected area S of the pit, according to ω=ω min Adjust by +0.02(S / S0), where S is the projected area of ​​the pothole in m². 2 S0 is the cross-sectional area of ​​the fabric rod, in meters. 2 ω min3) The minimum rotational speed is given in r / min; 4) The extension distance L is dynamically adjusted according to the pit volume V, satisfying L=H0-V / A*k, where V is the pit volume in m³. 3 H0 is the reference height in meters (m), which is the preset initial height relative to the design elevation. A is the target grid area in square meters (m²). 2 k is the packing compression coefficient, which ranges from 1.2 to 1.5.

[0009] Preferably, in S4, a level and measuring rod are used for elevation verification and acceptance.

[0010] Preferably, the discharge port includes: a rotary bearing, the inner wall of which is fixedly connected to the lower end of the fabric rod, and a driven gear fixedly mounted on the outer wall of the rotary bearing; a drive motor, which is fixedly mounted on the fabric rod via a first mounting plate, and the output end of the drive motor is connected to the driven gear; a guide rail, which is arranged radially along the rotary bearing and fixedly connected to its inner wall, the top surface of the guide rail having a first guide groove along its length, and a guide hole penetrating vertically in the middle; and a folding baffle, which includes a semi-circular first baffle and a second baffle, the straight edges of the first baffle and the second baffle being connected by a rotating shaft, the ends of the first baffle and the second baffle away from the rotating shaft being hinged to a connector, and the connector sliding with the first guide groove. The device consists of a snap-fit, foldable baffle that, when fully unfolded, can block the outlet of the fabric rod; a first hydraulic telescopic rod, vertically positioned below the guide rail, with its extended end passing through a guide hole and abutting against the foldable baffle; and a cylinder end of the first telescopic rod fixed to the inner wall of the slewing bearing via a U-shaped bracket; a telescopic guide cylinder comprising an inner cylinder and an outer cylinder slidably connected vertically, with the top of the inner cylinder fixedly connected to the outer wall of the slewing bearing, and a drive ring fixedly mounted on the bottom outer wall of the outer cylinder, the top surface of which has a second guide groove along its circumference; and at least one second hydraulic telescopic rod, vertically positioned, with its extended end slidably snap-fitted against the second guide groove, and its cylinder end fixedly connected to the fabric rod via a second mounting plate.

[0011] Preferably, the width of the first guide groove is smaller than the particle size of the stone.

[0012] Preferably, in step S13: the gridding process uses a fixed grid size of 1m×1m to uniformly divide the three-dimensional digital terrain model; the outlier removal includes: calculating the median of elevation data within each grid; if a data point in a grid deviates from the median by more than ±0.2m, it is determined to be an outlier and removed; the automatic identification of the boundary of the depression area specifically involves: using the lowest elevation point as the seed point, using a region growing algorithm to expand to adjacent grids; when the elevation difference between the adjacent grid and the seed point is less than 0.1m, it is included in the depression area, until the expansion terminates when the elevation difference between all adjacent grids is ≥0.1m; the calculation of the maximum depth, projected area, and volume includes: the maximum depth is the vertical distance between the lowest point of the depression area and the design elevation; the projected area is the area of ​​the closed polygon of the depression area on the horizontal plane, calculated through grid accumulation and edge correction algorithms; the volume is the sum of the products of the elevation deviation value Δh within each grid and the grid area, multiplied by the filler compression coefficient k, which is 1.2~1.5.

[0013] Preferably, a sealing ring is provided between the top of the outer cylinder and the inner cylinder.

[0014] The present invention has at least the following beneficial effects:

[0015] This invention accurately acquires underwater topographic data using technologies such as multibeam echo sounding, median filtering, and Kriging interpolation, guiding the precise operation of the screed machine and improving construction accuracy. It dynamically adjusts the outlet opening, rotation speed, and extension distance of the material placing boom based on pothole parameters, achieving uniform material distribution, avoiding waste, and improving resource utilization. Precise verification and acceptance of elevation using a level and measuring rod ensures the screeding quality of each target area, providing a flat and stable foundation for subsequent projects. The rationally designed outlet structure allows for flexible adjustment to adapt to different terrains and construction requirements, improving the accuracy and efficiency of material placement.

[0016] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0017] Figure 1 This is a top view of a leveling machine according to an embodiment of the present invention;

[0018] Figure 2 This is a cross-sectional view of the discharge port according to an embodiment of the present invention.

[0019] Figure descriptions: 1. Leveling machine, 2. Fabric bar, 3. First guide frame, 4. Second guide frame, 5. Rotary bearing, 6. Driven gear, 7. Drive motor, 8. First mounting plate, 9. Guide rail, 10. Folding baffle plate, 11. First hydraulic telescopic rod, 12. U-shaped bracket, 13. Inner cylinder, 14. Outer cylinder, 15. Drive ring, 16. Second hydraulic telescopic rod, 17. Second mounting plate. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the embodiments and accompanying drawings, so that those skilled in the art can implement it based on the description.

