A device and method for automatically detecting the compaction degree of a broken pebble filler

Abstract

The present application relates to the technical field of gravel fill compaction degree detection, and provides a gravel fill compaction degree automatic detection device and method, the detection device comprises a support cylinder, a sand filling measurement assembly and a laser measurement assembly, the support cylinder is arranged through the detection frame at the bottom, and the sand filling pipe is arranged through the support cylinder at the bottom of the sand bin; the telescopic unit is arranged on the top wall of the support cylinder, the output end of the driving part is provided with a spiral blade; the discharge pipe is arranged obliquely at the discharge port, and the screening and weighing assembly is arranged on the detection frame; the laser measurement assembly is arranged at the bottom of the detection frame and on one side of the support cylinder; the detection method comprises drilling and collecting gravel fill, screening and weighing, and obtaining the volume of the dug hole and the gravel fill compaction degree evaluation by the laser measurement method. The non-contact dynamic measurement of the test pit volume, combined with the weight distribution algorithm, comprehensively combines the laser and sand filling data, significantly improves the volume calculation accuracy, and solves the single method failure problem caused by the gravel fill due to the difference in grading, the rough surface or the dust environment.

Description

Technical Field

[0001] This invention relates to the field of crushed pebble packing compaction degree testing technology, and in particular to an automatic crushed pebble packing compaction degree testing device and testing method. Background Technology

[0002] When crushed gravel is used as roadbed filler, density monitoring is crucial for the stability and durability of the roadbed. Traditional methods such as the ring cutter method and sand cone method are unsuitable due to the irregular shape and large size of the crushed gravel particles. They are also inefficient, complex to operate, and highly susceptible to human factors.

[0003] Traditional compaction testing relies on manual operation, which makes it difficult to meet the needs of efficient and accurate testing, especially in crushed gravel filler, where the accuracy of test pit volume measurement and compaction calculation is difficult to guarantee.

[0004] Therefore, to address the above problems, an automatic detection device and method for the compaction degree of crushed gravel filler are proposed to solve these problems. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention develops an automatic detection device and method for the compaction degree of crushed pebble filler. This invention uses non-contact dynamic measurement of the test pit volume, combined with a weighted allocation algorithm to integrate laser and sand filling data, significantly improving the accuracy of volume calculation and solving the problem of single-method failure caused by gradation differences, surface roughness, or dusty environments of crushed pebble filler.

[0006] The technical solution to the technical problem solved by the present invention is as follows: The present invention provides an automatic detection device for the compaction degree of crushed gravel filler, including a detection frame, a drilling assembly, and a screening and weighing assembly, and further including a support cylinder, a sand filling measurement assembly, and a laser measurement assembly. The sand filling measurement assembly includes a sand bin, a sand filling pipe, and a weighing device. The bottom of the support cylinder passes through the detection frame, the top of the support cylinder is equipped with the weighing device, the sand bin is mounted on the weighing device, and the bottom of the sand bin passes through the support cylinder to form the sand filling pipe. The drilling assembly includes a moving cylinder, a driving component, a spiral blade, and a telescopic unit. The telescopic unit is located on the top wall of the support cylinder, the output end of the telescopic unit is connected to the moving cylinder, the moving cylinder is coaxially arranged inside the support cylinder, the driving component is located on the top wall of the moving cylinder, the output end of the driving component is equipped with a spiral blade, and the bottom of the spiral blade extends out of the bottom of the detection frame and is equipped with several drill teeth. The moving cylinder and the support cylinder have corresponding discharge ports, and the discharge pipe is inclinedly arranged at the discharge port. The screening and weighing assembly is located at the bottom of the discharge pipe and is situated on the detection frame. The laser measurement assembly is located at the bottom of the detection frame and on one side of the support cylinder.

[0007] As an optimization, the screening and weighing assembly includes a screening box and a second weighing device. The second weighing device is set on the detection frame, and the screening box is set above the second weighing device.

[0008] As an optimization, the driving component is a servo motor, the telescopic unit is a cylinder, a hand handle is provided on the side of the inspection frame, and a moving component is provided at the bottom of the inspection frame.

