Millimeter-level roadbed high-precision finishing construction method based on 3D control technology

Abstract

The invention relates to the technical field of roadbed high-precision finishing construction, in particular to a millimeter-level roadbed high-precision finishing construction method based on a 3D control technology. The method specifically comprises the steps of construction site preparation, construction machine preparation, construction technology preparation and test preparation. Carrying out BIM (Building Information Modeling); erecting a base station; constructing a roadbed; leveling a roadbed; compacting the roadbed; and acceptance. According to the invention, a three-dimensional design reference is generated through BIM modeling, and construction data is analyzed in real time in combination with a vehicle-mounted control system, so that seamless joint of'design-construction-detection 'is realized. The inclination angle sensor, the millimeter wave radar and other devices are used for monitoring the mechanical posture, the working face state and millisecond-level response deviation in real time and automatically adjusting the deviation. According to the method, geological survey data, meteorological information and equipment operation parameters are integrated, the self-adaptive construction decision model is constructed, and construction risks under complex geological conditions are effectively dealt with.

Description

Technical Field

[0001] This invention relates to the field of high-precision roadbed repair construction technology, specifically a millimeter-level high-precision roadbed repair construction method based on 3D control technology. Background Technology

[0002] As my country's transportation infrastructure construction moves towards a high-quality development stage, the limitations of traditional subgrade construction techniques in terms of precision control, efficiency improvement, and quality stability are becoming increasingly apparent. Traditional subgrade finishing relies on manual measurement and experience-based judgment, making it susceptible to environmental interference that can lead to centimeter-level flatness errors (e.g., current standards require a flatness deviation of ≤10mm), failing to meet the stringent requirements of modern traffic loads for roadbed uniformity and durability. Furthermore, traditional techniques are prone to causing subgrade settlement and poor drainage, increasing subsequent maintenance costs. Against this backdrop, digital and intelligent construction technologies have become a key path to overcome industry bottlenecks. Summary of the Invention

[0003] This invention aims to provide a millimeter-level high-precision roadbed repair construction method based on 3D control technology. It integrates 3D control technology and intelligent equipment to achieve millimeter-level precision control of roadbed repair, systematically solving the problems of insufficient precision and low efficiency of traditional processes.

[0004] To achieve the above objectives, the following technical solution is provided:

[0005] A high-precision roadbed trimming construction method based on 3D control technology, with millimeter-level precision, is characterized by the following steps:

[0006] Step 1: Construction preparation; specifically including construction site preparation, construction equipment preparation, construction technology preparation, and testing preparation.

[0007] The construction site preparation includes: conducting a survey along the road to be constructed according to the design drawings, understanding the environmental conditions along the construction route, and determining the station numbers along the route; clearing the topsoil along the designed road, with the thickness of the topsoil removed controlled according to the thickness of the topsoil in the exploration, and the clearing standard being to remove grass roots, tree roots, and loose soil.

[0008] The preparation of construction equipment is as follows: according to the demand plan for construction equipment, the construction equipment is dispatched to the site. Before entering the site, all construction equipment is inspected to ensure its working performance and safety performance.

[0009] The construction technology preparation includes: preparing a special construction plan and providing detailed instructions to the workers to ensure that all workers are informed.

[0010] The test preparation includes: conducting a detailed investigation of the geological and hydrological conditions of the roadbed engineering area, and determining its properties and scope through sampling tests; in accordance with the provisions of the "Technical Specification for Highway Roadbed Construction" (JTG / T3610-2019), performing the following tests on soil samples from the construction section: particle size analysis test, moisture content test, density test, relative density test, soil compaction test, and soil strength test (CBR value), with at least 2 points taken per kilometer. When the soil quality varies greatly, the number of sampling points will be increased as appropriate; at the same time, the test section construction will be carried out to determine various construction parameters.

