Continuous detection method and system for differential settlement of stone-filled roadbed

Abstract

The invention discloses a continuous detection method and system for the settlement difference of a stone-filled roadbed, and the method comprises the steps: setting a test section in a soil-stone mixed filling roadbed project, and measuring the space coordinates of a measurement point and the elevation of the measurement point before rolling; carrying out vibration compaction on the test section, and recording a space coordinate corresponding to a continuous compaction detection index; measuring the elevation of each measuring point after rolling, and making a difference between the elevation of each measuring point and the elevation of each measuring point before rolling to obtain the settlement difference of each measuring point; constructing a regression model between the continuous compaction detection index and the settlement difference; and subsequently collected compaction detection indexes and corresponding space coordinates are input into the regression model, and continuous detection of the settlement difference of the rock-filled roadbed is completed. According to the method, the continuous compaction technology is taken as an entry point, and the regression model of the continuous compaction detection index and the settlement difference of the soil-stone mixed filling roadbed is established, so that the continuous detection of the settlement difference of the soil-stone mixed filling roadbed is realized, and the detection efficiency and accuracy of the settlement difference are greatly improved.

Description

Technical Field

[0001] The present invention relates to the field of settlement difference detection of rock-filled roadbeds, and in particular to a continuous detection method and system for settlement difference of rock-filled roadbeds. Background Art

[0002] When constructing roads in mountainous areas, tunneling, rock blasting, and road cuttings leave behind large amounts of earth and rock. Due to both engineering costs and the environmental impact of material disposal, existing earth and rock are often used directly for roadbed backfill. In roadbed construction, compaction is the most critical process for ensuring the support capacity of the fill layer, and its quality often determines its service life and performance. Unlike the degree of compaction used for earth-fill roadbeds, differential settlement is often used to characterize compaction quality for earth-rock mixed roadbeds.

[0003] Traditional settlement differential testing methods are point-based, using single-point test results to characterize the compaction quality of the soil-rock fill roadbed within a specific area. This approach presents a number of problems, including: ① random sampling of test points, lacking representativeness; ② a limited testing range, which can easily miss areas of weak compaction; ③ testing lags behind construction, resulting in a lack of real-time performance; and ④ low testing efficiency and susceptibility to human interference from testers.

[0004] At present, the research objects in the field of continuous compaction are all concentrated on the continuous detection of the compaction degree of fill roadbed, such as the "A method for continuous compaction detection of roadbed based on artificial intelligence" published in invention patent CN115952437A, the "System and method for continuous detection of roadbed compaction quality based on actual amplitude of vibration wheel" published in invention patent CN114134784A, and the "Evaluation method for compaction quality of earth-rock dam material" published in invention patent CN113640175B. However, no relevant technology for continuous detection of settlement difference of rock-fill roadbed has been published.

[0005] In terms of large-scale detection of soil-rock mixed roadbed, laser or measurement is used, such as the "Rapid large-scale soil-rock mixed roadbed settlement measurement method" published in invention patent CN115262516B and the "A soil-rock mixed roadbed settlement measurement device" published in utility model patent CN216308967U. No related technology based on the vibration roller response principle for detection has been published. Summary of the Invention

[0006] To address the technical problems outlined above, the present invention aims to measure the differential settlement of a soil-rock mixed roadbed by leveraging the interaction between the roadbed and a vibratory roller. This, combined with a spatial positioning system and a display system for real-time visualization, allows for a comprehensive, real-time assessment of the compaction quality of the soil-rock mixed roadbed during rolling.

[0007] To achieve the above object, the present invention provides a method for continuously detecting the settlement difference of a rock-filled roadbed, the steps comprising:

[0008] Set up a test section in the soil-rock mixed roadbed project to measure the spatial coordinates of the measuring points and their elevations before rolling;

[0009] Performing vibration compaction on the test section and recording the spatial coordinates corresponding to the continuous compaction detection index;

[0010] Measuring the elevation of the measuring point after rolling and subtracting it from the elevation before rolling to obtain the settlement difference of each measuring point;

[0011] Constructing a regression model between the continuous compaction detection index and the settlement difference;

[0012] The compaction detection index and the corresponding spatial coordinates collected subsequently are input into the regression model to complete the continuous detection of the settlement difference of the stone-filled roadbed.