[0009] A method for detecting the compaction degree of crushed gravel packing material, applicable to the automatic detection device for the compaction degree of crushed gravel packing material described in any of the above-mentioned embodiments, includes the following steps:

[0010] S1: Drilling and collecting broken pebbles as fill material.

[0011] Select the survey roadbed, install the testing device, excavate holes using the drilling assembly, and fill the holes with sand using the sand-filling measurement assembly.

[0012] S2: Screening and weighing

[0013] The screening and weighing assembly screens and weighs the packing material.

[0014] S3: The volume of the excavated hole is obtained by laser measurement.

[0015] This includes point cloud acquisition and distance calculation, point cloud preprocessing, 3D model reconstruction and volume calculation, followed by sand filling and volume calculation using the sand filling measurement component.

[0016] S4: Evaluation of compaction degree of crushed gravel filler.

[0017] As an optimization, in S3 point cloud acquisition and distance calculation, the distance from the laser to a point on the surface of the pit is measured. :

[0018] in, At the speed of light, This represents the round-trip time of the laser.

[0019] As an optimization, the first step in S3 point cloud preprocessing is to statistically remove outliers.

[0020] Secondly, multi-view calculation of registration error.

[0021] ,

[0022] in, For rotation matrix, It is a translation vector. The first point in the source cloud The three-dimensional coordinates of each point ; In the target point cloud The corresponding three-dimensional coordinates of the point To match the number of point pairs, The regularization coefficient is . For geometric error terms, Here, is the regularization term, For matrix trace operations,

[0023] Then, the surface roughness is calculated. ,

[0024] Extract local surface contours, calculate baseline and deviation values, and fit the baseline: ,

[0025] Deviation calculation: Calculate the perpendicular deviation of each point from the baseline.

[0026] Calculate roughness:

[0027] in, This represents the absolute deviation at each point.

[0028] As an optimization, in 3D model reconstruction and volume calculation, the mesh quality is determined first.

[0029]

[0030] in, This represents the mesh quality coefficient.

[0031] For the first The radius of the inscribed circle of a triangle;

[0032] The radius of the circumcircle;

[0033] Secondly, the volume is calculated using the voxelization integral method, dividing the triangular mesh into 0.1mm segments. 3 cubic unit,

[0034] Laser measurement method to obtain the volume of the excavated hole :

[0035]

[0036] in, Three-dimensional region The total volume For indicator functions, The volume of a single voxel.

[0037] As an optimization, in S4, the excavated fill material is first dried, weighed to obtain the mass of the fill material, and the gradation is calculated.

[0038] Calculate the volume of sand to be poured based on the mass and density of the sand. :

[0039] in, For the quality of the sand poured in, The density of sand,

[0040] Calculate the volume of the excavated pit.

[0041] for The weight, for The weight,

[0042] according to The results were compared with 2.5%, and then assigned accordingly. and Different weights and ,

[0043] when hour, , ;

[0044] when Furthermore, when the gradation is poor and the proportion of fine materials is less than 10%, , ;

[0045] when and surface roughness hour, , ;

[0046] when ,and Or the effective data ratio of laser point cloud is less than 85%. These are solid and liquid particulate matter with a particle size of 10 micrometers or less that floats in the air. , ;

[0047] Then, a test section was constructed to determine the density.

[0048] The length of the test section was selected, and the compaction threshold was tested. The test was conducted every 20m, and the density changes under different compaction degrees and different gradations were recorded.

[0049] Calculate the compaction energy index :

[0050] in, For the equipment-material coupling coefficient, crushed pebbles The value is 2.5-4.5. This refers to the amplitude of the road roller. For the frequency of the road roller, This refers to the compaction speed of the road roller.