[0011] Step 2: BIM Modeling; During the construction preparation process, the construction model of the proposed road will be established simultaneously. The requirements for model establishment are as follows:

[0012] A three-dimensional model of the roadbed is established based on the roadbed design data (elevation, intersection coordinates, longitudinal slope, cross slope, etc.);

[0013] Using UAV oblique photography technology combined with high-precision GPS or BeiDou satellite positioning and measurement technology, topographic data along the proposed road is collected, a geographic model of the proposed road is established, and integrated into a geographic information system (GIS);

[0014] By integrating the BIM model of the designed road with the GIS model, the construction parameters of the proposed road at each construction point are determined.

[0015] The 3D model is imported into the vehicle-mounted computer to provide a construction benchmark model for subsequent construction.

[0016] Step 3: Base station construction; Observation piers for placing Beidou reference stations are built on the project site using reinforced concrete pouring, with a burial depth greater than the frost layer to prevent soil loosening or thermal expansion and contraction.

[0017] Step 4: Subgrade construction; including the following requirements:

[0018] Before roadbed construction, the roadbed base shall be compacted, and the compaction degree (heavy) of the base shall not be less than 90%.

[0019] The excavated roadbed adopts stepped excavation, with a slope ratio of 1:1.0 to 1:2.0 and a grade height of 6.0 to 8.0m. Each grade of slope is equipped with a 2.0m wide platform. The location of the platform or slope change point in heterogeneous soil layer should be determined comprehensively in combination with the location of the interface of different soil layers.

[0020] Before filling the embankment, the fill material must be inspected, and the embankment can only be filled after the inspection is qualified.

[0021] The subgrade filling was carried out in layers, and parameters such as the layer thickness were controlled according to the data determined by the test section.

[0022] After each subgrade layer is filled, a bulldozer is used for rough leveling, and then a grader is used for fine leveling.

[0023] Step 5: Roadbed leveling; specifically including the following steps:

[0024] (1) Modify bulldozers and graders by adding GNSS receivers, slope sensors, millimeter-wave radar, vehicle computers and other equipment;

[0025] (2) Use bulldozers and graders equipped with 3D control systems to carry out roadbed leveling operations. First, use bulldozers for rough leveling, and then use graders for fine leveling.

[0026] (3) With the help of sensors and millimeter-wave radar, the on-board computer can compare with the equipment to understand the specific position of the blade and the relevant motion data information generated, and then automatically adjust the control signal. The precise coarse adjustment measurement of the bulldozer and the precise coarse adjustment measurement of the flat sweeper are carried out twice in a row, which greatly saves the measurement time of mechanical measurement and manual setting. The application of this automatic controller enables system users to automatically control the data information such as the fixed height, flatness and slope of each roadbed. With the three-dimensional transmission digital model as the main reference, the blade cutting data is fully utilized to find the actual running position and moving direction of a grader, and compare it with the platform set value data. The information about the configuration value is then transmitted to the platform hydraulic transmission control.

[0027] Step 6: Subgrade compaction; specifically includes the following steps:

[0028] (1) After the leveling is completed, a road roller is used to compact the leveled roadbed. The roadbed compaction is carried out by a road roller equipped with a direction sensor, vibration sensor, GNSS receiver, vehicle computer and other equipment.

[0029] (2) Before starting the compaction machinery, the construction parameters are set, including the number of compaction passes and compaction speed. The specific parameters are determined by the construction organization design, relevant technical specifications and compaction test. During the construction process, if there are any phenomena such as speeding or deviation from the track, the system will automatically alarm and correct the non-compliant behavior through the intervention of on-site management personnel.

[0030] (3) Real-time monitoring and analysis of roadbed compaction: mainly to automatically generate plan view of road surface at different station numbers during construction, and display the station number and scale of different parts on the plan view. Then, load the real-time construction process information of the compaction equipment and corresponding drivers on the plan, so that the construction unit, supervision unit and project construction management unit can control and schedule the real-time construction process of road dam compaction, and ensure that the dam compaction construction process is orderly and efficient.

[0031] Step 7: Acceptance; After the roadbed construction is completed, a self-inspection is carried out first. After the self-inspection is qualified, the project is reported to the supervision unit for acceptance. Then, the next layer of roadbed filling, trimming and compaction are carried out.

