Asphalt pavement post-implantation sensor monitoring system

Abstract

A post-implantation sensor monitoring system for asphalt pavement belongs to the technical field of pavement monitoring. The present invention addresses the problem in existing asphalt pavement performance monitoring that burying sensors in the pavement structure is highly destructive to the original pavement and affects the monitoring results. It includes: a mechanical response test rod is inserted into a pre-set pavement mechanical monitoring hole in the vertical direction to measure the mechanical response amplitude of each pavement layer in the longitudinal position under the action of external load; a temperature test rod is inserted into a pre-set pavement temperature monitoring hole in the vertical direction to measure the temperature of each pavement layer; a traffic axle load test rod is arranged in a horizontal direction in a pre-set pavement surface layer monitoring groove to measure the mechanical response amplitude of the pavement surface layer in the lateral position under the action of external load; a data acquisition system is used to collect monitoring data of the mechanical response test rod, the temperature test rod, and the traffic axle load test rod. The present invention is used for pavement condition monitoring.

Description

Technical Field

[0001] The invention relates to a post-implantation sensor monitoring system for an asphalt pavement, belonging to the technical field of pavement monitoring. Background Art

[0002] As the focus of highway development shifts from large-scale construction to large-scale maintenance, pavement performance is gradually degrading under repeated traffic loads and complex environmental conditions. By embedding various sensors in various pavement layers, we can monitor information such as vehicle axle weight and number of axles, as well as the pavement's internal mechanical response in real time, thereby helping to assess the pavement's remaining service life.

[0003] In road performance evaluation, road inspection vehicles and other tools are often used to inspect the road surface. Vehicle information such as axle weight, number of axles, and speed is often identified using strain sensors and dynamic weighing platforms. However, these road data processing and analysis methods have the following shortcomings:

[0004] 1) Vertical strain sensors, horizontal strain sensors, temperature sensors, etc. need to be buried in newly constructed or expanded pavement, which is impossible to implement on many existing pavements that urgently need performance evaluation to guide subsequent maintenance. 2) Previous sensor-based pavement data analysis required the cooperation of multiple types of sensors, which required a large number of buried sensors and complex cable routing, and later data collection required a high number of equipment channels. 3) The deployment of sensors caused significant damage to the original pavement structure, affecting the test accuracy of vehicle information recognition and the internal mechanical response of the pavement. Summary of the Invention

[0005] Aiming at the problem that in the existing asphalt pavement performance monitoring, burying sensors in the pavement structure is highly destructive to the original pavement and affects the monitoring results, the present invention provides an asphalt pavement post-implantation sensor monitoring system.

[0006] The present invention provides an asphalt pavement post-implantation sensor monitoring system, comprising a mechanical response test rod, a temperature test rod, a traffic axle load test rod, and a data acquisition system.

[0007] The mechanical response test rod is inserted vertically into a pre-set pavement mechanical monitoring hole; the mechanical response test rod has the same number of segments as the monitored pavement layers, and the lengths and positions of the segments correspond to the pavement layers; the material modulus of each segmented rod approaches the modulus of the corresponding pavement layer; a fiber grating string is embedded in the axis of the mechanical response test rod, and a grating is engraved at the center point of each segmented rod to measure the mechanical response amplitude of each pavement layer in the longitudinal position under the action of external load;

[0008] A temperature test rod is vertically inserted into a pre-set road surface temperature monitoring hole; the length of the temperature test rod is the same as that of the mechanical response test rod; a fiber grating string is embedded in the axis of the temperature test rod, and a grating is engraved on the fiber grating string at a position corresponding to the center point of each road surface layer to measure the temperature of each road surface layer;

[0009] The traffic axle load test rod is arranged horizontally in a pre-set road surface monitoring groove; the thickness of the traffic axle load test rod is less than that of the road surface, and the material modulus is close to the modulus of the road surface; the axis of the traffic axle load test rod is embedded with a fiber optic Bragg grating string, and the gratings are engraved at preset intervals to measure the mechanical response amplitude of the road surface layer in the lateral position under the action of external load;

[0010] The data acquisition system is used to collect monitoring data of the mechanical response test rod, the temperature test rod, and the traffic axle load test rod;

[0011] Analyze the monitoring data to obtain the asphalt pavement monitoring results.