[0051] Calculate the attenuation coefficient and , ,

[0052]

[0053] in, The thickness of the compacted layer is in meters (m). To determine the proportion of filler particles with a diameter less than 5mm, To determine the proportion of filler particles with a diameter less than 30mm,

[0054] Calculate the density measured in the test section. ,

[0055] in, This is the gradation correction factor. , To increase the number of compaction passes,

[0056] As the number of compaction passes increases, when the density measured in the test section increases by ≤0.5% for two consecutive passes, it can be considered to have reached the maximum dry density, which is denoted as . ,

[0057] ,

[0058] in, This refers to the density measured on a normal road section.

[0059] The effects described in the invention are merely those of the embodiments, and not all the effects of the invention. The above technical solutions have the following advantages or beneficial effects:

[0060] 1. By integrating automated sand filling measurement with high-precision three-dimensional laser scanning technology, non-contact dynamic measurement of test pit volume is achieved. Combined with a weighted allocation algorithm to integrate laser and sand filling data, the accuracy of volume calculation is significantly improved. In particular, it solves the problem of single-method failure caused by gradation differences, surface roughness, or dusty environment of crushed gravel filler. At the same time, this device can shorten the single-point detection time by more than 50%, reduce labor costs and avoid fatigue errors, and further ensure the reliability of data under complex working conditions.

[0061] 2. This device accurately matches the actual material characteristics in the compaction calculation by quantifying the gradation parameters in real time and dynamically adjusting the correction coefficient. It adjusts the parameters according to the actual situation, which solves the systematic error caused by gradation differences. Especially in complex working conditions where coarse particles dominate or fine materials fluctuate, it ensures that the test results truly reflect the compaction state of the roadbed and provides a reliable scientific basis for construction. Attached Figure Description

[0062] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0063] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0064] Figure 2 This is the front view of the present invention;

[0065] Figure 3 This is a structural diagram of the inside of the support cylinder of the present invention.

[0066] In the diagram, 1. Detection frame; 2. Support cylinder; 3. Sand bin; 4. Sand filling pipe; 5. Moving cylinder; 6. Drive unit; 7. Spiral blade; 8. Discharge port; 9. Discharge pipe; 10. Screening box; 11. Weighing device two; 12. Weighing device one; 13. Telescopic unit; 14. Control panel; 15. Display screen; 16. Hand handle; 17. Moving component; 18. Laser measurement component; 19. Drill teeth. Detailed Implementation

[0067] To clearly illustrate the technical features of this solution, the invention will be described in detail below through specific embodiments and in conjunction with the accompanying drawings. The following disclosure provides many different embodiments or examples for implementing different structures of the invention. To simplify the disclosure of the invention, components and arrangements of specific examples are described below. Furthermore, reference numerals and / or letters may be repeated in different examples. This repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. It should be noted that the components illustrated in the drawings are not necessarily drawn to scale. Descriptions of well-known components and processing techniques and processes are omitted to avoid unnecessarily limiting the invention. Terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the drawings and are only for the convenience of describing the 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, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0068] like Figures 1 to 3 As shown, an automatic detection device for the compaction degree of crushed gravel fill includes a detection frame 1, a drilling assembly, and a screening and weighing assembly, as well as a support cylinder 2, a sand filling measurement assembly, and a laser measurement assembly 18.

[0069] The sand filling measurement assembly includes a sand chamber 3, a sand filling pipe 4, and a weighing device 12. The bottom of the support cylinder 2 passes through the detection frame 1, and the weighing device 12 is set at the top of the support cylinder 2. The sand chamber 3 is set on the weighing device 12, and the sand filling pipe 4 passes through the bottom of the sand chamber 3. A control valve is set at the connection between the sand filling pipe 4 and the sand chamber 3. The opening and closing of the sand filling pipe 4 is controlled by a controller. The control assembly here is an existing structure that can realize the opening and closing of the valve, which will not be described in detail. The weighing device 12 can calculate the mass of the sand poured into the pit, and then measure the volume of the sand poured into the pit. First, it weighs the entire sand chamber 3 and the mass of the sand in the chamber. Then, it weighs the mass of the sand chamber 3 and the remaining sand after the sand filling is completed, so as to obtain the mass of the sand poured into the pit.