[0013] Preferably, the test section is used to separate a number of test strips, and a number of measuring points are arranged on each of the test strips to measure the spatial coordinates of the measuring points and their elevations before being rolled.

[0014] Preferably, the test section is subjected to vibration compaction, and a vertical acceleration time-domain curve of the vibrating wheel of the vibrating roller during the vibration compaction process is obtained. The vertical acceleration time-domain curve is subjected to Fourier transform to calculate the continuous compaction index CMV and output:

[0015]

[0016] Where A1 is the amplitude of the first harmonic component of acceleration; A0 is the amplitude of the fundamental frequency of acceleration; and C is the proportional expansion coefficient.

[0017] Preferably, the regression model is constructed by converting the calculated continuous compaction index and the settlement difference under the same spatial coordinates into a univariate linear algorithm model.

[0018] Preferably, after the settlement difference is converted, it is mapped to a high-precision map base map according to the spatial coordinate information, and a visualization platform is constructed to guide the construction workers' work.

[0019] The present invention also provides a continuous detection system for settlement difference of stone-filled roadbed, the system is used to implement the above method, including: a measurement module, a compaction module, a calculation module, a construction module and a detection module;

[0020] The measurement module is used to set up a test section in a soil-rock mixed filling roadbed project, and measure the spatial coordinates of the measuring points and their elevations before rolling;

[0021] The compaction module is used to perform vibration compaction on the test section and record the spatial coordinates corresponding to the continuous compaction detection index;

[0022] The calculation module is used to measure the elevation of the measuring point after rolling, and to calculate the settlement difference of each measuring point by subtracting the elevation from the elevation before rolling.

[0023] The construction module is used to construct a regression model between the continuous compaction detection index and the settlement difference;

[0024] The detection module is used to input the compaction detection indicators and corresponding spatial coordinates collected subsequently into the regression model to complete the continuous detection of the settlement difference of the stone-filled roadbed.

[0025] Preferably, the working process of the measurement module includes: using the test section to separate a number of test strips, arranging a number of measuring points on each of the test strips, and measuring the spatial coordinates of the measuring points and their elevations before being rolled.

[0026] Preferably, the workflow of the compaction module includes: performing vibration compaction on the test section, obtaining a vertical acceleration time-domain curve of the vibrating wheel of the vibratory roller during the vibration compaction process, performing Fourier transform on the vertical acceleration time-domain curve, calculating a continuous compaction index CMV, and outputting the result:

[0027]

[0028] Where A1 is the amplitude of the first harmonic component of acceleration; A0 is the amplitude of the fundamental frequency of acceleration; and C is the proportional expansion coefficient.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The present invention takes continuous compaction technology as the starting point, and realizes continuous detection of settlement difference of soil-rock mixed roadbed by establishing a regression model between continuous compaction detection index and settlement difference of soil-rock mixed roadbed, thereby greatly improving the detection efficiency and accuracy of settlement difference. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 This is a schematic diagram of the layout of the test strips and measuring points according to an embodiment of the present invention;

[0033] Figure 2 Schematic diagram of a vibratory roller signal acquisition device according to an embodiment of the present invention;

[0034] Figure 3 Schematic diagram of the Fourier transform of the vertical acceleration time domain curve according to an embodiment of the present invention;

[0035] Figure 4 Schematic diagram of a one-dimensional regression model of continuous compaction detection index and settlement difference according to an embodiment of the present invention;

[0036] Figure 5 Schematic diagram of an artificial neural network model for continuous compaction detection indicators and settlement differences according to an embodiment of the present invention.

[0037] Description of reference numerals:

[0038] 1. Measuring points; 2. Test strips; 3. Measuring point spacing; 4. Vertical acceleration sensor; 5. Roller-mounted RTK; 6. Roller-mounted display industrial tablet. DETAILED DESCRIPTION

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0040] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] Example 1

[0042] This embodiment provides a method for continuously detecting the settlement difference of a rock-filled roadbed, the steps comprising:

[0043] S1. Establish a test section in the soil-rock mixed roadbed project and measure the spatial coordinates of the measuring points and their elevations before rolling.