[0021] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0022] It should be noted that, unless otherwise specified, the experimental methods described in the following embodiments are all conventional methods, and the reagents and materials described are all commercially available unless otherwise specified. In the description of this invention, the terms "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0023] Example 1:

[0024] This embodiment provides a method for leveling a subgrade bed, including: S1, after ramming and compacting the subgrade bed, a sweeping analysis is performed on the underwater area to be leveled to obtain the location, depth, projected area, and volume of the pits and depressions in the area to be leveled, and the area to be leveled is divided into multiple target areas to be leveled according to the size of the leveling machine, with adjacent target areas to be leveled overlapping each other; S2, the leveling machine is lowered to the first target area to be leveled and adjusted to the design elevation; S3, stones are added to the placing rod 2 of the leveling machine, and the placing rod 2 is driven to move back and forth along the first guide frame 3. At the same time, according to the location, depth, projected area, and volume of the pits and depressions in the first area to be leveled, the opening, rotation speed, and extension distance of the discharge port located at the lower end of the placing rod 2 are controlled to achieve uniform material distribution. Then, the first guide frame 3 is driven to move left and right along the second guide frame 4, and the stones are leveled by the scraper located below the first guide frame 3. The placing rod 2 is driven alternately and repeatedly. S2 and S3, together with the first guide frame 3, complete the laying and leveling of the first target area to be leveled; S4, measure the elevation of the first target area to be leveled, and after acceptance, move the leveling machine to the next target area to be leveled; S5, repeat S2~S4, without repeating the laying of material in the overlapping area, until the laying and leveling of the predetermined area to be leveled is completed.

[0025] Specifically, in the actual construction process, the first step is to complete the riprap compaction of the foundation bed to ensure it has a certain degree of density and stability. Then, specialized underwater sweeping equipment is used to comprehensively scan and analyze the designated underwater leveling area. This designated leveling area is a part of the total leveling area; that is, the entire leveling area needs to be divided into multiple designated leveling areas based on the leveling machine's construction area, actual water flow conditions, and construction efficiency. The area of ​​each designated leveling area is at least twice the construction area of ​​the leveling machine to reduce the frequency of sweeping. After each sweeping analysis of a designated leveling area, leveling is immediately carried out to minimize the impact of water flow conditions and construction vibrations on the sweeping results and ensure construction quality. During sweeping, a multibeam echo sounder system is used to acquire high-density water depth point cloud data, which accurately reflects the undulations of the underwater topography. Next, median filtering technology is used to remove interference factors such as waves and suspended matter, and then Kriging interpolation is used to construct a three-dimensional digital terrain model, which can intuitively display detailed information about the underwater topography. Subsequently, the 3D digital terrain model is gridded to remove outliers, automatically identify the boundaries of depressed areas, and calculate parameters such as maximum depth, projected area, and volume. This accurately obtains the location, depth, projected area, and volume of potholes in the predetermined area to be leveled. Based on the size of the leveling machine, the predetermined area to be leveled is rationally divided into multiple target areas, with adjacent target areas overlapping to ensure continuity and integrity of the leveling process. During leveling, the leveling machine is first lowered to the first target area, and then precisely adjusted to the design elevation using remote-controlled hydraulic outriggers and measuring tools such as a level, ensuring the accuracy of the starting height for the leveling operation. An appropriate amount of stone is added to the leveling machine's placing boom 2; the stone's particle size and gradation should meet design requirements to guarantee the leveling effect. The material placing boom 2 moves back and forth along the first guide frame 3. During this movement, the opening, rotation speed, and extension distance of the discharge port located at the lower end of the material placing boom 2 are precisely controlled based on parameters such as the location, depth, projected area, and volume of the pits in the first area to be leveled, to achieve uniform material distribution. For example, in areas with deeper pits, the opening and rotation speed of the discharge port are appropriately increased to increase the output of stone; in areas with shallower pits, the opening and rotation speed of the discharge port are decreased to avoid stone waste. Simultaneously, the first guide frame 3 is driven to move left and right along the second guide frame 4, and the distributed stone is leveled by the scraper located below the first guide frame 3. The material placing boom 2 and the first guide frame 3 are driven alternately until the material distribution and leveling operation of the first target area to be leveled is completed. After the operation of one target area to be leveled is completed, the elevation is accurately measured and verified using tools such as a level and measuring rod to ensure that it meets the design requirements. If the inspection fails, manual local material placement and leveling are performed. If the inspection passes, the leveling machine is moved to the next target area to be leveled, and the above operation process is repeated.When working on the next target area to be leveled, since the overlapping area has already been laid and leveled during the work on the previous target area, the overlapping area will not be laid again. However, an elevation check is required to ensure the flatness of the overlapping area and improve the construction quality. Through meticulous leveling work in each area, the laying and leveling of all the planned areas to be leveled will be completed, providing a flat and stable foundation for subsequent projects.

[0026] Example 2:

[0027] Based on Example 1, this example specifies the sea-scanning analysis in S1, including: S11, using a multibeam echo sounder to perform a full-coverage scan of the predetermined area to be leveled, and obtaining high-density water depth point cloud data; S12, eliminating wave and suspended object interference through median filtering, and constructing a three-dimensional digital terrain model using Kriging interpolation; S13, performing gridding processing on the three-dimensional digital terrain model, removing outliers, automatically identifying the boundaries of depression areas and calculating the maximum depth, projected area, and volume parameters, to obtain the location, depth, projected area, and volume of the depressions in the predetermined area to be leveled; wherein, the area of ​​the predetermined area to be leveled is adjusted according to the water flow conditions, the construction area of ​​the leveling machine, and the construction efficiency, and two adjacent predetermined areas to be leveled overlap each other.