[0012] According to the asphalt pavement post-implantation sensor monitoring system of the present invention, at least two mechanical response test rods are arranged at a set distance along the same wheel track.

[0013] According to the asphalt pavement post-implantation sensor monitoring system of the present invention, the traffic axle load test rod is arranged along the width direction of the pavement surface layer, and the length of the traffic axle load test rod is the same as the width of the pavement surface layer.

[0014] According to the asphalt pavement post-implantation sensor monitoring system of the present invention, the mechanical response amplitude of the longitudinal position and the mechanical response amplitude of the lateral position obtained by the mechanical response test rod and the traffic axle load test rod when the vehicle travels along the asphalt pavement wheel track are used to draw a pavement mechanical response measurement value image.

[0015] According to the asphalt pavement post-implantation sensor monitoring system of the present invention, based on the mechanical response measurement value image, the time difference is obtained according to the occurrence time corresponding to the mechanical response amplitude of the longitudinal position obtained by two adjacent mechanical response test rods, and then combined with the set distance between the two adjacent mechanical response test rods, the vehicle speed is calculated.

[0016] According to the asphalt pavement post-implantation sensor monitoring system of the present invention, based on the mechanical response measurement value image, the action point corresponding to the maximum mechanical response amplitude of the lateral position is used as the current lateral action position of the vehicle on the asphalt pavement.

[0017] According to the asphalt pavement post-implantation sensor monitoring system of the present invention, based on the mechanical response measurement value image, the current vehicle axle load type is determined according to the number of response peaks in the mechanical response amplitude at the lateral position.

[0018] According to the asphalt pavement post-implantation sensor monitoring system of the present invention, the modulus of each pavement layer is back-calculated based on the monitoring data:

[0019] A vehicle with a known axle load is driven along the asphalt pavement wheel track at a set speed. Based on the mechanical response amplitudes at the longitudinal position and the mechanical response amplitudes at the lateral position obtained from the mechanical response test rod and the traffic axle load test rod, a sample image of the pavement mechanical response measurement value is drawn.

[0020] The mechanics theory of layered elastic system is adopted to set the initial design value of each pavement layer modulus, and calculate the theoretical value of the mechanical response of each pavement layer in the longitudinal position; the error is calculated from the theoretical value of the mechanical response and the corresponding measurement value in the sample image of the mechanical response measurement value; based on the error, the optimization algorithm is used for iterative calculation to update the design value of each pavement layer modulus until the error between the calculated theoretical value of the mechanical response and the corresponding measurement value is less than the preset threshold, and the current design value of each pavement layer modulus is used as the final value of each pavement layer modulus.

[0021] According to the asphalt pavement post-implantation sensor monitoring system of the present invention, the final value of the modulus of each pavement layer is analyzed in combination with the temperature of each pavement layer and the time-temperature equivalence principle of viscoelastic materials, and a curve of the change law of the modulus of each pavement layer at different temperatures is obtained.

[0022] According to the asphalt pavement post-implantation sensor monitoring system of the present invention, the calculation method of the unknown axle load is:

[0023] The obtained pavement base modulus is taken as a fixed value;

[0024] Based on the mechanical theory of layered elastic systems, the initial design value of the unknown axle load is set, and the theoretical value of the mechanical response of each pavement layer's longitudinal position is calculated. The error value is obtained by comparing the calculated theoretical value with the corresponding measured value. Based on the error value, an optimization algorithm is used for iterative calculation to update the unknown axle load design value until the error value is less than the amplitude threshold. The current unknown axle load design value is used as the final calculated value of the unknown axle load.