[0032] The principle of this invention is as follows: Before roadbed leveling, surveyors establish a three-dimensional model of the roadbed based on the roadbed design data (elevation, intersection coordinates, longitudinal slope, cross slope, etc.). This three-dimensional model is then combined with the traverse points at the construction site to complete the benchmark measurement. When bulldozers and graders perform leveling operations, the corrected three-dimensional model is imported into the onboard computer. The GNSS receiver acquires the current three-dimensional coordinates of the bulldozer and grader blades in real time, the slope sensor acquires the blade attitude angle information in real time, and the millimeter-wave radar acquires the roadbed smoothness data in real time. The current three-dimensional coordinates are substituted into the coordinate calculation equation to obtain the coordinate deviation, and the current blade attitude angle is substituted into the tilt angle calculation equation to obtain the angle difference. The onboard computer sends the deviation signal to the control converter. The control converter calculates the control command based on the control algorithm and sends it to the valve control module. The valve control module converts the current magnitude into valve core displacement, controls the valve opening, changes the oil flow rate and direction, controls the extension and retraction of the hydraulic cylinder, and thus controls the blade lifting and lowering, achieving millimeter-level precision control of roadbed smoothness.

[0033] The beneficial effects of this invention are as follows:

[0034] 1. Full-process digital management and control: This invention generates a three-dimensional design benchmark through BIM modeling and combines it with the vehicle control system to analyze construction data in real time, achieving seamless integration of "design-construction-inspection".

[0035] 2. Dynamic accuracy correction: This invention utilizes tilt sensors, millimeter-wave radar and other equipment to monitor the mechanical attitude and working surface status in real time, responding to deviations in milliseconds and automatically adjusting accordingly.

[0036] 3. Multi-source data fusion application: This invention integrates geological exploration data, meteorological information and equipment operating parameters to construct an adaptive construction decision model, effectively addressing construction risks under complex geological conditions.

[0037] 4. Multiple benefits combined: In terms of quality, this invention reduces the risk of stress concentration in the pavement structure layer and extends the service life of the road; in terms of efficiency, it improves work efficiency by more than 40%; in terms of cost, it reduces the overall cost by 15%-20%; in terms of green construction, it reduces mechanical energy consumption and carbon emissions, which is in line with the policy guidance of intelligent construction and green construction. Attached Figure Description

[0038] Figure 1 This is a flowchart of the construction process of the present invention;

[0039] Figure 2 This is a schematic diagram of the process principle of the present invention;

[0040] Figure 3 This is a construction preparation diagram for the present invention;

[0041] Figure 4 This is an oblique photograph taken by the UAV according to the present invention;

[0042] Figure 5 This is a road construction modeling diagram for the present invention;

[0043] Figure 6 A base station preparation diagram for the present invention;

[0044] Figure 7 This is a diagram showing the completed installation of the base station according to the present invention;

[0045] Figure 8 This is a test diagram of the connection stability of the base station and mobile station according to the present invention;

[0046] Figure 9 This is a roadbed excavation diagram for the present invention;

[0047] Figure 10 This is a roadbed filling diagram for the present invention;

[0048] Figure 11 This is an installation diagram of the GNSS receiver of the present invention;

[0049] Figure 12 This is an installation diagram of the sensor and millimeter-wave radar of the present invention;

[0050] Figure 13 This is a rough plan view of the bulldozer of the present invention;

[0051] Figure 14 This is a precision leveling diagram of the grader of the present invention;

[0052] Figure 15 This is an installation diagram of the roller sensor of the present invention;

[0053] Figure 16 This is a diagram of the onboard computer system for the road roller of the present invention;

[0054] Figure 17 This is the roadbed acceptance diagram for the present invention;

[0055] Figure 18 This is a diagram illustrating the effect of roadbed repair according to the present invention. Detailed Implementation

[0056] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0057] Example 1

[0058] High-precision roadbed finishing construction method based on 3D control technology at the millimeter level, such as Figure 1 As shown, it includes the following steps:

[0059] Step 1: Construction preparation, such as Figure 3 As shown,

[0060] 1. Construction site preparation: According to the design drawings, conduct a survey along the construction road to understand the environmental conditions along the construction route and determine the station numbers along the route; clear the topsoil along the designed road, and control the thickness of the topsoil removal according to the thickness of the topsoil in the exploration. The clearing standard is to remove grass roots, tree roots and loose soil.