[0044] A test section is set up in the soil-rock mixed roadbed project, and the test section is divided into several test strips, and several measuring points are arranged on each test strip. In this embodiment, a test section with a length of 200m and a width of 8m is set up in the soil-rock mixed roadbed project, and four test strips 2 are separated according to the width of the vibratory wheel of the roller as the driving path of the vibratory roller. 20 measuring points 1 are arranged in each test strip 2, and are arranged at intervals of 10m along the length direction of the test strip 2. The spatial coordinates of the measuring point 1 are measured by handheld RTK, and the elevation of the measuring point 1 before being rolled is measured by a level. The layout of the test strip 2 and the measuring point 1 is shown as follows Figure 1 shown.

[0045] S2. Perform vibration compaction on the test section and record the spatial coordinates corresponding to the continuous compaction test indicators.

[0046] The test section was vibrated and compacted to obtain the vertical acceleration time domain curve of the vibratory roller during the vibration compaction process. The continuous compaction test index of the soil-rock mixed roadbed was calculated, and the spatial coordinates corresponding to the continuous compaction test index were recorded.

[0047] The test section was vibrated and compacted, and the vibration roller signal acquisition equipment (such as Figure 2 (As shown in the figure, the vertical acceleration time domain curve of the vibratory roller during vibratory compaction is obtained.) The vibratory roller signal acquisition equipment consists of a vertical acceleration sensor 4, a roller-mounted RTK 5, and an onboard industrial display tablet 6. The data acquisition frequency of the vertical acceleration sensor 4 is greater than four times the roller's operating vibration frequency.

[0048] Perform Fourier transform on the vertical acceleration time domain curve (such as Figure 3 ) is calculated and output using Equation 1 at a rate of four per second, representing the overall mechanical properties of the area rolled by the vibratory roller within 0.25 seconds. The spatial coordinates corresponding to the continuous compaction measurement index are recorded using the roller's onboard RTK5, part of the vibratory roller's vibration signal acquisition system.

[0049]

[0050] Where A1 is the amplitude of the first harmonic component of acceleration; A0 is the amplitude of the fundamental frequency of acceleration; and C is the proportional expansion coefficient, which is 300 here.

[0051] S3. Measure the elevation of the measuring point after rolling and subtract it from the elevation before rolling to determine the settlement difference of each measuring point.

[0052] The elevation of measuring point 1 after rolling is measured by a level, and the difference is made with the elevation before rolling measured by S1 and the absolute value is calculated to obtain the settlement difference of each measuring point 1.

[0053] S4. Construct a regression model between continuous compaction test indicators and settlement difference.

[0054] The CMV obtained by S2 and the settlement difference obtained by S3 under the same spatial coordinates were used to construct a regression model by converting the model using a univariate linear algorithm (e.g. Figure 4 The coefficient of determination is 0.71. This model is the settlement difference conversion model, based on which CMV can be converted into settlement difference.

[0055] S5. Input the subsequently collected compaction test indicators and the corresponding spatial coordinates into the regression model to complete the continuous detection of the settlement difference of the stone-filled roadbed.

[0056] Receive and store data in real time, process it using an imported conversion model, and output it. The data received and stored are continuous compaction test indicators and their corresponding spatial coordinates. The imported conversion model is derived from S4, and the output data is differential settlement. For the soil-rock fill roadbed undergoing continuous differential settlement testing, the soil gradation remains consistent with the test section, and the moisture content is within ±1% of the test section.

[0057] A platform for visualizing soil-rock subgrade settlement differences has been established. The converted settlement differences are mapped onto a high-precision basemap using spatial coordinates. The high-precision digital map is obtained through BeiDou. The platform features a tablet computer that displays the soil-rock subgrade settlement differences in real time via an onboard tablet computer on a road roller, providing guidance to construction workers.