[0025] The beneficial effects of the present invention are as follows: the present invention collects and processes the mechanical response data generated by known vehicle loads, draws an image of the pavement mechanical response measurement value, and realizes the calculation and evaluation of information such as the speed, lateral action position, axle load type, and axle weight of an unknown vehicle; and iteratively calculates the modulus of each layer of the pavement under the elastic and viscoelastic systems through an optimization algorithm to ensure that the error between the theoretical value and the measured value is less than the set threshold, and can calculate the axle load of vehicles with unknown axle loads in subsequent use, thereby expanding the scope of pavement data acquisition, further improving the accuracy of pavement data processing, and providing a reference for subsequent road maintenance decision-making.

[0026] By embedding fiber optic Bragg grating sensors in mechanical response test rods, temperature test rods, and traffic axle load information test pieces, the present invention reduces the types and number of sensors, simplifies the complexity of sensor and cable layout, and reduces the requirement for the number of equipment channels. At the same time, it can be directly applied to existing pavements, solving the problem that traditional methods cannot be implemented in existing pavements. In addition, the present invention causes less damage to the original pavement structure, preserves the integrity of the pavement, and reduces the impact on the pavement structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a top view of the arrangement of the asphalt pavement rear-implanted sensor monitoring system in the pavement structure of the present invention;

[0028] Figure 2 yes Figure 1 Schematic diagram of the longitudinal section;

[0029] Figure 3 This is a flow chart of the modulus back-calculation method based on monitoring data;

[0030] Figure 4 It is a flow chart of vehicle information identification and axle load back calculation based on monitoring data. DETAILED DESCRIPTION

[0031] 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 any creative efforts shall fall within the scope of protection of the present invention.

[0032] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0033] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0034] Specific implementation method 1. Combination Figure 1 and Figure 2 As shown, the present invention provides an asphalt pavement post-implantation sensor monitoring system, including a mechanical response test rod 1, a temperature test rod 2, a traffic axle load test rod 3 and a data acquisition system.

[0035] The mechanical response test rod 1 is used for mechanical response testing and is inserted into a pre-set pavement mechanical monitoring hole along its vertical direction. The mechanical response test rod 1 has the same number of segments as the monitored pavement layers, and the length and location of the segments correspond to the pavement layers. The material modulus of each segmented rod approaches or is close to the modulus of the corresponding pavement layer. A fiber grating string is embedded in the axis of the mechanical response test rod 1, and a grating is engraved at the center point of each segmented rod to measure the mechanical response amplitude of each pavement layer in the longitudinal position under the action of external load. The pavement mechanical monitoring hole must be set on the pavement wheel track. The mechanical response amplitude in the longitudinal position is the vertical strain.

[0036] The temperature test rod 2 is vertically inserted into a pre-set road surface temperature monitoring hole; the length of the temperature test rod 2 is the same as that of the mechanical response test rod 1; a fiber optic Bragg grating (FBG) string is embedded in the axis of the temperature test rod 2, and gratings are engraved on the fiber optic Bragg grating string at positions corresponding to the center points of each road surface layer to measure the temperature of each road surface layer; the length of each section of the temperature test rod 2 corresponds to the thickness of the road surface layer, base layer, and soil base; the road surface temperature monitoring hole can be set at the roadside;

[0037] The traffic axle load test rod 3 is horizontally arranged in a pre-set road surface monitoring groove; the thickness of the traffic axle load test rod 3 is less than that of the road surface, and the material modulus approaches or is close to the modulus of the road surface; the axis of the traffic axle load test rod 3 is embedded with a fiber optic Bragg grating string, and the gratings are engraved at preset intervals to measure the mechanical response amplitude of the lateral position of the road surface under external load; the preset interval can be 5 mm;

[0038] The data acquisition system is used to collect monitoring data of the mechanical response test rod 1, the temperature test rod 2, and the traffic axle load test rod 3;

[0039] Analyze the monitoring data to obtain the asphalt pavement monitoring results.