[0061] 2. Construction Equipment Preparation: Deploy construction equipment to the site according to the required equipment schedule. Before arrival, inspect all construction equipment to ensure its working performance and safety performance.

[0062] 3. Construction technology preparation: Prepare a special construction plan and provide detailed instructions to the workers to ensure that all workers are informed.

[0063] 4. Test Preparation: A detailed investigation of the geological and hydrological conditions within the subgrade engineering area shall be conducted, and its properties and extent shall be determined through sampling tests. In accordance with the "Technical Specification for Highway Subgrade Construction" (JTG / T3610-2019), the following tests shall be performed on soil samples from the construction section: particle size analysis, moisture content test, density test, relative density test, soil compaction test, and soil strength test (CBR value). At least two sampling points shall be taken per kilometer. If there are significant variations in soil quality, the number of sampling points shall be increased as needed. Simultaneously, test section construction shall be carried out to determine various construction parameters.

[0064] Step 2, BIM modeling, such as Figure 4 and Figure 5 As shown,

[0065] During the construction preparation process, the construction model of the proposed road will be established simultaneously. The requirements for model establishment are as follows:

[0066] 1. Establish a three-dimensional model of the roadbed based on the roadbed design data (elevation, intersection coordinates, longitudinal slope, cross slope, etc.).

[0067] 2. Using UAV oblique photography technology combined with high-precision GPS or BeiDou satellite positioning and measurement technology, topographic data along the proposed road will be collected, a geographic model of the proposed road will be established, and integrated into a geographic information system (GIS).

[0068] 3. Integrate the BIM model of the designed road with the GIS model to determine the construction parameters of the proposed road at each construction point.

[0069] 4. Import the 3D model into the vehicle-mounted computer to provide a construction benchmark model for subsequent construction.

[0070] Step 3: Base station setup, such as... Figures 6-8 As shown,

[0071] The observation piers for the BeiDou reference stations are constructed at the project site using reinforced concrete. The burial depth must exceed the frost line to prevent soil loosening or thermal expansion and contraction. The industrial-grade reference stations are robust, durable, and differentially stable, ensuring trouble-free operation; they feature self-starting data transmission radios for unattended operation; high power output for long-distance coverage; and high-performance antennas with enhanced anti-interference capabilities, improving positioning efficiency.

[0072] Step 4: Subgrade construction, such as... Figure 9 and Figure 10 As shown,

[0073] 1. Before roadbed construction, the roadbed base shall be compacted, and the compaction degree (heavy) of the base shall not be less than 90%.

[0074] 2. The excavated roadbed adopts stepped excavation, with a slope ratio of 1:1.0 to 1:2.0 and a grade height of 6.0 to 8.0m. A 2.0m wide platform is set for each grade of slope. The location of the platform or slope change point in heterogeneous soil layer should be determined comprehensively in combination with the location of the interface of different soil layers.

[0075] 3. Before filling the embankment, the fill material must be inspected, and the embankment can only be filled after the inspection is qualified.

[0076] 4. The roadbed filling shall be carried out in layers, and the layer thickness and other parameters shall be controlled according to the data determined by the test section.

[0077] 5. After each layer of roadbed is filled, a bulldozer is used for rough leveling, and then a grader is used for fine leveling.

[0078] Step 5: Level the roadbed, such as... Figure 11-14 As shown,

[0079] 1. Modify bulldozers and graders by adding GNSS receivers, slope sensors, millimeter-wave radar, onboard computers, and other equipment.

[0080] 2. Use bulldozers and graders equipped with 3D control systems for roadbed leveling. First, use bulldozers for rough leveling, then use graders for fine leveling.