[0070] The drilling assembly includes a moving cylinder 5, a driving component 6, a spiral blade 7, and a telescopic unit 13. The telescopic unit 13 is located on the top wall of the support cylinder 2. The output end of the telescopic unit 13 is connected to the moving cylinder 5. The moving cylinder 5 is coaxially located inside the support cylinder 2. The driving component 6 is located on the top wall of the moving cylinder 5. The spiral blade 7 is located at the output end of the driving component 6. The bottom of the spiral blade 7 extends out of the bottom of the detection frame 1.

[0071] The moving cylinder 5 and the support cylinder 2 are respectively opened with discharge ports 8. The discharge pipe 9 is inclinedly set at the discharge port 8. The bottom of the discharge pipe 9 is set with a screening and weighing component, which is located on the detection frame 1. After the drilling component digs out the crushed gravel filler, the crushed gravel filler enters the screening and weighing component through the discharge port 8 and the discharge pipe 9.

[0072] The laser measurement component 18 is located at the bottom of the detection frame 1 and on one side of the support cylinder 2. The laser measurement component 18 emits a highly stable laser beam, providing a light source for measurement. Here, the laser measurement component 18 can be mechanically controlled to adjust the angle and position of the laser scanning. The specific mechanical structure for adjusting the angle and position of the laser measurement component 18 is existing technology and will not be described in detail here.

[0073] In this embodiment, the screening and weighing assembly includes a screening box 10 and a second weighing device 11. The second weighing device 11 is mounted on the detection frame 1, and the screening box 10 is mounted above the second weighing device 11. Here, the screening box 10 is a drawer-type screen body. Two screens are installed inside the screening box 10, dividing the screening box 10 into three layers. The two screens have 10mm and 5mm screen holes respectively, from top to bottom. The second weighing device 11 can weigh the crushed pebbles entering the screening box 10. During screening, a vibrating motor can be set to drive the screen to vibrate, thereby screening the crushed pebbles. The vibration motor driving the screen to vibrate and screen is existing technology and will not be described in detail here. The second weighing device 11 and the first weighing device 12 are existing structures and will not be described in detail here.

[0074] In this embodiment, the driving component 6 is a servo motor, the telescopic unit 13 is a cylinder, a hand handle 16 is provided on the upper side of the testing frame 1, and a moving component 17 is provided at the bottom of the testing frame 1. The moving component 17 can be a caster wheel. The testing frame 1 is also provided with a control board 14 and a display screen 15. The control board 14 is provided with a first switch and a second switch that are electrically connected to the driving component 6 and the telescopic unit 13, respectively. The display screen 15 is electrically connected to the second weighing device 11 and the first weighing device 12 to display the weighing results.

[0075] A method for detecting the compaction degree of crushed gravel packing material, applicable to the automatic detection device for the compaction degree of crushed gravel packing material described in any of the above-mentioned embodiments, includes the following steps:

[0076] S1: Drilling and collecting broken pebbles as fill material.

[0077] Select the survey roadbed, install the testing device, excavate holes using the drilling assembly, and fill the holes with sand using the sand-filling measurement assembly.

[0078] S2: Screening and weighing

[0079] The screening and weighing assembly screens and weighs the packing material.

[0080] S3: The volume of the excavated hole is obtained by laser measurement.

[0081] This includes point cloud acquisition and distance calculation, point cloud preprocessing, 3D model reconstruction and volume calculation, followed by sand filling using a sand-filling measurement component to calculate the volume.

[0082] S4: Evaluation of compaction degree of crushed gravel filler.

[0083] In this embodiment, during the S3 point cloud acquisition and distance calculation, the laser beam is reflected after hitting the surface of the pit, and the device records the round-trip time. Using the speed of light Calculate the distance to a single point By combining the scanning angle, the three-dimensional coordinates of each point on the surface of the pit are generated. This forms the initial point cloud.

[0084] Measuring the distance from the laser to a point on the surface of the pit. :

[0085] in, At the speed of light, This represents the round-trip time of the laser.