[0040] In this embodiment, the mechanical response test rod 1 is divided into sections according to the number and thickness of the road surface, base layer and soil base layer.

[0041] The length of the temperature test rod 2 corresponds to the sum of the thickness of the road surface layer, base layer and soil foundation. The outer material of the temperature test rod 2 is made of steel pipe. The temperature of the road surface layer, base layer and soil foundation is monitored by grating.

[0042] In this embodiment, at least two mechanical response test rods 1 are arranged at a set distance along the same wheel track.

[0043] The traffic axle load test rod 3 is arranged along the width direction of the road surface layer, and the length of the traffic axle load test rod 3 is the same as the width of the road surface layer.

[0044] Furthermore, the mechanical response amplitudes at the longitudinal position and the mechanical response amplitudes at the lateral position obtained by the mechanical response test rod 1 and the traffic axle load test rod 3 when the vehicle travels along the asphalt pavement wheel track are used to draw a pavement mechanical response measurement value image.

[0045] Combine Figure 4 As shown, based on the mechanical response measurement value image, the time difference is obtained according to the occurrence time corresponding to the mechanical response amplitude of the longitudinal position obtained by two adjacent mechanical response test rods 1, and then combined with the set distance between the two adjacent mechanical response test rods 1, the vehicle speed is calculated.

[0046] Combine Figure 4 As shown, based on the mechanical response measurement value image, the maximum mechanical response amplitude at the lateral position is determined, and combined with the initial buried position of the traffic axle load test rod 3, the lateral action position of the current vehicle on the asphalt road surface is determined.

[0047] Based on the mechanical response measurement value image, the current vehicle axle load type is determined according to the number of response peaks in the mechanical response amplitude at the lateral position.

[0048] Combine Figure 3 As shown in the figure, the modulus of each pavement layer is back-calculated based on the monitoring data:

[0049] A vehicle with a known axle load is driven along the asphalt pavement wheel track at a set speed. Based on the mechanical response amplitudes at the longitudinal position and the mechanical response amplitudes at the lateral position obtained from the mechanical response test rod 1 and the traffic axle load test rod 3, a sample image of the pavement mechanical response measurement value is drawn.

[0050] The mechanics theory of layered elastic system is adopted to set the initial design value of each pavement layer modulus, and calculate the theoretical value of the mechanical response of each pavement layer in the longitudinal position; the error is calculated from the theoretical value of the mechanical response and the corresponding measurement value in the sample image of the mechanical response measurement value; based on the error, the optimization algorithm is used for iterative calculation to update the design value of each pavement layer modulus until the error between the calculated theoretical value of the mechanical response and the corresponding measurement value is less than the preset threshold, and the current design value of each pavement layer modulus is used as the final value of each pavement layer modulus.

[0051] Furthermore, combined with the temperature of each pavement layer and using the time-temperature equivalence principle of viscoelastic materials, the final value of the pavement layer modulus was analyzed, and the change curve of the pavement layer modulus at different temperatures was obtained.

[0052] The time-temperature equivalence principle of viscoelastic materials includes the principle of analytical solution method.

[0053] Going further, combined Figure 4 As shown, the calculation method for unknown axle load is:

[0054] In the pavement structure, the base modulus basically does not change over time due to its material reasons. Therefore, the pavement base modulus obtained by back calculation can be used as a fixed value input. Based on the mechanical theory of layered elastic system, the initial design value of the unknown axle load is set, and the theoretical value of the mechanical response of each pavement layer longitudinal position is calculated. The error value is obtained by dividing the calculated theoretical value with the corresponding measured value. Based on the error value, an optimization algorithm is used for iterative calculation to update the unknown axle load design value. The criterion is that the error between the calculated value of the mechanical response amplitude and the actual measured value of the mechanical response amplitude collected by the current sensor is less than the amplitude threshold. The iteration is repeated until the error value obtained is less than the amplitude threshold, and the current unknown axle load design value is used as the final calculated value of the unknown axle load.