[0081] 3. With the help of sensors and millimeter-wave radar, the onboard computer can compare with the equipment to understand the specific position of the blade and the relevant motion data, and then automatically adjust the control signals. The precise coarse adjustment measurement of the bulldozer and the precise coarse adjustment measurement of the sweeper are performed twice consecutively, which greatly saves the measurement time of mechanical measurement and manual setting. The application of this automatic controller enables system users to automatically control data such as the fixed height, flatness, and slope of each roadbed. Using the three-dimensional transmission digital model as the main reference, the blade cutting data is fully utilized to find the actual operating position and direction of movement of a grader, and compare it with the platform set value data. The information about the configuration value is then transmitted to the platform hydraulic transmission control.

[0082] Step 6: Subgrade compaction, such as... Figure 15 and Figure 16 As shown,

[0083] 1. After the leveling is completed, a road roller is used to compact the leveled roadbed. The roadbed compaction is carried out by a road roller equipped with a direction sensor, vibration sensor, GNSS receiver, on-board computer and other equipment.

[0084] 2. Before starting the compaction machinery, the construction parameters should be set, including the number of compaction passes and compaction speed. Specific parameters are determined by the construction organization design, relevant technical specifications, and compaction tests. During construction, if speeding or deviation from the designated path occurs, the system will automatically alarm, and on-site management personnel will intervene to correct the non-compliant behavior.

[0085] 3. Real-time monitoring and analysis of roadbed compaction: This mainly involves automatically generating plan views of road surfaces at different station numbers during construction. The plan views display the station numbers and scales of different locations. Then, the real-time construction process information of the compaction equipment and corresponding drivers on the plan is loaded. This allows the construction unit, supervision unit, and project construction management unit to control and schedule the road dam compaction process in real time, ensuring that the dam compaction process is orderly and efficient.

[0086] Step 7: Acceptance, such as Figure 17 and Figure 18 As shown,

[0087] After the subgrade construction is completed, a self-inspection is carried out first. After the self-inspection is qualified, the project is submitted to the supervision unit for acceptance before the next layer of subgrade filling, trimming and compaction are carried out.

[0088] Example 2 Benefit Analysis

[0089] 1. Economic benefits

[0090] The construction method employed, along with seamless digital management of the entire "design-construction-inspection" process, significantly reduced on-site labor costs, achieved precise project cost control, accurate measurement during construction, and a substantial improvement in construction quality. This reduced rework due to quality issues and also adapted to various complex construction environments, enhancing construction efficiency. This resulted in significant economic benefits. Specific economic benefit calculations are as follows:

[0091] Cost items Compared with traditional processes, it saves money Sources of cost savings Calculation data basis labor costs 20-25％ Fewer surveyors, increased efficiency Gansu Highway Labor Unit Price Material costs 40-50％ Precise measurement reduces material waste Gansu building materials prices Machinery cost 15-20％ Digital scheduling reduces idle rate Equipment rental market price Quality rework cost 5-8％ Reduce the rate of subgrade compaction failure Historical project data Indirect costs 10-15％ Shorten the construction period and reduce management fees Company financial data

[0092] In summary, using this construction method will save approximately 246,000 yuan in project costs.

[0093] 2. Social benefits

[0094] This construction method employs full-process digital management, leveraging BIM modeling and vehicle-mounted systems to achieve seamless digital control across the entire "design-construction-inspection" process. Dynamic accuracy correction utilizes sensors to monitor mechanical posture in real time, enabling automatic correction of millisecond-level deviations. Multi-source data fusion integrates geological, meteorological, and other data to construct an adaptive model, effectively addressing complex geological risks. Its application value is evident: In terms of quality, it improves the uniformity of the roadbed and extends road lifespan; in terms of efficiency, it eliminates manual layout procedures, increasing work efficiency by over 40%; in terms of cost, it achieves precise quantity control and reduces rework, lowering overall costs by 15%-20%; and in terms of green construction, it aligns with policy guidance and supports operations in complex environments. This method responds to intelligent construction planning, promoting the transformation of roadbed construction from "experience-driven" to "data-driven," and will be expanded to roadbed and pavement collaborative control and full life-cycle operation and maintenance scenarios in the future.