[0086] In this embodiment, during the S3 point cloud preprocessing, outliers are first statistically removed. After the point cloud is generated, the neighborhood radius and standard deviation factor are input, and the three-dimensional distance (not the original laser ranging value) between each point and other points in its neighborhood is calculated. The mean and standard deviation of these distance values ​​are then calculated. If the deviation of a point's distance from the neighborhood mean is greater than the product of the standard deviation factor and the standard deviation, then that point is removed.

[0087] Secondly, multi-view calculation of registration error aligns the local coordinate system point cloud to the global coordinate system. Through iterative optimization, the point cloud that meets the requirements will be unified into the same coordinate system for surface roughness calculation and 3D reconstruction.

[0088] ,

[0089] in, This is a rotation matrix used to align the coordinate systems of the two point clouds;

[0090] This is a translation vector used to adjust the position offset of the point cloud;

[0091] The first point cloud in the source point cloud (a point cloud from a certain perspective) The three-dimensional coordinates of each point ;

[0092] For the target point cloud (point cloud from another perspective) and The corresponding three-dimensional coordinates of the point;

[0093] The number of matching point pairs (i.e., the number of points in the two point clouds that have established a corresponding relationship);

[0094] These are regularization coefficients used to constrain the rotation matrix. Orthogonality;

[0095] The geometric error term represents the sum of squared positional deviations of the matched point pairs, directly reflecting the registration accuracy. The registration error is the square root of its mean, i.e. ;

[0096] Here, is the regularization term, For matrix trace operation, it means The sum of the diagonal elements is used to prevent Excessive deviation from orthogonality;

[0097] Input parameters: point cloud coordinates from different viewpoints (Local coordinate system) and (Global coordinate system), regularization coefficient ;

[0098] Calculation process: The rotation matrix is ​​found through iterative optimization. Translation vector Align the two point clouds; regularization term Prevent excessive distortion of the rotation matrix;

[0099] Output result: Registration error ≤ 0.2 mm;

[0100] Purpose: To unify point clouds from multiple viewpoints into the same coordinate system and reconstruct a complete pit model.

[0101] Then, the surface roughness is calculated. ,

[0102] Extract local surface contours, calculate baseline and deviation values, and fit the baseline: The least squares method is used to fit the trend line (polynomial fitting or straight line) of the profile points.

[0103] Deviation calculation: Calculate the perpendicular deviation of each point from the baseline.

[0104] Calculate roughness:

[0105] in, The absolute deviation at each point (unit: mm).

[0106] In this embodiment, during the 3D model reconstruction and volume calculation, the mesh quality is first determined to avoid volume calculation errors caused by narrow triangular pieces, thus ensuring model accuracy.

[0107]

[0108] in, This represents the mesh quality coefficient. For the first The radius of the inscribed circle of a triangle; The radius of the circumcircle; If the mesh is deemed acceptable, it is re-divided; otherwise, it is re-divided.

[0109] Secondly, the volume is calculated using the voxelization integral method, dividing the triangular mesh into 0.1 mm sections.3 cubic units (voxels)

[0110] Laser measurement method to obtain the volume of the excavated hole :

[0111]

[0112] in, Three-dimensional region The total volume This is an indicator function (1 if the voxel center is inside the crater, 0 otherwise). The number of internal voxels. The volume of a single voxel.

[0113] In this embodiment, in step S4, the excavated filler is first dried, weighed to obtain the mass of the filler, and its gradation is calculated.

[0114] Calculate the volume of sand to be poured based on the mass and density of the sand. :

[0115] in, For the quality of the sand poured in, The density of sand,

[0116] Calculate the volume of the excavated pit.

[0117] for The weight, for The weight,

[0118] according to The results were compared with 2.5%, and then assigned accordingly. and Different weights and ,

[0119] when At that time, the differences are small, and equal weighting is applied. , ;

[0120] when Furthermore, poor gradation, with fine material accounting for less than 10%, leads to an overestimation of volume in the sand-filling method (due to sand flowing into the gaps). Therefore, increasing the laser weighting... , ;

[0121] when and surface roughness At times, high surface roughness and uneven inner walls of pits can affect the accuracy of laser measurements. , ;

[0122] when ,and Or the effective data ratio of laser point cloud is less than 85%, For solid and liquid particles with a diameter of 10 micrometers or less floating in the air, the reliability of laser scanning is reduced by dust or strong light, so the sand-filling method is preferred. , ;

[0123] Then, a test section was constructed to determine the density.