[0055] This embodiment collects the mechanical response amplitude data of each point of the mechanical response test rod and traffic axle load information test piece of the wheel track of the road surface to be tested when the vehicle with known axle load passes through it, and draws an image of the pavement mechanical response measurement value; then identifies the time when the mechanical response amplitude is generated, the maximum value point and the number of peaks, calculates the vehicle speed and determines the vehicle lateral position and vehicle axle load type; finally, through the optimization algorithm, iteratively calculates the modulus of each layer of the pavement under the elastic and viscoelastic systems, and combines the calculation results of the above-mentioned pavement base modulus and the basic information of the pavement to obtain the axle load of the unknown vehicle through the measured pavement mechanical response.

[0056] In this embodiment, the sensing elements in the mechanical response test rod, the temperature test rod, and the traffic axle load test rod may be, in addition to fiber gratings, resistance strain gauges, piezoelectric ceramics, or thermocouples.

[0057] The optimization algorithms used in this embodiment include Newton's method, pattern search, genetic algorithm, particle swarm optimization or agent model method.

[0058] In this embodiment, the layered elastic system mechanics theory method includes an analytical solution method or a finite element method.

[0059] In actual use, vehicles with known axle loads can be used regularly to perform modulus back calculation according to the above inverse calculation method to obtain the pavement modulus attenuation time curve, and then evaluate the pavement service performance. The recommended cycle is once every 6 months.

[0060] Based on the regularly updated pavement base modulus, more accurate vehicle axle load calculation values ​​can be further obtained.

[0061] Example 1:

[0062] Combine Figure 1As shown in the figure, taking a 7-layer pavement structure as an example, the thickness of each layer of the pavement from top to bottom are 0.05, 0.06, 0.07, 0.2, 0.2, 0.2, +∞m, the Poisson's ratio of each layer from top to bottom are 0.25, 0.25, 0.25, 0.25, 0.25, 0.25, 0.35, and the density of each layer from top to bottom are 2400, 2400, 2400, 2200, 2200, 2200, 1900 kg / m 3 .

[0063] The mechanical response test rod 1, the traffic axle load test rod 3, and the temperature test rod 2 are all 0.98m long. A fiber Bragg grating (FBG) string is embedded in the axis of the test rod, with the FBG points located at 0.025, 0.08, 0.145, 0.28, 0.48, 0.68, and 0.88m along the test rod. Two holes were drilled 5m apart in the right wheel track of the road surface. The two mechanical response test rods were vertically inserted and secured into each of the holes. A hole was drilled in the roadside parallel to the right wheel track. The temperature test rod was vertically inserted and secured into the hole, ensuring that the FBG points were located at the midpoint of each pavement layer.

[0064] The length of the traffic axle load test rod is 1.3m. A fiber optic Bragg grating string is embedded in the axis of the traffic axle load test piece. The grating is engraved every 0.05m. A groove is cut in the road surface perpendicular to the right wheel track direction. The traffic axle load test piece is buried horizontally and fixed to the groove. Figure 1 shown.

[0065] Combine Figure 2 , to process real-time road data:

[0066] In the first step, a known moving load was applied to the road surface. The load was a standard axle load for a double-circle single wheel set, with a tire ground stress of 0.7 MPa, a load circle radius of 0.1065 m, a distance between the two circles of 0.3195 m, and a moving speed of 10 m / s. One of the wheel tracks of the load was directly above the mechanical response test rod. The mechanical response amplitudes at each raster point on the mechanical response test rod were collected and plotted. At the midpoints of each layer of mechanical response test rod 1 (at 0.025, 0.08, 0.145, 0.28, 0.48, 0.68, and 0.88 m), the mechanical response amplitudes were -65.8, -92.7, -65.1, -16.3, -8.7, -6.4, and -28.3 με, respectively. Combining the analytical solution of the mechanics of the layered elastic system and the particle swarm optimization algorithm, the theoretical value of the mechanical response of the midpoint of each layer of the pavement is calculated based on the set initial modulus of each layer of the pavement. The measured value of the mechanical response amplitude of the midpoint of each layer of the pavement obtained by the fiber optic Bragg grating string test of the mechanical response test rod is consistent with the theoretical value of the mechanical response amplitude of the midpoint of each layer of the pavement obtained by the mechanics theory of the layered elastic system as much as possible. The modulus of each layer is obtained by backcalculation through repeated iterations. The backcalculated modulus results of layers 1 to 7 are 7551, 5245, 4834, 8234, 6785, 6235, and 153 MPa, respectively.