[0095] Example 3: Application Case

[0096] 1. Construction of G312 line from Fengle to Mayingkou (including Yongchang bypass) FMSG-2 section

[0097] 1.1 Project Overview

[0098] The G312 highway construction project, specifically the Fengle to Mayingkou section (including the Yongchang bypass) FMSG-2 section, is 25.37km long. The bridge and culvert design vehicle load rating is Highway-I, and other technical specifications comply with the "Technical Standards for Highway Engineering" (JTGB01-2014) issued by the Ministry of Transport. The newly constructed bridges and culverts are designed for Highway-I vehicle loads, with a bridge deck width of 25.5 meters. The main works of FMSG-2 section include pavement engineering, roadbed engineering, bridge and culvert engineering, and landscaping. The planned start date is February 15, 2023, and the planned completion date is December 10, 2024.

[0099] 1.2 Application Effect

[0100] This project employed this construction method, which, through seamless digital management of the entire "design-construction-inspection" process, significantly reduced on-site labor costs, achieved precise project cost control, accurate measurement during construction, and a substantial improvement in construction quality. It also reduced rework caused by quality issues, implemented dynamic accuracy correction, and used sensors to monitor machinery posture in real time, achieving automatic correction of millisecond-level deviations. Furthermore, it utilized multi-source data fusion, integrating geological, meteorological, and other data to construct an adaptive model, effectively addressing complex geological risks. The application value is evident: at the quality level, it improves the uniformity of the roadbed and extends road lifespan; at the efficiency level, it aligns with policy guidance for green construction and can support operations in complex environments. It has received unanimous praise from the construction and supervision units.

[0101] 2. Yinkun Expressway (G85) Pengyang to Daqiao Village Section Highway Project PDSG2 Section

[0102] 2.1 Project Overview

[0103] The Pengyang to Daqiao Village section of the Yinkun Expressway (G85) highway project, section PDSG2, is located in Kongtong District, Pingliang City. It starts in Caofeng Town, Kongtong District, and ends in Miaozhuang Village, Kongtong District, with chainages from K26+400 to K37+400, and a total length of 9.98 km. The main works include roadbed engineering, bridge engineering, and tunnel engineering. The single-lane roadbed is 10.21 km long. The planned start date is September 10, 2019, and the planned completion date is October 31, 2021.

[0104] 2.2 Application Effect

[0105] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A millimeter-level high-precision roadbed finishing construction method based on 3D control technology, characterized in that: Includes the following steps: Step 1: Construction preparation; specifically including construction site preparation, construction equipment preparation, construction technology preparation, and testing preparation. Step 2: BIM Modeling; During the construction preparation process, the construction model of the proposed road will be established simultaneously. The model establishment requirements are as follows: A 3D model of the roadbed will be established based on the roadbed design data; UAV oblique photogrammetry technology combined with high-precision GPS or BeiDou satellite positioning measurement technology will be used to collect topographic data along the proposed road, establish a geographic model along the proposed road, and integrate it with a Geographic Information System (GIS); The BIM model of the designed road will be integrated with the GIS model to determine the construction parameters of the proposed road at each construction point; The 3D model will be imported into the vehicle-mounted computer to provide a construction benchmark model for subsequent construction. Step 3: Base station construction; Construct observation piers for placing Beidou reference stations at the project site, using reinforced concrete pouring, with a burial depth greater than the frost layer to prevent soil loosening or thermal expansion and contraction. Step 4: Subgrade construction; Step 5: Roadbed Leveling; specifically including the following steps: Modifying bulldozers and graders by adding GNSS receivers, slope sensors, millimeter-wave radar, onboard computers, and other equipment; using bulldozers and graders equipped with 3D control systems for roadbed leveling, first using bulldozers for rough leveling, then using graders for fine leveling; under the action of sensors and millimeter-wave radar, the onboard computer can compare with the equipment to understand the specific position of the blades and the relevant motion data information generated, and then automatically adjust the control signals. The precise coarse adjustment measurement of the bulldozer and the precise coarse adjustment measurement of the sweeper are performed twice consecutively, thus greatly saving the measurement time of mechanical measurement and manual setting; the application of this automatic controller enables system users to automatically control the fixed height, flatness, and slope of each roadbed; using the three-dimensional transmission digital model as the main reference, the blade cutting data is fully utilized to find the actual operating position and movement direction of a grader, and compare it with the platform set value data, and transmit the information about the configuration value to the platform hydraulic transmission control; Step 6: Subgrade compaction; Step 7: Acceptance; After the roadbed construction is completed, a self-inspection is carried out first. After the self-inspection is qualified, the project is reported to the supervision unit for acceptance. Then, the next layer of roadbed filling, trimming and compaction are carried out.