[0028] Specifically, during the oceanographic analysis, a multibeam echo sounder is first used to comprehensively scan the designated area to be leveled. The multibeam echo sounder can emit multiple acoustic beams and simultaneously receive reflected signals, thereby acquiring high-density depth point cloud data. These data points are dense and accurate, reflecting subtle changes in underwater topography in detail, providing a reliable foundation for subsequent analysis. After acquiring the high-density depth point cloud data, a median filtering algorithm is used to process the data to eliminate interference factors such as waves and suspended objects. Median filtering effectively removes outliers and noise from the data, preserving the true characteristics of the topography. The filtered data is smoother and more accurate, better reflecting the actual underwater topography. Next, a three-dimensional digital terrain model is constructed based on the processed data using Kriging interpolation. Kriging interpolation is a geostatistical method that comprehensively considers the spatial correlation between data points to generate a more accurate terrain model. This model visually displays the undulations and contours of the underwater topography in a three-dimensional form, providing strong support for subsequent pothole identification and parameter calculation. Subsequently, the constructed 3D digital terrain model is gridded, dividing the entire area into regular grid cells. During the gridding process, any outliers are removed to ensure data reliability. Specific algorithms, such as region growing algorithms, automatically identify the boundaries of depressions, which are clearly represented on the model. Then, for the identified depressions, key parameters such as maximum depth, projected area, and volume are calculated. Maximum depth reflects the height difference between the deepest point of the depression and the surrounding area; projected area is the area occupied by the depression's projection onto the horizontal plane; and volume represents the amount of stone required to fill the depression. These parameters are crucial for subsequent material placement and leveling operations. When determining the area to be leveled, factors such as water flow conditions, the leveling machine's working area, and construction efficiency need to be comprehensively considered. Water flow conditions affect the placement and distribution of stone and the stability of the foundation; therefore, the area needs to be rationally planned based on the speed and direction of the water flow. Meanwhile, the construction area and efficiency of the screed are also important considerations. The area should be matched with the screed's capacity to ensure that the screeding work in each designated area can be completed within the preset time, minimizing the impact of water flow conditions and construction vibrations on the screeding results and ensuring construction quality. Adjacent designated areas to be screed overlap, ensuring the continuity and integrity of the screeding operation and avoiding omissions or poor connections. No duplicate material is applied to the overlapping areas, but elevation verification is required. This detailed screeding analysis and area planning provides accurate data support and a reasonable construction layout for subsequent subgrade screeding operations.

[0029] Example 3:

[0030] Based on Example 2, this example limits the overlap width in S1. The overlap area is 0.1 to 0.3 times the short side length of the leveling machine. Furthermore, the overlap width is dynamically adjusted according to the location of potholes in the three-dimensional digital terrain model, ensuring that the boundaries of all potholes fall completely within a single target area to be leveled. When a pothole is close to the boundary of an adjacent area, the overlap width is increased to 0.3 times the short side length to ensure complete coverage. When a pothole is far from the boundary, the overlap width is decreased to 0.1 times the short side length to optimize construction efficiency. Specifically, when planning the target area to be leveled, considering the continuity and quality requirements of the leveling operation, two adjacent target areas to be leveled form an overlap area along the long side of the leveling machine. The width of the overlap area is set to 0.1 to 0.3 times the short side length of the leveling machine. This ratio range ensures sufficient overlap area without excessive overlap that would waste resources and reduce construction efficiency. In practice, the overlap width is flexibly adjusted according to the location of the potholes. If a pothole is located near the boundary between two target areas to be leveled, the overlap width should be appropriately increased to ensure that the pothole is completely contained within one target area, avoiding a situation where neither area can effectively level the pothole. Conversely, if the pothole is far from the boundary, the overlap width can be appropriately reduced to optimize the construction layout. For example, when the short side length of the leveling machine is 10 meters, the overlap width can be adjusted between 1 meter and 3 meters. If a pothole in a certain area is close to the boundary, the overlap width can be adjusted to 3 meters to ensure that the pothole is fully leveled within the overlap area; if the pothole is far from the boundary, the overlap width can be adjusted to 1 meter to improve construction efficiency. By dynamically adjusting the overlap width according to the location of the pothole, it is possible to ensure that the entire subgrade of the planned area to be leveled is uniformly and thoroughly leveled, avoiding leveling dead spots or repetitive work caused by unreasonable overlap, improving construction quality and efficiency, and also optimizing resource utilization.

[0031] Example 4:

[0032] Based on Example 3, this example limits the elevation adjustment of the leveling machine in S2, including: after the leveling machine is in place, making measurement marks on the material placing rod 2, moving the material placing rod 2 to the four corner points of the leveling machine, and adjusting the leveling machine to the design elevation by remotely controlling the hydraulic outriggers and cooperating with the level.