[0067] Step 2: For vehicles with unknown axle loads, identify the difference in the time measurement of the mechanical response amplitudes in the two mechanical response test rods 1, which is 0.48s. Calculate the vehicle speed to be 10.42m / s based on the displacement-time formula in kinematics. Identify the mechanical response amplitudes at each grating in the traffic axle load information test piece. The maximum mechanical response amplitude action point is the seventh grating from left to right, that is, the lateral action position of the vehicle's double-circle single-wheel group is 0.35m. Identify the number of mechanical response peaks in the traffic axle load information test piece as 1, and determine that the vehicle has a single-axle load.

[0068] In step 3, for vehicles with unknown axle loads, the vehicle speed, lateral action position, axle load type calculated in step 2, and the pavement base modulus calculated in step 1 (assuming the modulus of the fourth layer remains essentially unchanged during short-term service) are first used as input, along with the thickness, density, and Poisson's ratio of each pavement layer. A layered elastic system mechanical model is used, assuming the vehicle axle load, to calculate the theoretical value of the mechanical response amplitude at the midpoint of the pavement base. Then, based on the optimization algorithm, the measured mechanical response amplitude at the midpoint of the pavement base obtained from the mechanical response test rod test is repeated iteratively, with the criterion being that the measured value of the mechanical response amplitude obtained from the above model is as close as possible to the calculated value. The moduli of each layer except the fourth layer and the tire ground contact stress inverse calculation results are then obtained. The inverse calculated moduli of layers 1, 2, 3, 5, 6, and 7 are 7389, 5132, 4645, 6785, 6123, and 142 MPa, respectively, and the tire ground contact stress inverse calculation result is 0.75 MPa.

[0069] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the invention. It should be understood that many modifications may be made to the illustrative embodiments, and that other arrangements may be devised, without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in ways other than those described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be used in conjunction with other described embodiments.

Claims

1. A post-implantation sensor monitoring system for asphalt pavement, characterized in that: It includes a mechanical response test rod (1), a temperature test rod (2), a traffic axle load test rod (3) and a data acquisition system. The mechanical response test rod (1) is inserted into a pre-set pavement mechanical monitoring hole in a vertical direction; the mechanical response test rod (1) has the same number of segments as the monitored pavement layers, and the lengths and arrangement positions of the segments correspond to the pavement layers; the material modulus of each segmented rod approaches the modulus of the corresponding pavement layer; a fiber optic Bragg grating string is embedded in the axis of the mechanical response test rod (1), and a grating is engraved at the center point of each segmented rod to measure the mechanical response amplitude of each pavement layer at a longitudinal position under the action of an external load; The temperature test rod (2) is inserted into a pre-set road surface temperature monitoring hole in a vertical direction; the length of the temperature test rod (2) is the same as the length of the mechanical response test rod (1); a fiber optic Bragg grating string is embedded in the axis of the temperature test rod (2), and a grating is engraved on the fiber optic Bragg grating string at a position corresponding to the center point of each road surface layer to measure the temperature of each road surface layer; The traffic axle load test rod (3) is arranged in a horizontal direction in a pre-set road surface monitoring groove; the thickness of the traffic axle load test rod (3) is less than that of the road surface, and the material modulus is close to the modulus of the road surface; the axis of the traffic axle load test rod (3) is embedded with a fiber optic Bragg grating string, and the grating is engraved at a preset interval to measure the mechanical response amplitude of the road surface layer at a lateral position under the action of an external load; The data acquisition system is used to collect monitoring data of a mechanical response test rod (1), a temperature test rod (2), and a traffic axle load test rod (3); Analyze the monitoring data to obtain the asphalt pavement monitoring results.