[0058] Example 2

[0059] This embodiment also provides a different implementation method, and the specific steps are as follows:

[0060] S1. A test section 100m long and 6m wide was established in the soil-rock mixed roadbed project. Three test strips 2 were separated according to the width of the roller's vibration wheel as the driving path of the vibratory roller. Ten measuring points 1 were arranged in each test strip 2, spaced 10m apart along the length of the test strip 2. The spatial coordinates of the measuring points 1 were measured using a handheld RTK, and the elevation of the measuring points 1 before rolling was measured using a total station. The layout of the test strips 2 and measuring points 1 is shown below: Figure 1 shown.

[0061] S2. Perform vibration compaction on the test section, and use the vibration roller signal acquisition equipment (such as Figure 2 (As shown in the figure), a time-domain curve of the vertical acceleration of the vibratory roller during vibratory compaction is obtained. The vibratory roller signal acquisition equipment consists of a vertical acceleration sensor 4, a roller-mounted RTK 5, and an onboard industrial display tablet 6. The data acquisition frequency of the vertical acceleration sensor 4 is greater than six times the roller's operating vibration frequency.

[0062] Using Equations 2-4, the continuous compaction metrics CMV, CCV, and Evib are calculated and output at a rate of two per second, representing the overall mechanical properties of the area compacted by the vibratory roller within 0.5 seconds. The spatial coordinates corresponding to the continuous compaction metrics are recorded using the roller's onboard RTK5, part of the vibratory roller's vibration signal acquisition system.

[0063]

[0064] Where A(iΩ) is the amplitude corresponding to i (i=0.5, 1.5, 2.5, 3) times the fundamental frequency.

[0065]

[0066] Where v is the Poisson's ratio of the soil; b is the contact width between the vibrating wheel and the soil (along the direction of roller travel), which can be solved by the Lundberg equation; R is the radius of the rolling wheel; L is the width of the rolling wheel (perpendicular to the direction of roller travel); z d is the soil deformation.

[0067] S3. Use a total station to measure the elevation of measuring point 1 after compaction, and subtract it from the elevation before compaction measured in S1 and calculate the absolute value to obtain the settlement difference of each measuring point.

[0068] S4. Using the CMV, CCV, Evib obtained in S2 and the settlement difference obtained in S3 under the same spatial coordinates, a conversion model was established using an artificial neural network algorithm (e.g. Figure 5 When using the artificial neural network algorithm, 80% of the data collected from the test section was used as the training set, and the remaining 20% ​​was used as the test set. The average error between the subgrade settlement differences output by the established model on the test set and the corresponding measured settlement differences calculated using S3 was 15%, which can be used as a settlement difference conversion model. Based on this, CMV, CCV, and Evib can be converted into settlement differences.

[0069] S5. Receive and store data in real time, process the data using the imported conversion model, and output the data. The data received and stored are the continuous compaction test indicators and their corresponding spatial coordinates. The imported conversion model is derived from S4, and the output data is the settlement difference. For the soil-rock fill roadbed undergoing continuous settlement difference testing, the soil gradation remains consistent with that of the test section, and the moisture content is within ±1.5% of the test section.

[0070] A platform for visualizing soil-rock subgrade settlement differences has been established. The converted settlement differences are mapped onto a high-precision basemap using spatial coordinates. The high-precision digital map is obtained through BeiDou. The platform features a tablet computer that displays the soil-rock subgrade settlement differences in real time via an onboard tablet computer on a road roller, providing guidance to construction workers.

[0071] Example 3

[0072] This embodiment also provides a continuous detection system for the settlement difference of a rock-filled roadbed, comprising: a measurement module, a compaction module, a calculation module, a construction module and a detection module; the measurement module is used to set up a test section in a soil-rock mixed roadbed project, measure the spatial coordinates of the measuring points and their elevations before being rolled; the compaction module is used to vibrate and compact the test section, and record the spatial coordinates corresponding to the continuous compaction detection index; the calculation module is used to measure the elevation of the measuring point after being rolled, and subtract it from the elevation before being rolled to obtain the settlement difference of each measuring point; the construction module is used to construct a regression model between the continuous compaction detection index and the settlement difference; the detection module is used to input the subsequently collected compaction detection index and the corresponding spatial coordinates into the regression model to complete the continuous detection of the settlement difference of the rock-filled roadbed.

[0073] The workflow of the measurement module includes: using the test section to separate several test strips, setting up several measuring points on each test strip, and measuring the spatial coordinates of the measuring points and their elevations before being rolled.