[0033] Specifically, after the leveling machine descends to the target leveling area and is in place, measurement marks are first made on the placing boom 2. The position and spacing of these marks are predetermined based on the design elevation and the structural characteristics of the leveling machine, and are used as a reference for subsequent height measurement and adjustment. Then, the placing boom 2 is moved to the four corner positions of the leveling machine, ensuring that the placing boom 2 remains stable and accurate during the movement. After reaching the corner positions, the height of the leveling machine is adjusted using remote-controlled hydraulic outriggers. The remote-controlled hydraulic outriggers have precise control functions and can adjust the extension length of each outrigger individually or synchronously as needed. At the same time, a level instrument is used for real-time monitoring, which can accurately measure the leveling machine's horizontal state and height deviation. By continuously adjusting the extension of the hydraulic outriggers and referring to the level instrument readings, the leveling machine is gradually adjusted to the design elevation. For example, during the adjustment process, the hydraulic outriggers at one corner are adjusted first to reach the design elevation, and then, using this as a reference, the hydraulic outriggers at other corners are adjusted sequentially until the entire leveling machine is on the same horizontal plane and the height meets the design requirements. This adjustment method not only improves the positioning accuracy of the leveling machine, but also makes it easy to operate and can quickly respond to different construction environments and requirements, providing a solid foundation for subsequent material placement and leveling operations, and ensuring the accuracy and efficiency of construction.

[0034] Example 5:

[0035] Based on Example 4, this example further limits the control of the opening, rotation speed, and extension distance of the discharge port located at the lower end of the placing rod 2 in S3 according to the location, depth, projected area, and volume of the pits in the first target area to be leveled. This includes: S31, dividing the first target area to be leveled into a 1m×1m grid, and extracting the real-time elevation deviation value Δh of each grid based on a three-dimensional digital terrain model. Δh is the difference between the pit depth h and the design elevation, in meters. S32, when the placing rod 2 moves to the target grid: 1) The opening D of the discharge port is controlled according to Δh using a piecewise function: if Δh ≥ 0.3m, D = 0.8D. max If 0.1m ≤ Δh < 0.3m, then D = 0.5D max If 0 < Δh < 0.1m, then D = 0.3D max If Δh≤0m, then D=0, where D max 1) The maximum opening of the discharge port; 2) The rotational speed ω is related to the projected area S of the pit, according to ω=ω min Adjust by +0.02(S / S0), where S is the projected area of ​​the pothole in m². 2 S0 is the cross-sectional area of ​​the fabric rod, in meters. 2 ω min3) The minimum rotational speed is given in r / min; 4) The extension distance L is dynamically adjusted according to the pit volume V, satisfying L=H0-V / A×k, where V is the pit volume in m³. 3 H0 is the reference height in meters (m), which is the preset initial height relative to the design elevation. A is the target grid area in square meters (m²). 2 k is the packing compression coefficient, which ranges from 1.2 to 1.5. L has a minimum value of 0m and a maximum value of H0.

[0036] Specifically, during the laying and leveling of the first target area, the area is first divided into a regular grid of 1m x 1m dimensions. This fine grid division accurately locates the terrain conditions of each small area, providing a foundation for subsequent precise laying. Based on the previously constructed 3D digital terrain model, the real-time elevation deviation value Δh of each grid is extracted, which is the difference between the pit depth h and the design elevation, in meters. This value directly reflects the thickness of stone required to fill each grid. When the laying rod 2 moves above the target grid, the opening D of the discharge port is precisely controlled according to the Δh value of that grid and a preset piecewise function. Specifically, if Δh ≥ 0.3m, it indicates that the pit is deep and requires a large amount of stone to fill; in this case, the opening D of the discharge port is set to 0.8 times the maximum opening D. max To ensure a rapid and sufficient output of stone; if 0.1m ≤ Δh < 0.3m, and the pit depth is moderate, the outlet opening D should be adjusted to 0.5D. max This method satisfies the filling requirements without wasting stone; if 0 < Δh < 0.1m, the pit is shallow, and the outlet opening D is reduced to 0.3D. max A suitable amount of stone is output for fine-tuning; if Δh≤0m, it indicates that no filling is needed at this location, and the outlet opening D is 0 to avoid accidental stone placement. Simultaneously, the rotational speed ω is related to the projected area S of the pit, according to the formula ω=ω min Adjust by +0.02(S / S0). Where S is the projected area of ​​the pothole, in meters. 2 S0 is the cross-sectional area of ​​the fabric rod 2, in meters. 2 ;ω min This represents the minimum rotational speed, expressed in r / min. For example, when the projected area S of the pit is large, the ratio S / S0 increases, and the rotational speed ω increases accordingly, thereby accelerating the output speed of the stone to meet the filling requirements of a larger area. Conversely, when the projected area S of the pit is small, the rotational speed ω decreases to precisely control the output of stone and avoid overfilling. The extension distance L is dynamically adjusted according to the pit volume V, satisfying the formula L=H0-V / A×k. Where V is the pit volume, expressed in meters. 3, H0 is the reference height, in m, that is, the preset initial height relative to the design elevation. A is the target grid area, in m 2 , k is the compression coefficient of the filler, with a value range of 1.2 to 1.5. The minimum value of L is 0 m and the maximum value is H0. By dynamically adjusting the extension distance L, the extension degree of the distributing boom 2 can be precisely controlled, ensuring that the stone materials can be accurately placed at the required positions and the filling amount is appropriate. This distributing method based on grid division and multi-parameter linkage control realizes precise distribution for each small area, improves the uniformity of distribution and the leveling accuracy, effectively avoids waste and overfilling of stone materials, and creates good conditions for subsequent leveling operations.

[0037] Example 6:

[0038] Based on Example 5, in this example, a level and a measuring rod are used for elevation recheck and acceptance.