[0124] Select the length of the test section and conduct compaction threshold testing. Test every 20m and record the density changes under different compaction degrees and different gradations.

[0125] Calculate the compaction energy index :

[0126] in, For the equipment-material coupling coefficient, crushed pebbles It ranges from 2.5 to 4.5. This refers to the amplitude of the road roller. For the frequency of the road roller, This refers to the compaction speed of the road roller.

[0127] Calculate the attenuation coefficient and , ,

[0128]

[0129] in, The thickness of the compacted layer is in meters (m). To determine the proportion of filler particles with a diameter less than 5mm, To determine the proportion of filler particles with a diameter less than 30mm,

[0130] Calculate the density measured in the test section. ,

[0131] in, This is the gradation correction factor. For every 5% increase in fine material content from 10%, k increases by 0.03. To increase the number of compaction passes,

[0132] As the number of compaction passes increases, when the density measured in the test section increases by ≤0.5% for two consecutive passes, it can be considered to have reached the maximum dry density, which is denoted as . ,

[0133] ,

[0134] in, This refers to the density measured on a normal road section.

[0135] This device represents a systematic optimization and innovation of traditional testing methods. Traditional methods like sand filling and ring cutter methods suffer from significant errors in test pit volume measurement due to the irregular shape, large size, and complex pore structure of crushed gravel particles. Furthermore, these methods rely on manual operation, leading to low efficiency and susceptibility to human experience. This device integrates automated sand filling measurement with high-precision 3D laser scanning technology to achieve non-contact dynamic measurement of test pit volume. By combining laser and sand filling data with a weighted allocation algorithm, it significantly improves the accuracy of volume calculation, particularly addressing the failure of single methods due to gradation differences, surface roughness, or dusty environments affecting crushed gravel fillers. Simultaneously, this device can reduce single-point testing time by more than 50%, lowering labor costs and avoiding fatigue errors, further ensuring data reliability under complex conditions. By quantifying gradation parameters in real time and dynamically adjusting correction coefficients, the device accurately matches compaction calculations to actual material characteristics. Adjusting parameters according to actual conditions resolves systematic errors caused by gradation differences, especially in complex conditions where coarse particles dominate or fine particles fluctuate, ensuring that test results accurately reflect the roadbed compaction state and providing a reliable scientific basis for construction.

[0136] Calculation process:

[0137] Quality of poured sand It weighs 19199.47g. 1.52 g / cm 3 (Coarse sand (1.0-2.36mm) prevents sand leakage between large gravel gaps)

[0138] Calculate the volume of sand to be poured based on the mass and density of the sand. :

[0139]

[0140] Comparative example: Calculation of the compaction qualification rate of crushed gravel fill using the traditional sand cone method.

[0141] First, dry and weigh the excavated fill material. ,

[0142] Volume of the excavated pit , ,

[0143] Calculate dry density , ,

[0144] Calculate the degree of compaction, where the maximum dry density is determined by a standard laboratory compaction test. ,

[0145] ,

[0146] .

[0147] This device calculates the pass rate of compaction degree for crushed gravel fill:

[0148] Test section to determine maximum dry density ,

[0149] First, the volume of the excavated hole is obtained using laser measurement. , , Given 126940000, we obtain... ,

[0150] Then, the volume of sand poured in is determined using the sand-filling method. : ,

[0151] ,therefore, , ,

[0152] ,

[0153] Take 3.5, , , ,

[0154] Seeking ,

[0155] Take 20%, Take 60%, ,

[0156] Seeking ,

[0157] ,

[0158] at last, The density obtained by taking values ​​1-6 in sequence See Table 1:

[0159] Table 1 Relationship between number of compaction passes and density

[0160]

[0161] The volume used in this calculation is the volume corresponding to 6 compaction passes. It does not take into account the decrease in volume as the number of compaction passes increases. Therefore, the density result is too large. However, it can still be seen that the formula corrects the result as the number of compaction passes increases.