2. The asphalt pavement post-implantation sensor monitoring system according to claim 1 is characterized in that: At least two mechanical response test rods (1) are arranged at a set distance along the same wheel track.

3. The asphalt pavement post-implantation sensor monitoring system according to claim 1 or 2, characterized in that: The traffic axle load test rod (3) is arranged along the width direction of the road surface layer, and the length of the traffic axle load test rod (3) is the same as the width of the road surface layer.

4. The asphalt pavement post-implantation sensor monitoring system according to claim 3, characterized in that: The mechanical response amplitudes at the longitudinal position and the mechanical response amplitudes at the transverse position obtained by the mechanical response test rod (1) and the traffic axle load test rod (3) during the vehicle's travel along the asphalt pavement wheel track are used to draw a pavement mechanical response measurement value image.

5. The asphalt pavement post-implantation sensor monitoring system according to claim 4, characterized in that: Based on the mechanical response measurement value image, the time difference is obtained according to the occurrence time corresponding to the mechanical response amplitude at the longitudinal position obtained by two adjacent mechanical response test rods (1), and then combined with the set distance between the two adjacent mechanical response test rods (1), the vehicle speed is calculated.

6. The asphalt pavement post-implantation sensor monitoring system according to claim 5, characterized in that: Based on the mechanical response measurement value image, the action point corresponding to the maximum mechanical response amplitude value at the lateral position is used as the current lateral action position of the vehicle on the asphalt road surface.

7. The asphalt pavement post-implantation sensor monitoring system according to claim 6, characterized in that: Based on the mechanical response measurement value image, the current vehicle axle load type is determined according to the number of response peaks in the mechanical response amplitude at the lateral position.

8. The asphalt pavement post-implantation sensor monitoring system according to claim 7, characterized in that: Back-calculate the modulus of each pavement layer based on the monitoring data: A vehicle with a known axle load is caused to travel along the wheel track of an asphalt pavement at a set speed, and a sample image of the pavement mechanical response measurement value is drawn based on the mechanical response amplitude at the longitudinal position and the mechanical response amplitude at the lateral position obtained by the mechanical response test rod (1) and the traffic axle load test rod (3); Adopting the mechanics theory of layered elastic system, the initial design value of each pavement layer modulus is set, and the theoretical value of the mechanical response of each pavement layer at the longitudinal position is calculated; The error is calculated from the theoretical value of the mechanical response and the corresponding measured value in the sample image of the mechanical response measurement value. Based on the error, an optimization algorithm is used for iterative calculation to update the design value of each pavement layering modulus until the error between the calculated theoretical value of the mechanical response and the corresponding measured value is less than a preset threshold. The current design value of each pavement layering modulus is used as the final value of each pavement layering modulus.

9. The asphalt pavement post-implantation sensor monitoring system according to claim 8, characterized in that: Combined with the temperature of each pavement layer and the time-temperature equivalence principle of viscoelastic materials, the final value of the pavement layer modulus was analyzed, and the change curve of the pavement layer modulus at different temperatures was obtained.

10. The asphalt pavement post-implantation sensor monitoring system according to claim 8, characterized in that: The calculation method for unknown axle load is: The obtained pavement base modulus is taken as a fixed value; Based on the mechanical theory of layered elastic systems, the initial design value of the unknown axle load is set, and the theoretical value of the mechanical response of each pavement layer's longitudinal position is calculated. The error value is obtained by comparing the calculated theoretical value with the corresponding measured value. Based on the error value, an optimization algorithm is used for iterative calculation to update the unknown axle load design value until the error value is less than the amplitude threshold. The current unknown axle load design value is used as the final calculated value of the unknown axle load.

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