[0039] Specifically, after completing the distribution and leveling operations on the first target area to be leveled, it is necessary to conduct precise elevation recheck and acceptance to ensure that it meets the design requirements. At this time, a level and a measuring rod are used as the main measuring tools. The level can provide a precise horizontal reference plane, and the measuring rod is used to measure the height difference between the measured point and the reference plane of the level. During specific operations, the level is placed at a suitable position to cover the entire measured area. Then, the measuring rod is erected at different positions in the target area to be leveled, usually selecting representative points, such as the four corner points, the center point of the area, and parts where elevation changes may occur. By reading the scale values on the measuring rod through the level, the elevation data of each point can be obtained. The measured elevation data is compared and analyzed with the design elevation to check for elevation deviations. If the deviation is within the allowable error range, it is determined that the leveling operation in this area is qualified; if the deviation exceeds the allowable range, the unqualified parts need to be readjusted, such as adding or reducing stone materials, and the leveling operation is carried out again until the recheck and acceptance are qualified. This elevation recheck and acceptance process is rigorous and accurate, can effectively ensure the leveling quality of each target area to be leveled, and provides a reliable foundation bed for subsequent construction links.

[0040] Example 7:

[0041] Based on Embodiment 1, this embodiment defines the structure of the discharge port, including: a rotary bearing 5, whose inner wall is fixedly connected to the lower end of the fabric rod 2, and a driven gear 6 is fixedly mounted on the outer wall of the rotary bearing 5; a drive motor 7, which is fixedly mounted on the fabric rod 2 via a first mounting plate 8, and the output end of the drive motor 7 is connected to the driven gear 6; a guide rail 9, which is arranged radially along the rotary bearing 5 and fixedly connected to its inner wall, and the top surface of the guide rail 9 is provided with a first guide groove along its length direction, and a guide hole that runs vertically through the middle; a folding baffle 10, which includes a semi-circular first baffle and a second baffle, the straight edges of the first baffle and the second baffle are connected by a rotating shaft, and the ends of the first baffle and the second baffle away from the rotating shaft are hinged to a connector, the connector is slidably engaged with the first guide groove, and the folding baffle 10 can block the outlet of the fabric rod 2 when fully unfolded; and a first hydraulic telescopic rod 11, which is vertically mounted on the guide rail 9. Below, the extended end of the first hydraulic telescopic rod 11 passes through the guide hole and abuts against the folding baffle plate 10. The cylinder end of the first telescopic rod is fixed to the inner wall of the rotary bearing 5 by a U-shaped bracket 12. The telescopic guide cylinder includes an inner cylinder 13 and an outer cylinder 14 that are slidably connected. The top of the inner cylinder 13 is fixedly connected to the outer wall of the rotary bearing 5. The bottom outer wall of the outer cylinder 14 is fixedly provided with a drive ring 15. The top surface of the drive ring 15 is provided with a second guide groove along its circumference. At least one second hydraulic telescopic rod 16 is vertically arranged. The extended end of the second hydraulic telescopic rod 16 is slidably engaged with the second guide groove. The cylinder end of the second hydraulic telescopic rod 16 is fixedly connected to the cloth rod 2 by a second mounting plate 17.

[0042] Specifically, the main components of the discharge port include a rotary bearing 5, a driven gear 6, a drive motor 7, a guide rail 9, a folding baffle 10, a first hydraulic telescopic rod 11, a telescopic guide cylinder, and a second hydraulic telescopic rod 16. The inner wall of the rotary bearing 5 is fixedly connected to the lower end of the material distribution rod 2 to ensure synchronous rotation. The driven gear 6 is fixedly mounted on the outer wall of the rotary bearing 5, and the driven gear 6 is connected to the output end of the drive motor 7. The drive motor 7 is fixedly mounted on the material distribution rod 2 via a first mounting plate 8. When the drive motor 7 is powered on, its output end drives the driven gear 6 to rotate, thereby causing the rotary bearing 5 and the telescopic guide cylinder to rotate together, thus adjusting the speed of the telescopic guide cylinder. The guide rail 9 is arranged radially along the rotary bearing 5 and fixedly connected to its inner wall. The top surface of the guide rail 9 has a first guide groove along its length, and a through guide hole in the middle. The foldable baffle 10 consists of a semi-circular first baffle and a second baffle, whose straight edges are connected by a pivot to form a foldable structure. The ends of the first and second baffles away from the pivot are hinged to a connector, which is slidably engaged with the first guide groove. When it is necessary to control the opening of the discharge port, the foldable baffle 10 is unfolded or retracted by extending or retracting the first hydraulic telescopic rod 11. When the foldable baffle 10 is fully unfolded, it can tightly seal the outlet of the material distribution rod 2, preventing the stone from being output; while in the retracted state, the stone can pass smoothly through the discharge port. The first hydraulic telescopic rod 11 is vertically set below the guide rail 9, and its extended end passes through the guide hole and abuts against the foldable baffle 10. The cylinder end of the first hydraulic telescopic rod 11 is fixed to the inner wall of the rotary bearing 5 by a U-shaped bracket 12. By controlling the extension and retraction of the first hydraulic telescopic rod 11, the position and opening of the folding baffle 10 can be precisely adjusted, thereby controlling the size of the discharge port and achieving fine adjustment of the stone output. The telescopic guide cylinder consists of an inner cylinder 13 and an outer cylinder 14, which are slidably connected vertically. The top of the inner cylinder 13 is fixedly connected to the outer wall of the rotary bearing 5, and a drive ring 15 is fixedly provided on the bottom outer wall of the outer cylinder 14. The top surface of the drive ring 15 is provided with a second guide groove along its circumference. The second hydraulic telescopic rod 16 is vertically set, and its extended end is slidably engaged with the second guide groove. The cylinder end is fixedly connected to the material distribution rod 2 through the second mounting plate 17. When it is necessary to adjust the extension distance of the telescopic guide cylinder, the extension and retraction of the second hydraulic telescopic rod 16 is controlled, which drives the drive ring 15 to move along the second guide groove, thereby realizing the vertical sliding of the outer cylinder 14 relative to the inner cylinder 13, and precisely adjusting the length of the telescopic guide cylinder to adapt to the material distribution requirements of different depths and positions.