[0162] when When the density is 6, if the density of the test section increases by ≤0.5% for two consecutive tests, it is considered to have reached the maximum dry density. Therefore, ,

[0163] The density of the normal test road section is recorded as: ,

[0164] Example 1:

[0165] After the roller compacts the road at point P1 on the normal road section three times, the compaction degree is measured using this device (in this example, for ease of calculation, the gradation information of a certain point on the normal road section is the same as that of the test section).

[0166] , , , , ,

[0167] , , ,

[0168] , ,

[0169] ,therefore, , ,

[0170] , ,

[0171] ,

[0172] ,

[0173] ,

[0174] Further compaction is needed.

[0175] When the number of compaction passes is 6 ;

[0176] After three passes of compaction by a roller at point P2 on a normal road section, the volume is the volume corresponding to three compaction passes, with the proportion of particles larger than 30mm reduced in the gradation. Take 20%, Take 50%, , , , , ,

[0177] , , ,

[0178] , ,

[0179] ,therefore, , ,

[0180] , ,

[0181] ,

[0182] ,

[0183] ,

[0184] visible, This is because The gradation compared to The gradation has more coarse particles, which quickly form the skeleton;

[0185] After three passes of compaction by a roller at point P3 on a normal road section, the volume is the volume corresponding to three compaction passes, with a reduction in the proportion of particles smaller than 5mm in the gradation. Take 15%, Take 60%, , , , , , , , , , ,

[0186] ,therefore, , ,

[0187] , ,

[0188] ,

[0189] ,

[0190] ,

[0191] visible, , and Quite, this is due to The gradation compared to Insufficient fine aggregate in the graded material leads to inadequate filling, and the remaining voids reduce the density.

[0192] Although the specific embodiments of the invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the invention. Based on the technical solutions of the invention, various modifications or variations that can be made by those skilled in the art without creative effort are still within the scope of protection of the invention.

Claims

1. A method for detecting the compaction degree of crushed gravel filler, comprising an automatic detection device, the automatic detection device including a detection frame (1), a drilling assembly and a screening and weighing assembly, characterized in that: It also includes a support cylinder (2), a sand filling measurement component, and a laser measurement component (18). The sand filling measurement assembly includes a sand bin (3), a sand filling pipe (4), and a weighing device (12). The bottom of the support cylinder (2) passes through the test frame (1), the top of the support cylinder (2) is equipped with a weighing device (12), the sand bin (3) is installed on the weighing device (12), and the bottom of the sand bin (3) passes through the support cylinder (2) to install the sand filling pipe (4). The drilling assembly includes a moving cylinder (5), a drive unit (6), a spiral blade (7), and a telescopic unit (13). The telescopic unit (13) is located on the top wall of the support cylinder (2). The output end of the telescopic unit (13) is connected to the moving cylinder (5). The moving cylinder (5) is coaxially located inside the support cylinder (2). The drive unit (6) is located on the top wall of the moving cylinder (5). The spiral blade (7) is located at the output end of the drive unit (6). The bottom of the spiral blade (7) extends out of the bottom of the inspection frame (1) and several drill teeth (19) are provided. The moving cylinder (5) and the support cylinder (2) are respectively opened with discharge ports (8), and the discharge pipe (9) is inclined at the discharge port (8). The bottom of the discharge pipe (9) is equipped with a screening and weighing component, which is located on the detection frame (1). The laser measurement assembly (18) is located at the bottom of the detection frame (1) and on one side of the support cylinder (2); characterized in that the detection method includes the following steps: S1: Drilling and collecting broken pebbles as fill material. Select the survey roadbed, install the testing device, excavate holes using the drilling assembly, and fill the holes with sand using the sand-filling measurement assembly. S2: Screening and weighing The screening and weighing assembly screens and weighs the packing material. S3: The volume of the excavated hole is obtained by laser measurement. This includes point cloud acquisition and distance calculation, point cloud preprocessing, and 3D model reconstruction and volume calculation. S4: Evaluation of compaction degree of crushed gravel filler; First, the excavated fill material is dried, weighed to obtain its mass, and its gradation is calculated. Calculate the volume of sand to be poured based on the mass and density of the sand. : in, For the quality of the sand poured in, The density of sand, Calculate the volume of the excavated pit. for The weight, for The weight, according to The results were compared with 2.5%, and then assigned accordingly. and Different weights and , when hour, , ; when Furthermore, when the gradation is poor and the proportion of fine materials is less than 10%, , ; when and surface roughness hour, , ; when ,and Or the effective data ratio of laser point cloud is less than 85%. These are solid and liquid particulate matter with a particle size of 10 micrometers or less that floats in the air. , ; Then, a test section was constructed to determine the density. Select the length of the test section and conduct compaction threshold testing. Test every 20m and record the density changes under different compaction degrees and different gradations. Calculate the compaction energy index : in, For the equipment-material coupling coefficient, crushed pebbles The value is 2.5-4.