[0074] The workflow of the compaction module includes: vibrating and compacting the test section, obtaining the vertical acceleration time domain curve of the vibratory roller during the vibration compaction process, performing Fourier transform on the vertical acceleration time domain curve, calculating the continuous compaction index CMV, and outputting it:

[0075]

[0076] Where A1 is the amplitude of the first harmonic component of acceleration; A0 is the amplitude of the fundamental frequency of acceleration; and C is the proportional expansion coefficient.

[0077] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for continuously detecting the settlement difference of a rock-filled roadbed, characterized in that the steps include: Set up a test section in the soil-rock mixed roadbed project to measure the spatial coordinates of the measuring points and their elevations before rolling; Performing vibration compaction on the test section and recording the spatial coordinates corresponding to the continuous compaction detection index; Measuring the elevation of the measuring point after rolling and subtracting it from the elevation before rolling to obtain the settlement difference of each measuring point; Constructing a regression model between the continuous compaction detection index and the settlement difference; The compaction detection index and the corresponding spatial coordinates collected subsequently are input into the regression model to complete the continuous detection of the settlement difference of the stone-filled roadbed.

2. The continuous detection method for settlement difference of rock-filled roadbed according to claim 1, characterized in that: The test section is used to separate a number of test strips, and a number of measuring points are arranged on each of the test strips to measure the spatial coordinates of the measuring points and their elevations before being rolled.

3. The continuous detection method for settlement difference of rock-filled roadbed according to claim 1, characterized in that: The test section is subjected to vibration compaction to obtain the vertical acceleration time domain curve of the vibratory roller during the vibration compaction process. The vertical acceleration time domain curve is subjected to Fourier transform to calculate the continuous compaction index CMV and output: Where A1 is the amplitude of the first harmonic component of acceleration; A0 is the amplitude of the fundamental frequency of acceleration; and C is the proportional expansion coefficient.

4. The continuous detection method for settlement difference of rock-filled roadbed according to claim 3, characterized in that: The regression model is constructed by using the calculated continuous compaction index and the settlement difference under the same spatial coordinates through a univariate linear algorithm conversion model.

5. The continuous detection method of the settlement difference of the rock-filled roadbed according to claim 1, characterized in that: After the settlement difference is converted, it is mapped to a high-precision map base map according to the spatial coordinate information, and a visualization platform is built to guide the construction workers' work.

6. A continuous detection system for settlement difference of a rock-filled roadbed, the system being used to implement the method according to any one of claims 1 to 5, characterized in that: include: measurement module, compaction module, calculation module, construction module and detection module; The measurement module is used to set up a test section in a soil-rock mixed filling roadbed project, and measure the spatial coordinates of the measuring points and their elevations before rolling; The compaction module is used to perform vibration compaction on the test section and record the spatial coordinates corresponding to the continuous compaction detection index; The calculation module is used to measure the elevation of the measuring point after rolling, and to calculate the settlement difference of each measuring point by subtracting the elevation from the elevation before rolling. The construction module is used to construct a regression model between the continuous compaction detection index and the settlement difference; The detection module is used to input the compaction detection indicators and corresponding spatial coordinates collected subsequently into the regression model to complete the continuous detection of the settlement difference of the stone-filled roadbed.

7. The continuous detection system for settlement difference of rock-filled roadbed according to claim 6, characterized in that: The working process of the measurement module includes: using the test section to separate a number of test strips, arranging a number of measuring points on each of the test strips, and measuring the spatial coordinates of the measuring points and their elevations before being rolled.

8. The continuous detection system for settlement difference of rock-filled roadbed according to claim 6, characterized in that: The workflow of the compaction module includes: vibrating and compacting the test section, obtaining a vertical acceleration time-domain curve of the vibrating wheel of the vibrating roller during the vibration compaction process, performing Fourier transform on the vertical acceleration time-domain curve, calculating the continuous compaction index CMV, and outputting the result: Where A1 is the amplitude of the first harmonic component of acceleration; A0 is the amplitude of the fundamental frequency of acceleration; and C is the proportional expansion coefficient.

Images