[0043] During operation, once the material placing boom 2 reaches the target position, the drive motor 7 rotates the telescopic guide cylinder according to preset control parameters. Simultaneously, the first hydraulic telescopic boom 11 and the second hydraulic telescopic boom 16 adjust the opening of the folding baffle 10 and the extension distance of the telescopic guide cylinder, respectively, achieving precise control over the stone output. This type of outlet structure can flexibly adapt to different terrains and construction requirements, improving the accuracy and efficiency of material placement.

[0044] Furthermore, a winch (not shown) is fixed inside the inner cylinder 13, and the winch rotates synchronously with the inner cylinder 13 to adjust the output speed of the stone.

[0045] Furthermore, to achieve closed-loop control of the discharge port, an angle sensor (such as an SST HITEC angle sensor) is installed on the bottom surface of the folding baffle 10, a displacement sensor (such as an MTS R-Series magnetostrictive displacement sensor) is installed on the drive ring 15, and a speed sensor (such as a Beijing Xinwei Xingye Technology CS-1-G-100-03-01 magnetoresistive speed sensor) is installed on the output shaft of the drive motor 7 to monitor the opening degree of the folding baffle 10 and the extension distance and speed of the telescopic guide cylinder in real time. The speed of the telescopic guide cylinder can be calculated based on the detection value of the speed sensor and the reduction ratio between the drive motor and the telescopic guide cylinder.

[0046] Example 8:

[0047] Based on Example 7, the width of the first guide groove is smaller than the particle size of the stone. This design is mainly to prevent the stone from getting stuck in the first guide groove during the material spreading process, thus affecting the opening and closing of the folding baffle plate 10.

[0048] Example 9:

[0049] Based on Example 7, the connecting component is a universal joint. Universal joints have unique structural characteristics, enabling them to transmit motion and force at different angles and directions, while allowing for certain axial and angular displacements. Using a universal joint to connect the folding baffle 10 and the guide rail 9 allows for flexible adaptation to the relative movement between the guide rail 9 and the folding baffle 10 when the position and opening of the folding baffle 10 need adjustment. Furthermore, the universal joint possesses high strength and durability, capable of withstanding the impact and friction forces generated during stone output, ensuring the reliability and stability of the connection.

[0050] Example 10:

[0051] Based on Example 7, a sealing ring is provided between the top of the outer cylinder 14 and the inner cylinder 13. The main function of the sealing ring is to prevent external impurities such as mud and sand from entering between the outer cylinder 14 and the inner cylinder 13, affecting the relative sliding of the outer cylinder 14 and the inner cylinder 13. At the same time, the elastic structure of the sealing ring can absorb the minor vibrations and impacts generated during the extension and retraction of the telescopic guide cylinder to a certain extent, improving the stability of the equipment operation.

[0052] Example 11:

[0053] Based on Example 1, the overlap width refers to the lateral distance of the overlapping part of adjacent construction sub-areas; the pit boundary is the outline of the concave area identified by the algorithm; the minimum distance d represents the shortest vertical distance from the edge of the pit to the boundary line of the adjacent area.

[0054] During the area segmentation phase, the system extracts the boundary coordinates of each pothole from the 3D terrain model and calculates its minimum distance to the boundary line of adjacent areas. If the edge of a pothole is less than 1 meter from the boundary line (i.e., 10% of the shorter side length), the overlap width is extended to 3 meters (30% of the shorter side length) to ensure that the pothole falls completely within the current construction area. If the pothole is far from the boundary line (greater than 1 meter), the overlap width is reduced to 1 meter (10% of the shorter side length) to reduce redundant construction area. After adjustment, the system further verifies whether the distance between the center point of the pothole and the boundary line is not less than 0.5 meters (5% of the shorter side length). If not, the overlap range is fine-tuned again.

[0055] The leveling machine's guide rail system automatically extends and retracts according to the adjusted overlap width, with a hydraulic drive accuracy error of less than 0.1 meters. During construction, the material placement rod moves along a preset path, avoiding already treated overlap areas. The controller monitors the pothole coverage status in real time; if an uncovered depression is detected at the junction, an alarm is immediately triggered, construction is paused, and manual intervention is requested for correction.

[0056] Final result: The dynamic overlapping design reduces the rate of missing potholes at the junction from 15% in the traditional method to below 2%, reduces the amount of stone used in the overlapping area by 12%-18%, and reduces the overall construction cost by about 10%.