2. The millimeter-level high-precision roadbed repair construction method based on 3D control technology according to claim 1, characterized in that: In step one, the construction site preparation includes: conducting a site survey along the road to be constructed according to the design drawings to understand the environmental conditions along the construction route and determine the station numbers along the route; clearing the topsoil along the designed road, with the topsoil thickness controlled according to the thickness of the topsoil layer explored, and the clearing standard being to remove grass roots, tree roots, and loose debris; the construction equipment preparation includes: dispatching construction equipment to the site according to the equipment demand plan, and inspecting all construction equipment before arrival to ensure its working performance and safety performance; the construction technology preparation includes: preparing a special construction plan and providing detailed instructions to the workers to ensure all... The work personnel were properly briefed; the test preparation included: conducting a detailed investigation of the geological and hydrological conditions of the roadbed engineering area, and determining its properties and scope through sampling tests; in accordance with the provisions of the "Technical Specification for Highway Roadbed Construction" (JTG / T3610-2019), the following tests were performed on the soil samples of the construction section: particle size analysis test, moisture content test, density test, relative density test, soil compaction test, and soil strength test (CBR value), with at least 2 points taken per kilometer. When the soil quality changes significantly, the number of sampling points was increased as appropriate; at the same time, the test section construction was carried out to determine various construction parameters.

3. The millimeter-level high-precision roadbed repair construction method based on 3D control technology according to claim 1, characterized in that: In step four, the roadbed construction includes the following requirements: Before roadbed construction, the roadbed base shall be compacted, and the compaction degree of the base shall not be less than 90%; for excavated roadbeds, stepped excavation shall be adopted, with a slope ratio of 1:1.0 to 1:2.0, a grade height of 6.0 to 8.0m, and a 2.0m wide platform set for each grade of slope. The location of the platform or slope change point in heterogeneous soil layers shall be determined comprehensively in combination with the location of the interface of different soil layers; before filling the embankment roadbed, the filling material shall be inspected, and the roadbed filling can only be carried out after the inspection is qualified. The subgrade filling was carried out in layers, and parameters such as the layer thickness were controlled according to the data determined by the test section. After each subgrade layer is filled, a bulldozer is used for rough leveling, and then a grader is used for fine leveling.

4. The millimeter-level high-precision roadbed repair construction method based on 3D control technology according to claim 1, characterized in that: In step six, the roadbed compaction includes the following steps: After leveling, a road roller is used to compact the leveled roadbed. The roadbed compaction is carried out using a road roller equipped with a direction sensor, vibration sensor, GNSS receiver, on-board computer, and other equipment. Before starting the compaction machinery, the construction parameters are set, including the number of compaction passes and compaction speed. The specific parameters are determined by the construction organization design, relevant technical specifications, and compaction tests. During construction, if speeding or deviation from the trajectory occurs, the system will automatically alarm, and the non-compliant behavior will be corrected through intervention by on-site management personnel. Real-time monitoring and analysis of roadbed compaction mainly involves automatically generating plan views for different station numbers of the road surface during construction. The plan view displays the station numbers and scales of different locations, and then loads the real-time construction process information of the compaction equipment and corresponding drivers on that plan. This allows the construction unit, supervision unit, and project construction management unit to control and schedule the real-time construction process of the road dam compaction, ensuring that the dam compaction construction process is orderly and efficient.

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