5. This refers to the amplitude of the road roller. For the frequency of the road roller, This refers to the compaction speed of the road roller. Calculate the attenuation coefficient and , , in, The thickness of the compacted layer is in meters (m). To determine the proportion of filler particles with a diameter less than 5mm, To determine the proportion of filler particles with a diameter less than 30mm, Calculate the density measured in the test section. , in, This is the gradation correction factor. , To increase the number of compaction passes, As the number of compaction passes increases, when the density measured in the test section increases by ≤0.5% for two consecutive passes, it can be considered to have reached the maximum dry density, which is denoted as . , ， in, This refers to the density measured on a normal road section.

2. The method for detecting the compaction degree of crushed gravel filler according to claim 1, characterized in that: in the S3 point cloud acquisition and distance calculation, the distance from the laser to a certain point on the surface of the pit is measured. : in, At the speed of light, This represents the round-trip time of the laser.

3. The method for detecting the compaction degree of crushed gravel filler according to claim 2 is characterized in that: in the S3 point cloud preprocessing, firstly, outliers are statistically removed. Secondly, multi-view calculation of registration error. , in, For rotation matrix, It is a translation vector. The first point in the source cloud The three-dimensional coordinates of each point ; In the target point cloud The corresponding three-dimensional coordinates of the point To match the number of point pairs, The regularization coefficient is . For geometric error terms, Here, is the regularization term, For matrix trace operations, Then, the surface roughness is calculated. , Extract local surface contours, calculate baseline and deviation values, and fit the baseline: , Deviation calculation: Calculate the perpendicular deviation of each point from the baseline. Calculate roughness: in, This represents the absolute deviation at each point.

4. The method for detecting the compaction degree of crushed gravel filler according to claim 3 is characterized in that: in the three-dimensional model reconstruction and volume calculation, the mesh quality is first determined. in, This represents the mesh quality coefficient. For the first The radius of the inscribed circle of a triangle; The radius of the circumcircle; Secondly, the volume is calculated using the voxelization integral method, dividing the triangular mesh into 0.1mm segments. 3 cubic unit, Laser measurement method to obtain the volume of the excavated hole : in, Three-dimensional region The total volume For indicator functions, The volume of a single voxel.

5. The method for detecting the compaction degree of crushed gravel filler according to claim 1, characterized in that: The screening and weighing assembly includes a screening box (10) and a second weighing device (11). The second weighing device (11) is set on the detection frame (1), and the screening box (10) is set above the second weighing device (11).

6. The method for detecting the compaction degree of crushed gravel filler according to claim 5, characterized in that: The driving component (6) is a servo motor, the telescopic unit (13) is a cylinder, the upper side of the testing frame (1) is provided with a hand handle (16), and the bottom of the testing frame (1) is provided with a moving component (17).

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