[0057] Example 12:

[0058] Based on Example 1, the three-dimensional digital terrain model of the subgrade must first be processed before leveling the subgrade. Here, a fixed grid size of 1m × 1m is used to uniformly divide the three-dimensional digital terrain model. This division method regularizes the entire terrain model into grid areas of the same size, facilitating subsequent data processing and analysis. After division, outlier removal is required for the elevation data within each grid. Specifically, the median of the elevation data within each grid is calculated, representing the median level of the grid's elevation data. If a data point in a grid deviates from this median by more than ±0.2m, it can be considered an outlier. The presence of outliers may affect subsequent judgment and calculation of terrain features, so they must be removed to ensure the accuracy and reliability of the data.

[0059] After completing the gridding process and outlier removal, the next step is to automatically identify the boundaries of the depression region. First, the lowest point is found from the elevation data of all grid cells and used as the seed point. This seed point acts as a starting point, and subsequent operations will revolve around it. Based on this seed point, a region growing algorithm is used to expand to adjacent grid cells. The core of the region growing algorithm is to determine the elevation difference between adjacent grid cells and the seed point. When the elevation difference between an adjacent grid cell and the seed point is less than 0.1m, that adjacent grid cell is included in the depression region. This expansion process is repeated until the elevation difference between all adjacent grid cells and the seed point is greater than or equal to 0.1m, at which point the expansion process terminates. This accurately determines the boundary range of the depression region.

[0060] After determining the boundaries of the recessed area, it is necessary to calculate its maximum depth, projected area, and volume. The maximum depth is calculated by comparing the lowest point of the recessed area with the design elevation. The design elevation is a pre-defined standard height; the vertical distance between the lowest point of the recessed area and the design elevation represents the maximum depth, reflecting the degree of recess. The projected area refers to the area of ​​the closed polygon of the recessed area on the horizontal plane, calculated using a grid accumulation and edge correction algorithm. This algorithm comprehensively considers the number of grids and the condition of the edges to obtain an accurate projected area. The volume is calculated by first multiplying the elevation deviation value within each grid by the grid area, then summing these products across all grids, and finally multiplying by a filler compression coefficient. This filler compression coefficient ranges from 1.2 to 1.5, taking into account the compression of the filler during the filling process, making the calculated volume more consistent with actual needs. These parameter calculations provide important reference data for subgrade leveling work.

[0061] The number of devices and processing scale described herein are for the purpose of simplifying the description of the invention. Applications, modifications, and variations of the bed leveling method of the present invention will be readily apparent to those skilled in the art.

[0062] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A method for leveling a subgrade bed, characterized in that, include: S1. After the foundation bed is rammed and compacted, the underwater area to be leveled will be swept and analyzed to obtain the location, depth, projected area and volume of the pits and depressions in the area to be leveled. According to the size of the leveling machine, the area to be leveled will be divided into multiple target areas to be leveled, and the two adjacent target areas to be leveled will overlap. S2. Lower the leveling machine to the first target area to be leveled and adjust it to the design elevation; S3. Use a leveling machine to lay and level the first target area to be leveled; S4. Measure the elevation of the first target area to be leveled. After acceptance, move the leveling machine to the next target area to be leveled. S5. Repeat S2 to S4, without repeating the fabric in the overlapping area, until the fabric and flattening of the predetermined area to be flattened are completed. The width of the overlap area is 0.1 to 0.3 times the length of the shorter side of the leveling machine; and The overlap width is dynamically adjusted according to the location of potholes in the 3D digital terrain model, so that the boundaries of all potholes fall completely within the single target area to be leveled: when a pothole is close to the boundary of an adjacent area, the overlap width is increased to 0.3 times the short side length to ensure that the pothole is completely covered; when a pothole is far from the boundary, the overlap width is reduced to 0.1 times the short side length to optimize construction efficiency.

2. The method for leveling the subgrade as described in claim 1, characterized in that, In S1, the sea-scanning analysis specifically includes: S11, using a multibeam echo sounder to perform a full-coverage scan of the predetermined area to be leveled, acquiring high-density water depth point cloud data; S12, eliminating wave and suspended object interference through median filtering, and constructing a three-dimensional digital terrain model using Kriging interpolation; S13, performing gridding processing on the three-dimensional digital terrain model, removing outliers, automatically identifying the boundaries of depression areas, and calculating the maximum depth, projected area, and volume parameters to obtain the location, depth, projected area, and volume of the depressions in the predetermined area to be leveled; wherein, the area of ​​the predetermined area to be leveled is adjusted according to the water flow conditions, the construction area of ​​the leveling machine, and the construction efficiency, and two adjacent predetermined areas to be leveled overlap each other.

3. The method for leveling the subgrade bed as described in claim 1, characterized in that, In S1, the dynamic adjustment of the overlap width specifically includes: Based on the aforementioned three-dimensional digital terrain model, the minimum distance d between the boundary of the pothole and the adjacent target area to be leveled is extracted; If d ≤ 0.1 times the short side length of the leveling machine, then the overlap width should be adjusted to 0.3 times the short side length; If d > 0.1 times the length of the shorter side, then the overlap width is adjusted to 0.1 times the length of the shorter side; The adjusted overlap area completely covers the edge of the pothole, and the distance between the center of the pothole projection and the boundary line of the adjacent area is not less than 0.05 times the length of the shorter side.

4. The method for leveling the subgrade as described in claim 3, characterized in that, S2 includes, after the leveling machine is in place, making measurement marks on the material placing rod, moving the material placing rod to the four corners of the leveling machine, and adjusting the leveling machine to the design elevation by remotely controlling the hydraulic outriggers and cooperating with the level instrument; The steps of using a leveling machine to distribute and level the first target area to be leveled include: adding stones to the distribution bar of the leveling machine, driving the distribution bar to move back and forth along the first guide frame, and controlling the opening, rotation speed and extension distance of the discharge port located at the lower end of the distribution bar according to the location, depth, projected area and volume of the pits in the first area to be leveled to achieve uniform distribution of the material, then driving the first guide frame to move left and right along the second guide frame, and leveling the stones by the scraper located below the first guide frame, and repeating the alternating driving of the distribution bar and the first guide frame to complete the distribution and leveling of the first target area to be leveled.

5. The method for leveling the subgrade as described in claim 4, characterized in that, In S3, based on the location, depth, projected area, and volume of the pits in the first target area to be leveled, the opening, rotation speed, and extension distance of the discharge port located at the lower end of the placing boom are controlled. Specifically, this includes: S31, dividing the first target area to be leveled into a 1m×1m grid, and extracting the real-time elevation deviation value Δh of each grid based on the three-dimensional digital terrain model. Δh is the difference between the pit depth h and the design elevation, in meters; S32, when the placing boom moves to the target grid: 1) The opening D of the discharge port is controlled according to Δh using a piecewise function: if Δh ≥ 0.3m, D = 0.8D max If 0.1m ≤ Δh < 0.3m, then D = 0.5D max If 0 < Δh < 0.1m, then D = 0.3D max If Δh≤0m, then D=0, where D max 1) The maximum opening of the discharge port; 2) The rotational speed ω is related to the projected area S of the pit, according to ω=ω min Adjust by +0.02(S / S0), where S is the projected area of ​​the pothole in m². 2 S0 is the cross-sectional area of ​​the fabric rod, in meters. 2 ω min 3) The minimum rotational speed is given in r / min; 4) The extension distance L is dynamically adjusted according to the pit volume V, satisfying L=H0-V / A×k, where V is the pit volume in m³. 3 H0 is the reference height in meters (m), which is the preset initial height relative to the design elevation. A is the target grid area in square meters (m²). 2 k is the packing compression coefficient, which ranges from 1.2 to 1.

5.

6. The method for leveling the subgrade as described in claim 5, characterized in that, In S4, a level and measuring rod are used to verify and accept the elevation.

7. The method for leveling the subgrade as described in claim 4, characterized in that, The discharge port includes: a rotary bearing, the inner wall of which is fixedly connected to the lower end of the fabric rod, and a driven gear fixedly mounted on the outer wall of the rotary bearing; a drive motor, which is fixedly mounted on the fabric rod via a first mounting plate, and the output end of the drive motor is connected to the driven gear; a guide rail, which is arranged radially along the rotary bearing and fixedly connected to its inner wall, and the top surface of the guide rail is provided with a first guide groove along its length, and a guide hole extending vertically through the middle; and a folding baffle, which includes a semi-circular first baffle and a second baffle, the straight edges of which are connected by a rotating shaft, and the ends of the first baffle and the second baffle away from the rotating shaft are hinged to a connector, which is slidably engaged with the first guide groove. The folding baffle, when fully unfolded, can block the outlet of the fabric rod; the first hydraulic telescopic rod, vertically positioned below the guide rail, has its extended end passing through a guide hole and abutting against the folding baffle, and its cylinder end fixed to the inner wall of the slewing bearing via a U-shaped bracket; the telescopic guide cylinder includes an inner cylinder and an outer cylinder that slide vertically together, the top of the inner cylinder being fixedly connected to the outer wall of the slewing bearing, and a drive ring fixedly provided on the bottom outer wall of the outer cylinder, with a second guide groove provided on the top surface of the drive ring along its circumference; at least one second hydraulic telescopic rod, vertically positioned, has its extended end slidably engaged with the second guide groove, and its cylinder end fixedly connected to the fabric rod via a second mounting plate.

8. The method for leveling the subgrade as described in claim 7, characterized in that, The width of the first guide groove is smaller than the particle size of the stone.

9. The method for leveling the subgrade as described in claim 2, characterized in that, In S13: The gridding process uses a fixed grid size of 1m×1m to uniformly divide the three-dimensional digital terrain model; The process of removing outliers includes: calculating the median of elevation data within each grid cell; if a data point in a grid cell deviates from the median by more than ±0.2m, it is identified as an outlier and removed. The automatic identification of the boundary of the depression area is specifically as follows: using the lowest elevation point as the seed point, the region growing algorithm is used to expand to the adjacent grid. When the elevation difference between the adjacent grid and the seed point is less than 0.1m, the depression area is included, and the expansion is terminated when the elevation difference between all adjacent grids is ≥0.1m. The calculation of the maximum depth, projected area, and volume includes: The maximum depth is the vertical distance between the lowest point of the recessed area and the design elevation. The projected area is the area of ​​the closed polygon of the concave region on the horizontal plane, calculated by grid accumulation and edge correction algorithms; The volume is the sum of the products of the elevation deviation Δh within each grid and the grid area, multiplied by the filler compressibility coefficient k, which is 1.2 to 1.

5.

10. The method for leveling the subgrade as described in claim 7, characterized in that, A sealing ring is provided between the top of the outer cylinder and the inner cylinder.

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